JP7366662B2 - Positive electrode active material composite for lithium ion secondary battery and method for manufacturing the same - Google Patents
Positive electrode active material composite for lithium ion secondary battery and method for manufacturing the same Download PDFInfo
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- JP7366662B2 JP7366662B2 JP2019169644A JP2019169644A JP7366662B2 JP 7366662 B2 JP7366662 B2 JP 7366662B2 JP 2019169644 A JP2019169644 A JP 2019169644A JP 2019169644 A JP2019169644 A JP 2019169644A JP 7366662 B2 JP7366662 B2 JP 7366662B2
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- lithium
- particles
- positive electrode
- electrode active
- active material
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- 239000007774 positive electrode material Substances 0.000 title claims description 289
- 239000002131 composite material Substances 0.000 title claims description 284
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims description 85
- 229910001416 lithium ion Inorganic materials 0.000 title claims description 85
- 238000004519 manufacturing process Methods 0.000 title claims description 66
- 238000000034 method Methods 0.000 title description 11
- 229910052744 lithium Inorganic materials 0.000 claims description 538
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 536
- 239000002245 particle Substances 0.000 claims description 401
- 239000011163 secondary particle Substances 0.000 claims description 140
- 239000011246 composite particle Substances 0.000 claims description 120
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 74
- 239000007784 solid electrolyte Substances 0.000 claims description 64
- 229910052799 carbon Inorganic materials 0.000 claims description 62
- 239000002002 slurry Substances 0.000 claims description 57
- 239000008187 granular material Substances 0.000 claims description 44
- 239000000203 mixture Substances 0.000 claims description 36
- 229910021293 PO 4 Inorganic materials 0.000 claims description 26
- 239000002121 nanofiber Substances 0.000 claims description 26
- 229910004283 SiO 4 Inorganic materials 0.000 claims description 24
- 238000001694 spray drying Methods 0.000 claims description 20
- 229910052726 zirconium Inorganic materials 0.000 claims description 20
- 239000011248 coating agent Substances 0.000 claims description 19
- 238000000576 coating method Methods 0.000 claims description 19
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- 150000001875 compounds Chemical class 0.000 claims description 18
- 239000002994 raw material Substances 0.000 claims description 18
- 229910009178 Li1.3Al0.3Ti1.7(PO4)3 Inorganic materials 0.000 claims description 17
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- 229910052715 tantalum Inorganic materials 0.000 claims description 8
- 229910052727 yttrium Inorganic materials 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
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- 230000008859 change Effects 0.000 claims description 4
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 19
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- 229910015645 LiMn Inorganic materials 0.000 description 7
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- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
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- 229910010707 LiFePO 4 Inorganic materials 0.000 description 3
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
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- 238000010009 beating Methods 0.000 description 1
- GUBGYTABKSRVRQ-QUYVBRFLSA-N beta-maltose Chemical compound OC[C@H]1O[C@H](O[C@H]2[C@H](O)[C@@H](O)[C@H](O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@@H]1O GUBGYTABKSRVRQ-QUYVBRFLSA-N 0.000 description 1
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 239000006231 channel black Substances 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 229910021446 cobalt carbonate Inorganic materials 0.000 description 1
- MEYVLGVRTYSQHI-UHFFFAOYSA-L cobalt(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Co+2].[O-]S([O-])(=O)=O MEYVLGVRTYSQHI-UHFFFAOYSA-L 0.000 description 1
- ZOTKGJBKKKVBJZ-UHFFFAOYSA-L cobalt(2+);carbonate Chemical compound [Co+2].[O-]C([O-])=O ZOTKGJBKKKVBJZ-UHFFFAOYSA-L 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010277 constant-current charging Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 150000002009 diols Chemical class 0.000 description 1
- XPPKVPWEQAFLFU-UHFFFAOYSA-N diphosphoric acid Chemical compound OP(O)(=O)OP(O)(O)=O XPPKVPWEQAFLFU-UHFFFAOYSA-N 0.000 description 1
- 150000002016 disaccharides Chemical class 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000006232 furnace black Substances 0.000 description 1
- 229930182830 galactose Natural products 0.000 description 1
- YVIVRJLWYJGJTJ-UHFFFAOYSA-N gamma-Valerolactam Chemical compound CC1CCC(=O)N1 YVIVRJLWYJGJTJ-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009775 high-speed stirring Methods 0.000 description 1
- 238000009396 hybridization Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 150000003893 lactate salts Chemical class 0.000 description 1
- 150000002596 lactones Chemical class 0.000 description 1
- 239000006233 lamp black Substances 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 150000002641 lithium Chemical class 0.000 description 1
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 description 1
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 1
- 150000002642 lithium compounds Chemical class 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 1
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- SCVOEYLBXCPATR-UHFFFAOYSA-L manganese(II) sulfate pentahydrate Chemical compound O.O.O.O.O.[Mn+2].[O-]S([O-])(=O)=O SCVOEYLBXCPATR-UHFFFAOYSA-L 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 150000002772 monosaccharides Chemical class 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- RRIWRJBSCGCBID-UHFFFAOYSA-L nickel sulfate hexahydrate Chemical compound O.O.O.O.O.O.[Ni+2].[O-]S([O-])(=O)=O RRIWRJBSCGCBID-UHFFFAOYSA-L 0.000 description 1
- 229940116202 nickel sulfate hexahydrate Drugs 0.000 description 1
- 229910000008 nickel(II) carbonate Inorganic materials 0.000 description 1
- ZULUUIKRFGGGTL-UHFFFAOYSA-L nickel(ii) carbonate Chemical compound [Ni+2].[O-]C([O-])=O ZULUUIKRFGGGTL-UHFFFAOYSA-L 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 150000003891 oxalate salts Chemical class 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- ULWHHBHJGPPBCO-UHFFFAOYSA-N propane-1,1-diol Chemical compound CCC(O)O ULWHHBHJGPPBCO-UHFFFAOYSA-N 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 229940005657 pyrophosphoric acid Drugs 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 description 1
- 150000007984 tetrahydrofuranes Chemical class 0.000 description 1
- 239000006234 thermal black Substances 0.000 description 1
- 150000003608 titanium Chemical class 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 1
- 229910000349 titanium oxysulfate Inorganic materials 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- UNXRWKVEANCORM-UHFFFAOYSA-N triphosphoric acid Chemical compound OP(O)(=O)OP(O)(=O)OP(O)(O)=O UNXRWKVEANCORM-UHFFFAOYSA-N 0.000 description 1
- 229940048102 triphosphoric acid Drugs 0.000 description 1
- VXYADVIJALMOEQ-UHFFFAOYSA-K tris(lactato)aluminium Chemical compound CC(O)C(=O)O[Al](OC(=O)C(C)O)OC(=O)C(C)O VXYADVIJALMOEQ-UHFFFAOYSA-K 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 150000003755 zirconium compounds Chemical class 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Description
本発明は、リチウム複合酸化物を正極活物質の主成分とする、サイクル特性に優れたリチウムイオン二次電池用正極活物質複合体、及びその製造方法に関する。 The present invention relates to a positive electrode active material composite for a lithium ion secondary battery, which has a lithium composite oxide as a main component of the positive electrode active material and has excellent cycle characteristics, and a method for manufacturing the same.
リチウム複合酸化物は、高出力及び高容量のリチウムイオン二次電池を構成できる正極活物質として使用されているが、かかるリチウム複合酸化物を正極活物質として用いたリチウムイオン二次電池では、通常、充放電サイクルを重ねるにつれて容量低下が生じ、特に長期間使用すると、電池の容量低下が著しくなるおそれがある。この原因は、充電時に遷移金属成分が電解液へ溶出することにより、リチウム複合酸化物の結晶構造の崩壊が生じやすくなることにあると考えられている。また、リチウム複合酸化物の結晶構造の崩壊が生じると、リチウム複合酸化物の遷移金属成分が周囲の電解液へ溶出し、熱的安定性が低下して安全性が損なわれるおそれもある。 Lithium composite oxides are used as positive electrode active materials that can construct high-power and high-capacity lithium ion secondary batteries, but lithium ion secondary batteries that use such lithium composite oxides as positive electrode active materials usually As charge and discharge cycles are repeated, the capacity decreases, and especially when used for a long period of time, there is a possibility that the capacity decrease of the battery becomes significant. The reason for this is thought to be that the crystal structure of the lithium composite oxide tends to collapse due to elution of transition metal components into the electrolyte during charging. Furthermore, if the crystal structure of the lithium composite oxide collapses, the transition metal component of the lithium composite oxide will be eluted into the surrounding electrolyte, which may reduce thermal stability and impair safety.
こうしたなか、より優れた電池特性を有するリチウムイオン二次電池を実現すべく、種々の正極活物質が開発されている。例えば、特許文献１には、リチウム複合酸化物粒子の表面の少なくとも一部にリチウム系ポリアニオン粒子と炭素材料の混合物である被覆層が形成されてなる正極活物質が開示されており、電子伝導性や高温特性を高める試みがなされている。また、特許文献２には、リチウム系ポリアニオン粒子がリチウム複合酸化物の表面に部分的に接するようにメカニカルミリング処理された正極活物質が開示されており、充放電容量密度や熱安定性の向上を図っている。さらに特許文献３では、表面に良好な導電性を持つ炭素コート層を有するリチウム系ポリアニオン粒子をリチウム複合酸化物に被覆させて、高容量で高温保存特性に優れた正極活物質を得ている。 Under these circumstances, various positive electrode active materials have been developed in order to realize lithium ion secondary batteries with better battery characteristics. For example, Patent Document 1 discloses a positive electrode active material in which a coating layer made of a mixture of lithium-based polyanion particles and a carbon material is formed on at least a part of the surface of lithium composite oxide particles, and has electronic conductivity. Attempts have been made to improve high-temperature properties. In addition, Patent Document 2 discloses a positive electrode active material that is mechanically milled so that lithium-based polyanion particles are partially in contact with the surface of a lithium composite oxide, which improves charge/discharge capacity density and thermal stability. We are trying to Further, in Patent Document 3, lithium-based polyanion particles having a carbon coating layer with good conductivity on the surface are coated with a lithium composite oxide to obtain a positive electrode active material with high capacity and excellent high-temperature storage characteristics.
しかしながら、本発明者の検討により、上記特許文献に記載の技術であっても、二次電池を形成した際、そのサイクル特性、特に高温環境下でのサイクル特性は未だ不充分であることが判明した。そして、さらなる本発明者らの検討により、炭素コート層を有するリチウム系ポリアニオン粒子のみでリチウム複合酸化物粒子の表面の全てを十分に被覆するのは困難であるために、リチウム複合酸化物粒子からの遷移金属成分の溶出を確実に抑制することが困難であることも判明した。 However, the inventor's study revealed that even with the technology described in the above patent document, when forming a secondary battery, its cycle characteristics, especially in a high temperature environment, are still insufficient. did. Further study by the present inventors revealed that it is difficult to sufficiently cover the entire surface of lithium composite oxide particles with only lithium-based polyanion particles having a carbon coating layer. It has also been found that it is difficult to reliably suppress the elution of transition metal components.
したがって、本発明の課題は、リチウム複合酸化物粒子からの遷移金属成分の溶出を有効に抑制し、優れた高温サイクル特性を有するリチウムイオン二次電池を実現することのできる、リチウムイオン二次電池用正極活物質複合体を提供することにある。 Therefore, an object of the present invention is to provide a lithium ion secondary battery that can effectively suppress elution of transition metal components from lithium composite oxide particles and realize a lithium ion secondary battery that has excellent high-temperature cycle characteristics. An object of the present invention is to provide a positive electrode active material composite for use.
そこで本発明者は、上記課題を解決すべく鋭意検討を行った結果、特定のリチウム複合粒子（Ａ）の表面に、特定のリチウム正極活物質粒子（Ｂ）が特定の質量比で担持してなるリチウムイオン二次電池用正極活物質複合体（Ｃ）であれば、リチウム複合酸化物粒子からの遷移金属成分の溶出を効果的に抑制することができ、かかるリチウムイオン二次電池用正極活物質複合体（Ｃ）を用いて得られるリチウムイオン二次電池の高温サイクル特性の向上を有効に図ることが可能になることを見出した。 Therefore, as a result of intensive studies to solve the above problems, the present inventor found that specific lithium positive electrode active material particles (B) are supported on the surface of specific lithium composite particles (A) at a specific mass ratio. The positive electrode active material composite (C) for lithium ion secondary batteries can effectively suppress the elution of transition metal components from the lithium composite oxide particles, and the positive electrode active material composite (C) for lithium ion secondary batteries It has been found that it is possible to effectively improve the high-temperature cycle characteristics of a lithium ion secondary battery obtained using the material composite (C).
したがって、本発明は、リチウム複合粒子（Ａ）の表面にリチウム正極活物質粒子（Ｂ）が担持してなり、かつリチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）との質量比（（Ａ）：（Ｂ））が９５：５～５０：５０であるリチウムイオン二次電池用正極活物質複合体であって、
リチウム複合粒子（Ａ）は、下記式（１）、又は式（２）：
ＬｉＮｉaＣｏbＭｎcＭ1
vＯ2・・・（１）
（式（１）中、Ｍ1はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ａ、ｂ、ｃ、ｖは、０．３≦ａ＜１、０＜ｂ≦０．７、０＜ｃ≦０．７、０≦ｖ≦０．３、かつ３ａ＋３ｂ＋３ｃ＋（Ｍ1の価数）×ｖ＝３を満たす数を示す。）
ＬｉＮｉdＣｏeＡｌfＭ2
wＯ2 ・・・（２）
（式（２）中、Ｍ2はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ｄ、ｅ、ｆ、ｗは、０．４≦ｄ＜１、０＜ｅ≦０．６、０＜ｆ≦０．３、０≦ｗ≦０．３、かつ３ｄ＋３ｅ＋３ｆ＋（Ｍ2の価数）×ｗ＝３を満たす数を示す。）
で表されるリチウム複合酸化物粒子からなるリチウム複合酸化物二次粒子（ａ）の表面を、下記式（３）又は式（４）:
Ｌｉ1+gＡｌhＭ3
xＴｉi（ＰＯ4）3 ・・・（３）
（式（３）中、Ｍ3はＳｃ、Ｉｎ、Ｆｅ、Ｃｒ、Ｇａ、Ｙ、Ｌａ、Ｚｎ、Ｓｉ、Ｍｎ、Ｇｅ、Ｎｄ、Ｓｒ又はＶから選ばれる１種又は２種以上を示し、ｇ、ｈ、ｉ及びｘは、０≦ｇ≦４、０＜ｈ≦２、０＜ｉ＜２、０≦ｘ≦２、ｇ＋３ｈ＋（Ｍ3の価数）×ｘ＋４ｉ＝８を満たす数を示す。）
Ｌｉ3ＰＯ4－Ｌｉ4ＳｉＯ4 ・・・（４）
で表される１種以上のリチウム系固体電解質（ｂ）が被覆してなる粒子であり、
リチウム正極活物質粒子（Ｂ）は、下記式（５）、式（６）、式（７）、式（８）、式（９）、又は式（１０）：
ＬｉjＭｎkＦｅlＭ5
yＰＯ4 ・・・（５）
（式（５）中、Ｍ5はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ又はＧｄを示す。ｊ、ｋ、ｌ、及びｙは、０＜ｊ≦１．２、０．３≦ｋ≦１、０≦ｌ≦０．７、及び０≦ｙ≦０．３を満たし、かつｊ＋（Ｍｎの価数）×ｋ＋（Ｆｅの価数）×ｌ＋（Ｍ5の価数）×ｙ＝３を満たす数を示す。）
ＬｉmＭｎnＦｅoＭ6
zＳｉＯ4 ・・・（６）
（式（６）中、Ｍ6はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ、Ａｌ、Ｚｎ、Ｖ又はＧｄを示す。ｍ、ｎ、ｏ、及びｚは、０＜ｍ≦２．４、０≦ｎ≦１．２、０≦ｏ≦１．２、０≦ｚ≦１．２、及びｎ＋ｏ≠０を満たし、かつｍ＋（Ｍｎの価数）×ｎ＋（Ｆｅの価数）×ｏ＋（Ｍ6の価数）×ｚ＝４を満たす数を示す。）
ＬｉＭ7
pＣｏqＯ2 ・・・（７）
（式（７）中、Ｍ7はＮｉ、Ｍｎ、Ａｌ、Ｍｇ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｚｒ、Ｇａ、及びＳｉから選ばれる1種または２種以上の元素を示す。また、式（７）中、ｐ及びｑは、０≦ｐ≦０．１、０＜ｑ≦１、及び（Ｍ7の価数）×ｐ＋３ｑ＝３を満たす数を示す。）
ＬｉＭ8
rＭｎsＯ4 ・・・（８）
（式（８）中、Ｍ8はＮｉ、Ｃｏ、Ａｌ、Ｍｇ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｚｒ、Ｇａ、Ｃｕ、及びＳｉから選ばれる1種または２種以上の元素を示す。また、式（８）中、ｏ及びｐは、０≦ｒ≦０．１、０＜ｓ≦２、及び（Ｍ8の価数）×ｒ＋（Ｍｎの価数）×ｓ＝７を満たす数を示す。）
ＬｉＮｉtＭｎ1-tＯ4 ・・・（９）
（式（９）中、ｔは０．３≦ｔ≦０．７を満たす数を示す。）
Ｌｉ2ＭｎＯ3－ＬｉＭ10Ｏ2 ・・・（１０）
（式（１０）中、Ｍ10はＮｉ、Ｍｎ、Ｃｏ、Ａｌ、Ｆｅ、Ｃｒ、Ｖ、Ｍｇ、Ｔｉ、Ｚｒ、Ｎｂ、Ｍｏ、Ｗ、Ｃｕ、Ｚｎ、Ｇａ、Ｉｎ、Ｓｎ、Ｌａ、及びＣｅから選ばれる１種または２種以上の元素を示す。）
で表されるいずれか１種以上の粒子である、リチウムイオン二次電池用正極活物質複合体を提供するものである。
Therefore, in the present invention, the lithium positive electrode active material particles (B) are supported on the surface of the lithium composite particles (A), and the mass ratio of the lithium composite particles (A) to the lithium positive electrode active material particles (B) is ( A positive electrode active material composite for a lithium ion secondary battery in which (A):(B)) is 95:5 to 50:50,
The lithium composite particles (A) have the following formula (1) or formula (2):
LiNia Co b Mn c M 1 v O 2 ...(1)
(In formula (1), M 1 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. a, b, c, v are 0.3≦a<1, 0<b≦0.7, 0<c≦0.7, 0≦ Indicates a number that satisfies v≦0.3 and 3a+3b+3c+(valence of M1 )×v=3.)
LiNi d Co e Al f M 2 w O 2 ...(2)
(In formula (2), M2 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. d, e, f, w are 0.4≦d<1, 0<e≦0.6, 0<f≦0.3, 0≦ Indicates a number that satisfies w≦0.3 and 3d+3e+3f+(valence of M2 )×w=3.)
The surface of lithium composite oxide secondary particles (a) consisting of lithium composite oxide particles represented by the following formula (3) or formula (4):
Li 1+g Al h M 3 x Ti i (PO 4 ) 3 ...(3)
(In formula (3), M 3 represents one or more selected from Sc, In, Fe, Cr, Ga, Y, La, Zn, Si, Mn, Ge, Nd, Sr, or V, and g , h, i and x represent numbers satisfying 0≦g≦4, 0<h≦2, 0<i<2, 0≦x≦2, g+3h+(valence of M 3 )×x+4i=8. )
Li 3 PO 4 -Li 4 SiO 4 ...(4)
Particles coated with one or more lithium-based solid electrolytes (b) represented by
The lithium positive electrode active material particles (B) have the following formula (5), formula (6), formula (7), formula (8), formula (9), or formula (10):
Li j Mn k Fe l M 5 y PO 4 ...(5)
(In formula (5), M 5 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, or Gd. j, k, l, and y are 0<j≦1.2, 0.3≦k≦1, 0≦l≦0.7, and 0≦y≦0.3, and j+(valence of Mn)×k+(valence of Fe )×l+(valence of M5 )×y=3.)
Li m Mn n Fe o M 6 z SiO 4 ...(6)
(In formula (6), M 6 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, Al, Zn, V or Gd. m, n, o and z satisfy 0<m≦2.4, 0≦n≦1.2, 0≦o≦1.2, 0≦z≦1.2, and n+o≠0, and m+(Mn (Valency) x n + (Fe valence) x o + (M 6 valence) x z = 4.)
LiM7pCoqO2 ... ( 7 )
(In formula (7), M 7 represents one or more elements selected from Ni, Mn, Al, Mg, Ti, V, Cr, Fe, Zr, Ga, and Si. 7) In, p and q indicate numbers satisfying 0≦p≦0.1, 0<q≦1, and (valence of M7 )×p+3q=3.)
LiM8rMnsO4 ... ( 8 )
(In formula (8), M 8 represents one or more elements selected from Ni, Co, Al, Mg, Ti, V, Cr, Fe, Zr, Ga, Cu, and Si. In formula (8), o and p represent numbers satisfying 0≦r≦0.1, 0<s≦2, and (valence of M8 )×r+(valence of Mn)×s=7. .)
LiNitMn1 -tO4 ... (9)
(In formula (9), t indicates a number satisfying 0.3≦t≦0.7.)
Li2MnO3 - LiM10O2 ... (10)
(In formula (10), M 10 is Ni, Mn, Co, Al, Fe, Cr, V, Mg, Ti, Zr, Nb, Mo, W, Cu, Zn, Ga, In, Sn, La, and Ce. (Indicates one or more elements selected from.)
The object of the present invention is to provide a positive electrode active material composite for a lithium ion secondary battery, which is any one or more particles represented by the following.
また、本発明は、次の工程（Ｉ）～（IV）：
（Ｉ）リチウム系固体電解質（ｂ）の原料となる水溶性化合物が溶解した水溶液にリチウム複合酸化物二次粒子（ａ）を混合した後、噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程、
（II）得られた複合体（ｄ）を、酸素雰囲気下、６００℃～１０００℃で３０分間～６時間焼成して、リチウム複合酸化物二次粒子（ａ）の表面をリチウム系固体電解質（ｂ）が被覆してなるリチウム複合粒子（Ａ）を得る工程、
（III）リチウム正極活物質粒子（Ｂ）を含むスラリーを噴霧乾燥して、リチウム正極活物質粒子（Ｂ）の造粒体（ｅ）を得る工程、並びに
（IV）リチウム複合粒子（Ａ）及び造粒体（ｅ）を、圧縮力及びせん断力を付加しながら混合して、造粒体（ｅ）を解砕させながら、リチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）とを複合化する工程
を備える、上記リチウムイオン二次電池用正極活物質複合体の製造方法を提供するものである。
Further, the present invention provides the following steps (I) to (IV):
(I) After mixing the lithium composite oxide secondary particles (a) with an aqueous solution containing a water-soluble compound that is a raw material for the lithium-based solid electrolyte (b), the mixture is spray-dried to form the lithium-based solid electrolyte (b). a step of obtaining a composite (d) consisting of lithium composite oxide secondary particles (a) carrying a raw material compound on the surface;
(II) The obtained composite (d) is fired in an oxygen atmosphere at 600°C to 1000°C for 30 minutes to 6 hours to change the surface of the lithium composite oxide secondary particles (a) to a lithium-based solid electrolyte ( b) obtaining lithium composite particles (A) coated with
(III) Spray-drying the slurry containing the lithium positive electrode active material particles (B) to obtain granules (e) of the lithium positive electrode active material particles (B), and (IV) Lithium composite particles (A) and The granules (e) are mixed while applying compressive force and shear force, and the lithium composite particles (A) and lithium positive electrode active material particles (B) are crushed while the granules (e) are crushed. The present invention provides a method for manufacturing the above-mentioned positive electrode active material composite for a lithium ion secondary battery, which includes a step of composite.
本発明のリチウムイオン二次電池用正極活物質複合体によれば、リチウム複合酸化物粒子の表面にリチウム系固体電解質とリチウム正極活物質粒子とが重層的に被覆又は担持してなるため、リチウム複合酸化物粒子からの遷移金属成分の溶出を効果的に抑制することができ、高温環境下でのサイクル特性を高めるのに大いに寄与することとなる。
したがって、かかるリチウムイオン二次電池用正極活物質複合体を正極材料として適用すれば、優れた電池特性を発現するリチウムイオン二次電池を実現することが可能となる。
According to the positive electrode active material composite for a lithium ion secondary battery of the present invention, the lithium-based solid electrolyte and the lithium positive electrode active material particles are coated or supported in multiple layers on the surface of the lithium composite oxide particles, so that lithium The elution of transition metal components from composite oxide particles can be effectively suppressed, and this greatly contributes to improving cycle characteristics in high-temperature environments.
Therefore, if such a positive electrode active material composite for a lithium ion secondary battery is applied as a positive electrode material, it becomes possible to realize a lithium ion secondary battery that exhibits excellent battery characteristics.
以下、本発明について詳細に説明する。
本発明のリチウムイオン二次電池用正極活物質複合体は、リチウム複合粒子（Ａ）の表面にリチウム正極活物質粒子（Ｂ）が担持してなり、かつリチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）との質量比（（Ａ）：（Ｂ））が９５：５～５０：５０である。
上記リチウム複合粒子（Ａ）を構成するリチウム複合酸化物二次粒子（ａ）は、下記式（１）、又は式（２）：
ＬｉＮｉaＣｏbＭｎcＭ1
vＯ2・・・（１）
（式（１）中、Ｍ1はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ａ、ｂ、ｃ、ｖは、０．３≦ａ＜１、０＜ｂ≦０．７、０＜ｃ≦０．７、０≦ｖ≦０．３、かつ３ａ＋３ｂ＋３ｃ＋（Ｍ1の価数）×ｖ＝３を満たす数を示す。）
ＬｉＮｉdＣｏeＡｌfＭ2
wＯ2 ・・・（２）
（式（２）中、Ｍ2はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ｄ、ｅ、ｆ、ｗは、０．４≦ｄ＜１、０＜ｅ≦０．６、０＜ｆ≦０．３、０≦ｗ≦０．３、かつ３ｄ＋３ｅ＋３ｆ＋（Ｍ2の価数）×ｗ＝３を満たす数を示す。）
で表されるリチウム複合酸化物粒子からなる二次粒子である。
The present invention will be explained in detail below.
The positive electrode active material composite for a lithium ion secondary battery of the present invention has lithium positive electrode active material particles (B) supported on the surface of lithium composite particles (A), and the lithium composite particles (A) and lithium positive electrode active material The mass ratio ((A):(B)) to the material particles (B) is 95:5 to 50:50.
