WO2022048346A1 - Vanadium pentoxide/rgo-coated lithium nickel cobalt manganese oxide positive electrode material and preparation method therefor - Google Patents
Vanadium pentoxide/rgo-coated lithium nickel cobalt manganese oxide positive electrode material and preparation method therefor Download PDFInfo
- Publication number
- WO2022048346A1 WO2022048346A1 PCT/CN2021/108587 CN2021108587W WO2022048346A1 WO 2022048346 A1 WO2022048346 A1 WO 2022048346A1 CN 2021108587 W CN2021108587 W CN 2021108587W WO 2022048346 A1 WO2022048346 A1 WO 2022048346A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- nickel
- cobalt
- rgo
- vanadium pentoxide
- manganese
- Prior art date
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- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 title claims abstract description 260
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 66
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 title claims abstract description 10
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 title abstract 6
- 229910013716 LiNi Inorganic materials 0.000 claims abstract description 51
- 239000002131 composite material Substances 0.000 claims abstract description 31
- 239000002245 particle Substances 0.000 claims abstract description 21
- 239000010410 layer Substances 0.000 claims abstract description 15
- 239000011247 coating layer Substances 0.000 claims abstract description 10
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000000126 substance Substances 0.000 claims abstract description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 130
- 239000011572 manganese Substances 0.000 claims description 76
- 229910052759 nickel Inorganic materials 0.000 claims description 65
- 239000000463 material Substances 0.000 claims description 62
- 239000000243 solution Substances 0.000 claims description 47
- 238000006243 chemical reaction Methods 0.000 claims description 44
- 239000010406 cathode material Substances 0.000 claims description 38
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 claims description 36
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 claims description 30
- 238000003756 stirring Methods 0.000 claims description 29
- 238000005245 sintering Methods 0.000 claims description 26
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 24
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 23
- 239000010941 cobalt Substances 0.000 claims description 23
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 23
- 229910052748 manganese Inorganic materials 0.000 claims description 21
- 239000011259 mixed solution Substances 0.000 claims description 21
- 229910052720 vanadium Inorganic materials 0.000 claims description 21
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 21
- 229910021389 graphene Inorganic materials 0.000 claims description 20
- 239000012298 atmosphere Substances 0.000 claims description 17
- 229910017052 cobalt Inorganic materials 0.000 claims description 17
- 238000001035 drying Methods 0.000 claims description 16
- 239000002243 precursor Substances 0.000 claims description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 15
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 15
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 13
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 12
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical group [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 12
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 claims description 12
- SEVNKUSLDMZOTL-UHFFFAOYSA-H cobalt(2+);manganese(2+);nickel(2+);hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mn+2].[Co+2].[Ni+2] SEVNKUSLDMZOTL-UHFFFAOYSA-H 0.000 claims description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 11
- 229910052744 lithium Inorganic materials 0.000 claims description 11
- 239000008367 deionised water Substances 0.000 claims description 10
- 229910021641 deionized water Inorganic materials 0.000 claims description 10
- 239000003960 organic solvent Substances 0.000 claims description 10
- 238000004729 solvothermal method Methods 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical group [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 9
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 9
- 230000032683 aging Effects 0.000 claims description 9
- 238000000975 co-precipitation Methods 0.000 claims description 9
- 239000011258 core-shell material Substances 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 230000007423 decrease Effects 0.000 claims description 8
- 150000004677 hydrates Chemical class 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 7
- 238000005406 washing Methods 0.000 claims description 7
- 229910021529 ammonia Inorganic materials 0.000 claims description 6
- 150000001868 cobalt Chemical class 0.000 claims description 6
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 claims description 6
- 229910001429 cobalt ion Inorganic materials 0.000 claims description 6
- 229910001981 cobalt nitrate Inorganic materials 0.000 claims description 6
- 229910001437 manganese ion Inorganic materials 0.000 claims description 6
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 claims description 6
- 150000002815 nickel Chemical class 0.000 claims description 6
- 229910001453 nickel ion Inorganic materials 0.000 claims description 6
- 239000002244 precipitate Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 239000000706 filtrate Substances 0.000 claims description 5
- FSJSYDFBTIVUFD-SUKNRPLKSA-N (z)-4-hydroxypent-3-en-2-one;oxovanadium Chemical compound [V]=O.C\C(O)=C\C(C)=O.C\C(O)=C\C(C)=O FSJSYDFBTIVUFD-SUKNRPLKSA-N 0.000 claims description 4
- 229910000361 cobalt sulfate Inorganic materials 0.000 claims description 4
- 229940044175 cobalt sulfate Drugs 0.000 claims description 4
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical group [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 claims description 4
- 238000004108 freeze drying Methods 0.000 claims description 4
- 150000002696 manganese Chemical class 0.000 claims description 4
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical group [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 claims description 4