The lithium composite oxide secondary particles (a) constituting the lithium composite particles (A) have the following formula (1) or formula (2):
LiNia Co b Mn c M 1 v O 2 ...(1)
(In formula (1), M 1 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. a, b, c, v are 0.3≦a<1, 0<b≦0.7, 0<c≦0.7, 0≦ Indicates a number that satisfies v≦0.3 and 3a+3b+3c+(valence of M1 )×v=3.)
LiNi d Co e Al f M 2 w O 2 ...(2)
(In formula (2), M2 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. d, e, f, w are 0.4≦d<1, 0<e≦0.6, 0<f≦0.3, 0≦ Indicates a number that satisfies w≦0.3 and 3d+3e+3f+(valence of M2 )×w=3.)
These are secondary particles made of lithium composite oxide particles represented by:
上記式（１）で表されるリチウム複合酸化物粒子（いわゆるＮｉ－Ｃｏ－Ｍｎ酸化物であり、以後「ＮＣＭ系複合酸化物」と称する。）及び上記式（２）で表されるリチウム複合酸化物粒子（いわゆるＮｉ－Ｃｏ－Ａｌ酸化物であり、以後「ＮＣＡ系複合酸化物」と称する。）は共に層状岩塩型構造を有する粒子であり、凝集することによって、リチウム複合酸化物二次粒子（ａ）を形成する。したがって、二次粒子についても「ＮＣＭ系複合酸化物二次粒子（ａ）」、「ＮＣＡ系複合酸化物二次粒子（ａ）」等と称する。 Lithium composite oxide particles represented by the above formula (1) (so-called Ni-Co-Mn oxide, hereinafter referred to as "NCM-based composite oxide") and lithium composite represented by the above formula (2) Oxide particles (so-called Ni-Co-Al oxides, hereinafter referred to as "NCA-based composite oxides") are particles with a layered rock salt structure, and by agglomerating, they form secondary lithium composite oxides. Form particles (a). Therefore, the secondary particles are also referred to as "NCM composite oxide secondary particles (a)", "NCA composite oxide secondary particles (a)", etc.
上記式（１）で表されるＮＣＭ系複合酸化物粒子は、リチウム複合酸化物二次粒子（ａ）を形成する。式（１）中のＭ1は、Ｍｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。
また、上記式（１）中のａ、ｂ、ｃ、ｖは、０．３≦ａ＜１、０＜ｂ≦０．７、０＜ｃ≦０．７、０≦ｖ≦０．３、かつ３ａ＋３ｂ＋３ｃ＋（Ｍ1の価数）×ｖ＝３を満たす数である。
The NCM-based composite oxide particles represented by the above formula (1) form lithium composite oxide secondary particles (a). M 1 in formula (1) is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Indicates one or more elements selected from Ge.
In addition, a, b, c, and v in the above formula (1) are 0.3≦a<1, 0<b≦0.7, 0<c≦0.7, 0≦v≦0.3, And it is a number that satisfies 3a+3b+3c+(valence of M1 )×v=3.
上記式（１）で表されるＮＣＭ系複合酸化物粒子において、Ｎｉ、Ｃｏ及びＭｎは、電子伝導性に優れ、電池容量及び出力特性に寄与することが知られている。また、サイクル特性の観点からは、かかる遷移元素の一部が他の金属元素Ｍ1により置換されていることが好ましい。これら金属元素Ｍ1により置換されることにより、式（１）で表されるＮＣＭ系複合酸化物粒子の結晶構造が安定化されるため、充放電を繰り返しても結晶構造の崩壊が抑制でき、優れたサイクル特性が実現し得ると考えられる。
上記式（１）で表されるＮＣＭ系複合酸化物粒子としては、具体的には、例えばＬｉＮｉ0.33Ｃｏ0.33 Ｍｎ0.34Ｏ2、ＬｉＮｉ0.8Ｃｏ0.1Ｍｎ0.1Ｏ2、ＬｉＮｉ0.6Ｃｏ0.2Ｍｎ0.2Ｏ2、ＬｉＮｉ0.2Ｃｏ0.4Ｍｎ0.4Ｏ2、ＬｉＮｉ0.33Ｃｏ0.31Ｍｎ0.33Ｍｇ0.03Ｏ2、又はＬｉＮｉ0.33Ｃｏ0.31Ｍｎ0.33Ｚｎ0.03Ｏ2等が挙げられる。なかでも、サイクル特性を一層高める観点から、ＬｉＮｉ0.33Ｃｏ0.33 Ｍｎ0.34Ｏ2、ＬｉＮｉ0.33Ｃｏ0.31Ｍｎ0.33Ｍｇ0.03Ｏ2からなる粒子が好ましい。
In the NCM-based composite oxide particles represented by the above formula (1), Ni, Co, and Mn are known to have excellent electronic conductivity and contribute to battery capacity and output characteristics. Further, from the viewpoint of cycle characteristics, it is preferable that a part of the transition element is replaced by another metal element M 1 . By being substituted with these metal elements M 1 , the crystal structure of the NCM-based composite oxide particles represented by formula (1) is stabilized, so even if charging and discharging are repeated, collapse of the crystal structure can be suppressed, It is believed that excellent cycle characteristics can be achieved.
Specifically, the NCM-based composite oxide particles represented by the above formula (1) include, for example, LiNi 0.33 Co 0.33 Mn 0.34 O 2 , LiNi 0.8 Co 0.1 Mn 0.1 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 , LiNi 0.2 Co 0.4 Mn 0.4 O 2 , LiNi 0.33 Co 0.31 Mn 0.33 Mg 0.03 O 2 , or LiNi 0.33 Co 0.31 Mn 0.33 Zn 0.03 O 2 . Among these, particles made of LiNi 0.33 Co 0.33 Mn 0.34 O 2 and LiNi 0.33 Co 0.31 Mn 0.33 Mg 0.03 O 2 are preferred from the viewpoint of further improving cycle characteristics.
さらに、互いに組成が異なる２種以上の上記式（１）で表されるＮＣＭ系複合酸化物粒子は、コア部（内部）とシェル部（表層部）とを有するコア－シェル構造のリチウム複合酸化物二次粒子（ａ）（ＮＣＭ系複合酸化物二次粒子（ａ））を形成してもよい。 Furthermore, two or more types of NCM-based composite oxide particles represented by the above formula (1) having different compositions have a core-shell structure of lithium composite oxide particles having a core part (interior) and a shell part (surface layer part). secondary particles (a) (NCM-based composite oxide secondary particles (a)) may be formed.
このコア－シェル構造を形成してなるＮＣＭ系複合酸化物二次粒子（ａ）とすることによって、電解液に溶出しやすいＮｉ濃度の高いＮＣＭ系複合酸化物粒子をコア部に配置し、電解液に接するシェル部にはＮｉ濃度の低いＮＣＭ系複合酸化物粒子を配置することができるので、サイクル特性の低下の抑制と安全性の確保をより向上させることができる。このとき、コア部は１相であってもよいし、組成の異なる２相以上で構成していてもよい。コア部を２相以上で構成する態様として、同心円状に複数の相が層状となって積層された構造でもよいし、コア部の表面から中心部に向けて遷移的に組成が変化する構造でもよい。
さらに、シェル部は、コア部の外側に形成されてなるものであればよく、コア部同様に１相であってもよいし、組成の異なる２相以上で構成していてもよい。
By forming the NCM-based composite oxide secondary particles (a) formed with this core-shell structure, NCM-based composite oxide particles with a high Ni concentration that are easily eluted into the electrolytic solution are placed in the core part, and electrolytic Since NCM-based composite oxide particles with a low Ni concentration can be placed in the shell portion that comes into contact with the liquid, it is possible to further suppress deterioration of cycle characteristics and ensure safety. At this time, the core portion may be composed of one phase, or may be composed of two or more phases having different compositions. As an embodiment in which the core part is composed of two or more phases, it may be a structure in which a plurality of phases are laminated in concentric circles, or a structure in which the composition changes transitionally from the surface of the core part toward the center part. good.
Further, the shell portion may be formed outside the core portion, and may be formed of one phase like the core portion, or may be formed of two or more phases having different compositions.
このような組成が異なる２種以上のＮＣＭ系複合酸化物粒子によってコア－シェル構造を形成してなるＮＣＭ系複合酸化物二次粒子（ａ）として、具体的には（コア部）－（シェル部）が、例えば（ＬｉＮｉ0.8Ｃｏ0.1Ｍｎ0.1Ｏ2）－（ＬｉＮｉ0.2Ｃｏ0.4Ｍｎ0.4Ｏ2）、（ＬｉＮｉ0.8Ｃｏ0.1Ｍｎ0.1Ｏ2）－（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）、又は（ＬｉＮｉ0.8Ｃｏ0.1Ｍｎ0.1Ｏ2）－（ＬｉＮｉ0.33Ｃｏ0.31Ｍｎ0.33Ｍｇ0.03Ｏ2）等からなる粒子が挙げられる。 Specifically, the NCM-based composite oxide secondary particles (a) formed by forming a core-shell structure by two or more types of NCM-based composite oxide particles having different compositions include (core part) - (shell part). For example, (LiNi 0.8 Co 0.1 Mn 0.1 O 2 )-(LiNi 0.2 Co 0.4 Mn 0.4 O 2 ), (LiNi 0.8 Co 0.1 Mn 0.1 O 2 )-(LiNi 0.33 Co 0.33 Mn 0.34 O 2 ), or Examples include particles consisting of (LiNi 0.8 Co 0.1 Mn 0.1 O 2 )-(LiNi 0.33 Co 0.31 Mn 0.33 Mg 0.03 O 2 ).
上記式（１）で表されるＮＣＭ系複合酸化物粒子の一次粒子としての平均粒径は、好ましくは５００ｎｍ以下であり、より好ましくは３００ｎｍ以下である。このように、ＮＣＭ系複合酸化物粒子の一次粒子としての平均粒径を少なくとも５００ｎｍ以下にすることで、リチウムイオンの挿入及び脱離に伴う上記一次粒子の膨張収縮量を抑制することができ、粒子割れを有効に防止することができる。なお、上記一次粒子の平均粒径の下限値は特に限定されないが、ハンドリングの観点から、５０ｎｍ以上が好ましい。
ここで、平均粒径とは、ＳＥＭ又はＴＥＭの電子顕微鏡観察において、数十個の粒子の粒径（長軸の長さ）の測定値の平均値を意味し、以後の説明においても同義である。
The average particle diameter of the NCM-based composite oxide particles represented by the above formula (1) as primary particles is preferably 500 nm or less, more preferably 300 nm or less. In this way, by setting the average particle diameter of the NCM-based composite oxide particles as primary particles to at least 500 nm or less, it is possible to suppress the amount of expansion and contraction of the primary particles due to insertion and desorption of lithium ions, Particle cracking can be effectively prevented. Note that the lower limit of the average particle diameter of the primary particles is not particularly limited, but from the viewpoint of handling, it is preferably 50 nm or more.
Here, the average particle size means the average value of the measured values of the particle size (long axis length) of several dozen particles in SEM or TEM electron microscope observation, and it has the same meaning in the following explanation. be.
また、上記一次粒子が凝集して形成するＮＣＭ系複合酸化物二次粒子（ａ）の平均粒径は、好ましくは２５μｍ以下であり、より好ましくは２０μｍ以下である。かかる二次粒子の平均粒径が２５μｍ以下であると、サイクル特性に優れた電池を得ることができる。なお、上記二次粒子の平均粒径の下限値は特に限定されないが、後述する製造方法において噴霧乾燥を用いて得られる複合体（ｄ）が、複数のＮＣＭ系複合酸化物二次粒子（ａ）の凝集体とさせない観点から１μｍ以上が好ましく、５μｍ以上がより好ましい。 Further, the average particle size of the NCM-based composite oxide secondary particles (a) formed by agglomeration of the primary particles is preferably 25 μm or less, more preferably 20 μm or less. When the average particle size of such secondary particles is 25 μm or less, a battery with excellent cycle characteristics can be obtained. Note that the lower limit of the average particle size of the secondary particles is not particularly limited, but the composite (d) obtained by spray drying in the production method described below has a plurality of NCM-based composite oxide secondary particles (a ) is preferably 1 μm or more, more preferably 5 μm or more from the viewpoint of preventing the formation of aggregates.
上記式（１）で表されるＮＣＭ系複合酸化物粒子が、ＮＣＭ系複合酸化物二次粒子（ａ）においてコア－シェル構造を形成してなる場合、コア部を形成する一次粒子としての平均粒径は、好ましくは５０ｎｍ～５００ｎｍであり、より好ましくは５０ｎｍ～３００ｎｍである。そして、上記一次粒子が凝集して形成するコア部の平均粒径は、好ましくは１μｍ～２５μｍであり、より好ましくは１μｍ～２０μｍである。
また、かかるコア部の表面を被覆するシェル部を構成するＮＣＭ系複合酸化物粒子の一次粒子としての平均粒径は、好ましくは５０ｎｍ～５００ｎｍであり、より好ましくは５０ｎｍ～３００ｎｍであって、かかる一次粒子が凝集して形成するシェル部の層厚は、好ましくは０．１μｍ～５μｍであり、より好ましくは０．１μｍ～２．５μｍである。
When the NCM-based composite oxide particles represented by the above formula (1) form a core-shell structure in the NCM-based composite oxide secondary particles (a), the average as the primary particles forming the core part The particle size is preferably 50 nm to 500 nm, more preferably 50 nm to 300 nm. The average particle diameter of the core portion formed by agglomeration of the primary particles is preferably 1 μm to 25 μm, more preferably 1 μm to 20 μm.
Further, the average particle diameter of the NCM-based composite oxide particles as primary particles constituting the shell portion covering the surface of the core portion is preferably 50 nm to 500 nm, more preferably 50 nm to 300 nm, and The layer thickness of the shell portion formed by agglomeration of primary particles is preferably 0.1 μm to 5 μm, more preferably 0.1 μm to 2.5 μm.
上記式（１）で表されるＮＣＭ系複合酸化物粒子からなるＮＣＭ系複合酸化物二次粒子（ａ）の内部空隙率は、リチウムイオンの挿入に伴うＮＣＭ系複合酸化物の膨張を二次粒子の内部空隙内で許容させる観点から、ＮＣＭ系複合酸化物二次粒子（ａ）の１００体積％中、４体積％～１２体積％が好ましく、５体積％～１０体積％がより好ましい。
かかる平均粒径及び内部空隙率を有することで、上記式（１）で表されるＮＣＭ系複合酸化物粒子からなるＮＣＭ系複合酸化物二次粒子（ａ）の表面では、ＮＣＭ系複合酸化物粒子をリチウム系固体電解質（ｂ）が被覆して存在するため、ＮＣＭ系複合酸化物粒子に含まれる金属成分（Ｎｉ、Ｃｏ、Ｍｎ、Ｍ1）の溶出を効果的に抑制し、高温サイクル特性の向上に寄与することができる。
The internal porosity of the NCM-based composite oxide secondary particles (a) consisting of the NCM-based composite oxide particles represented by the above formula (1) is determined by the expansion of the NCM-based composite oxide due to insertion of lithium ions. From the viewpoint of allowing it within the internal voids of the particles, it is preferably 4% to 12% by volume, more preferably 5% to 10% by volume, based on 100% by volume of the NCM-based composite oxide secondary particles (a).
By having such an average particle size and internal porosity, on the surface of the NCM-based composite oxide secondary particles (a) consisting of the NCM-based composite oxide particles represented by the above formula (1), the NCM-based composite oxide Since the particles are coated with the lithium-based solid electrolyte (b), the elution of metal components (Ni, Co, Mn, M 1 ) contained in the NCM-based composite oxide particles is effectively suppressed, and high-temperature cycle characteristics are improved. can contribute to the improvement of
上記式（２）で表されるＮＣＡ系複合酸化物粒子は、上記ＮＣＭ系複合酸化物粒子と同様、リチウム複合酸化物二次粒子（ａ）を形成する。式（２）中のＭ2は、Ｍｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。
また、上記式（２）中のｄ、ｅ、ｆ、ｗは、０．４≦ｄ＜１、０＜ｅ≦０．６、０＜ｆ≦０．３、０≦ｗ≦０．３、かつ３ｄ＋３ｅ＋３ｆ＋（Ｍ2の価数）×ｗ＝３を満たす数である。
The NCA-based composite oxide particles represented by the above formula (2) form lithium composite oxide secondary particles (a) similarly to the above-mentioned NCM-based composite oxide particles. M 2 in formula (2) is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Indicates one or more elements selected from Ge.
In addition, d, e, f, and w in the above formula (2) are 0.4≦d<1, 0<e≦0.6, 0<f≦0.3, 0≦w≦0.3, And it is a number that satisfies 3d+3e+3f+(valence of M 2 )×w=3.
上記式（２）で表されるＮＣＡ系複合酸化物粒子は、式（１）で表されるＮＣＭ系複合酸化物粒子よりも、さらに電池容量及び出力特性に優れている。加えて、Ａｌの含有により、雰囲気中の湿分による変質も生じ難く、安全性にも優れている。
上記式（２）で表されるＮＣＡ系複合酸化物粒子としては、具体的には、例えばＬｉＮｉ0.33Ｃｏ0.33Ａｌ0.34Ｏ2、ＬｉＮｉ0.8Ｃｏ0.1Ａｌ0.1Ｏ2、ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.03Ｍｇ0.03Ｏ2、ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.03Ｚｎ0.03Ｏ2等からなる粒子が挙げられる。なかでも、ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2、ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.03Ｍｇ0.03Ｏ2からなる粒子が好ましい。
The NCA-based composite oxide particles represented by the above formula (2) are even more excellent in battery capacity and output characteristics than the NCM-based composite oxide particles represented by the formula (1). In addition, because of the Al content, deterioration due to moisture in the atmosphere is less likely to occur, resulting in excellent safety.
Specifically, the NCA-based composite oxide particles represented by the above formula (2) include, for example, LiNi 0.33 Co 0.33 Al 0.34 O 2 , LiNi 0.8 Co 0.1 Al 0.1 O 2 , LiNi 0.8 Co 0.15 Al 0.03 Mg 0.03 Examples include particles made of O 2 , LiNi 0.8 Co 0.15 Al 0.03 Zn 0.03 O 2 , and the like. Among these, particles consisting of LiNi 0.8 Co 0.15 Al 0.05 O 2 and LiNi 0.8 Co 0.15 Al 0.03 Mg 0.03 O 2 are preferred.
さらに、ＮＣＭ系複合酸化物粒子同様に、互いに組成が異なる２種以上の上記式（２）で表されるＮＣＡ系複合酸化物粒子は、コア部（内部）とシェル部（表層部）とを有するコア－シェル構造のリチウム複合酸化物二次粒子（ａ）（ＮＣＡ系複合酸化物二次粒子（ａ））を形成していてもよい。 Furthermore, like the NCM-based composite oxide particles, the NCA-based composite oxide particles represented by the above formula (2), which have two or more different compositions, have a core part (inside) and a shell part (surface layer part). Lithium composite oxide secondary particles (a) (NCA-based composite oxide secondary particles (a)) having a core-shell structure may be formed.
上記式（２）で表されるＮＣＡ系複合酸化物の一次粒子としての平均粒径、及び上記一次粒子が凝集して形成される複合酸化物二次粒子（ａ）の平均粒径、並びにかかる二次粒子の内部空隙率は、上記のＮＣＭ系複合酸化物粒子及びＮＣＭ系複合酸化物二次粒子（ａ）と同様である。すなわち、上記式（２）で表されるＮＣＡ系複合酸化物粒子の一次粒子としての平均粒径は、好ましくは５００ｎｍ以下であり、より好ましくは３００ｎｍ以下であり、上記一次粒子からなるＮＣＡ系複合酸化物二次粒子（ａ）の平均粒径は、好ましくは２５μｍ以下であり、より好ましくは２０μｍ以下である。また、上記式（２）で表されるＮＣＡ系複合酸化物粒子からなるＮＣＡ系複合酸化物二次粒子（ａ）の内部空隙率は、かかる二次粒子の体積１００％中、４体積％～１２体積％が好ましく、５体積％～１０体積％がより好ましい。
かかる平均粒径及び内部空隙率を有することで、ＮＣＭ系複合酸化物粒子同様に、上記式（２）で表されるＮＣＡ系複合酸化物粒子からなるＮＣＡ系複合酸化物二次粒子（ａ）の表面では、ＮＣＡ系複合酸化物粒子をリチウム系固体電解質（ｂ）が被覆して存在するため、ＮＣＡ系複合酸化物粒子に含まれる金属成分（Ｎｉ、Ｃｏ、Ａｌ、Ｍ2）の溶出を効果的に抑制し、高温サイクル特性の向上に寄与することができる。
The average particle size as primary particles of the NCA-based composite oxide represented by the above formula (2), the average particle size of the composite oxide secondary particles (a) formed by agglomeration of the above primary particles, and The internal porosity of the secondary particles is the same as that of the above NCM-based composite oxide particles and NCM-based composite oxide secondary particles (a). That is, the average particle diameter of the NCA-based composite oxide particles represented by the above formula (2) as primary particles is preferably 500 nm or less, more preferably 300 nm or less, and the NCA-based composite oxide particles consisting of the above primary particles The average particle size of the oxide secondary particles (a) is preferably 25 μm or less, more preferably 20 μm or less. Furthermore, the internal porosity of the NCA-based composite oxide secondary particles (a) consisting of the NCA-based composite oxide particles represented by the above formula (2) is 4% by volume to 4% by volume based on 100% of the volume of the secondary particles. 12% by volume is preferred, and 5% to 10% by volume is more preferred.
By having such an average particle size and internal porosity, NCA-based composite oxide secondary particles (a) consisting of NCA-based composite oxide particles represented by the above formula (2), like NCM-based composite oxide particles, can be obtained. Since the lithium-based solid electrolyte (b) exists on the surface of the NCA-based composite oxide particles, the metal components (Ni, Co, Al, M 2 ) contained in the NCA-based composite oxide particles are prevented from eluting. This can be effectively suppressed and contribute to improving high-temperature cycle characteristics.
本発明のリチウム複合酸化物二次粒子（ａ）は、上記式（１）で表されるＮＣＭ系複合酸化物粒子と上記式（２）で表されるＮＣＡ系複合酸化物粒子が混在していてもよい。その混在状態は、上記式（１）で表されるＮＣＭ系複合酸化物粒子である一次粒子と上記式（２）で表されるＮＣＡ系複合酸化物粒子である一次粒子が共存してなる二次粒子を形成してもよく、また上記式（１）で表されるＮＣＭ系複合酸化物粒子のみからなる二次粒子と上記式（２）で表されるＮＣＡ系複合酸化物粒子のみからなる二次粒子とが混在してもよく、さらには上記式（１）で表されるＮＣＭ系複合酸化物粒子である一次粒子と上記式（２）で表されるＮＣＡ系複合酸化物粒子である一次粒子が共存してなる二次粒子、上記式（１）で表されるＮＣＭ系複合酸化物粒子のみからなる二次粒子と上記式（２）で表されるＮＣＡ系複合酸化物粒子のみからなる二次粒子とが混在するものであってもよい。 The lithium composite oxide secondary particles (a) of the present invention are a mixture of NCM-based composite oxide particles represented by the above formula (1) and NCA-based composite oxide particles represented by the above formula (2). It's okay. The mixed state is a secondary particle formed by the coexistence of primary particles that are NCM-based composite oxide particles represented by the above formula (1) and primary particles that are NCA-based composite oxide particles represented by the above formula (2). Secondary particles may be formed, and secondary particles may be formed only of NCM-based composite oxide particles represented by the above formula (1) and NCA-based composite oxide particles represented by the above formula (2). Secondary particles may be mixed, and further, primary particles that are NCM-based composite oxide particles represented by the above formula (1) and NCA-based composite oxide particles represented by the above formula (2) may be mixed. Secondary particles formed by the coexistence of primary particles, secondary particles consisting only of NCM-based composite oxide particles expressed by the above formula (1), and only NCA-based complex oxide particles expressed by the above formula (2) The secondary particles may also be mixed.
次に、上記リチウム複合酸化物二次粒子（ａ）の表面を被覆する、リチウム系固体電解質（ｂ）を説明する。リチウム系固体電解質（ｂ）とは、少なくとも良好なリチウムイオン伝導性を有するものであり、後述する製造方法では、焼成工程において形成できるリチウム系固体電解質である。 Next, the lithium-based solid electrolyte (b) that coats the surface of the lithium composite oxide secondary particles (a) will be explained. The lithium-based solid electrolyte (b) has at least good lithium ion conductivity, and is a lithium-based solid electrolyte that can be formed in the firing process in the manufacturing method described below.
リチウム複合酸化物二次粒子（ａ）の表面を被覆する、リチウム系固体電解質（ｂ）は、下記式（３）、又は（４）:
Ｌｉ1+gＡｌhＭ3
xＴｉi（ＰＯ4）3 ・・・（３）
（式（３）中、Ｍ3はＳｃ、Ｉｎ、Ｆｅ、Ｃｒ、Ｇａ、Ｙ、Ｌａ、Ｚｎ、Ｓｉ、Ｍｎ、Ｇｅ、Ｎｄ、Ｓｒ又はＶから選ばれる１種又は２種以上を示し、ｇ、ｈ、ｉ及びｘは、０≦ｇ≦４、０＜ｈ≦２、０＜ｉ＜２、０≦ｘ≦２、ｇ＋３ｈ＋（Ｍ3の価数）×ｘ＋４ｉ＝８を満たす数を示す。）
Ｌｉ3ＰＯ4－Ｌｉ4ＳｉＯ4 ・・・（４）
で表される。
The lithium-based solid electrolyte (b) that coats the surface of the lithium composite oxide secondary particles (a) has the following formula (3) or (4):
Li 1+g Al h M 3 x Ti i (PO 4 ) 3 ...(3)
(In formula (3), M 3 represents one or more selected from Sc, In, Fe, Cr, Ga, Y, La, Zn, Si, Mn, Ge, Nd, Sr, or V, and g , h, i and x represent numbers satisfying 0≦g≦4, 0<h≦2, 0<i<2, 0≦x≦2, g+3h+(valence of M 3 )×x+4i=8. )
Li 3 PO 4 -Li 4 SiO 4 ...(4)
It is expressed as
上記式（３）で表されるリチウム系固体電解質（ｂ）は、ＮＡＳＩＣＯＮ型の結晶構造を有する化学的安定性に優れる酸化物系の固体電解質であり、室温において１０-4Ｓ／ｃｍ台の高いリチウムイオン伝導度を示す。 The lithium-based solid electrolyte (b) represented by the above formula (3) is an oxide-based solid electrolyte that has a NASICON type crystal structure and has excellent chemical stability, and has a lithium-based solid electrolyte on the order of 10 -4 S/cm at room temperature. Shows high lithium ion conductivity.
式（３）中のＭ3はＳｃ、Ｉｎ、Ｆｅ、Ｃｒ、Ｇａ、Ｙ、Ｌａ、Ｚｎ、Ｓｉ、Ｍｎ、Ｇｅ、Ｎｄ、Ｓｒ又はＶから選ばれる１種又は２種以上の元素を示す。
また、上記式（３）中のｇ、ｈ、ｉ及びｘは、０≦ｇ≦４、０＜ｈ≦２、０＜ｉ＜２、０≦ｘ≦２、ｇ＋３ｈ＋（Ｍ3の価数）×ｘ＋４ｉ＝８を満たす数である。
より具体的には、例えば、Ｌｉ1.4Ａｌ0.4Ｔｉ1.6（ＰＯ4）3、Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3、Ｌｉ1.2Ａｌ0.2Ｔｉ1.8（ＰＯ4）3、Ｌｉ1.1Ａｌ0.1Ｔｉ1.9（ＰＯ4）3、Ｌｉ1.3Ａｌ0.27Ｇａ0.03Ｔｉ1.7（ＰＯ4）3、Ｌｉ1.3Ａｌ0.27Ｓｃ0.03Ｔｉ1.7（ＰＯ4）3、Ｌｉ1.3Ａｌ0.27Ｙ0.03Ｔｉ1.7（ＰＯ4）3が挙げられる。なかでも、Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3が好ましい。
M 3 in formula (3) represents one or more elements selected from Sc, In, Fe, Cr, Ga, Y, La, Zn, Si, Mn, Ge, Nd, Sr, or V.
In addition, g, h, i, and x in the above formula (3) are 0≦g≦4, 0<h≦2, 0<i<2, 0≦x≦2, g+3h+(valence of M 3 ) This is a number that satisfies xx+4i=8.
More specifically, for example, Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 , Li 1.1 Al 0.1 Ti 1.9 (PO 4 ) 3 , Li 1.3 Al 0.27 Ga 0.03 Ti 1.7 (PO 4 ) 3 , Li 1.3 Al 0.27 Sc 0.03 Ti 1.7 (PO 4 ) 3 , Li 1.3 Al 0.27 Y 0.03 Ti 1.7 (PO 4 ) 3 can be mentioned. . Among them, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 is preferred.
式（３）で表されるリチウム系固体電解質（ｂ）の被覆量は、リチウム複合酸化物二次粒子（ａ）の活物質としての性能を最大限に使用する観点から、リチウム複合酸化物二次粒子（ａ）の表面をリチウム系固体電解質（ｂ）が被覆してなるリチウム複合粒子（Ａ）の全量１００質量％中に、好ましくは０．１質量％～１０質量％であり、より好ましくは０．１質量％～５質量％であり、さらに好ましくは０．１質量％～１質量％である。 From the viewpoint of maximizing the performance of the lithium composite oxide secondary particles (a) as an active material, the coating amount of the lithium-based solid electrolyte (b) represented by formula (3) is determined by It is preferably 0.1% by mass to 10% by mass, more preferably 0.1% by mass to 10% by mass in the total amount of 100% by mass of lithium composite particles (A) formed by coating the surface of secondary particles (a) with lithium-based solid electrolyte (b). is 0.1% by mass to 5% by mass, more preferably 0.1% by mass to 1% by mass.
また、式（３）で表されるリチウム系固体電解質（ｂ）の被覆厚さは、リチウム複合酸化物二次粒子（ａ）からの遷移金属成分の溶出を効果的に抑制する観点から、好ましくは３ｎｍ～２０ｎｍであり、より好ましくは７ｎｍ～２０ｎｍであり、さらに好ましくは１０ｎｍ～２０ｎｍである。
ここで、リチウム系固体電解質（ｂ）の被覆厚さとは、リチウム複合粒子（Ａ）の断面（クロスセクション）に関するＴＥＭ観察において、十個のリチウム複合粒子（Ａ）表面におけるリチウム系固体電解質（ｂ）被覆層の厚さの測定値の平均値を意味し、以後の説明においても同義である。
Further, the coating thickness of the lithium-based solid electrolyte (b) represented by formula (3) is preferably set from the viewpoint of effectively suppressing the elution of the transition metal component from the lithium composite oxide secondary particles (a). is 3 nm to 20 nm, more preferably 7 nm to 20 nm, even more preferably 10 nm to 20 nm.
Here, the coating thickness of the lithium-based solid electrolyte (b) refers to the coating thickness of the lithium-based solid electrolyte (b) on the surface of ten lithium composite particles (A) in TEM observation of the cross section of the lithium composite particles (A). ) Means the average value of the measured values of the thickness of the coating layer, and has the same meaning in the following description.
上記式（４）で表されるリチウム系固体電解質（ｂ）は、固溶体（Ｌｉ3ＰＯ4－Ｌｉ4ＳｉＯ4）であって、構造上、高いリチウムイオン濃度を保有することができる。そのため、室温において１０-6Ｓ／ｃｍ台の高いリチウムイオン伝導度を示す。 The lithium-based solid electrolyte (b) represented by the above formula (4) is a solid solution (Li 3 PO 4 --Li 4 SiO 4 ) and can have a high lithium ion concentration due to its structure. Therefore, it exhibits a high lithium ion conductivity on the order of 10 -6 S/cm at room temperature.
リチウム複合粒子（Ａ）における式（４）で表されるリチウム系固体電解質（ｂ）の被覆量及び被覆厚さは、上記式（３）で表されるリチウム系固体電解質（ｂ）と同じであって、被覆量は、リチウム複合粒子（Ａ）の全量１００質量％中に、好ましくは０．１質量％～１０質量％であり、より好ましくは０．１質量％～５質量％であり、さらに好ましくは０．１質量％～１質量％であり、被覆厚さは、好ましくは３ｎｍ～２０ｎｍであり、より好ましくは７ｎｍ～２０ｎｍであり、さらに好ましくは１０ｎｍ～２０ｎｍである。 The coating amount and coating thickness of the lithium-based solid electrolyte (b) represented by the formula (4) in the lithium composite particles (A) are the same as the lithium-based solid electrolyte (b) represented by the above formula (3). The coating amount is preferably 0.1% by mass to 10% by mass, more preferably 0.1% by mass to 5% by mass, based on the total amount of 100% by mass of the lithium composite particles (A). More preferably, it is 0.1% by mass to 1% by mass, and the coating thickness is preferably 3nm to 20nm, more preferably 7nm to 20nm, even more preferably 10nm to 20nm.
次に、上記リチウム複合粒子（Ａ）の表面に担持してなる、リチウム正極活物質粒子（Ｂ）を説明する。
下記式（５）、又は式（６）：
ＬｉjＭｎkＦｅlＭ5
yＰＯ4 ・・・（５）
（式（５）中、Ｍ5はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ又はＧｄを示す。ｊ、ｋ、ｌ、及びｙは、０＜ｊ≦１．２、０．３≦ｋ≦１、０≦ｌ≦０．７、及び０≦ｙ≦０．３を満たし、かつｊ＋（Ｍｎの価数）×ｋ＋（Ｆｅの価数）×ｌ＋（Ｍ5の価数）×ｙ＝３を満たす数を示す。）
ＬｉmＭｎnＦｅoＭ6
zＳｉＯ4 ・・・（６）
（式（６）中、Ｍ6はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ、Ａｌ、Ｚｎ、Ｖ又はＧｄを示す。ｍ、ｎ、ｏ、及びｚは、０＜ｍ≦２．４、０≦ｎ≦１．２、０≦ｏ≦１．２、０≦ｚ≦１．２、及びｎ＋ｏ≠０を満たし、かつｍ＋（Ｍｎの価数）×ｎ＋（Ｆｅの価数）×ｏ＋（Ｍ6の価数）×ｚ＝４を満たす数を示す。）
で表されるリチウム正極活物質粒子（Ｂ）は、オリビン型構造を有する正極活物質からなる粒子である。
Next, the lithium positive electrode active material particles (B) supported on the surface of the lithium composite particles (A) will be explained.
The following formula (5) or formula (6):
Li j Mn k Fe l M 5 y PO 4 ...(5)
(In formula (5), M 5 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, or Gd. j, k, l, and y are 0<j≦1.2, 0.3≦k≦1, 0≦l≦0.7, and 0≦y≦0.3, and j+(valence of Mn)×k+(valence of Fe )×l+(valence of M5 )×y=3.)
Li m Mn n Fe o M 6 z SiO 4 ...(6)
(In formula (6), M 6 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, Al, Zn, V or Gd. m, n, o and z satisfy 0<m≦2.4, 0≦n≦1.2, 0≦o≦1.2, 0≦z≦1.2, and n+o≠0, and m+(Mn (Valency) x n + (Fe valence) x o + (M 6 valence) x z = 4.)
The lithium positive electrode active material particles (B) represented by are particles made of a positive electrode active material having an olivine structure.
上記式（５）で表されるリチウム正極活物質粒子（Ｂ）としては、リチウムイオン二次電池用正極活物質複合体（Ｃ）の平均放電電圧の観点から、０．５≦ｊ≦１．２が好ましく、０．６≦ｊ≦１．１がより好ましく、０．６５≦ｊ≦１．０５がさらに好ましい。具体的には、例えばＬｉＭｎＰＯ4、ＬｉＭｎ0.9Ｆｅ0.1ＰＯ4、ＬｉＭｎ0.8Ｆｅ0.2ＰＯ4、ＬｉＭｎ0.75Ｆｅ0.15Ｍｇ0.1ＰＯ4、ＬｉＭｎ0.75Ｆｅ0.19Ｚｒ0.03ＰＯ4、ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4、ＬｉＭｎ0.6Ｆｅ0.4ＰＯ4、ＬｉＭｎ0.5Ｆｅ0.5ＰＯ4、Ｌｉ1.2Ｍｎ0.63Ｆｅ0.27ＰＯ4、Ｌｉ0.6Ｍｎ0.84Ｆｅ0.36ＰＯ4等が挙げられる。なかでも、ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4、ＬｉＭｎ0.8Ｆｅ0.2ＰＯ4、Ｌｉ1.2Ｍｎ0.63Ｆｅ0.27ＰＯ4、又はＬｉ0.6Ｍｎ0.84Ｆｅ0.36ＰＯ4が好ましい。 From the viewpoint of the average discharge voltage of the positive electrode active material composite (C) for a lithium ion secondary battery, the lithium positive electrode active material particles (B) represented by the above formula (5) are 0.5≦j≦1. 2 is preferable, 0.6≦j≦1.1 is more preferable, and 0.65≦j≦1.05 is even more preferable. Specifically, for example, LiMnPO 4 , LiMn 0.9 Fe 0.1 PO 4 , LiMn 0.8 Fe 0.2 PO 4 , LiMn 0.75 Fe 0.15 Mg 0.1 PO 4 , LiMn 0.75 Fe 0.19 Zr 0.03 PO 4 , LiMn 0.7 Fe 0.3 PO 4 , LiMn 0.6 Examples include Fe 0.4 PO 4 , LiMn 0.5 Fe 0.5 PO 4 , Li 1.2 Mn 0.63 Fe 0.27 PO 4 , Li 0.6 Mn 0.84 Fe 0.36 PO 4 . Among these, LiMn 0.7 Fe 0.3 PO 4 , LiMn 0.8 Fe 0.2 PO 4 , Li 1.2 Mn 0.63 Fe 0.27 PO 4 or Li 0.6 Mn 0.84 Fe 0.36 PO 4 is preferred.
また、上記式（６）で表されるリチウム正極活物質粒子（Ｂ）としては、具体的には、例えばＬｉ2Ｍｎ0.45Ｆｅ0.45Ｃｏ0.1ＳｉＯ4、Ｌｉ2Ｍｎ0.54Ｆｅ0.36Ａｌ0.066ＳｉＯ4、Ｌｉ2Ｍｎ0.45Ｆｅ0.45Ｚｎ0.1ＳｉＯ4、Ｌｉ2Ｍｎ0.54Ｆｅ0.36Ｖ0.066ＳｉＯ4、Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4、Ｌｉ2Ｍｎ0.658Ｆｅ0.282Ｚｒ0.02ＳｉＯ4、Ｌｉ2.2Ｍｎ0.594Ｆｅ0.252Ｚｒ0.027ＳｉＯ4、Ｌｉ1.2Ｍｎ0.294Ｆｅ0.392Ｚｒ0.042ＳｉＯ4等が挙げられる。なかでも、Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4、Ｌｉ2Ｍｎ0.658Ｆｅ0.282Ｚｒ0.02ＳｉＯ4、Ｌｉ2.2Ｍｎ0.594Ｆｅ0.252Ｚｒ0.027ＳｉＯ4、又はＬｉ1.2Ｍｎ0.294Ｆｅ0.392Ｚｒ0.042ＳｉＯ4が好ましい。 Further, the lithium positive electrode active material particles (B) represented by the above formula (6) include, for example, Li 2 Mn 0.45 Fe 0.45 Co 0.1 SiO 4 , Li 2 Mn 0.54 Fe 0.36 Al 0.066 SiO 4 , Li 2 Mn 0.45 Fe 0.45 Zn 0.1 SiO 4 , Li 2 Mn 0.54 Fe 0.36 V 0.066 SiO 4 , Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 , Li 2 Mn 0. 658 Fe 0.282 Zr 0.02 SiO 4 , Li 2.2 Mn 0.594 Fe 0.252 Examples include Zr 0.027 SiO 4 , Li 1.2 Mn 0.294 Fe 0.392 Zr 0.042 SiO 4 . Among them, Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 , Li 2 Mn 0.658 Fe 0.282 Zr 0.02 SiO 4 , Li 2.2 Mn 0.594 Fe 0.252 Zr 0.027 SiO 4 or Li 1.2 Mn 0.294 Fe 0.392 Zr 0.042 SiO 4 is preferred.
さらに、上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）は、式（５）又は式（６）で表されるリチウム系ポリアニオン粒子からなるコア部（内部）とシェル部（表層部）を有するコア－シェル構造を形成するものであってもよい。 Furthermore, the lithium positive electrode active material particles (B) represented by the above formula (5) or (6) have a core portion (inside) consisting of lithium-based polyanion particles represented by the formula (5) or (6). It may form a core-shell structure having a shell portion (surface layer portion) and a shell portion (surface layer portion).
このリチウム系ポリアニオン粒子のコア－シェル構造によって、リチウム正極活物質粒子（Ｂ）から電解液に溶出しやすいＭｎ含有量の多いリチウム系ポリアニオンをコア部に配置し、電解液に接し易いシェル部にはＭｎ含有量の少ないリチウム系ポリアニオンを配置したりすることによって、リチウム系ポリアニオン粒子に起因するサイクル特性の低下の抑制と安全性の確保をより向上させることができる。このとき、コア部は１相であってもよいし、組成の異なる２相以上で構成していてもよい。コア部を２相以上で構成する態様として、同心円状に複数の相が層状となって積層された構造でもよいし、コア部の表面から中心部に向けて遷移的に組成が変化する構造でもよい。
さらに、シェル部は、コア部の外側に形成されてなるものであればよく、コア部同様に１相であってもよいし、組成の異なる２相以上で構成していてもよい。
Due to the core-shell structure of this lithium-based polyanion particle, the lithium-based polyanion with a high Mn content that is easily eluted from the lithium positive electrode active material particle (B) into the electrolyte is placed in the core part, and the lithium-based polyanion that is easily eluted into the electrolyte from the lithium positive electrode active material particle (B) is placed in the shell part that easily comes into contact with the electrolyte. By disposing a lithium-based polyanion having a low Mn content, it is possible to further improve suppression of deterioration in cycle characteristics caused by lithium-based polyanion particles and ensure safety. At this time, the core portion may be composed of one phase, or may be composed of two or more phases having different compositions. As an embodiment in which the core part is composed of two or more phases, it may be a structure in which a plurality of phases are laminated in concentric circles, or a structure in which the composition changes transitionally from the surface of the core part toward the center part. good.
Further, the shell portion may be formed outside the core portion, and may be formed of one phase like the core portion, or may be formed of two or more phases having different compositions.
このような組成が異なる２種以上のリチウム系ポリアニオン粒子によってコア－シェル構造を形成してなるリチウム正極活物質粒子（Ｂ）として、具体的には（コア部）－（シェル部）が、例えば（ＬｉＭｎＰＯ4）－（ＬｉＦｅＰＯ4）、（ＬｉＭｎ0.5Ｃｏ0.5ＰＯ4）－（ＬｉＦｅＰＯ4）、（Ｌｉ2ＭｎＳｉＯ4）－（ＬｉＦｅＰＯ4）、又は（Ｌｉ2ＭｎＳｉＯ4）－（Ｌｉ2ＦｅＳｉＯ4）等からなる粒子が挙げられる。 Specifically, as the lithium positive electrode active material particles (B) formed by forming a core-shell structure with two or more types of lithium-based polyanion particles having different compositions, (core part) - (shell part) are, for example, (LiMnPO 4 )-(LiFePO 4 ), (LiMn 0.5 Co 0.5 PO 4 )-(LiFePO 4 ), (Li 2 MnSiO 4 )-(LiFePO 4 ), or (Li 2 MnSiO 4 )-(Li 2 FeSiO 4 ) Examples include particles consisting of.
上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の平均粒径は、リチウム複合粒子（Ａ）の表面のみにおいて、リチウム複合酸化物粒子と密に複合化する観点から、リチウム正極活物質粒子（Ｂ）が式（５）で表される場合には、好ましくは５０ｎｍ～２００ｎｍであり、より好ましくは５０ｎｍ～１５０ｎｍであり、さらに好ましくは５０ｎｍ～１００ｎｍである。また、リチウム正極活物質粒子（Ｂ）が式（６）で表される場合には、好ましくは２０ｎｍ～２００ｎｍであり、より好ましくは２０ｎｍ～１５０ｎｍであり、さらに好ましくは２０ｎｍ～１００ｎｍである。
なお、コア－シェル構造を形成してなるリチウム正極活物質粒子（Ｂ）の平均粒径は、かかるリチウム正極活物質粒子（Ｂ）に式（５）で表されるリチウム系ポリアニオンを含む場合には、好ましくは５０ｎｍ～２００ｎｍであり、より好ましくは５０ｎｍ～１５０ｎｍであり、さらに好ましくは５０ｎｍ～１００ｎｍであり、式（６）で表されるリチウム系ポリアニオンを含む場合には、好ましくは２０ｎｍ～２００ｎｍであり、より好ましくは２０ｎｍ～１５０ｎｍであり、さらに好ましくは２０ｎｍ～１００ｎｍである。
The average particle size of the lithium positive electrode active material particles (B) represented by the above formula (5) or formula (6) is such that it is densely composited with the lithium composite oxide particles only on the surface of the lithium composite particles (A). From this point of view, when the lithium positive electrode active material particles (B) are represented by formula (5), the diameter is preferably 50 nm to 200 nm, more preferably 50 nm to 150 nm, and even more preferably 50 nm to 100 nm. Further, when the lithium positive electrode active material particles (B) are represented by formula (6), the particle size is preferably 20 nm to 200 nm, more preferably 20 nm to 150 nm, and even more preferably 20 nm to 100 nm.
Note that the average particle diameter of the lithium positive electrode active material particles (B) forming a core-shell structure is, when the lithium positive electrode active material particles (B) contain a lithium-based polyanion represented by formula (5). is preferably 50 nm to 200 nm, more preferably 50 nm to 150 nm, still more preferably 50 nm to 100 nm, and preferably 20 nm to 200 nm when containing a lithium polyanion represented by formula (6). , more preferably 20 nm to 150 nm, still more preferably 20 nm to 100 nm.
上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の２５℃での２０ＭＰａ加圧時におけるリチウムイオン伝導度は、１×１０-7Ｓ／ｃｍ以上であることが好ましく、１×１０-6Ｓ／ｃｍ以上であることがより好ましい。 The lithium ion conductivity of the lithium positive electrode active material particles (B) represented by the above formula (5) or formula (6) when pressurized at 20 MPa at 25°C shall be 1 x 10 -7 S/cm or more. is preferable, and more preferably 1×10 −6 S/cm or more.
上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）は、その表面に炭素（ｃ）が担持されてなるのが好ましい。このリチウム正極活物質粒子（Ｂ）の表面における炭素（ｃ）の担持量は、炭素（ｃ）が担持されてなるリチウム正極活物質粒子（Ｂ）全量１００質量％中に、好ましくは０．１質量％～１０質量％であり、より好ましくは０．１質量％～７質量％であり、さらに好ましくは０．１質量％～５質量％である。 The lithium positive electrode active material particles (B) represented by the above formula (5) or formula (6) preferably have carbon (c) supported on their surfaces. The amount of carbon (c) supported on the surface of the lithium positive electrode active material particles (B) is preferably 0.1% in 100% by mass of the total amount of the lithium positive electrode active material particles (B) on which carbon (c) is supported. The content is from 10% by weight to 10% by weight, more preferably from 0.1% to 7% by weight, even more preferably from 0.1% to 5% by weight.
式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の表面に担持される炭素（ｃ）は、リチウム正極活物質粒子（Ｂ）と炭素源（ｃ’）とが一括して焼成されることによって、リチウム正極活物質粒子（Ｂ）の表面上に堅固に担持されるか、リチウム正極活物質粒子（Ｂ）とともに圧縮力及びせん断力を付加されながら混合されて、リチウム正極活物質粒子（Ｂ）の表面上に堅固に担持される。焼成されて炭素（ｃ）となる炭素源（ｃ’）として、セルロースナノファイバー（ｃ’－１）、リグノセルロースナノファイバー（ｃ’－２）、水溶性炭素材料（ｃ’－３）から選ばれる１種又は２種以上が挙げられ、また圧縮力及びせん断力を付加されながら混合される炭素（ｃ）として、水不溶性炭素材料（ｃ４）が挙げられる。 The carbon (c) supported on the surface of the lithium positive electrode active material particles (B) represented by formula (5) or formula (6) is the carbon (c) supported on the surface of the lithium positive electrode active material particles (B) and the carbon source (c'). By being fired all at once, it is firmly supported on the surface of the lithium positive electrode active material particles (B), or mixed with the lithium positive electrode active material particles (B) while being subjected to compressive force and shearing force, It is firmly supported on the surface of the lithium positive electrode active material particles (B). The carbon source (c') that becomes carbon (c) when fired is selected from cellulose nanofibers (c'-1), lignocellulose nanofibers (c'-2), and water-soluble carbon materials (c'-3). Examples of carbon (c) to be mixed while applying compressive force and shear force include a water-insoluble carbon material (c4).
上記炭素源（ｃ’）としてのセルロースナノファイバー（ｃ’－１）とは、全ての植物細胞壁の約５割を占める骨格成分であって、かかる細胞壁を構成する植物繊維をナノサイズまで解繊等することにより得ることができる軽量高強度繊維であり、セルロースナノファイバー（ｃ’－１）由来の炭素（ｃ１）は、周期的構造を有する。かかるセルロースナノファイバー（ｃ’－１）の繊維径は、１ｎｍ～１００ｎｍであり、水への良好な分散性も有している。また、セルロースナノファイバー（ｃ’－１）を構成するセルロース分子鎖では、炭素による周期的構造が形成されていることから、これが炭化されつつ、上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）とも相まって、かかる粒子の表面に堅固に担持されることにより、良好な電子伝導性を付与することができる。 The cellulose nanofiber (c'-1) as the carbon source (c') is a skeletal component that accounts for about 50% of all plant cell walls, and the plant fibers that make up the cell wall are defibrated to nano-size. Carbon (c1) derived from cellulose nanofibers (c'-1) has a periodic structure. The cellulose nanofibers (c'-1) have a fiber diameter of 1 nm to 100 nm and also have good dispersibility in water. Furthermore, since a periodic structure of carbon is formed in the cellulose molecular chains constituting cellulose nanofibers (c'-1), as this is carbonized, it is expressed by the above formula (5) or (6). In combination with the lithium positive electrode active material particles (B), it is firmly supported on the surface of the particles, thereby imparting good electronic conductivity.
上記炭素源（ｃ’）としてのリグノセルロースナノファイバー（ｃ’－２）とは、セルロースナノファイバー（ｃ’－１）よりもさらに優れた水への分散性を有している。そして、リグノセルロースナノファイバー（ｃ’－２）が炭化されてなる炭素（ｃ２）は、セルロースナノファイバー由来の周期的構造とリグニン由来の三次元網目構造を有する複合的な三次元構造を形成し、上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）に有効に担持されることができる。かかるリグノセルロースナノファイバー（ｃ’－２）の繊維径は、３０ｎｍ～１０００ｎｍである。 The lignocellulose nanofiber (c'-2) as the carbon source (c') has even better dispersibility in water than the cellulose nanofiber (c'-1). The carbon (c2) obtained by carbonizing the lignocellulose nanofibers (c'-2) forms a composite three-dimensional structure having a periodic structure derived from cellulose nanofibers and a three-dimensional network structure derived from lignin. , can be effectively supported on the lithium positive electrode active material particles (B) represented by the above formula (5) or formula (6). The fiber diameter of such lignocellulose nanofibers (c'-2) is 30 nm to 1000 nm.
上記炭素源（ｃ’）としての水溶性炭素材料（ｃ’－３）とは、２５℃の水１００ｇに、水溶性炭素材料（ｃ’－３）の炭素原子換算量で０．４ｇ以上、好ましくは１．０ｇ以上溶解する炭素材料を意味し、炭化されることで炭素として上記リチウム正極活物質粒子（Ｂ）の表面に存在することとなる。かかる水溶性炭素材料（ｃ’－３）としては、例えば、糖類、ポリオール、ポリエーテル、及び有機酸から選ばれる１種又は２種以上が挙げられる。より具体的には、例えば、グルコース、フルクトース、ガラクトース、マンノース等の単糖類；マルトース、スクロース、セロビオース等の二糖類；デンプン、デキストリン等の多糖類；エチレングリコール、プロピレングリコール、ジエチレングリコール、ポリエチレングリコール、ブタンジオール、プロパンジオール、ポリビニルアルコール、グリセリン等のポリオールやポリエーテル；クエン酸、酒石酸、アスコルビン酸等の有機酸が挙げられる。なかでも、溶媒への溶解性及び分散性を高めて炭素源として効果的に機能させる観点から、グルコース、フルクトース、スクロース、デキストリンが好ましく、グルコースがより好ましい。 The water-soluble carbon material (c'-3) as the carbon source (c') is 0.4 g or more of the water-soluble carbon material (c'-3) in terms of carbon atoms per 100 g of water at 25°C. Preferably, it refers to a carbon material that dissolves in an amount of 1.0 g or more, and when carbonized, it exists as carbon on the surface of the lithium positive electrode active material particles (B). Examples of such water-soluble carbon material (c'-3) include one or more selected from saccharides, polyols, polyethers, and organic acids. More specifically, for example, monosaccharides such as glucose, fructose, galactose, and mannose; disaccharides such as maltose, sucrose, and cellobiose; polysaccharides such as starch and dextrin; ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, and butane. Examples include polyols and polyethers such as diol, propanediol, polyvinyl alcohol, and glycerin; and organic acids such as citric acid, tartaric acid, and ascorbic acid. Among these, glucose, fructose, sucrose, and dextrin are preferred, and glucose is more preferred, from the viewpoint of improving solubility and dispersibility in solvents and effectively functioning as a carbon source.
なお、式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の表面に存在する、セルロースナノファイバー（ｃ’－１）由来の炭素（ｃ１）、リグノセルロースナノファイバー（ｃ’－２）由来の炭素（ｃ２）、又は水溶性炭素材料（ｃ’－３）由来の炭素（ｃ３）の原子換算量（炭素の担持量）は、式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）について炭素・硫黄分析装置を用いて測定した炭素量として、確認することができる。 In addition, carbon (c1) derived from cellulose nanofiber (c'-1), lignocellulose nanofiber ( The atomic equivalent amount (carrying amount of carbon) of carbon (c2) derived from c'-2) or carbon (c3) derived from water-soluble carbon material (c'-3) is expressed by formula (5) or formula (6). It can be confirmed as the amount of carbon measured using a carbon/sulfur analyzer for the lithium positive electrode active material particles (B) represented by:
炭素（ｃ）として式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）に担持される水不溶性炭素材料（ｃ４）とは、２５℃の水１００ｇに対する溶解量が、水不溶性炭素材料（ｃ４）の炭素原子換算量で０．４ｇ未満である水不溶性の炭素材料であって、焼成等せずともそのもの自体が導電性を有する。かかる水不溶性炭素材料（ｃ４）としては、グラファイト、アセチレンブラック、ケッチェンブラック、チャンネルブラック、ファーネスブラック、ランプブラック、及びサーマルブラックから選ばれる１種又は２種以上が挙げられる。なかでも、吸着水分量低減の観点から、グラファイトが好ましい。グラファイトとしては、人造グラファイト（鱗片状、塊状、土状、グラフェン）、天然グラファイトのいずれであってもよい。水不溶性炭素材料（ｃ４）の平均粒径は、複合化の観点から、好ましくは０．５μｍ～２０μｍであり、より好ましくは１．０μｍ～１５μｍである。 The water-insoluble carbon material (c4) supported on the lithium positive electrode active material particles (B) represented by formula (5) or formula (6) as carbon (c) has a dissolution amount in 100 g of water at 25 ° C. The water-insoluble carbon material (c4) is a water-insoluble carbon material whose amount is less than 0.4 g in terms of carbon atoms, and has electrical conductivity itself even without firing or the like. Examples of the water-insoluble carbon material (c4) include one or more selected from graphite, acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black. Among these, graphite is preferred from the viewpoint of reducing the amount of adsorbed water. The graphite may be either artificial graphite (scale-like, lump-like, earth-like, graphene) or natural graphite. The average particle size of the water-insoluble carbon material (c4) is preferably 0.5 μm to 20 μm, more preferably 1.0 μm to 15 μm, from the viewpoint of compositing.
リチウム複合粒子（Ａ）への複合化によって担持される、上記式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の担持量は、リチウム複合酸化物二次粒子（ａ）の活物質としての性能を最大限に使用する観点から、複合化して得られるリチウムイオン二次電池用正極活物質複合体（Ｃ）の全量１００質量％中に、好ましくは５質量％～４５質量％であり、より好ましくは１０質量％～４５質量％であり、さらに好ましくは１５質量％～４５質量％である。
なお、ここでのリチウム正極活物質粒子（Ｂ）の被覆量は、上記炭素（ｃ）の担持量を含むものである。
The amount of the lithium positive electrode active material particles (B) represented by the above formula (5) or formula (6) supported by the lithium composite particles (A) is the amount of the lithium positive electrode active material particles (B) supported by the lithium composite oxide secondary particles ( From the viewpoint of maximizing the performance of a) as an active material, preferably from 5% by mass to 100% by mass of the total amount of the positive electrode active material composite (C) for lithium ion secondary batteries obtained by composite. The content is 45% by mass, more preferably 10% by mass to 45% by mass, and even more preferably 15% by mass to 45% by mass.
Note that the amount of lithium positive electrode active material particles (B) covered here includes the amount of carbon (c) supported.
また、式（５）又は式（６）で表されるリチウム正極活物質粒子（Ｂ）の担持によりリチウム複合粒子（Ａ）の表面に形成される担持層の厚さは、リチウム複合酸化物二次粒子（ａ）からの遷移金属成分の溶出を効果的に抑制する観点から、好ましくは１００ｎｍ～３μｍであり、より好ましくは３００ｎｍ～３μｍであり、さらに好ましくは５００ｎｍ～３μｍである。 Furthermore, the thickness of the supporting layer formed on the surface of the lithium composite particles (A) by supporting the lithium positive electrode active material particles (B) represented by formula (5) or formula (6) is From the viewpoint of effectively suppressing the elution of transition metal components from the secondary particles (a), the diameter is preferably 100 nm to 3 μm, more preferably 300 nm to 3 μm, and even more preferably 500 nm to 3 μm.
下記式（７）：
ＬｉＭ7
pＣｏqＯ2 ・・・（７）
（式（７）中、Ｍ7はＮｉ、Ｍｎ、Ａｌ、Ｍｇ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｚｒ、Ｇａ、及びＳｉから選ばれる1種または２種以上の元素を示す。また、式（７）中、ｐ及びｑは、０≦ｐ≦０．１、０＜ｑ≦１、及び（Ｍ7の価数）×ｐ＋３ｑ＝３を満たす数を示す。）
で表されるリチウム正極活物質粒子（Ｂ）は、層状岩塩型構造の結晶構造を有する正極活物質からなる粒子である。
The following formula (7):
LiM7pCoqO2 ... ( 7 )
(In formula (7), M 7 represents one or more elements selected from Ni, Mn, Al, Mg, Ti, V, Cr, Fe, Zr, Ga, and Si. 7) In, p and q indicate numbers satisfying 0≦p≦0.1, 0<q≦1, and (valence of M7 )×p+3q=3.)
The lithium positive electrode active material particles (B) represented by are particles made of a positive electrode active material having a layered rock salt crystal structure.
上記式（７）で表されるリチウム正極活物質粒子（Ｂ）としては、高温サイクル特性の観点からは、Ｍ7としてＮｉ及びＭｎから選択されるいずれか１種以上の元素であるものが好ましく、より好ましくはＭ7の５０モル％以上がＮｉである。
具体的には、ＬｉＣｏＯ2、ＬｉＭｎ0.05Ｃｏ0.95Ｏ2、ＬｉＡｌ0.05Ｃｏ0.95Ｏ2、ＬｉＭｇ0.03Ｃｏ0.98Ｏ2、ＬｉＳｉ0.03Ｃｏ0.96Ｏ2を用いることができる。なかでも、ＬｉＣｏＯ2が好ましい。
In the lithium positive electrode active material particles (B) represented by the above formula (7), from the viewpoint of high temperature cycle characteristics, it is preferable that M 7 is one or more elements selected from Ni and Mn. More preferably, 50 mol% or more of M 7 is Ni.
Specifically, LiCoO 2 , LiMn 0.05 Co 0.95 O 2 , LiAl 0.05 Co 0.95 O 2 , LiMg 0.03 Co 0.98 O 2 , and LiSi 0.03 Co 0.96 O 2 can be used. Among them, LiCoO 2 is preferred.
上記式（７）で表されるリチウム正極活物質粒子（Ｂ）の平均粒径は、リチウム複合粒子（Ａ）の表面のみにおいて、リチウム複合酸化物粒子と密に複合化する観点から、好ましくは１００ｎｍ～５００ｎｍであり、より好ましくは１００ｎｍ～４００ｎｍであり、さらに好ましくは１００ｎｍ～３００ｎｍである。 The average particle diameter of the lithium positive electrode active material particles (B) represented by the above formula (7) is preferably from the viewpoint of densely compounding with the lithium composite oxide particles only on the surface of the lithium composite particles (A). The wavelength is 100 nm to 500 nm, more preferably 100 nm to 400 nm, even more preferably 100 nm to 300 nm.
リチウム複合粒子（Ａ）への複合化によって担持される、上記式（７）で表されるリチウム正極活物質粒子（Ｂ）の担持量は、リチウム複合酸化物二次粒子（ａ）の活物質としての性能を最大限に使用する観点から、複合化して得られるリチウムイオン二次電池用正極活物質複合体（Ｃ）の全量１００質量％中に、好ましくは５質量％～５０質量％であり、より好ましくは１０質量％～５０質量％であり、さらに好ましくは１５質量％～５０質量％である。 The amount of the lithium positive electrode active material particles (B) represented by the above formula (7) supported by the lithium composite particles (A) is the same as the amount of the active material of the lithium composite oxide secondary particles (a). From the viewpoint of maximizing the performance as a lithium ion secondary battery, it is preferably 5% by mass to 50% by mass in 100% by mass of the total amount of the positive electrode active material composite (C) for lithium ion secondary batteries obtained by composite. , more preferably 10% by mass to 50% by mass, still more preferably 15% by mass to 50% by mass.
この際の、式（７）で表されるリチウム正極活物質粒子（Ｂ）の担持によりリチウム複合粒子（Ａ）の表面に形成される担持層の厚さは、好ましくは１００ｎｍ～３μｍであり、より好ましくは３００ｎｍ～３μｍであり、さらに好ましくは５００ｎｍ～３μｍである。 At this time, the thickness of the support layer formed on the surface of the lithium composite particles (A) by supporting the lithium positive electrode active material particles (B) represented by formula (7) is preferably 100 nm to 3 μm, More preferably 300 nm to 3 μm, still more preferably 500 nm to 3 μm.
下記式（８）：
ＬｉＭ8
rＭｎsＯ4 ・・・（８）
（式（８）中、Ｍ8はＮｉ、Ｃｏ、Ａｌ、Ｍｇ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｚｒ、Ｇａ、Ｃｕ、及びＳｉから選ばれる1種または２種以上の元素を示す。また、式（８）中、ｏ及びｐは、０≦ｒ≦０．１、０＜ｓ≦２、及び（Ｍ8の価数）×ｒ＋（Ｍｎの価数）×ｓ＝７を満たす数を示す。）
で表されるリチウム正極活物質粒子（Ｂ）は、層状岩塩型構造の結晶構造を有する正極活物質からなる粒子である。
The following formula (8):
LiM8rMnsO4 ... ( 8 )
(In formula (8), M 8 represents one or more elements selected from Ni, Co, Al, Mg, Ti, V, Cr, Fe, Zr, Ga, Cu, and Si. In formula (8), o and p represent numbers satisfying 0≦r≦0.1, 0<s≦2, and (valence of M8 )×r+(valence of Mn)×s=7. .)
The lithium positive electrode active material particles (B) represented by are particles made of a positive electrode active material having a layered rock salt crystal structure.
上記式（８）で表されるリチウム正極活物質粒子（Ｂ）としては、具体的には、ＬｉＭｎ2Ｏ4、ＬｉＮｉ0.5Ｍｎ1.5Ｏ4、ＬｉＣｏＭｎＯ4、ＬｉＣｒＭｎＯ4、ＬｉＦｅＭｎＯ4、ＬｉＡｌＭｎＯ4、ＬｉＣｕ0.5Ｍｎ1.5Ｏ4を用いることができる。なかでも、ＬｉＭｎ2Ｏ4が好ましい。 Specifically, the lithium positive electrode active material particles (B) represented by the above formula (8) include LiMn 2 O 4 , LiNi 0.5 Mn 1.5 O 4 , LiCoMnO 4 , LiCrMnO 4 , LiFeMnO 4 , LiAlMnO 4 , LiCu 0.5 Mn 1.5 O 4 can be used. Among them, LiMn 2 O 4 is preferred.
上記式（８）で表されるリチウム正極活物質粒子（Ｂ）の平均粒径は、リチウム複合粒子（Ａ）の表面のみにおいて、リチウム複合酸化物粒子と密に複合化する観点から、好ましくは１００ｎｍ～５００ｎｍであり、より好ましくは１００ｎｍ～４００ｎｍであり、さらに好ましくは１００ｎｍ～３００ｎｍである。 The average particle diameter of the lithium positive electrode active material particles (B) represented by the above formula (8) is preferably from the viewpoint of forming a dense composite with the lithium composite oxide particles only on the surface of the lithium composite particles (A). The wavelength is 100 nm to 500 nm, more preferably 100 nm to 400 nm, even more preferably 100 nm to 300 nm.
リチウムイオン二次電池用正極活物質複合体（Ｃ）における式（８）で表されるリチウム正極活物質粒子（Ｂ）の担持量及び担持により形成される担持層の厚さは、上記式（７）で表されるリチウム正極活物質粒子（Ｂ）と同じであって、担持量は、リチウムイオン二次電池用正極活物質複合体（Ｃ）の全量１００質量％中に、好ましくは５質量％～５０質量％であり、より好ましくは１０質量％～５０質量％であり、さらに好ましくは１５質量％～５０質量％である。また、担持層の厚さは、好ましくは１００ｎｍ～３μｍであり、より好ましくは３００ｎｍ～３μｍであり、さらに好ましくは５００ｎｍ～３μｍである。 The amount of supported lithium positive electrode active material particles (B) represented by formula (8) in the positive electrode active material composite (C) for lithium ion secondary batteries and the thickness of the support layer formed by the support are determined by the above formula ( It is the same as the lithium positive electrode active material particles (B) represented by 7), and the supported amount is preferably 5% by mass in 100% by mass of the total amount of the positive electrode active material composite (C) for lithium ion secondary batteries. % to 50% by weight, more preferably 10% to 50% by weight, even more preferably 15% to 50% by weight. Further, the thickness of the support layer is preferably 100 nm to 3 μm, more preferably 300 nm to 3 μm, even more preferably 500 nm to 3 μm.
下記式（９）：
ＬｉＮｉtＭｎ1-tＯ4 ・・・（９）
（式（９）中、ｔは０．３≦ｔ≦０．７を満たす数を示す。）
で表されるリチウム正極活物質粒子（Ｂ）は、スピネル構造を有する正極活物質からなる粒子である。
The following formula (9):
LiNitMn1 -tO4 ... (9)
(In formula (9), t indicates a number satisfying 0.3≦t≦0.7.)
The lithium positive electrode active material particles (B) represented by are particles made of a positive electrode active material having a spinel structure.
上記式（９）で表されるリチウム正極活物質粒子（Ｂ）としては、具体的には、ＬｉＮｉ0.4Ｍｎ0.6Ｏ4、ＬｉＮｉ0.5Ｍｎ0.5Ｏ4、ＬｉＮｉ0.6Ｍｎ0.4Ｏ4を用いることができる。なかでも、ＬｉＮｉ0.5Ｍｎ0.5Ｏ4が好ましい。 Specifically, as the lithium positive electrode active material particles (B) represented by the above formula (9), LiNi 0.4 Mn 0.6 O 4 , LiNi 0.5 Mn 0.5 O 4 , and LiNi 0.6 Mn 0.4 O 4 can be used. . Among them, LiNi 0.5 Mn 0.5 O 4 is preferred.
上記式（９）で表されるリチウム正極活物質粒子（Ｂ）の平均粒径は、リチウム複合粒子（Ａ）の表面のみにおいて、リチウム複合酸化物粒子と密に複合化する観点から、好ましくは１００ｎｍ～５００ｎｍであり、より好ましくは１００ｎｍ～４００ｎｍであり、さらに好ましくは１００ｎｍ～３００ｎｍである。 The average particle diameter of the lithium positive electrode active material particles (B) represented by the above formula (9) is preferably from the viewpoint of densely compounding with the lithium composite oxide particles only on the surface of the lithium composite particles (A). The wavelength is 100 nm to 500 nm, more preferably 100 nm to 400 nm, even more preferably 100 nm to 300 nm.
リチウムイオン二次電池用正極活物質複合体（Ｃ）における式（９）で表されるリチウム正極活物質粒子（Ｂ）の担持量及び担持により形成される担持層の厚さは、上記式（７）及び式（８）で表されるリチウム正極活物質粒子（Ｂ）と同じであって、担持量は、リチウムイオン二次電池用正極活物質複合体（Ｃ）の全量１００質量％中に、好ましくは５質量％～５０質量％であり、より好ましくは１０質量％～５０質量％であり、さらに好ましくは１５質量％～５０質量％である。また、担持層の厚さは、好ましくは１００ｎｍ～３μｍであり、より好ましくは３００ｎｍ～３μｍであり、さらに好ましくは５００ｎｍ～３μｍである。 The amount of supported lithium positive electrode active material particles (B) represented by formula (9) in the positive electrode active material composite (C) for lithium ion secondary batteries and the thickness of the support layer formed by the support are determined by the above formula ( 7) and the lithium positive electrode active material particles (B) represented by formula (8), and the supported amount is 100% by mass of the total amount of the positive electrode active material composite (C) for lithium ion secondary batteries. , preferably 5% to 50% by weight, more preferably 10% to 50% by weight, even more preferably 15% to 50% by weight. Further, the thickness of the support layer is preferably 100 nm to 3 μm, more preferably 300 nm to 3 μm, even more preferably 500 nm to 3 μm.
下記式（１０）：
Ｌｉ2ＭｎＯ3－ＬｉＭ10Ｏ2 ・・・（１０）
（式（１０）中、Ｍ10はＮｉ、Ｍｎ、Ｃｏ、Ａｌ、Ｆｅ、Ｃｒ、Ｖ、Ｍｇ、Ｔｉ、Ｚｒ、Ｎｂ、Ｍｏ、Ｗ、Ｃｕ、Ｚｎ、Ｇａ、Ｉｎ、Ｓｎ、Ｌａ、及びＣｅから選ばれる１種または２種以上の元素を示す。）
で表されるリチウム正極活物質粒子（Ｂ）は、層状岩塩型構造の結晶構造を有する固溶体を形成する正極活物質からなる粒子である。
The following formula (10):
Li2MnO3 - LiM10O2 ... (10)
(In formula (10), M 10 is Ni, Mn, Co, Al, Fe, Cr, V, Mg, Ti, Zr, Nb, Mo, W, Cu, Zn, Ga, In, Sn, La, and Ce. (Indicates one or more elements selected from.)
The lithium positive electrode active material particles (B) represented by are particles made of a positive electrode active material that forms a solid solution having a layered rock salt crystal structure.
上記式（１０）で表されるリチウム正極活物質粒子（Ｂ）としては、高温サイクル特性の観点からは、Ｍ10としてＣｏ、Ｎｉ及びＭｎから選択される１種または２種以上の元素であるものが好ましい。
具体的には、Ｌｉ2ＭｎＯ3－ＬｉＮｉＯ2、Ｌｉ2ＭｎＯ3－ＬｉＣｏＯ2、Ｌｉ2ＭｎＯ3－ＬｉＭｎ2Ｏ4、Ｌｉ2ＭｎＯ3－ＬｉＮｉxＭｎ1-xＯ2（０＜ｘ＜１）、Ｌｉ2ＭｎＯ3－ＬｉＮｉxＣｏ1-xＯ2（０＜ｘ＜１）、Ｌｉ2ＭｎＯ3－ＬｉＣｏxＭｎ1-xＯ2（０＜ｘ＜１）、Ｌｉ2ＭｎＯ3－ＬｉＮｉ1-x-yＣｏxＭｎyＯ2（０＜ｘ＜１、０＜ｙ＜１、０＜ｘ＋ｙ＜１）を用いることができる。なかでも、Ｌｉ2ＭｎＯ3－ＬｉＮｉ1/3Ｃｏ1/3Ｍｎ1/3Ｏ2が好ましい。
From the viewpoint of high-temperature cycle characteristics, the lithium positive electrode active material particles (B) represented by the above formula (10) include one or more elements selected from Co, Ni, and Mn as M10 . Preferably.
Specifically, Li 2 MnO 3 -LiNiO 2 , Li 2 MnO 3 -LiCoO 2 , Li 2 MnO 3 -LiMn 2 O 4 , Li 2 MnO 3 -LiNi x Mn 1-x O 2 (0<x<1 ), Li 2 MnO 3 -LiNi x Co 1-x O 2 (0<x<1), Li 2 MnO 3 -LiCo x Mn 1-x O 2 (0<x<1), Li 2 MnO 3 -LiNi 1-xy Co x Mny O 2 (0<x<1, 0<y<1, 0<x+y<1) can be used. Among them, Li 2 MnO 3 --LiNi 1/3 Co 1/3 Mn 1/3 O 2 is preferred.
上記式（１０）で表されるリチウム正極活物質粒子（Ｂ）の平均粒径は、リチウム複合粒子（Ａ）の表面のみにおいて、リチウム複合酸化物粒子と密に複合化する観点から、好ましくは５０ｎｍ～２００ｎｍであり、より好ましくは５０ｎｍ～１５０ｎｍであり、さらに好ましくは５０ｎｍ～１００ｎｍである。 The average particle size of the lithium positive electrode active material particles (B) represented by the above formula (10) is preferably from the viewpoint of being densely composited with the lithium composite oxide particles only on the surface of the lithium composite particles (A). The wavelength is 50 nm to 200 nm, more preferably 50 nm to 150 nm, and even more preferably 50 nm to 100 nm.
リチウムイオン二次電池用正極活物質複合体（Ｃ）における式（１０）で表されるリチウム正極活物質粒子（Ｂ）の担持量及び担持により形成される担持層の厚さは、上記式（５）及び式（６）で表されるリチウム正極活物質粒子（Ｂ）と同じであって、担持量は、リチウムイオン二次電池用正極活物質複合体（Ｃ）の全量１００質量％中に、好ましくは５質量％～４５質量％であり、より好ましくは１０質量％～４５質量％であり、さらに好ましくは１５質量％～４５質量％である。また、担持層の厚さは、好ましくは１００ｎｍ～３μｍであり、より好ましくは３００ｎｍ～３μｍであり、さらに好ましくは５００ｎｍ～３μｍである。 The amount of supported lithium positive electrode active material particles (B) represented by formula (10) in the positive electrode active material composite (C) for lithium ion secondary batteries and the thickness of the support layer formed by the support are determined by the above formula ( 5) and the lithium positive electrode active material particles (B) represented by formula (6), and the supported amount is 100% by mass of the total amount of the positive electrode active material composite (C) for lithium ion secondary batteries. , preferably 5% to 45% by weight, more preferably 10% to 45% by weight, even more preferably 15% to 45% by weight. Further, the thickness of the support layer is preferably 100 nm to 3 μm, more preferably 300 nm to 3 μm, even more preferably 500 nm to 3 μm.
本発明のリチウムイオン二次電池用正極活物質複合体（Ｃ）の平均粒径は、５μｍ～２５μｍであり、好ましくは７μｍ～２０μｍであり、より好ましくは１０μｍ～１６μｍである。かかるリチウムイオン二次電池用正極活物質複合体（Ｃ）の平均粒径が５μｍよりも小さい場合、タップ密度が低下して作成した電極に十分な剥離強度が付与できず、電池のサイクル特性が低下するおそれがある。また、平均粒径が２５μｍよりも大きい場合、電極を均一に塗工することが困難になって均一な電極が得られず、電池の放電容量が低下するおそれがある。
また、本発明のリチウムイオン二次電池用正極活物質複合体（Ｃ）のタップ密度は、好ましくは０．８ｇ／ｃｍ3～２．５ｇ／ｃｍ3であり、より好ましくは１．０ｇ／ｃｍ3～２．０ｇ／ｃｍ3である。かかる正極活物質複合体のタップ密度が０．８ｇ／ｃｍ3よりも小さい場合、上述のとおり電池のサイクル特性が低下するおそれがある。
The average particle size of the positive electrode active material composite (C) for lithium ion secondary batteries of the present invention is 5 μm to 25 μm, preferably 7 μm to 20 μm, and more preferably 10 μm to 16 μm. When the average particle size of the positive electrode active material composite (C) for lithium ion secondary batteries is smaller than 5 μm, the tap density decreases and sufficient peel strength cannot be imparted to the prepared electrode, resulting in poor cycle characteristics of the battery. There is a risk that it will decrease. Moreover, if the average particle size is larger than 25 μm, it becomes difficult to uniformly apply the electrode, and a uniform electrode may not be obtained, which may reduce the discharge capacity of the battery.
Further, the tap density of the positive electrode active material composite (C) for lithium ion secondary batteries of the present invention is preferably 0.8 g/cm 3 to 2.5 g/cm 3 , more preferably 1.0 g/cm 3 3 to 2.0 g/cm 3 . If the tap density of such a positive electrode active material composite is smaller than 0.8 g/cm 3 , the cycle characteristics of the battery may deteriorate as described above.
本発明のリチウムイオン二次電池用正極活物質複合体（Ｃ）の製造方法は、次の工程（Ｉ）～（IV）：
（Ｉ）リチウム系固体電解質（ｂ）の原料となる水溶性化合物が溶解した水溶液にリチウム複合酸化物二次粒子（ａ）を混合した後、噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程、
（II）得られた複合体（ｄ）を、酸素雰囲気下、６００℃～１０００℃で３０分間～６時間焼成して、リチウム複合酸化物二次粒子（ａ）の表面をリチウム系固体電解質（ｂ）が被覆してなるリチウム複合粒子（Ａ）を得る工程、
（III）リチウム正極活物質粒子（Ｂ）を含むスラリーを噴霧乾燥して、リチウム正極活物質粒子（Ｂ）の造粒体（ｅ）を得る工程、並びに、
（IV）リチウム複合粒子（Ａ）及び造粒体（ｅ）を、圧縮力及びせん断力を付加しながら混合して、造粒体（ｅ）を解砕させながら、リチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）とを複合化する工程
を備える。
The method for producing the positive electrode active material composite (C) for lithium ion secondary batteries of the present invention includes the following steps (I) to (IV):
(I) After mixing the lithium composite oxide secondary particles (a) with an aqueous solution containing a water-soluble compound that is a raw material for the lithium-based solid electrolyte (b), the mixture is spray-dried to form the lithium-based solid electrolyte (b). A step of obtaining a composite (d) consisting of lithium composite oxide secondary particles (a) carrying a raw material compound on the surface,
(II) The obtained composite (d) is fired in an oxygen atmosphere at 600°C to 1000°C for 30 minutes to 6 hours to change the surface of the lithium composite oxide secondary particles (a) to a lithium-based solid electrolyte ( b) obtaining lithium composite particles (A) coated with
(III) spray-drying the slurry containing the lithium positive electrode active material particles (B) to obtain granules (e) of the lithium positive electrode active material particles (B), and
(IV) The lithium composite particles (A) and the granules (e) are mixed while applying compressive force and shear force, and the lithium composite particles (A) are mixed while the granules (e) are crushed. A step of compounding the lithium positive electrode active material particles (B) is provided.
本発明の製造方法が備える工程（Ｉ）は、リチウム系固体電解質（ｂ）の原料となる水溶性化合物が溶解した水溶液にリチウム複合酸化物二次粒子（ａ）を混合した後、噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程である。
より具体的には、次の工程（ｉ）～（ii）：
（ｉ）水に、リチウム系固体電解質（ｂ）の原料となる水溶性化合物を添加して水溶液（ｂ－１）を得た後、得られた水溶液（ｂ－１）に、リチウム複合酸化物二次粒子（ａ）とｐＨ調整剤を混合して、スラリー（ａｂ－１）を得る工程
（ii）スラリー（ａｂ－１）を噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程
を備えるのが好ましい。
Step (I) included in the production method of the present invention includes mixing the lithium composite oxide secondary particles (a) with an aqueous solution in which a water-soluble compound serving as a raw material for the lithium-based solid electrolyte (b) is dissolved, and then spray-drying the mixture. This is a step of obtaining a composite (d) consisting of lithium composite oxide secondary particles (a) on whose surface the raw material compound of the lithium-based solid electrolyte (b) is supported.
More specifically, the following steps (i) to (ii):
(i) After obtaining an aqueous solution (b-1) by adding a water-soluble compound that is a raw material for the lithium-based solid electrolyte (b) to water, add a lithium composite oxide to the obtained aqueous solution (b-1). Step of mixing secondary particles (a) and pH adjuster to obtain slurry (ab-1) (ii) Spray drying slurry (ab-1) to obtain raw material compound of lithium-based solid electrolyte (b) It is preferable to include a step of obtaining a composite (d) consisting of lithium composite oxide secondary particles (a) supported on the surface.
工程（ｉ）は、リチウム系固体電解質（ｂ）の原料となる水溶性化合物とｐＨ調整剤を、水に添加して水溶液（ｂ－１）を得た後、得られた水溶液（ｂ－１）に、リチウム複合酸化物二次粒子（ａ）を混合して、スラリー（ａｂ－１）を得る工程である。
用い得るリチウム系固体電解質（ｂ）の原料としては、次工程（ii）で、リチウム複合酸化物二次粒子（ａ）の表面に担持させる必要があることから、水溶性化合物である必要がある。例えば、リチウム化合物の場合は、水酸化リチウム（例えばＬｉＯＨ、ＬｉＯＨ・Ｈ2Ｏ）、炭酸リチウム、硫酸リチウム、酢酸リチウムが挙げられる。なかでも水酸化リチウムが好ましい。
In step (i), a water-soluble compound and a pH adjuster that are raw materials for the lithium-based solid electrolyte (b) are added to water to obtain an aqueous solution (b-1), and then the obtained aqueous solution (b-1 ) and lithium composite oxide secondary particles (a) to obtain a slurry (ab-1).
The raw material for the lithium-based solid electrolyte (b) that can be used needs to be a water-soluble compound since it needs to be supported on the surface of the lithium composite oxide secondary particles (a) in the next step (ii). . For example, examples of lithium compounds include lithium hydroxide (eg, LiOH, LiOH.H 2 O), lithium carbonate, lithium sulfate, and lithium acetate. Among them, lithium hydroxide is preferred.
水溶性化合物としてのアルミニウム化合物は、例えば、アルミニウムの硫酸塩、硝酸塩、炭酸塩、酢酸塩、乳酸塩、シュウ酸塩、酸化物、水酸化物、ハロゲン化物等が挙げられる。具体的には、例えば、硫酸アルミニウム、酢酸アルミニウム、乳酸アルミニウム等が挙げられる。 Examples of the aluminum compound as a water-soluble compound include aluminum sulfates, nitrates, carbonates, acetates, lactates, oxalates, oxides, hydroxides, and halides. Specific examples include aluminum sulfate, aluminum acetate, aluminum lactate, and the like.
水溶性化合物としてのチタン化合物については、チタンアルコキシド（チタンエトキシド、チタンテトラブトキシド、チタンイソプロポキシド等）、チタン塩（硫酸チタン、硝酸チタン等）、及びチタン塩化物（四塩化チタン等）から選ばれる１種又は２種以上が挙げられる。なかでも、反応性や操作性、及び熱処理を効果的に短縮化する観点から、硫酸チタニル、硫酸チタン、チタンアルコキシドが好ましい。 Titanium compounds as water-soluble compounds include titanium alkoxides (titanium ethoxide, titanium tetrabutoxide, titanium isopropoxide, etc.), titanium salts (titanium sulfate, titanium nitrate, etc.), and titanium chlorides (titanium tetrachloride, etc.). One or more selected types may be mentioned. Among these, titanyl sulfate, titanium sulfate, and titanium alkoxide are preferred from the viewpoint of reactivity, operability, and effectively shortening heat treatment.
また、水溶性化合物としてのリン酸化合物の場合は、オルトリン酸（Ｈ3ＰＯ4、リン酸）、メタリン酸、ピロリン酸、三リン酸、四リン酸、リン酸アンモニウム、リン酸水素アンモニウム等が挙げられる。なかでもリン酸を用いるのが好ましい。 In the case of phosphoric acid compounds as water-soluble compounds, orthophosphoric acid (H 3 PO 4 , phosphoric acid), metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, ammonium phosphate, ammonium hydrogen phosphate, etc. Can be mentioned. Among them, it is preferable to use phosphoric acid.
水溶性化合物としてのケイ酸化合物は、反応性のあるシリカ化合物であれば特に限定されず、非晶質シリカ、Ｎａ4ＳｉＯ4（例えばＮａ4ＳｉＯ4・Ｈ2Ｏ）等が挙げられる。 The silicic acid compound as a water-soluble compound is not particularly limited as long as it is a reactive silica compound, and examples thereof include amorphous silica, Na 4 SiO 4 (for example, Na 4 SiO 4 .H 2 O), and the like.
水溶液（ｂ－１）における原料化合物の合計含有量は、次工程（ii）の噴霧乾燥でリチウム複合酸化物二次粒子（ａ）を凝集させない観点から、水１００質量部に対し、好ましくは０．５質量部～２０質量部であり、より好ましくは０．５質量部～１５質量部である。 The total content of the raw material compounds in the aqueous solution (b-1) is preferably 0 with respect to 100 parts by mass of water, from the viewpoint of preventing the lithium composite oxide secondary particles (a) from agglomerating in the spray drying in the next step (ii). The amount is from .5 parts by weight to 20 parts by weight, more preferably from 0.5 parts by weight to 15 parts by weight.
水溶液（ｂ－１）にリチウム複合酸化物二次粒子（ａ）とｐＨ調整剤を混合する前に、予め水溶液（ｂ－１）を撹拌しておくのが好ましい。かかる水溶液（ｂ－１）の撹拌時間は、好ましくは１分間～１５分間であり、より好ましくは３分間～１０分間である。また、水溶液（ｂ－１）の温度は、好ましくは２０℃～９０℃であり、より好ましくは２０℃～７０℃である。 It is preferable to stir the aqueous solution (b-1) in advance before mixing the lithium composite oxide secondary particles (a) and the pH adjuster into the aqueous solution (b-1). The aqueous solution (b-1) is stirred for preferably 1 minute to 15 minutes, more preferably 3 minutes to 10 minutes. Further, the temperature of the aqueous solution (b-1) is preferably 20°C to 90°C, more preferably 20°C to 70°C.
スラリー（ａｂ－１）におけるリチウム複合酸化物二次粒子（ａ）の含有量は、次工程（ii）の噴霧乾燥でリチウム複合酸化物二次粒子（ａ）を凝集させない観点から、スラリー（ａｂ－１）１００質量％中に、好ましくは１０質量％～６０質量％であり、より好ましくは１０質量％～５０質量％である。 The content of the lithium composite oxide secondary particles (a) in the slurry (ab-1) is determined from the viewpoint of preventing the lithium composite oxide secondary particles (a) from agglomerating in the next step (ii) of spray drying. -1) In 100% by mass, it is preferably 10% by mass to 60% by mass, more preferably 10% by mass to 50% by mass.
工程（ｉ）では、さらに上記スラリー（ａｂ－１）にアルカリ溶液を添加して、中和反応によって、スラリー（ａｂ－１）に溶解している金属成分を金属水酸化物にするのが好ましい。アルカリ溶液を添加するには、スラリー（ａｂ－１）の２５℃におけるｐＨが１０～１４に保持するのに充分な量を滴下するのが好ましい。かかるアルカリ溶液としては、例えば、水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム、アンモニア等の水溶液を用いることができるが、なかでもアンモニア、水酸化ナトリウム、炭酸ナトリウム又はこれらの混合溶液を用いることが好ましい。 In step (i), it is preferable to further add an alkaline solution to the slurry (ab-1) and convert the metal component dissolved in the slurry (ab-1) into a metal hydroxide through a neutralization reaction. . When adding the alkaline solution, it is preferable to drop an amount sufficient to maintain the pH of the slurry (ab-1) at 25° C. from 10 to 14. As such an alkaline solution, for example, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, etc. can be used, but it is particularly preferable to use ammonia, sodium hydroxide, sodium carbonate, or a mixed solution thereof. .
上記スラリー（ａｂ－１）内では、リチウム複合酸化物二次粒子（ａ）の表面を核形成又は結晶成長の場として、金属水酸化物が形成される。金属水酸化物を良好に生成させる観点から、撹拌して中和反応を進行させるのが好ましい。中和反応中におけるスラリー（ａｂ－１）の温度は、５℃以上が好ましく、より好ましくは１０～６０℃である。また、スラリー（ａｂ－１）の撹拌時間は、１分～６０分が好ましく、１分～３０分がより好ましい。 In the slurry (ab-1), metal hydroxide is formed using the surface of the lithium composite oxide secondary particles (a) as a site of nucleation or crystal growth. From the viewpoint of producing metal hydroxide well, it is preferable to proceed with the neutralization reaction by stirring. The temperature of the slurry (ab-1) during the neutralization reaction is preferably 5°C or higher, more preferably 10 to 60°C. Further, the stirring time of the slurry (ab-1) is preferably 1 minute to 60 minutes, more preferably 1 minute to 30 minutes.
続く工程（ii）は、スラリー（ａｂ－１）を噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程である。 In the subsequent step (ii), the slurry (ab-1) is spray-dried to form a composite (d ).
工程（ii）における噴霧乾燥としては、スプレードライ法による噴霧乾燥が好適であり、かかる装置として、例えば、４流体ノズルを備えたマイクロミストドライヤー（例えば、藤崎電気（株）製 ＭＤＬ－０５０Ｍ）を用いることができる。噴霧乾燥に用いる装置の処理条件としては、エアー圧が０．３ＭＰａ～０．８ＭＰａであるのが好ましく、０．５ＭＰａ～０．７ＭＰａであるのがより好ましく、エアー流量が２０ＮＬ／分～６０ＮＬ／分であるのが好ましく、５０ＮＬ／分～６０ＮＬ／分であるのがより好ましい。また、熱風量は０．６ｍ3／分～１．２ｍ3／分であるのが好ましく、０．８ｍ3／分～１．１ｍ3／分であるのがより好ましく、入口温度は、１００℃～２５０℃であるのが好ましく、１５０℃～２００℃であるのがより好ましい。さらに、排気温度は７０℃～１５０℃であるのが好ましく、８０℃～１２０℃であるのがより好ましく、スラリー（ａｂ－１）の流量は、リチウム複合酸化物二次粒子（ａ）を凝集させない観点から、２０ｇ／分～７０ｇ／分であるのが好ましく、５０ｇ／分～７０ｇ／分であるのがより好ましい。 As the spray drying in step (ii), spray drying by a spray drying method is suitable, and such a device may include, for example, a micro mist dryer equipped with a 4-fluid nozzle (for example, MDL-050M manufactured by Fujisaki Electric Co., Ltd.). Can be used. As for the processing conditions of the apparatus used for spray drying, the air pressure is preferably 0.3 MPa to 0.8 MPa, more preferably 0.5 MPa to 0.7 MPa, and the air flow rate is 20 NL/min to 60 NL/min. It is preferably 50 NL/min to 60 NL/min, more preferably 50 NL/min to 60 NL/min. Further, the hot air volume is preferably 0.6 m 3 /min to 1.2 m 3 /min, more preferably 0.8 m 3 /min to 1.1 m 3 /min, and the inlet temperature is 100°C. The temperature is preferably from 150°C to 250°C, more preferably from 150°C to 200°C. Furthermore, the exhaust temperature is preferably 70°C to 150°C, more preferably 80°C to 120°C, and the flow rate of the slurry (ab-1) is such that the lithium composite oxide secondary particles (a) are From the viewpoint of preventing this from occurring, the rate is preferably 20 g/min to 70 g/min, more preferably 50 g/min to 70 g/min.
なお、工程（ii）において得られる複合体（ｄ）の平均粒径は、リチウム複合酸化物二次粒子（ａ）を不要に凝集させない観点から、好ましくは１μｍ～２５μｍであり、より好ましくは５μｍ～２０μｍである。 Note that the average particle size of the composite (d) obtained in step (ii) is preferably 1 μm to 25 μm, more preferably 5 μm, from the viewpoint of preventing unnecessary agglomeration of the lithium composite oxide secondary particles (a). ~20 μm.
続く工程（II）は、得られた複合体（ｄ）を、酸素雰囲気下、６００℃～１０００℃で３０分間～６時間焼成して、リチウム複合酸化物二次粒子（ａ）の表面をリチウム系固体電解質（ｂ）が被覆してなるリチウム複合粒子（Ａ）を得る工程である。
かかる焼成により、リチウム複合酸化物二次粒子（ａ）の表面に担持されているリチウム系固体電解質（ｂ）の原料化合物からリチウム系固体電解質（ｂ）が生成すると共に、リチウム複合酸化物二次粒子（ａ）の表面全体を被覆するように、リチウム系固体電解質（ｂ）が担持される。これにより、リチウム複合酸化物二次粒子（ａ）からの遷移金属成分の電解液への溶出を有効に抑制することができる。
In the subsequent step (II), the obtained composite (d) is fired in an oxygen atmosphere at 600°C to 1000°C for 30 minutes to 6 hours to change the surface of the lithium composite oxide secondary particles (a) to lithium. This is a step of obtaining lithium composite particles (A) coated with a solid electrolyte (b).
By this firing, the lithium-based solid electrolyte (b) is generated from the raw material compound of the lithium-based solid electrolyte (b) supported on the surface of the lithium composite oxide secondary particles (a), and the lithium-based solid electrolyte (b) is A lithium-based solid electrolyte (b) is supported so as to cover the entire surface of the particles (a). Thereby, elution of the transition metal component from the lithium composite oxide secondary particles (a) into the electrolytic solution can be effectively suppressed.
焼成温度は、リチウム系固体電解質（ｂ）の原料化合物から有効にリチウム系固体電解質（ｂ）を生成させる観点から、６００℃～１０００℃であって、好ましくは６００℃～９００℃であり、より好ましくは６００℃～８００℃である。また、焼成時間は、３０分間～６時間、好ましくは３０分間～４時間とするのがよい。 The firing temperature is 600°C to 1000°C, preferably 600°C to 900°C, and more Preferably it is 600°C to 800°C. Further, the firing time is preferably 30 minutes to 6 hours, preferably 30 minutes to 4 hours.
工程（III）は、リチウム正極活物質粒子（Ｂ）を含むスラリーを噴霧乾燥して、リチウム正極活物質粒子（Ｂ）の造粒体（ｅ）を得る工程である。
より具体的には、所定の大きさを有するリチウム正極活物質粒子（Ｂ）を含むスラリー（Ｂ－１）を調製した後、スラリー（Ｂ－１）を噴霧乾燥して、リチウム正極活物質粒子（Ｂ）を含む造粒体（ｅ）を得る工程である。
Step (III) is a step of spray-drying the slurry containing the lithium positive electrode active material particles (B) to obtain granules (e) of the lithium positive electrode active material particles (B).
More specifically, after preparing a slurry (B-1) containing lithium positive electrode active material particles (B) having a predetermined size, the slurry (B-1) is spray-dried to form lithium positive electrode active material particles. This is a step of obtaining a granule (e) containing (B).
スラリー（Ｂ－１）における、リチウム正極活物質粒子（Ｂ）の含有量は、水１００質量部に対し、好ましくは１０質量部～３０質量部であり、より好ましくは１５質量部～３０質量部である。 The content of the lithium positive electrode active material particles (B) in the slurry (B-1) is preferably 10 parts by mass to 30 parts by mass, more preferably 15 parts by mass to 30 parts by mass, based on 100 parts by mass of water. It is.
用いるリチウム正極活物質粒子（Ｂ）が、上記式（３）又は式（４）のリチウム正極活物質粒子（Ｂ）であって、表面に炭素（ｃ）を担持させる場合、スラリー（Ｂ－１）に炭素源（ｃ’）を添加すればよい。スラリー（Ｂ－１）における、セルロースナノファイバー（ｃ’－１）及び／又はリグノセルロースナノファイバー（ｃ’－２）の含有量は、その炭素原子換算量が、リチウム正極活物質粒子（Ｂ）及び炭素（ｃ）の合計量１００質量％中に、０．１質量％～１２質量％となるような量であるのが望ましい。
さらに炭素源（ｃ’）として、セルロースナノファイバー（ｃ’－１）及び／又はリグノセルロースナノファイバー（ｃ’－２）と、水溶性炭素材料（ｃ’－３）とを用いる場合、スラリー（Ｂ－１）における、これら炭素源（ｃ’）の合計含有量は、リチウム正極活物質粒子（Ｂ）及び炭素（ｃ）の合計量１００質量％中に、炭素原子換算量で０．１質量％～１２質量％となるようにすればよい。
When the lithium positive electrode active material particles (B) used are the lithium positive electrode active material particles (B) of the above formula (3) or formula (4) and carbon (c) is supported on the surface, the slurry (B-1 ) may be added with a carbon source (c'). The content of cellulose nanofibers (c'-1) and/or lignocellulose nanofibers (c'-2) in the slurry (B-1) is such that the amount calculated in terms of carbon atoms is the same as that of the lithium positive electrode active material particles (B). The amount is preferably 0.1% by mass to 12% by mass in 100% by mass of the total amount of carbon (c).
Furthermore, when cellulose nanofibers (c'-1) and/or lignocellulose nanofibers (c'-2) and a water-soluble carbon material (c'-3) are used as carbon sources (c'), slurry ( In B-1), the total content of these carbon sources (c') is 0.1 mass% in terms of carbon atoms in 100% by mass of the lithium positive electrode active material particles (B) and carbon (c). % to 12% by mass.
かかるスラリー（Ｂ－１）を調製するにあたり、リチウム正極活物質粒子（Ｂ）を均一に分散させる観点から、または上記式（３）又は式（４）のリチウム正極活物質粒子（Ｂ）には、リチウム正極活物質粒子（Ｂ）と炭素源（ｃ’）を均一に分散させる観点から、分散機（ホモジナイザー）を用いた処理を行うことが好ましい。かかる分散機としては、例えば、離解機、叩解機、低圧ホモジナイザー、高圧ホモジナイザー、グラインダー、カッターミル、ボールミル、ジェットミル、短軸押出機、２軸押出機、超音波攪拌機、家庭用ジューサーミキサー等が挙げられる。なかでも、分散効率の観点から、超音波攪拌機が好ましい。スラリー（Ｂ－１）の分散均一性の程度は、例えば、ＵＶ・可視光分光装置を使用した光線透過率や、Ｅ型粘度計を使用した粘度で定量的に評価することもでき、また目視によって白濁度が均一であることを確認することで、簡便に評価することもできる。分散機で処理する時間は、好ましくは１分間～３０分間であり、より好ましくは２分間～１５分間である。 In preparing such slurry (B-1), from the viewpoint of uniformly dispersing the lithium positive electrode active material particles (B), or from the viewpoint of uniformly dispersing the lithium positive electrode active material particles (B) of the above formula (3) or formula (4), From the viewpoint of uniformly dispersing the lithium positive electrode active material particles (B) and the carbon source (c'), it is preferable to carry out the treatment using a disperser (homogenizer). Examples of such a dispersing machine include a disintegrating machine, a beating machine, a low-pressure homogenizer, a high-pressure homogenizer, a grinder, a cutter mill, a ball mill, a jet mill, a short-screw extruder, a twin-screw extruder, an ultrasonic stirrer, a household juicer mixer, etc. Can be mentioned. Among these, an ultrasonic stirrer is preferred from the viewpoint of dispersion efficiency. The degree of dispersion uniformity of the slurry (B-1) can be quantitatively evaluated, for example, by the light transmittance using a UV/visible light spectrometer or the viscosity using an E-type viscometer, or by visual observation. It can also be easily evaluated by confirming that the white turbidity is uniform. The time for treatment with a disperser is preferably 1 minute to 30 minutes, more preferably 2 minutes to 15 minutes.
スラリー（Ｂ－１）にセルロースナノファイバー（ｃ’－１）及び／又はリグノセルロースナノファイバー（ｃ’－２）を含む場合、上記スラリー（Ｂ－１）は、未だ凝集状態にあるセルロースナノファイバーを有効に取り除く観点から、さらに、湿式分級することが好ましい。湿式分級には、篩や市販の湿式分級機を使用することができる。篩の目開きは、用いるセルロースナノファイバー（ｃ’－１）及び／又はリグノセルロースナノファイバー（ｃ’－２）の繊維長により変動し得るが、作業効率の観点から、１５０μｍ前後であるのが好ましい。 When the slurry (B-1) contains cellulose nanofibers (c'-1) and/or lignocellulose nanofibers (c'-2), the slurry (B-1) contains cellulose nanofibers that are still in an aggregated state. From the viewpoint of effectively removing , it is preferable to further perform wet classification. For wet classification, a sieve or a commercially available wet classifier can be used. The opening of the sieve may vary depending on the fiber length of the cellulose nanofibers (c'-1) and/or lignocellulose nanofibers (c'-2) used, but from the viewpoint of work efficiency, it is recommended that it be around 150 μm. preferable.
以上より、得られるスラリー（Ｂ－１）の固形分濃度は、好ましくは１０質量％～３５質量％であり、より好ましくは１５質量％～３０質量％である。 From the above, the solid content concentration of the obtained slurry (B-1) is preferably 10% by mass to 35% by mass, more preferably 15% by mass to 30% by mass.
次いで、得られたスラリー（Ｂ－１）を噴霧乾燥して、造粒体（ｅ）を得る。本発明の製造方法では、リチウム正極活物質粒子（Ｂ）が堅固に凝集されてなる堅牢な二次粒子となることを回避して、過度な負荷を与えることなく容易に解砕させることのできる造粒体（ｅ）とする。 Next, the obtained slurry (B-1) is spray-dried to obtain granules (e). In the production method of the present invention, the lithium positive electrode active material particles (B) can be easily crushed without applying an excessive load, avoiding the formation of solid secondary particles formed by solid aggregation. Let it be a granule (e).
噴霧乾燥の際の熱風温度は、１１０℃～１６０℃が好ましく、１２０℃～１４０℃がより好ましい。かかる熱風の供給量Ｇ（Ｌ／分）と、スラリー（Ｂ－１）の供給量Ｓ（Ｌ／分）の比（Ｇ／Ｓ）は、５００～１００００が好ましく、１０００～９０００がより好ましい。 The hot air temperature during spray drying is preferably 110°C to 160°C, more preferably 120°C to 140°C. The ratio (G/S) between the hot air supply amount G (L/min) and the slurry (B-1) supply amount S (L/min) is preferably 500 to 10,000, more preferably 1,000 to 9,000.
工程（III）で得られる造粒体（ｅ）の粒径は、レーザー回折・散乱法に基づく粒度分布におけるＤ50値で、好ましくは５μｍ～２５μｍであり、より好ましくは５μｍ～１６μｍである。
ここで、粒度分布測定におけるＤ50値とは、レーザー回折・散乱法に基づく体積基準の粒度分布により得られる値であり、Ｄ50値は累積５０％での粒径（メジアン径）を意味する。
The particle size of the granules (e) obtained in step (III) is preferably 5 μm to 25 μm, more preferably 5 μm to 16 μm, in terms of D 50 value in particle size distribution based on laser diffraction/scattering method.
Here, the D 50 value in particle size distribution measurement is a value obtained by volume-based particle size distribution based on laser diffraction/scattering method, and the D 50 value means the particle size at 50% cumulative (median diameter). .
また、造粒体（ｅ）の空隙率は、水銀圧入法に基づく空隙率で、好ましくは４５体積％～８０体積％であり、より好ましくは５０体積％～８０体積％である。 Further, the porosity of the granule (e) is based on the mercury intrusion method, and is preferably 45% to 80% by volume, more preferably 50% to 80% by volume.
なお、上記式（３）又は式（４）のリチウム正極活物質粒子（Ｂ）と共に炭素源（ｃ’）を含むスラリー（Ｂ－１）から得られた造粒体（ｅ）については、焼成する必要がある。この焼成によって、炭素源（ｃ’）を炭化させて、式（３）又は式（４）のリチウム正極活物質粒子（Ｂ）の表面に炭素（ｃ）を担持させることができる。 In addition, regarding the granules (e) obtained from the slurry (B-1) containing the carbon source (c') together with the lithium positive electrode active material particles (B) of the above formula (3) or formula (4), the granules (e) are There is a need to. By this firing, the carbon source (c') can be carbonized, and carbon (c) can be supported on the surface of the lithium positive electrode active material particles (B) of formula (3) or formula (4).
焼成温度は、炭素源（ｃ’）を有効に炭化させる観点、及び焼成後の造粒体（ｅ）の空隙率を４５体積％～８０体積％に調整して適度な解砕性を付与する観点から、好ましくは５００℃～８００℃であり、より好ましくは６００℃～７７０℃であり、特に好ましくは６５０℃～７５０℃である。また、焼成時間は、好ましくは１０分間～３時間、より好ましくは３０分間～１．５時間とするのがよい。 The firing temperature is determined from the viewpoint of effectively carbonizing the carbon source (c'), and adjusting the porosity of the granulated body (e) after firing to 45% to 80% by volume to impart appropriate crushability. From this point of view, the temperature is preferably 500°C to 800°C, more preferably 600°C to 770°C, particularly preferably 650°C to 750°C. Further, the firing time is preferably 10 minutes to 3 hours, more preferably 30 minutes to 1.5 hours.
工程（III）で得られる造粒体（ｅ）の崩壊強度は、好ましくは１．８ＫＮ／ｍｍ以下であり、より好ましくは１．７５ＫＮ／ｍｍ以下である。かかる崩壊強度とは、リチウム正極活物質粒子（Ｂ）からなる造粒体（ｅ）の圧縮による解砕のし易さを示し、下記式（１１）により求められる値を意味する。
造粒体（ｅ）の崩壊強度（ＫＮ／ｍｍ）＝１０／（ｔ0－ｔ10） ・・・（１１）
式（１１）中のｔ0は、直径２０ｍｍの円筒容器内に表面に造粒体（ｅ）を３ｇ投入し、高さ１ｃｍからの落下によるタッピングを１０回繰返した後の密充填状態における造粒体（ｅ）の層厚（ｍｍ）を示し、ｔ10は、かかる密充填状態の造粒体（ｅ）に、上部から１０ＫＮの荷重を掛けた際の造粒体（ｅ）の層厚（ｍｍ）を示す。
The collapse strength of the granules (e) obtained in step (III) is preferably 1.8 KN/mm or less, more preferably 1.75 KN/mm or less. This collapse strength indicates the ease with which the granules (e) made of lithium positive electrode active material particles (B) can be crushed by compression, and means a value determined by the following formula (11).
Collapse strength of granule (e) (KN/mm) = 10/(t 0 - t 10 )...(11)
t 0 in formula (11) is the granule (e) in a tightly packed state after 3 g of granule (e) is placed on the surface of a cylindrical container with a diameter of 20 mm, and tapping by dropping from a height of 1 cm is repeated 10 times. The layer thickness (mm) of the granule (e) is shown, and t10 is the layer thickness of the granule (e) when a load of 10 KN is applied from the top to the granule (e) in a tightly packed state. (mm).
本発明の製造方法が備える工程（IV）は、工程（II）で得られたリチウム複合粒子（Ａ）と、工程（III）で得られた造粒体（ｅ）とを、圧縮力及びせん断力を付加しながら混合して、造粒体（ｅ）を解砕させながら、リチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）とを複合化する工程である。かかる工程を経ることにより、造粒体（ｅ）が解砕して、微細なリチウム正極活物質粒子（Ｂ）が緻密かつ広範囲にリチウム複合粒子（Ａ）の表面を被覆するように、リチウム複合粒子（Ａ）の表面にリチウム正極活物質粒子（Ｂ）が担持してなるリチウムイオン二次電池用正極活物質複合体（Ｃ）を得ることができる。 Step (IV) included in the production method of the present invention is to apply compressive force and shear to the lithium composite particles (A) obtained in step (II) and the granules (e) obtained in step (III). This is a step of compounding the lithium composite particles (A) and the lithium positive electrode active material particles (B) by mixing while applying force and crushing the granules (e). Through this process, the lithium composite particles (A) are crushed so that the granules (e) are crushed and the fine lithium positive electrode active material particles (B) densely and extensively cover the surface of the lithium composite particles (A). A positive electrode active material composite for a lithium ion secondary battery (C) can be obtained in which the lithium positive electrode active material particles (B) are supported on the surfaces of the particles (A).
工程（IV）では、圧縮力及びせん断力を付加しながら混合する前に、リチウム複合粒子（Ａ）と造粒体（ｅ）の混合物を、充分に乾式混合するのが好ましい。乾式混合の方法としては、ボールミルやＶブレンダー等の、通常の乾式混合機による混合であるのが好ましく、自公転可能な遊星ボールミルによる混合がより好ましい。 In step (IV), it is preferable that the mixture of lithium composite particles (A) and granules (e) is sufficiently dry mixed before being mixed while applying compressive force and shear force. As for the dry mixing method, it is preferable to use an ordinary dry mixer such as a ball mill or a V-blender, and mixing using a planetary ball mill that can rotate around its axis is more preferable.
圧縮力及びせん断力を付加しながら混合する（以下、「複合化する」ともいう）処理は、インペラやローター工具等を備える密閉容器で行うのがよい。かかる密閉容器を備える装置として、高速せん断ミル、ブレード型混練機、高速混合機等が挙げられ、具体的には、例えば、粒子設計装置 ＣＯＭＰＯＳＩ、メカノハイブリット、高性能流動式混合機ＦＭミキサー（日本コークス工業社製）微粒子複合化装置 メカノフュージョン、ノビルタ（ホソカワミクロン社製）、表面改質装置ミラーロ、ハイブリダイゼーションシステム（奈良機械製作所社製）、アイリッヒインテンシブミキサー（日本アイリッヒ社製）を好適に用いることができる。上記複合化する処理条件としては、温度が、好ましくは５℃～８０℃、より好ましくは１０℃～５０℃である。また、雰囲気としては、特に限定されないが、不活性ガス雰囲気又は還元性ガス雰囲気であるのが好ましい。 The process of mixing while applying compressive force and shear force (hereinafter also referred to as "compounding") is preferably performed in a closed container equipped with an impeller, rotor tool, etc. Examples of devices equipped with such a closed container include high-speed shear mills, blade-type kneaders, and high-speed mixers. Mechanofusion, a particle compounding device (manufactured by Coke Kogyo Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), a surface modification device Miraro, a hybridization system (manufactured by Nara Kikai Seisakusho Co., Ltd.), and an Eirich intensive mixer (manufactured by Nippon Eirich Co., Ltd.) are preferably used. be able to. The temperature is preferably 5°C to 80°C, more preferably 10°C to 50°C. Further, the atmosphere is not particularly limited, but is preferably an inert gas atmosphere or a reducing gas atmosphere.
より具体的には、例えば、複合化を行う装置として、インペラを備えた乾式粒子複合化装置であるノビルタ（ホソカワミクロン社製）を用いる場合、かかるインペラの回転数は、造粒体（ｅ）を効率的に解砕させつつ、リチウム複合粒子（Ａ）の表面をリチウム正極活物質粒子（Ｂ）が良好に被覆するよう、リチウム複合粒子（Ａ）の表面にリチウム正極活物質粒子（Ｂ）を担持させる観点から、好ましくは２０００ｒｐｍ～６０００ｒｐｍであり、より好ましくは２０００ｒｐｍ～４０００ｒｐｍである。また、複合化する時間は、好ましくは１分間～１０分間であり、より好ましくは１分間～７分間である。
また、かかる複合化を行う装置として、ローター工具を備えた高速攪拌混合機であるアイリッヒインテンシブミキサー（日本アイリッヒ社製）を用いた場合、かかるローター工具の回転数は、好ましくは２０００ｒｐｍ～８０００ｒｐｍであり、より好ましくは２０００ｒｐｍ～６０００ｒｐｍである。また、複合化する時間は、好ましくは１分間～１０分間であり、より好ましくは１分間～７分間である。
More specifically, for example, when Nobilta (manufactured by Hosokawa Micron Corporation), which is a dry particle compositing device equipped with an impeller, is used as the compositing device, the rotation speed of the impeller is set to The lithium positive electrode active material particles (B) are applied to the surface of the lithium composite particles (A) so that the surfaces of the lithium composite particles (A) are well coated with the lithium positive electrode active material particles (B) while being efficiently crushed. From the viewpoint of supporting, the speed is preferably 2000 rpm to 6000 rpm, more preferably 2000 rpm to 4000 rpm. Further, the time for compounding is preferably 1 minute to 10 minutes, more preferably 1 minute to 7 minutes.
Further, when an Eirich intensive mixer (manufactured by Nippon Eirich Co., Ltd.), which is a high-speed stirring mixer equipped with a rotor tool, is used as a device for performing such compounding, the rotation speed of the rotor tool is preferably 2000 rpm to 8000 rpm. The speed is more preferably 2000 rpm to 6000 rpm. Further, the time for compounding is preferably 1 minute to 10 minutes, more preferably 1 minute to 7 minutes.
工程（IV）における、上記複合化する時間及び／又はインペラ等の回転数は、密閉容器に投入するリチウム複合粒子（Ａ）と造粒体（ｅ）の混合物の量に応じて適宜調整する必要がある。そして、密閉容器を稼動させることにより、インペラ等と密閉容器内壁との間でこれら混合物に圧縮力及びせん断力が付加されつつ、造粒体（ｅ）を良好に解砕させながら、リチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）とを複合化する処理を行うことが可能となり、上記リチウム複合粒子（Ａ）の表面において、上記リチウム正極活物質粒子（Ｂ）が良好に複合化されてリチウム複合粒子（Ａ）の表面を被覆するよう担持してなる、リチウムイオン二次電池用正極活物質複合体（Ｃ）を得ることができる。
例えば、上記複合化の処理を、回転数２０００ｒｐｍ～５０００ｒｐｍで回転するインペラを備える密閉容器内で１分間～８分間行う場合、密閉容器に投入する上記混合物の量は、有効容器（インペラを備える密閉容器のうち、上記混合物を収容可能な部位に相当する容器）１ｃｍ3当たり、好ましくは０．１ｇ～０．７ｇであり、より好ましくは０．１５ｇ～０．４ｇである。
In step (IV), the time for compositing and/or the rotation speed of the impeller etc. need to be adjusted as appropriate depending on the amount of the mixture of lithium composite particles (A) and granules (e) to be introduced into the closed container. There is. Then, by operating the closed container, compressive force and shear force are applied to the mixture between the impeller etc. and the inner wall of the closed container, and while the granules (e) are finely crushed, the lithium composite particles are (A) and the lithium positive electrode active material particles (B) can be composited, and the lithium positive electrode active material particles (B) are successfully composited on the surface of the lithium composite particles (A). It is possible to obtain a positive electrode active material composite (C) for a lithium ion secondary battery, which is supported so as to cover the surface of the lithium composite particles (A).
For example, when the above-mentioned compounding process is performed for 1 minute to 8 minutes in a closed container equipped with an impeller that rotates at a rotation speed of 2000 rpm to 5000 rpm, the amount of the mixture to be put into the closed container is The amount is preferably 0.1 g to 0.7 g, more preferably 0.15 g to 0.4 g per 1 cm 3 of the container (corresponding to the part of the container that can accommodate the above mixture).
工程（IV）において複合化させるリチウム複合粒子（Ａ）の配合量と、リチウム正極活物質粒子（Ｂ）の配合量との質量比（粒子（Ａ）：粒子（Ｂ））は、リチウム複合粒子（Ａ）の表面に良好にリチウム正極活物質粒子（Ｂ）を担持させる観点から、好ましくは９５：５～５０：５０であり、より好ましくは９０：１０～５０：５０であり、さらに好ましくは８５：１５～５０：５０である。
より具体的には、用いるリチウム正極活物質粒子（Ｂ）が、上記式（５）、式（６）、及び式（１０）の場合の質量比（粒子（Ａ）：粒子（Ｂ））は、好ましくは９５：５～５５：４５であり、より好ましくは９０：１０～５５：４５であり、さらに好ましくは８５：１５～５５：４５であり、リチウム正極活物質粒子（Ｂ）が、上記式（７）、式（８）、及び式（９）の場合の質量比（粒子（Ａ）：粒子（Ｂ））は、好ましくは９５：５～５０：５０であり、より好ましくは９０：１０～５０：５０であり、さらに好ましくは８５：１５～５０：５０である。
かかる量となるよう、上記混合物中における造粒体（ｅ）の量を調整すればよい。
The mass ratio (particles (A):particles (B)) of the blending amount of lithium composite particles (A) to be composited in step (IV) and the blending amount of lithium positive electrode active material particles (B) is as follows: From the viewpoint of supporting the lithium positive electrode active material particles (B) well on the surface of (A), the ratio is preferably 95:5 to 50:50, more preferably 90:10 to 50:50, and even more preferably The time is from 85:15 to 50:50.
More specifically, when the lithium positive electrode active material particles (B) used satisfy the above formulas (5), (6), and (10), the mass ratio (particles (A):particles (B)) is , preferably 95:5 to 55:45, more preferably 90:10 to 55:45, even more preferably 85:15 to 55:45, and the lithium positive electrode active material particles (B) have the above-mentioned The mass ratio (particles (A):particles (B)) in the cases of formula (7), formula (8), and formula (9) is preferably 95:5 to 50:50, more preferably 90: The ratio is 10 to 50:50, more preferably 85:15 to 50:50.
What is necessary is just to adjust the amount of granules (e) in the said mixture so that it may become this amount.
なお、用いるリチウム正極活物質粒子（Ｂ）が上記式（５）及び式（６）の場合、上記方法のほか、前記工程で炭素源（ｃ’）を一切用いることなく、かかる工程（IV）において炭素（ｃ）として水不溶性炭素材料（ｃ４）を用いてもよい。この場合、工程（III）において得られる造粒体（ｅ）は、炭素（ｃ）を担持しておらず、工程（IV）において、リチウム複合粒子（Ａ）と造粒体（ｅ）に、さらに水不溶性炭素材料（ｃ４）を添加して、圧縮力及びせん断力を付加しながら混合すればよい。工程（IV）において水不溶性炭素材料（ｃ４）を添加する場合、リチウム複合粒子（Ａ）の配合量と、リチウム正極活物質粒子（Ｂ）及び水不溶性炭素材料（ｃ４）の合計配合量との質量比（粒子（Ａ）：（粒子（Ｂ）＋水不溶性炭素材料（ｃ４）））は、好ましくは９５：５～６０：４０であり、より好ましくは９２：８～６５：３５であり、さらに好ましくは９０：１０～７０：３０である。かかる量となるよう、上記混合物中における造粒体（ｅ）及び水不溶性炭素材料（ｃ４）の配合量を調整すればよい。 In addition, when the lithium positive electrode active material particles (B) used are of the above formulas (5) and (6), in addition to the above method, the step (IV) without using any carbon source (c') in the above step A water-insoluble carbon material (c4) may be used as the carbon (c). In this case, the granules (e) obtained in step (III) do not support carbon (c), and in step (IV), the lithium composite particles (A) and the granules (e) are Further, the water-insoluble carbon material (c4) may be added and mixed while applying compressive force and shear force. When adding the water-insoluble carbon material (c4) in step (IV), the blending amount of the lithium composite particles (A) and the total blending amount of the lithium positive electrode active material particles (B) and the water-insoluble carbon material (c4) The mass ratio (particles (A): (particles (B) + water-insoluble carbon material (c4))) is preferably 95:5 to 60:40, more preferably 92:8 to 65:35, More preferably, the ratio is 90:10 to 70:30. What is necessary is just to adjust the compounding quantity of the granule (e) and water-insoluble carbon material (c4) in the said mixture so that it may become this amount.
本発明のリチウムイオン二次電池用正極活物質複合体（Ｃ）を用いるリチウムイオン二次電池としては、正極と負極と電解液とセパレータを必須構成とするものであれば特に限定されない。 A lithium ion secondary battery using the positive electrode active material composite (C) for a lithium ion secondary battery of the present invention is not particularly limited as long as it includes a positive electrode, a negative electrode, an electrolyte, and a separator as essential components.
ここで、負極については、リチウムイオンを充電時には吸蔵し、かつ放電時には放出することができれば、その材料構成で特に限定されるものではなく、公知の材料構成のものを用いることができる。たとえば、リチウム金属、グラファイト、シリコン系（Ｓｉ、ＳｉＯｘ）、チタン酸リチウム又は非晶質炭素等の炭素材料等を用いることができる。そしてリチウムイオンを電気化学的に吸蔵・放出し得るインターカレート材料で形成された電極、特に炭素材料を用いることが好ましい。さらに、二種以上の上記の負極材料を併用してもよく、たとえばグラファイトとシリコン系の組み合わせを用いることができる。 Here, the material composition of the negative electrode is not particularly limited as long as it can occlude lithium ions during charging and release them during discharging, and any known material composition can be used. For example, lithium metal, graphite, silicon-based (Si, SiOx), lithium titanate, carbon materials such as amorphous carbon, etc. can be used. It is preferable to use an electrode made of an intercalating material that can electrochemically absorb and release lithium ions, particularly a carbon material. Furthermore, two or more of the above negative electrode materials may be used in combination; for example, a combination of graphite and silicon may be used.
電解液は、有機溶媒に支持塩を溶解させたものである。有機溶媒は、通常リチウムイオン二次電池の電解液に用いられる有機溶媒であれば特に限定されるものではなく、例えば、カーボネート類、ハロゲン化炭化水素、エーテル類、ケトン類、ニトリル類、ラクトン類、オキソラン化合物等を用いることができる。 The electrolytic solution is one in which a supporting salt is dissolved in an organic solvent. The organic solvent is not particularly limited as long as it is an organic solvent normally used in electrolytes of lithium ion secondary batteries, and examples include carbonates, halogenated hydrocarbons, ethers, ketones, nitriles, and lactones. , oxolane compounds, etc. can be used.
支持塩は、その種類が特に限定されるものではないが、ＬｉＰＦ6、ＬｉＢＦ4、ＬｉＣｌＯ4及びＬｉＡｓＦ6から選ばれる無機塩、該無機塩の誘導体、ＬｉＳＯ3ＣＦ3、ＬｉＣ（ＳＯ3ＣＦ3）2及びＬｉＮ（ＳＯ3ＣＦ3）2、ＬｉＮ（ＳＯ2Ｃ2Ｆ5）2及びＬｉＮ（ＳＯ2ＣＦ3）（ＳＯ2Ｃ4Ｆ9）から選ばれる有機塩、並びに該有機塩の誘導体の少なくとも１種であることが好ましい。 The supporting salt is not particularly limited in type, but includes inorganic salts selected from LiPF 6 , LiBF 4 , LiClO 4 and LiAsF 6 , derivatives of the inorganic salts, LiSO 3 CF 3 , LiC(SO 3 CF 3 ) 2 and an organic salt selected from LiN(SO 3 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 and LiN(SO 2 CF 3 )(SO 2 C 4 F 9 ), and derivatives of the organic salt. It is preferable that it is at least one kind of.
セパレータは、正極及び負極を電気的に絶縁し、電解液を保持する役割を果たすものである。たとえば、多孔性合成樹脂膜、特にポリオレフィン系高分子（ポリエチレン、ポリプロピレン）の多孔膜を用いればよい。 The separator serves to electrically insulate the positive electrode and the negative electrode and to retain the electrolyte. For example, a porous synthetic resin membrane, particularly a porous membrane of polyolefin polymer (polyethylene, polypropylene) may be used.
上記の構成を有するリチウムイオン二次電池の形状としては、特に制限を受けるものではなく、コイン型、円筒型、角型等種々の形状や、ラミネート外装体に封入した不定形状であってもよい。 The shape of the lithium ion secondary battery having the above configuration is not particularly limited, and may be various shapes such as a coin shape, a cylindrical shape, a square shape, or an irregular shape enclosed in a laminate exterior body. .
以下、本発明について、実施例に基づき具体的に説明するが、本発明はこれら実施例に限定されるものではない。 Hereinafter, the present invention will be specifically explained based on Examples, but the present invention is not limited to these Examples.
［製造例１：リチウム複合粒子（Ａ－１）の製造］
Ｎｉ：Ｃｏ：Ｍｎのモル比が１：１：１となるように、硫酸ニッケル六水和物 ２６３ｇ、硫酸コバルト七水和物 ２８１ｇ、硫酸マンガン五水和物 ２４１ｇ、及び水 ３Ｌを混合した後、かかる混合溶液に２５％アンモニア水を、滴下速度３００ｍｌ／分で滴下して、ｐＨが１１の金属複合水酸化物を含むスラリーＡ１を得た。
次いで、スラリーＡ１をろ過、乾燥して、金属複合水酸化物の混合物Ａ２を得た後、かかる混合物Ａ２に炭酸リチウム３７gをボールミルで混合して粉末混合物Ａ３を得た。
得られた粉末混合物Ａ３を、大気雰囲気下で８００℃×５時間仮焼成して解砕した後に造粒し、次いで本焼成として大気雰囲気下で８００℃×１０時間焼成し、リチウム複合酸化物二次粒子Ａ４（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2、平均粒径１０μｍ）を得た。
得られたリチウム複合酸化物二次粒子Ａ４を５００ｇ分取し、ＬｉＮＯ3 ０．９ｇ、Ａｌ（ＮＯ3）3・９Ｈ2Ｏ １．１３ｇ、ＴｉＣｌ4 ３．２３ｇ、Ｈ3ＰＯ4 ２．９４ｇと水５００ｍＬを添加し、さらにｐＨ調整剤として２８％アンモニア水１０．９３ｇを添加してスラリーＡ５を得た。得られたスラリーＡ５を超音波攪拌機（Ｔ２５、ＩＫＡ社製）で１分間分散処理して、全体を均一に呈色させた後、スプレードライ装置（ＭＤＬ－０５０Ｍ、藤崎電機株式会社製）を用いて噴霧乾燥に付して造粒体Ａ６を得た。
得られた造粒体Ａ６を、大気雰囲気下、７００℃で１時間焼成して、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3が被覆したリチウム複合粒子（Ａ－１）（平均粒径：１０μｍ、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3の被覆量：０．５質量％、被覆厚さ：５ｎｍ）を得た。
[Production Example 1: Production of lithium composite particles (A-1)]
After mixing 263 g of nickel sulfate hexahydrate, 281 g of cobalt sulfate heptahydrate, 241 g of manganese sulfate pentahydrate, and 3 L of water so that the molar ratio of Ni:Co:Mn was 1:1:1. 25% ammonia water was added dropwise to the mixed solution at a dropping rate of 300 ml/min to obtain slurry A1 containing the metal composite hydroxide having a pH of 11.
Next, the slurry A1 was filtered and dried to obtain a metal composite hydroxide mixture A2, and then 37 g of lithium carbonate was mixed with the mixture A2 using a ball mill to obtain a powder mixture A3.
The obtained powder mixture A3 was pre-calcined in the air at 800°C for 5 hours, pulverized, and then granulated.Then, the powder mixture A3 was calcined in the air at 800°C for 10 hours to form a lithium composite oxide. Secondary particles A4 (LiNi 0.33 Co 0.33 Mn 0.34 O 2 , average particle size 10 μm) were obtained.
500 g of the obtained lithium composite oxide secondary particles A4 were collected, and 0.9 g of LiNO 3 , 1.13 g of Al(NO 3 ) 3.9H 2 O, 3.23 g of TiCl 4 , and 2.94 g of H 3 PO 4 were collected. and 500 mL of water, and further added 10.93 g of 28% ammonia water as a pH adjuster to obtain slurry A5. The obtained slurry A5 was dispersed for 1 minute using an ultrasonic stirrer (T25, manufactured by IKA) to uniformly color the entire slurry, and then dispersed using a spray drying device (MDL-050M, manufactured by Fujisaki Electric Co., Ltd.). Granules A6 were obtained by spray drying.
The obtained granules A6 were fired at 700° C. for 1 hour in an air atmosphere to transform the surface of the lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) into solid electrolyte Li 1.3 Al 0.3 Ti. Lithium composite particles (A-1) coated with 1.7 (PO 4 ) 3 (average particle size: 10 μm, solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 coating amount: 0.5% by mass, coating thickness :5 nm) was obtained.
［製造例２：リチウム複合粒子（Ａ－２）の製造］
製造例１において、ＬｉＮＯ3 ０．９ｇを９．０ｇに、Ａｌ（ＮＯ3）3・９Ｈ2Ｏ １．１３ｇを１１．３ｇに、ＴｉＣｌ4 ３．２３ｇを３２．３ｇに、Ｈ3ＰＯ4 ２．９４ｇを２９．４ｇに、ｐＨ調整剤の２８％アンモニア水１０．９３ｇを１０９．３ｇに変更した以外、製造例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3が被覆したリチウム複合粒子（Ａ－２）（平均粒径：１０μｍ、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3の被覆量：５質量％、被覆厚さ：２０ｎｍ）を得た。
[Production Example 2: Production of lithium composite particles (A-2)]
In Production Example 1, 0.9 g of LiNO 3 was changed to 9.0 g, 1.13 g of Al(NO 3 ) 3.9H 2 O was changed to 11.3 g, 3.23 g of TiCl 4 was changed to 32.3 g, and H 3 PO 4 Lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn Lithium composite particles ( A - 2 ) in which the surface of solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 is coated with 0.34 O 2 ) (average particle size: 10 μm, solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) ) 3 coating amount: 5% by mass, coating thickness: 20 nm) was obtained.
［製造例３：リチウム複合粒子（Ａ－３）の製造］
Ｌｉ：Ｎｉ：Ｃｏ：Ａｌのモル比が１：０．８：０．１５：０．０５となるように、炭酸リチウム３７０ｇ、炭酸ニッケル９５０ｇ、炭酸コバルト１５０ｇ、炭酸アルミニウム５８ｇ、及び水３Ｌを混合した後、ボールミルで混合して粉末混合物Ａ７を得た。
得られた粉末混合物Ａ７を、大気雰囲気下で８００℃×５時間仮焼成して解砕した後、本焼成として大気雰囲気下で８００℃×２４時間焼成し、リチウム複合酸化物二次粒子Ａ８（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2、平均粒径１０μｍ）を得た。
得られたリチウム複合酸化物二次粒子Ａ８を５００ｇ分取し、ＬｉＮＯ3 ０．９ｇ、Ａｌ（ＮＯ3）3・９Ｈ2Ｏ １．１３ｇ、ＴｉＣｌ4 ３．２３ｇ、Ｈ3ＰＯ4 ２．９４ｇと水５００ｍＬを添加し、さらにｐＨ調整剤として２８％アンモニア水１０．９３ｇを添加してスラリーＡ９を得た。得られたスラリーＡ９を超音波攪拌機（同上）で１分間分散処理して、全体を均一に呈色させた後、スプレードライ装置（同上）を用いて噴霧乾燥に付して造粒体Ａ１０を得た。
得られた造粒体Ａ１０を、大気雰囲気下、７００℃で１時間焼成して、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3が被覆したリチウム複合粒子（Ａ－３）（平均粒径：１０μｍ、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3の被覆量：０．５質量％、被覆厚さ：５ｎｍ）を得た。
[Production Example 3: Production of lithium composite particles (A-3)]
Mix 370 g of lithium carbonate, 950 g of nickel carbonate, 150 g of cobalt carbonate, 58 g of aluminum carbonate, and 3 L of water so that the molar ratio of Li:Ni:Co:Al is 1:0.8:0.15:0.05. After that, the mixture was mixed in a ball mill to obtain a powder mixture A7.
The obtained powder mixture A7 was pre-calcined in the air at 800°C for 5 hours to be crushed, and then main calcination was performed at 800°C in the air for 24 hours to form lithium composite oxide secondary particles A8 ( LiNi 0.8 Co 0.15 Al 0.05 O 2 , average particle size 10 μm) was obtained.
500 g of the obtained lithium composite oxide secondary particles A8 were collected, and 0.9 g of LiNO 3 , 1.13 g of Al(NO 3 ) 3.9H 2 O, 3.23 g of TiCl 4 , and 2.94 g of H 3 PO 4 were collected. and 500 mL of water, and further added 10.93 g of 28% ammonia water as a pH adjuster to obtain slurry A9. The resulting slurry A9 was dispersed for 1 minute using an ultrasonic stirrer (same as above) to uniformly color the entire slurry, and then spray-dried using a spray dryer (same as above) to form granules A10. Obtained.
The obtained granules A10 were fired at 700° C. for 1 hour in an air atmosphere to transform the surface of the lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) into solid electrolyte Li 1.3 Al 0.3 Ti. Lithium composite particles (A-3) coated with 1.7 (PO 4 ) 3 (average particle size: 10 μm, solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 coating amount: 0.5% by mass, coating thickness :5 nm) was obtained.
［製造例４：リチウム複合粒子（Ａ－４）の製造］
製造例３において、ＬｉＮＯ3 ０．９ｇを９．０ｇに、Ａｌ（ＮＯ3）3・９Ｈ2Ｏ １．１３ｇを１１．３ｇに、ＴｉＣｌ4 ３．２３ｇを３２．３ｇに、Ｈ3ＰＯ4 ２．９４ｇを２９．４ｇに、ｐＨ調整剤の２８％アンモニア水１０．９３ｇを１０９．３ｇに変更した以外、製造例３と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3が被覆したリチウム複合粒子（Ａ－４）（平均粒径：１０μｍ、固体電解質Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3の被覆量：５質量％、被覆厚さ：２０ｎｍ）を得た。
[Production Example 4: Production of lithium composite particles (A-4)]
In Production Example 3, 0.9 g of LiNO 3 was changed to 9.0 g, 1.13 g of Al(NO 3 ) 3.9H 2 O was changed to 11.3 g, 3.23 g of TiCl 4 was changed to 32.3 g, and H 3 PO 4 Lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al Lithium composite particles (A-4) in which the surface of solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 is coated with 0.05 O 2 ) (average particle size: 10 μm, solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) ) 3 coating amount: 5% by mass, coating thickness: 20 nm) was obtained.
［製造例５：リチウム正極活物質粒子（Ｂ－１）の製造］
ＬｉＯＨ・Ｈ2Ｏ １２７２ｇ、及び水４Ｌを混合してスラリーＢ１を得た。次いで、得られたスラリーＢ１を、２５℃の温度に保持しながら３分間撹拌しつつ８５％のリン酸水溶液１１５３ｇを３５ｍＬ／分で滴下し、続いてセルロースナノファイバー（Ｗｍａ－１０００２、スギノマシン社製、繊維径４～２０ｎｍ）５８９２ｇを添加して、速度４００ｒｐｍで１２時間撹拌して、Ｌｉ3ＰＯ4を含むスラリーＢ２を得た。
得られたスラリーＢ２に窒素パージして、スラリーＢ２の溶存酸素濃度を０．５ｍｇ／Ｌとした後、スラリーＢ２全量に対し、ＭｎＳＯ4・５Ｈ2Ｏ １６８８ｇ、ＦｅＳＯ4・７Ｈ2Ｏ ８３４ｇを添加してスラリーＢ３を得た。添加したＭｎＳＯ4とＦｅＳＯ4のモル比（マンガン化合物：鉄化合物）は、７０：３０であった。
次いで、得られたスラリーＢ３をオートクレーブに投入し、１７０℃で１時間水熱反応を行った。オートクレーブ内の圧力は０．８ＭＰａであった。水熱反応後、生成した結晶をろ過し、次いで結晶１質量部に対し１２質量部の水により洗浄した。洗浄した結晶を－５０℃で１２時間凍結乾燥して複合体Ｂ４を得た。
得られた複合体Ｂ４を１０００ｇ分取し、水１Ｌを添加してスラリーＢ５を得た後、スラリーＢ５を超音波攪拌機（同上）で１分間分散処理して、全体を均一に呈色させた後、スプレードライ装置（同上）を用いて噴霧乾燥に付して造粒体Ｂ６を得た。
得られた造粒体Ｂ６を、アルゴン水素雰囲気下（水素濃度３％）、７００℃で１時間焼成して、２．０質量％のセルロースナノファイバー由来の炭素が担持されたリチウム正極活物質粒子（Ｂ－１）（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4、炭素の担持量：２．０質量％、平均粒径：１００ｎｍ）を得た。
[Production Example 5: Production of lithium positive electrode active material particles (B-1)]
Slurry B1 was obtained by mixing 1272 g of LiOH.H 2 O and 4 L of water. Next, 1153 g of an 85% phosphoric acid aqueous solution was added dropwise to the obtained slurry B1 at a rate of 35 mL/min while stirring for 3 minutes while maintaining the temperature at 25°C. 5,892 g of 4- to 20-nm fiber diameter) were added thereto and stirred at a speed of 400 rpm for 12 hours to obtain slurry B2 containing Li 3 PO 4 .
After purging the obtained slurry B2 with nitrogen to make the dissolved oxygen concentration of slurry B2 0.5 mg/L, 1688 g of MnSO 4 .5H 2 O and 834 g of FeSO 4 .7H 2 O were added to the total amount of slurry B2. Slurry B3 was obtained. The molar ratio of added MnSO 4 and FeSO 4 (manganese compound: iron compound) was 70:30.
Next, the obtained slurry B3 was put into an autoclave, and a hydrothermal reaction was performed at 170° C. for 1 hour. The pressure inside the autoclave was 0.8 MPa. After the hydrothermal reaction, the produced crystals were filtered and then washed with 12 parts by weight of water per 1 part by weight of the crystals. The washed crystals were freeze-dried at -50°C for 12 hours to obtain complex B4.
1000 g of the obtained composite B4 was taken, 1 L of water was added to obtain slurry B5, and slurry B5 was dispersed for 1 minute using an ultrasonic stirrer (same as above) to uniformly color the entire slurry. Thereafter, granules B6 were obtained by spray drying using a spray drying apparatus (same as above).
The obtained granules B6 were fired at 700° C. for 1 hour in an argon-hydrogen atmosphere (3% hydrogen concentration) to obtain lithium positive electrode active material particles on which 2.0% by mass of carbon derived from cellulose nanofibers was supported. (B-1) (LiMn 0.7 Fe 0.3 PO 4 , supported amount of carbon: 2.0% by mass, average particle size: 100 nm) was obtained.
［製造例６：リチウム正極活物質粒子（Ｂ－２）の製造］
ＬｉＯＨ・Ｈ2Ｏ ４２８ｇ、Ｎａ4ＳｉＯ4・ｎＨ2Ｏ １３９７ｇ、セルロースナノファイバー（同上）２９４６ｇ、及び水３．７５Ｌを混合してスラリーＢ７を得た。次いで、得られたスラリーＢ７に、ＭｎＳＯ4・５Ｈ2Ｏ ７９３ｇ、ＦｅＳＯ4・７Ｈ2Ｏ ３９２ｇ、及びＺｒ（ＳＯ4）2・４Ｈ2Ｏ ５３ｇを添加し、混合してスラリーＢ８を得た。このとき、添加したＦｅＳＯ4、ＭｎＳＯ4及びＺｒ（ＳＯ4）2のモル比（鉄化合物：マンガン化合物：ジルコニウム化合物）は、２８：６６：３であった。
次いで、得られたスラリーＢ８をオートクレーブに投入し、１７０℃で３時間水熱反応を行った。オートクレーブ内の圧力は０．４ＭＰａであった。水熱反応後、生成した結晶をろ過し、次いで結晶１質量部に対し１２質量部の水により洗浄した。洗浄した結晶を－５０℃で１２時間凍結乾燥して複合体Ｂ９を得た。
得られた複合体Ｂ９を５００ｇ分取し、水０．５Ｌを添加してスラリーＢ１０を得た後、スラリーＢ１０を超音波攪拌機（同上）で１分間分散処理して、全体を均一に呈色させた後、スプレードライ装置（同上）を用いて噴霧乾燥に付して造粒体Ｂ１１を得た。
得られた造粒体Ｂ１１を、アルゴン水素雰囲気下（水素濃度３％）、６５０℃で１時間焼成して、２．０質量％のセルロースナノファイバー由来の炭素が担持されたリチウム正極活物質粒子（Ｂ－２）（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4、炭素の担持量：２．０質量％、平均粒径：５０ｎｍ）を得た。
[Production Example 6: Production of lithium positive electrode active material particles (B-2)]
Slurry B7 was obtained by mixing 428 g of LiOH.H 2 O, 1397 g of Na 4 SiO 4 .nH 2 O, 2946 g of cellulose nanofibers (same as above), and 3.75 L of water. Next, 793 g of MnSO 4 .5H 2 O, 392 g of FeSO 4 .7H 2 O, and 53 g of Zr(SO 4 ) 2 .4H 2 O were added to the obtained slurry B7 and mixed to obtain slurry B8. At this time, the molar ratio of FeSO 4 , MnSO 4 and Zr(SO 4 ) 2 added (iron compound: manganese compound: zirconium compound) was 28:66:3.
Next, the obtained slurry B8 was put into an autoclave, and a hydrothermal reaction was performed at 170° C. for 3 hours. The pressure inside the autoclave was 0.4 MPa. After the hydrothermal reaction, the produced crystals were filtered and then washed with 12 parts by weight of water per 1 part by weight of the crystals. The washed crystals were freeze-dried at -50°C for 12 hours to obtain complex B9.
500 g of the obtained composite B9 was collected, 0.5 L of water was added to obtain slurry B10, and the slurry B10 was dispersed for 1 minute using an ultrasonic stirrer (same as above) to uniformly color the entire slurry. After that, the mixture was subjected to spray drying using a spray drying device (same as above) to obtain granules B11.
The obtained granules B11 were fired at 650° C. for 1 hour in an argon-hydrogen atmosphere (hydrogen concentration 3%) to obtain lithium positive electrode active material particles on which 2.0% by mass of carbon derived from cellulose nanofibers was supported. (B-2) (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 , supported amount of carbon: 2.0% by mass, average particle size: 50 nm) was obtained.
［製造例７：リチウム正極活物質粒子（Ｂ－３）の製造］
Ｌｉ2ＣＯ3 ２２２ｇ及びＣｏ3Ｏ4 ４８２ｇをボールミルで混合後、５００ｋｇ／ｃｍ3でのプレス圧で成型して、焼成用原料Ｂ１２を得た。得られた焼成用原料Ｂ１２を、大気雰囲気下、７００℃で５時間焼成することで脱炭酸処理して得られた焼成体Ｂ１３を、ボールミルで粉砕後に、１０００ｋｇ／ｃｍ3でのプレス圧で再度成型して、焼成用原料Ｂ１４を得た。得られた焼成用原料Ｂ１４を、大気雰囲気下、９００℃で１０時間焼成して焼成体Ｂ１５（ＬｉＣｏＯ2）を得た後、ディスクミルで粉砕してリチウム正極活物質粒子（Ｂ－３）（ＬｉＣｏＯ2、平均粒径：２００ｎｍ）を得た。
[Production Example 7: Production of lithium positive electrode active material particles (B-3)]
After mixing 222 g of Li 2 CO 3 and 482 g of Co 3 O 4 in a ball mill, the mixture was molded with a press pressure of 500 kg/cm 3 to obtain firing raw material B12. The obtained firing raw material B12 was decarboxylated by firing at 700°C for 5 hours in an air atmosphere, and the resulting fired body B13 was crushed in a ball mill and then crushed again with a press pressure of 1000 kg/cm 3 It was molded to obtain firing raw material B14. The obtained firing raw material B14 was fired at 900°C for 10 hours in an air atmosphere to obtain a fired body B15 (LiCoO 2 ), which was then pulverized with a disk mill to obtain lithium positive electrode active material particles (B-3) ( LiCoO 2 , average particle size: 200 nm) was obtained.
［製造例８：リチウム複合酸化物二次粒子（Ｅ－１）の製造］
製造例１の中間生成物である、リチウム複合酸化物二次粒子Ａ４（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2、平均粒径１０μｍ）を得た。製造方法は製造例１に準じた。
[Production Example 8: Production of lithium composite oxide secondary particles (E-1)]
Lithium composite oxide secondary particles A4 (LiNi 0.33 Co 0.33 Mn 0.34 O 2 , average particle size 10 μm), which is an intermediate product of Production Example 1, were obtained. The manufacturing method was based on Manufacturing Example 1.
［製造例９：リチウム複合酸化物二次粒子（Ｅ－２）の製造］
製造例３の中間生成物である、リチウム複合酸化物二次粒子Ａ８（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2、平均粒径１０μｍ）を得た。製造方法は製造例３に準じた。
[Production Example 9: Production of lithium composite oxide secondary particles (E-2)]
Lithium composite oxide secondary particles A8 (LiNi 0.8 Co 0.15 Al 0.05 O 2 , average particle size 10 μm), which is an intermediate product of Production Example 3, were obtained. The manufacturing method was similar to Manufacturing Example 3.
［実施例１：リチウム複合粒子（Ａ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
製造例１で得られたリチウム複合粒子（Ａ－１）３００ｇと、製造例５で得られたリチウム正極活物質粒子（Ｂ－１）２００ｇを、メカノフュージョン（ホソカワミクロン社製、ＡＭＳ－Ｌａｂ）を用いて、２６００ｒｐｍ（２０ｍ／秒）で１０分間の複合化処理を行い、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－１）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－１）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 1: 60% by mass of lithium composite particles (A-1) + 40% by mass of lithium positive electrode active material particles (B-1)]
300 g of lithium composite particles (A-1) obtained in Production Example 1 and 200 g of lithium positive electrode active material particles (B-1) obtained in Production Example 5 were mixed with Mechanofusion (manufactured by Hosokawa Micron Corporation, AMS-Lab). The surface of the lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li 1.3 Lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) carrying 2% by mass of carbon were composited on the surface of lithium composite particles (A - 1) coated with Al 0.3 Ti 1.7 (PO 4 ) 3 ) . Positive electrode active material composite (C-1) for lithium ion secondary batteries (lithium composite particles: lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , A support layer of lithium positive electrode active material particles having a thickness of 1.5 μm was obtained.
［実施例２：リチウム複合粒子（Ａ－２）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例２のリチウム複合粒子（Ａ－２）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－２）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－２）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 2: 60% by mass of lithium composite particles (A-2) + 40% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, lithium composite oxide secondary particles (LiNi 0.33 Co 2 mass % of carbon is supported on the surface of lithium composite particles (A-2) in which the surface of 0.33 Mn 0.34 O 2 ) is coated with 5 mass % of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). Positive electrode active material composite (C-2) for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) were composited (lithium composite particles: lithium positive electrode active material particles = 60:40 ( (mass ratio), average particle diameter of 13 μm, tap density of 1.4 g/cm 3 , and thickness of support layer of lithium positive electrode active material particles: 1.5 μm).
［実施例３：リチウム複合粒子（Ａ－３）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例３のリチウム複合粒子（Ａ－３）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－３）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－３）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 3: 60% by mass of lithium composite particles (A-3) + 40% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) coated with 0.5 mass % solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), 2 mass % carbon on the surface of lithium composite particles (A-3). Positive electrode active material composite (C-3) for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) supported on lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) are composited (lithium composite particles: lithium positive electrode active material particles = 60: 40 (mass ratio), average particle diameter of 13 μm, tap density of 1.4 g/cm 3 , and thickness of support layer of lithium positive electrode active material particles: 1.5 μm).
［実施例４：リチウム複合粒子（Ａ－４）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例４のリチウム複合粒子（Ａ－４）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－４）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－４）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 4: 60% by mass of lithium composite particles (A-4) + 40% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, lithium composite oxide secondary particles (LiNi 0.8 Co 2 mass % of carbon is supported on the surface of lithium composite particles (A-4) in which the surface of 0.15 Al 0.05 O 2 ) is coated with 5 mass % of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). Lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) were combined into a positive electrode active material composite for lithium ion secondary batteries (C-4) (lithium composite particles: lithium positive electrode active material particles = 60:40 ( (mass ratio), average particle diameter of 13 μm, tap density of 1.4 g/cm 3 , and thickness of support layer of lithium positive electrode active material particles: 1.5 μm).
［実施例５：リチウム複合粒子（Ａ－１）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－１）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－５）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Example 5: 90% by mass of lithium composite particles (A-1) + 10% by mass of lithium positive electrode active material particles (B-1)]
Lithium composite oxide secondary was prepared in the same manner as in Example 1 except that 300 g of lithium composite particles (A-1) was changed to 450 g and 200 g of lithium positive electrode active material particles (B-1) was changed to 50 g. On the surface of lithium composite particles (A-1), the surface of particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), Positive electrode active material composite for lithium ion secondary batteries (C - 5 ) (lithium composite particles : lithium positive electrode active material Material particles=90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of support layer of lithium positive electrode active material particles: 750 nm).
［実施例６：リチウム複合粒子（Ａ－２）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例２のリチウム複合粒子（Ａ－２）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－２）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－６）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Example 6: 90% by mass of lithium composite particles (A-2) + 10% by mass of lithium positive electrode active material particles (B-1)]
Examples except that in Example 1, 300 g of lithium composite particles (A-1) were changed to 450 g of lithium composite particles (A-2) of Production Example 2, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g. In the same manner as in 1, a lithium composite was prepared in which the surface of lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) was coated with 5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). A positive electrode active material composite for lithium ion secondary batteries ( C- 6) (Lithium composite particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of supported layer by lithium positive electrode active material particles: 750 nm ) was obtained.
［実施例７：リチウム複合粒子（Ａ－３）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例３のリチウム複合粒子（Ａ－３）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－３）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－７）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Example 7: 90% by mass of lithium composite particles (A-3) + 10% by mass of lithium positive electrode active material particles (B-1)]
Examples except that in Example 1, 300 g of lithium composite particles (A-1) were changed to 450 g of lithium composite particles (A-3) of Production Example 3, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g. In the same manner as in 1, the surface of lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). A positive electrode active material composite for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) having 2% by mass of carbon supported on the surface of lithium composite particles (A-3) are composited. C-7) (Lithium composite particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of support layer by lithium positive electrode active material particles :750 nm) was obtained.
［実施例８：リチウム複合粒子（Ａ－４）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例４のリチウム複合粒子（Ａ－４）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－４）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－８）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Example 8: 90% by mass of lithium composite particles (A-4) + 10% by mass of lithium positive electrode active material particles (B-1)]
Examples except that in Example 1, 300 g of lithium composite particles (A-1) were changed to 450 g of lithium composite particles (A-4) of Production Example 4, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g. In the same manner as in 1, a lithium composite was prepared in which the surface of lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) was coated with 5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). A positive electrode active material composite for lithium ion secondary batteries ( C- 8) (Lithium composite particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of supported layer by lithium positive electrode active material particles: 750 nm) ) was obtained.
［実施例９：リチウム複合粒子（Ａ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－２）４０質量％］
実施例１において、リチウム正極活物質粒子（Ｂ－１）を製造例６のリチウム正極活物質粒子（Ｂ－２）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－１）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－９）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 9: 60% by mass of lithium composite particles (A-1) + 40% by mass of lithium positive electrode active material particles (B-2)]
Lithium composite oxide secondary particles were prepared in the same manner as in Example 1, except that the lithium positive electrode active material particles (B-1) were changed to the lithium positive electrode active material particles (B-2) of Production Example 6. On the surface of lithium composite particles (A-1), the surface of (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), A positive electrode active material composite for lithium ion secondary batteries (C - 9 ) (lithium composite particles : Lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , thickness of support layer of lithium positive electrode active material particles: 1.5 μm) were obtained.
［実施例１０：リチウム複合粒子（Ａ－３）６０質量％＋リチウム正極活物質粒子（Ｂ－２）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例３のリチウム複合粒子（Ａ－３）に、リチウム正極活物質粒子（Ｂ－１）を製造例６のリチウム正極活物質粒子（Ｂ－２）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－３）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－１０）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 10: 60% by mass of lithium composite particles (A-3) + 40% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, the lithium composite particles (A-1) were replaced with the lithium composite particles (A-3) of Production Example 3, and the lithium positive electrode active material particles (B-1) were replaced with the lithium positive electrode active material particles (B-1) of Production Example 6. -2) except that the surface of the lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti). Lithium-based polyanion particles (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 ) carrying 2% by mass of carbon are composited on the surface of lithium composite particles (A-3) coated with 1.7 ( PO 4 ) 3 ). Positive electrode active material composite for lithium ion secondary batteries (C-10) (lithium composite particles: lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , the thickness of the support layer of lithium positive electrode active material particles: 1.5 μm) was obtained.
［実施例１１：リチウム複合粒子（Ａ－１）９０質量％＋リチウム正極活物質粒子（Ｂ－２）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを製造例６のリチウム正極活物質粒子（Ｂ－２）５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－１）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－１１）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 11: 90% by mass of lithium composite particles (A-1) + 10% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, except that 300 g of lithium composite particles (A-1) was changed to 450 g, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g of lithium positive electrode active material particles (B-2) of Production Example 6. In the same manner as in Example 1, 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) was applied to the surface of lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ). A lithium ion secondary battery in which lithium-based polyanion particles (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 ) carrying 2% by mass of carbon are composited on the surface of coated lithium composite particles (A-1). Positive electrode active material composite (C-11) (lithium composite particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , supported by lithium positive electrode active material particles A layer thickness of 1.5 μm) was obtained.
［実施例１２：リチウム複合粒子（Ａ－３）９０質量％＋リチウム正極活物質粒子（Ｂ－２）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例３のリチウム複合粒子（Ａ－３）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを製造例６のリチウム正極活物質粒子（Ｂ－２）５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－３）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－１２）（リチウム複合粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 12: 90% by mass of lithium composite particles (A-3) + 10% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, 300 g of lithium composite particles (A-1) were added to 450 g of lithium composite particles (A-3) of Production Example 3, and 200 g of lithium positive electrode active material particles (B-1) were added to the lithium positive electrode active material of Production Example 6. The surface of lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) was coated with 0.5% by mass of solid electrolyte (Li Lithium-based polyanion particles (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 ) with 2% by mass of carbon supported on the surface of lithium composite particles (A - 3 ) coated with 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) ) is composited with positive electrode active material composite for lithium ion secondary batteries (C-12) (lithium composite particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 13 μm, tap density 1. 4 g/cm 3 , and the thickness of the support layer made of lithium positive electrode active material particles: 1.5 μm) was obtained.
［実施例１３：リチウム複合粒子（Ａ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－３）４０質量％］
実施例１において、リチウム正極活物質粒子（Ｂ－１）を製造例７のリチウム正極活物質粒子（Ｂ－３）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面を０．５質量％の固体電解質（Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3）が被覆したリチウム複合粒子（Ａ－１）の表面に、コバルト酸リチウム粒子（ＬｉＣｏＯ2）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｃ－１３）（リチウム複合粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Example 13: 60% by mass of lithium composite particles (A-1) + 40% by mass of lithium positive electrode active material particles (B-3)]
Lithium composite oxide secondary particles were prepared in the same manner as in Example 1, except that the lithium positive electrode active material particles (B-1) were changed to the lithium positive electrode active material particles (B-3) of Production Example 7. Cobalt is applied to the surface of lithium composite particles (A-1) in which the surface of (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) is coated with 0.5% by mass of solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). Positive electrode active material composite (C-13) for lithium ion secondary batteries in which lithium oxide particles (LiCoO 2 ) are composited (lithium composite particles: lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, a tap density of 1.4 g/cm 3 , and a thickness of a support layer of lithium positive electrode active material particles: 1.5 μm).
［比較例１：リチウム複合酸化物二次粒子（Ｅ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例８のリチウム複合酸化物二次粒子（Ｅ－１）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－１）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Comparative Example 1: 60% by mass of lithium composite oxide secondary particles (E-1) + 40% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, lithium composite oxide secondary particles were produced in the same manner as in Example 1, except that the lithium composite particles (A-1) were changed to the lithium composite oxide secondary particles (E-1) of Production Example 8. A positive electrode active material composite for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) with 2% by mass of carbon supported on the surface of (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) are composited. Body (D-1) (Lithium composite oxide secondary particles: Lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , supported by lithium positive electrode active material particles) A layer thickness of 1.5 μm) was obtained.
［比較例２：リチウム複合酸化物二次粒子（Ｅ－１）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例８のリチウム複合酸化物二次粒子（Ｅ－１）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－２）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Comparative Example 2: 90% by mass of lithium composite oxide secondary particles (E-1) + 10% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, 300 g of lithium composite particles (A-1) were changed to 450 g of lithium composite oxide secondary particles (E-1) of Production Example 8, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g. In the same manner as in Example 1 except for this, lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO) in which 2% by mass of carbon was supported on the surface of lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) were prepared. 4 ) is composited into a positive electrode active material composite for lithium ion secondary batteries (D-2) (lithium composite oxide secondary particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11 .5 μm, a tap density of 1.6 g/cm 3 , and a thickness of a support layer of lithium positive electrode active material particles: 750 nm).
［比較例３：リチウム複合酸化物二次粒子（Ｅ－２）６０質量％＋リチウム正極活物質粒子（Ｂ－１）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例９のリチウム複合酸化物二次粒子（Ｅ－２）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－３）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Comparative Example 3: 60% by mass of lithium composite oxide secondary particles (E-2) + 40% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, lithium composite oxide secondary particles were produced in the same manner as in Example 1, except that the lithium composite particles (A-1) were changed to the lithium composite oxide secondary particles (E-2) of Production Example 9. A positive electrode active material composite for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) with 2% by mass of carbon supported on the surface of (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) are composited. Body (D-3) (Lithium composite oxide secondary particles: Lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , supported by lithium positive electrode active material particles) A layer thickness of 1.5 μm) was obtained.
［比較例４：リチウム複合酸化物二次粒子（Ｅ－２）９０質量％＋リチウム正極活物質粒子（Ｂ－１）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例９のリチウム複合酸化物二次粒子（Ｅ－２）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－４）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Comparative Example 4: 90% by mass of lithium composite oxide secondary particles (E-2) + 10% by mass of lithium positive electrode active material particles (B-1)]
In Example 1, 300 g of lithium composite particles (A-1) were changed to 450 g of lithium composite oxide secondary particles (E-2) of Production Example 9, and 200 g of lithium positive electrode active material particles (B-1) were changed to 50 g. Other than that, in the same manner as in Example 1, lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO) in which 2% by mass of carbon was supported on the surface of lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) were prepared. 4 ) is composited with positive electrode active material composite for lithium ion secondary batteries (D-4) (lithium composite oxide secondary particles: lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11 .5 μm, a tap density of 1.6 g/cm 3 , and a thickness of a support layer of lithium positive electrode active material particles: 750 nm).
［比較例５：リチウム複合酸化物二次粒子（Ｅ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－２）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例８のリチウム複合酸化物二次粒子（Ｅ－１）に、リチウム正極活物質粒子（Ｂ－１）を製造例６のリチウム正極活物質粒子（Ｂ－２）変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－５）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Comparative Example 5: 60% by mass of lithium composite oxide secondary particles (E-1) + 40% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, the lithium composite particles (A-1) were replaced with the lithium composite oxide secondary particles (E-1) of Production Example 8, and the lithium positive electrode active material particles (B-1) were replaced with the lithium positive electrode active material of Production Example 6. The material particles ( B-2) were prepared in the same manner as in Example 1 except that the material particles (B - 2 ) were changed. Lithium ion secondary battery positive electrode active material composite (D-5) in which system polyanion particles (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 ) are composited (lithium composite oxide secondary particles: lithium positive electrode active material particles) = 60:40 (mass ratio), average particle diameter of 13 μm, tap density of 1.4 g/cm 3 , and thickness of support layer of lithium positive electrode active material particles: 1.5 μm).
［比較例６：リチウム複合酸化物二次粒子（Ｅ－１）９０質量％＋リチウム正極活物質粒子（Ｂ－２）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例８のリチウム複合酸化物二次粒子（Ｅ－１）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを製造例６のリチウム正極活物質粒子（Ｂ－２）５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－６）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Comparative Example 6: 90% by mass of lithium composite oxide secondary particles (E-1) + 10% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, 300 g of lithium composite particles (A-1) were added to 450 g of lithium composite oxide secondary particles (E-1) of Production Example 8, and 200 g of lithium positive electrode active material particles (B-1) were added to 450 g of lithium composite oxide secondary particles (E-1) of Production Example 6. 2% by mass of carbon was added to the surface of lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) in the same manner as in Example 1 except that 50 g of lithium positive electrode active material particles (B-2) were used. Positive electrode active material composite for lithium ion secondary batteries (D - 6 ) (lithium composite oxide secondary particles: Lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of support layer of lithium positive electrode active material particles: 750 nm).
［比較例７：リチウム複合酸化物二次粒子（Ｅ－２）６０質量％＋リチウム正極活物質粒子（Ｂ－２）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例９のリチウム複合酸化物二次粒子（Ｅ－２）に、リチウム正極活物質粒子（Ｂ－１）を製造例６のリチウム正極活物質粒子（Ｂ－２）変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－７）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Comparative Example 7: 60% by mass of lithium composite oxide secondary particles (E-2) + 40% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, the lithium composite particles (A-1) were replaced with the lithium composite oxide secondary particles (E-2) of Production Example 9, and the lithium positive electrode active material particles (B-1) were replaced with the lithium positive electrode active material particles of Production Example 6. The material particles (B-2) were prepared in the same manner as in Example 1 except that the material particles (B - 2 ) were changed. Positive electrode active material composite for lithium ion secondary batteries (D-7) in which polyanion particles (Li 2 Mn 0.66 Fe 0.28 Zr 0.03 SiO 4 ) are composited (lithium composite oxide secondary particles: lithium positive electrode active material particles) = 60:40 (mass ratio), average particle diameter of 13 μm, tap density of 1.4 g/cm 3 , and thickness of support layer of lithium positive electrode active material particles: 1.5 μm).
［比較例８：リチウム複合酸化物二次粒子（Ｅ－２）９０質量％＋リチウム正極活物質粒子（Ｂ－２）１０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを製造例９のリチウム複合酸化物二次粒子（Ｅ－２）４５０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇ製造例６のリチウム正極活物質粒子（Ｂ－２）を５０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.8Ｃｏ0.15Ａｌ0.05Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（Ｌｉ2Ｍｎ0.66Ｆｅ0.28Ｚｒ0.03ＳｉＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－８）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝９０：１０（質量比）、平均粒径１１．５μｍ、タップ密度１．６ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：７５０ｎｍ）を得た。
[Comparative Example 8: 90% by mass of lithium composite oxide secondary particles (E-2) + 10% by mass of lithium positive electrode active material particles (B-2)]
In Example 1, 300 g of lithium composite particles (A-1) were added to 450 g of lithium composite oxide secondary particles (E-2) of Production Example 9, and 200 g of lithium positive electrode active material particles (B-1) of Production Example 6 were added. 2% by mass of carbon was added to the surface of lithium composite oxide secondary particles (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) in the same manner as in Example 1 except that the amount of positive electrode active material particles (B-2) was changed to 50 g. Positive electrode active material composite for lithium ion secondary batteries (D - 8 ) (lithium composite oxide secondary particles: Lithium positive electrode active material particles = 90:10 (mass ratio), average particle size 11.5 μm, tap density 1.6 g/cm 3 , thickness of support layer of lithium positive electrode active material particles: 750 nm).
［比較例９：リチウム複合酸化物二次粒子（Ｅ－１）６０質量％＋リチウム正極活物質粒子（Ｂ－３）４０質量％］
実施例１において、リチウム複合粒子（Ａ－１）を製造例８のリチウム複合酸化物二次粒子（Ｅ－１）に、リチウム正極活物質粒子（Ｂ－１）を製造例７のリチウム正極活物質粒子（Ｂ－３）に変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、コバルト酸リチウム粒子（ＬｉＣｏＯ2）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－９）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝６０：４０（質量比）、平均粒径１３μｍ、タップ密度１．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：１．５μｍ）を得た。
[Comparative Example 9: 60% by mass of lithium composite oxide secondary particles (E-1) + 40% by mass of lithium positive electrode active material particles (B-3)]
In Example 1, the lithium composite particles (A-1) were replaced with the lithium composite oxide secondary particles (E-1) of Production Example 8, and the lithium positive electrode active material particles (B-1) were replaced with the lithium positive electrode active material of Production Example 7. Lithium cobalt oxide particles (LiCoO 2 ) were formed on the surface of lithium composite oxide secondary particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) in the same manner as in Example 1 except that the substance particles (B- 3 ) were used. Composite positive electrode active material composite for lithium ion secondary batteries (D-9) (lithium composite oxide secondary particles: lithium positive electrode active material particles = 60:40 (mass ratio), average particle size 13 μm, tap density 1.4 g/cm 3 , and the thickness of the support layer made of lithium positive electrode active material particles: 1.5 μm) was obtained.
［比較例１０：リチウム複合酸化物二次粒子（Ａ－１）９８質量％＋リチウム正極活物質粒子（Ｂ－１）２質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを４９０ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを１０ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－１０）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝９８：２（質量比）、平均粒径１０μｍ、タップ密度２．４ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：８０ｎｍ）を得た。
[Comparative Example 10: 98% by mass of lithium composite oxide secondary particles (A-1) + 2% by mass of lithium positive electrode active material particles (B-1)]
Lithium composite oxide secondary was prepared in the same manner as in Example 1 except that 300 g of lithium composite particles (A-1) was changed to 490 g and 200 g of lithium positive electrode active material particles (B-1) was changed to 10 g. A positive electrode active material for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) with 2% by mass of carbon supported on the surface of particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) are composited. Composite (D-10) (Lithium composite oxide secondary particles: lithium positive electrode active material particles = 98:2 (mass ratio), average particle size 10 μm, tap density 2.4 g/cm 3 , lithium positive electrode active material particles) The thickness of the support layer: 80 nm) was obtained.
［比較例１１：リチウム複合酸化物二次粒子（Ａ－１）４０質量％＋リチウム正極活物質粒子（Ｂ－１）６０質量％］
実施例１において、リチウム複合粒子（Ａ－１）３００ｇを２００ｇに、リチウム正極活物質粒子（Ｂ－１）２００ｇを３００ｇに変更した以外、実施例１と同様にして、リチウム複合酸化物二次粒子（ＬｉＮｉ0.33Ｃｏ0.33Ｍｎ0.34Ｏ2）の表面に、２質量％の炭素が担持されたリチウム系ポリアニオン粒子（ＬｉＭｎ0.7Ｆｅ0.3ＰＯ4）が複合化されたリチウムイオン二次電池用正極活物質複合体（Ｄ－１１）（リチウム複合酸化物二次粒子：リチウム正極活物質粒子＝４０：６０（質量比）、平均粒径１７μｍ、タップ密度１．２ｇ／ｃｍ3、リチウム正極活物質粒子による担持層の厚さ：３．５μｍ）を得た。
[Comparative Example 11: 40% by mass of lithium composite oxide secondary particles (A-1) + 60% by mass of lithium positive electrode active material particles (B-1)]
Lithium composite oxide secondary was prepared in the same manner as in Example 1 except that 300 g of lithium composite particles (A-1) was changed to 200 g and 200 g of lithium positive electrode active material particles (B-1) was changed to 300 g. A positive electrode active material for lithium ion secondary batteries in which lithium-based polyanion particles (LiMn 0.7 Fe 0.3 PO 4 ) with 2% by mass of carbon supported on the surface of particles (LiNi 0.33 Co 0.33 Mn 0.34 O 2 ) are composited. Composite (D-11) (lithium composite oxide secondary particles: lithium positive electrode active material particles = 40:60 (mass ratio), average particle size 17 μm, tap density 1.2 g/cm 3 , lithium positive electrode active material particles) The thickness of the support layer: 3.5 μm) was obtained.
以上の全ての実施例及び比較例について、得られたリチウムイオン二次電池用正極活物質複合体の構成を表１に示す。 Table 1 shows the configurations of the positive electrode active material composites for lithium ion secondary batteries obtained for all of the above Examples and Comparative Examples.
≪正極の製造≫
実施例１～１３、及び比較例１～１１で得られた全てのリチウムイオン二次電池用正極活物質複合体を正極活物質として用い、リチウムイオン二次電池の正極を作製した。具体的には、得られた各リチウムイオン二次電池用正極活物質複合体、ケッチェンブラック、ポリフッ化ビニリデンを質量比９０：５：５の配合割合で混合し、これにＮ－メチル－２－ピロリドンを加えて充分混練し、正極スラリーを調製した。正極スラリーを厚さ２０μｍのアルミニウム箔からなる集電体に塗工機を用いて塗布し、８０℃で１２時間の真空乾燥を行った。その後、φ１４ｍｍの円盤状に打ち抜いてハンドプレスを用いて１６ＭＰａで２分間プレスして正極とした。
≪Manufacture of positive electrode≫
All of the positive electrode active material composites for lithium ion secondary batteries obtained in Examples 1 to 13 and Comparative Examples 1 to 11 were used as positive electrode active materials to produce positive electrodes for lithium ion secondary batteries. Specifically, each of the obtained positive electrode active material composites for lithium ion secondary batteries, Ketjen Black, and polyvinylidene fluoride were mixed at a mass ratio of 90:5:5, and N-methyl-2 - Pyrrolidone was added and thoroughly kneaded to prepare a positive electrode slurry. The positive electrode slurry was applied to a current collector made of aluminum foil with a thickness of 20 μm using a coating machine, and vacuum-dried at 80° C. for 12 hours. Thereafter, it was punched into a disk shape of 14 mm in diameter and pressed using a hand press at 16 MPa for 2 minutes to obtain a positive electrode.
≪二次電池の製造≫
次いで、上記正極を用いてコイン型二次電池を構築した。負極には、φ１５ｍｍに打ち抜いたリチウム箔を用いた。電解液には、エチレンカーボネート及びエチルメチルカーボネートを体積比３：７の割合で混合した混合溶媒に、ＬｉＰＦ6を１ｍｏｌ／Ｌの濃度で溶解したものを用いた。セパレータには、ポリプロピレンを用いた。これらの電池部品を露点が－５０℃以下の雰囲気で常法により組み込み収容し、コイン型二次電池（ＣＲ－２０３２）を得た。
≪Manufacture of secondary batteries≫
Next, a coin-type secondary battery was constructed using the positive electrode. A lithium foil punched to a diameter of 15 mm was used as the negative electrode. The electrolytic solution was prepared by dissolving LiPF 6 at a concentration of 1 mol/L in a mixed solvent of ethylene carbonate and ethyl methyl carbonate at a volume ratio of 3:7. Polypropylene was used for the separator. These battery parts were assembled and housed in an atmosphere with a dew point of −50° C. or lower by a conventional method to obtain a coin-type secondary battery (CR-2032).
≪高温サイクル特性の評価≫
得られた二次電池を用い、高温サイクル特性を評価した。具体的には、電流密度１７０ｍＡ／ｇ、電圧４．５Ｖの定電流充電後に、電流密度１７０ｍＡ／ｇ、終止電圧３．０Ｖの定電流放電を行い、放電容量測定装置（ＨＪ－１００１ＳＤ８、北斗電工（株）製）を用い、気温５０℃環境での、１Ｃ（１７０ｍＡｈ／ｇ）における放電容量を測定した。また、上記充放電サイクルを５０サイクル繰返し、下記式（１２）により高温サイクル特性（％）を求めた。
評価結果を表２に示す。
高温サイクル特性（％）＝（５０サイクル目の放電容量）／
（５０サイクル中の最大の放電容量）×１００ ・・・（１２）
≪Evaluation of high temperature cycle characteristics≫
Using the obtained secondary battery, high temperature cycle characteristics were evaluated. Specifically, after constant current charging with a current density of 170 mA/g and a voltage of 4.5 V, constant current discharging with a current density of 170 mA/g and a final voltage of 3.0 V was performed, and a discharge capacity measuring device (HJ-1001SD8, Hokuto Denko The discharge capacity at 1 C (170 mAh/g) was measured using a battery manufactured by INC. Co., Ltd. in an environment with a temperature of 50°C. Further, the above charge/discharge cycle was repeated 50 times, and high temperature cycle characteristics (%) were determined using the following formula (12).
The evaluation results are shown in Table 2.
High temperature cycle characteristics (%) = (discharge capacity at 50th cycle) /
(Maximum discharge capacity during 50 cycles) x 100 (12)
≪電極からの遷移金属溶出の評価≫
上記の高温サイクル特性の評価に用いた二次電池を解体し、取り出した正極を炭酸ジメチルで洗浄後、上記二次電池の製造で用いたものと同じ電解液に浸して、７０℃で１週間、密閉容器中に静置した。
静置後、正極を取り出した電解液を０．４５μｍのディスミックフィルタで濾過し、硝酸により酸分解した。酸分解した電解液に含まれるリチウム複合酸化物二次粒子由来のＭｎ、Ｎｉ、Ｃｏを、ＩＣＰ発光分光法を用いて定量した。
測定結果を表３に示す。
≪Evaluation of transition metal elution from electrodes≫
The secondary battery used for the evaluation of high-temperature cycle characteristics above was disassembled, the positive electrode taken out was washed with dimethyl carbonate, and then immersed in the same electrolyte solution used in the manufacture of the above secondary battery at 70°C for one week. , and left in a closed container.
After standing still, the electrolytic solution from which the positive electrode was taken out was filtered through a 0.45 μm dismic filter and acid-decomposed with nitric acid. Mn, Ni, and Co derived from lithium composite oxide secondary particles contained in the acid-decomposed electrolyte were quantified using ICP emission spectroscopy.
The measurement results are shown in Table 3.
表２～３から明らかなように、実施例で得られたリチウムイオン二次電池用正極活物質複合体を使用したリチウムイオン二次電池は、比較例で得られたリチウムイオン二次電池に比べ、正極活物質に含まれるリチウム複合酸化物二次粒子からの遷移金属溶出量を有効に抑制し、優れた高温サイクル特性を発現することがわかる。
これは、実施例のリチウムイオン二次電池用正極活物質複合体が、リチウム複合酸化物二次粒子が固体電解質と正極活物質粒子によって重層的に被覆又は担持されてなることから、高温下におけるリチウム複合酸化物の結晶構造の崩壊が抑制されているためと推定される。
As is clear from Tables 2 and 3, the lithium ion secondary batteries using the positive electrode active material composites for lithium ion secondary batteries obtained in the examples were compared with the lithium ion secondary batteries obtained in the comparative examples. It can be seen that the amount of transition metal eluted from the lithium composite oxide secondary particles contained in the positive electrode active material is effectively suppressed, and excellent high-temperature cycle characteristics are exhibited.
This is because the positive electrode active material composite for lithium ion secondary batteries of the example is composed of lithium composite oxide secondary particles covered or supported in a multilayered manner by a solid electrolyte and positive electrode active material particles, so that it can withstand high temperatures. This is presumed to be because the collapse of the crystal structure of the lithium composite oxide is suppressed.
また、比較例１０及び比較例１１からは、リチウム複合粒子（Ａ）の含有量と、リチウム正極活物質粒子（Ｂ）の含有量との質量比（（Ａ）：（Ｂ））が９５：５～５０：５０の範囲外であると、放電容量が低下するか、容量保持率が低下してしまうこともわかる。 Moreover, from Comparative Examples 10 and 11, the mass ratio ((A):(B)) of the content of lithium composite particles (A) and the content of lithium positive electrode active material particles (B) was 95: It can also be seen that when the ratio is outside the range of 5 to 50:50, the discharge capacity or capacity retention rate decreases.
Claims (6)
リチウム複合粒子（Ａ）は、下記式（１）、又は式（２）：
ＬｉＮｉaＣｏbＭｎcＭ1 vＯ2・・・（１）
（式（１）中、Ｍ1はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ａ、ｂ、ｃ、ｖは、０．３≦ａ＜１、０＜ｂ≦０．７、０＜ｃ≦０．７、０≦ｖ≦０．３、かつ３ａ＋３ｂ＋３ｃ＋（Ｍ1の価数）×ｖ＝３を満たす数を示す。）
ＬｉＮｉdＣｏeＡｌfＭ2 wＯ2 ・・・（２）
（式（２）中、Ｍ2はＭｇ、Ｔｉ、Ｎｂ、Ｆｅ、Ｃｒ、Ｓｉ、Ｇａ、Ｖ、Ｚｎ、Ｃｕ、Ｓｒ、Ｍｏ、Ｚｒ、Ｓｎ、Ｔａ、Ｗ、Ｌａ、Ｃｅ、Ｐｂ、Ｂｉ及びＧｅから選ばれる１種又は２種以上の元素を示す。ｄ、ｅ、ｆ、ｗは、０．４≦ｄ＜１、０＜ｅ≦０．６、０＜ｆ≦０．３、０≦ｗ≦０．３、かつ３ｄ＋３ｅ＋３ｆ＋（Ｍ2の価数）×ｗ＝３を満たす数を示す。）
で表されるリチウム複合酸化物粒子からなるリチウム複合酸化物二次粒子（ａ）の表面を、
Ｌｉ 1.3 Ａｌ 0.3 Ｔｉ 1.7 （ＰＯ 4 ） 3
で表されるリチウム系固体電解質（ｂ）が被覆してなる粒子であり、
リチウム正極活物質粒子（Ｂ）は、下記式（５）、又は式（６）：
ＬｉjＭｎkＦｅlＭ5 yＰＯ4 ・・・（５）
（式（５）中、Ｍ5はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ又はＧｄを示す。ｊ、ｋ、ｌ、及びｙは、０＜ｊ≦１．２、０．３≦ｋ≦１、０≦ｌ≦０．７、及び０≦ｙ≦０．３を満たし、かつｊ＋（Ｍｎの価数）×ｋ＋（Ｆｅの価数）×ｌ＋（Ｍ5の価数）×ｙ＝３を満たす数を示す。）
ＬｉmＭｎnＦｅoＭ6 zＳｉＯ4 ・・・（６）
（式（６）中、Ｍ6はＣｏ、Ｎｉ、Ｃａ、Ｓｒ、Ｙ、Ｚｒ、Ｍｏ、Ｂａ、Ｐｂ、Ｂｉ、Ｌａ、Ｃｅ、Ｎｄ、Ａｌ、Ｚｎ、Ｖ又はＧｄを示す。ｍ、ｎ、ｏ、及びｚは、０＜ｍ≦２．４、０≦ｎ≦１．２、０≦ｏ≦１．２、０≦ｚ≦１．２、及びｎ＋ｏ≠０を満たし、かつｍ＋（Ｍｎの価数）×ｎ＋（Ｆｅの価数）×ｏ＋（Ｍ6の価数）×ｚ＝４を満たす数を示す。）
で表されるいずれか１種以上の粒子である、リチウムイオン二次電池用正極活物質複合体。 Lithium positive electrode active material particles (B) are supported on the surface of lithium composite particles (A), and the mass ratio of lithium composite particles (A) to lithium positive electrode active material particles (B) ((A):(B) )) is 95:5 to 90:10 , the positive electrode active material composite for a lithium ion secondary battery,
The lithium composite particles (A) have the following formula (1) or formula (2):
LiNia Co b Mn c M 1 v O 2 ...(1)
(In formula (1), M 1 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. a, b, c, v are 0.3≦a<1, 0<b≦0.7, 0<c≦0.7, 0≦ Indicates a number that satisfies v≦0.3 and 3a+3b+3c+(valence of M1 )×v=3.)
LiNi d Co e Al f M 2 w O 2 ...(2)
(In formula (2), M2 is Mg, Ti, Nb, Fe, Cr, Si, Ga, V, Zn, Cu, Sr, Mo, Zr, Sn, Ta, W, La, Ce, Pb, Bi, and Represents one or more elements selected from Ge. d, e, f, w are 0.4≦d<1, 0<e≦0.6, 0<f≦0.3, 0≦ Indicates a number that satisfies w≦0.3 and 3d+3e+3f+(valence of M2 )×w=3.)
The surface of lithium composite oxide secondary particles (a) consisting of lithium composite oxide particles represented by
Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3
Particles coated with a lithium-based solid electrolyte (b) represented by
The lithium positive electrode active material particles (B) have the following formula (5) or formula (6) :
Li j Mn k Fe l M 5 y PO 4 ...(5)
(In formula (5), M 5 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, or Gd. j, k, l, and y are 0<j≦1.2, 0.3≦k≦1, 0≦l≦0.7, and 0≦y≦0.3, and j+(valence of Mn)×k+(valence of Fe )×l+(valence of M5 )×y=3.)
Li m Mn n Fe o M 6 z SiO 4 ...(6)
(In formula (6), M 6 represents Co, Ni, Ca, Sr, Y, Zr, Mo, Ba, Pb, Bi, La, Ce, Nd, Al, Zn, V or Gd. m, n, o and z satisfy 0<m≦2.4, 0≦n≦1.2, 0≦o≦1.2, 0≦z≦1.2, and n+o≠0, and m+(Mn (Valency) x n + (Fe valence) x o + (M 6 valence) x z = 4.)
A positive electrode active material composite for a lithium ion secondary battery, which is any one or more particles represented by :
（Ｉ）リチウム系固体電解質（ｂ）の原料となる水溶性化合物が溶解した水溶液にリチウム複合酸化物二次粒子（ａ）を混合した後、噴霧乾燥して、リチウム系固体電解質（ｂ）の原料化合物を表面に担持したリチウム複合酸化物二次粒子（ａ）からなる複合体（ｄ）を得る工程、
（II）得られた複合体（ｄ）を、酸素雰囲気下、６００℃～１０００℃で３０分間～６時間焼成して、リチウム複合酸化物二次粒子（ａ）の表面をリチウム系固体電解質（ｂ）が被覆してなるリチウム複合粒子（Ａ）を得る工程、
（III）リチウム正極活物質粒子（Ｂ）を含むスラリーを熱風の供給量Ｇ（Ｌ／分）と、スラリーの供給量Ｓ（Ｌ／分）の比（Ｇ／Ｓ）＝５００～１００００にて噴霧乾燥して、崩壊強度が１．８ＫＮ／ｍｍ以下であるリチウム正極活物質粒子（Ｂ）の造粒体（ｅ）を得る工程、並びに
（IV）リチウム複合粒子（Ａ）及び造粒体（ｅ）を、圧縮力及びせん断力を付加しながら混合して、造粒体（ｅ）を解砕させながら、リチウム複合粒子（Ａ）とリチウム正極活物質粒子（Ｂ）とを複合化する工程
を備える、請求項１～４のいずれか１項に記載のリチウムイオン二次電池用正極活物質複合体の製造方法。 Next steps (I) to (IV):
(I) After mixing the lithium composite oxide secondary particles (a) with an aqueous solution containing a water-soluble compound that is a raw material for the lithium-based solid electrolyte (b), the mixture is spray-dried to form the lithium-based solid electrolyte (b). A step of obtaining a composite (d) consisting of lithium composite oxide secondary particles (a) carrying a raw material compound on the surface,
(II) The obtained composite (d) is fired in an oxygen atmosphere at 600°C to 1000°C for 30 minutes to 6 hours to change the surface of the lithium composite oxide secondary particles (a) to a lithium-based solid electrolyte ( b) obtaining lithium composite particles (A) coated with
(III) The slurry containing the lithium positive electrode active material particles (B) is prepared at a ratio (G/S) of the supply amount G (L/min) of hot air to the supply amount S (L/min) of the slurry = 500 to 10,000. Spray drying to obtain granules (e) of lithium positive electrode active material particles (B) having a collapse strength of 1.8 KN/mm or less , and (IV) lithium composite particles (A) and granules ( e) is mixed while applying compressive force and shear force, and the granules (e) are crushed to form a composite of the lithium composite particles (A) and the lithium positive electrode active material particles (B). A method for producing a positive electrode active material composite for a lithium ion secondary battery according to any one of claims 1 to 4, comprising:
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| JP2018517243A (en) | 2015-04-30 | 2018-06-28 | エルジー・ケム・リミテッド | Positive electrode active material for lithium secondary battery, method for producing the same, and lithium secondary battery including the same |
| JP2019033016A (en) | 2017-08-09 | 2019-02-28 | 太平洋セメント株式会社 | Cathode active material for lithium ion secondary battery or cathode active material for sodium ion secondary battery, and manufacturing method thereof |
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| JP2018517243A (en) | 2015-04-30 | 2018-06-28 | エルジー・ケム・リミテッド | Positive electrode active material for lithium secondary battery, method for producing the same, and lithium secondary battery including the same |
| JP2019033016A (en) | 2017-08-09 | 2019-02-28 | 太平洋セメント株式会社 | Cathode active material for lithium ion secondary battery or cathode active material for sodium ion secondary battery, and manufacturing method thereof |
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