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 claims description 4
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 4
- 230000001681 protective effect Effects 0.000 claims description 4
- PPPKZBCCLMQHSN-UHFFFAOYSA-N [Co++].[Ni++].[O-][Mn]([O-])(=O)=O.[O-][Mn]([O-])(=O)=O Chemical compound [Co++].[Ni++].[O-][Mn]([O-])(=O)=O.[O-][Mn]([O-])(=O)=O PPPKZBCCLMQHSN-UHFFFAOYSA-N 0.000 claims description 3
- 239000012300 argon atmosphere Substances 0.000 claims description 3
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 claims description 3
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 3
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 3
- 229940099596 manganese sulfate Drugs 0.000 claims description 3
- 239000011702 manganese sulphate Substances 0.000 claims description 3
- 235000007079 manganese sulphate Nutrition 0.000 claims description 3
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 claims description 3
- MFWFDRBPQDXFRC-LNTINUHCSA-N (z)-4-hydroxypent-3-en-2-one;vanadium Chemical compound [V].C\C(O)=C\C(C)=O.C\C(O)=C\C(C)=O.C\C(O)=C\C(C)=O MFWFDRBPQDXFRC-LNTINUHCSA-N 0.000 claims description 2
- 229910021380 Manganese Chloride Inorganic materials 0.000 claims description 2
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 claims description 2
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 claims description 2
- SOXUFMZTHZXOGC-UHFFFAOYSA-N [Li].[Mn].[Co].[Ni] Chemical compound [Li].[Mn].[Co].[Ni] SOXUFMZTHZXOGC-UHFFFAOYSA-N 0.000 claims description 2
- MQRWBMAEBQOWAF-UHFFFAOYSA-N acetic acid;nickel Chemical compound [Ni].CC(O)=O.CC(O)=O MQRWBMAEBQOWAF-UHFFFAOYSA-N 0.000 claims description 2
- 229940011182 cobalt acetate Drugs 0.000 claims description 2
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 claims description 2
- QAHREYKOYSIQPH-UHFFFAOYSA-L cobalt(II) acetate Chemical compound [Co+2].CC([O-])=O.CC([O-])=O QAHREYKOYSIQPH-UHFFFAOYSA-L 0.000 claims description 2
- 229940071125 manganese acetate Drugs 0.000 claims description 2
- 239000011565 manganese chloride Substances 0.000 claims description 2
- 235000002867 manganese chloride Nutrition 0.000 claims description 2
- 229940099607 manganese chloride Drugs 0.000 claims description 2
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 claims description 2
- 229940078494 nickel acetate Drugs 0.000 claims description 2
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 claims description 2
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims 2
- 229910001947 lithium oxide Inorganic materials 0.000 claims 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims 1
- CXULZQWIHKYPTP-UHFFFAOYSA-N cobalt(2+) manganese(2+) nickel(2+) oxygen(2-) Chemical compound [O--].[O--].[O--].[Mn++].[Co++].[Ni++] CXULZQWIHKYPTP-UHFFFAOYSA-N 0.000 claims 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 claims 1
- 239000001257 hydrogen Substances 0.000 claims 1
- 229910052739 hydrogen Inorganic materials 0.000 claims 1
- 229910017604 nitric acid Inorganic materials 0.000 claims 1
- 239000011248 coating agent Substances 0.000 abstract description 33
- 238000000576 coating method Methods 0.000 abstract description 33
- 238000000034 method Methods 0.000 abstract description 26
- 238000009776 industrial production Methods 0.000 abstract description 7
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 4
- 238000004873 anchoring Methods 0.000 abstract description 2
- 229910015680 LiNi0.84Co0.11Mn0.05O2 Inorganic materials 0.000 description 49
- 230000008569 process Effects 0.000 description 18
- 238000012360 testing method Methods 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 14
- 150000002500 ions Chemical class 0.000 description 10
- 239000011163 secondary particle Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 238000007599 discharging Methods 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 230000014759 maintenance of location Effects 0.000 description 6
- 230000002441 reversible effect Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 5
- 239000010416 ion conductor Substances 0.000 description 5
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000001351 cycling effect Effects 0.000 description 4
- 239000011532 electronic conductor Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
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- 239000002002 slurry Substances 0.000 description 4
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 3
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- 229910052786 argon Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
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- 229940053662 nickel sulfate Drugs 0.000 description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 3
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 238000003917 TEM image Methods 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
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- PQVSTLUFSYVLTO-UHFFFAOYSA-N ethyl n-ethoxycarbonylcarbamate Chemical compound CCOC(=O)NC(=O)OCC PQVSTLUFSYVLTO-UHFFFAOYSA-N 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- AWKHTBXFNVGFRX-UHFFFAOYSA-K iron(2+);manganese(2+);phosphate Chemical compound [Mn+2].[Fe+2].[O-]P([O-])([O-])=O AWKHTBXFNVGFRX-UHFFFAOYSA-K 0.000 description 2
- GLXDVVHUTZTUQK-UHFFFAOYSA-M lithium hydroxide monohydrate Substances [Li+].O.[OH-] GLXDVVHUTZTUQK-UHFFFAOYSA-M 0.000 description 2
- 229940040692 lithium hydroxide monohydrate Drugs 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
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- 230000001105 regulatory effect Effects 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
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- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
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- OVAQODDUFGFVPR-UHFFFAOYSA-N lithium cobalt(2+) dioxido(dioxo)manganese Chemical compound [Li+].[Mn](=O)(=O)([O-])[O-].[Co+2] OVAQODDUFGFVPR-UHFFFAOYSA-N 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
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- 239000011435 rock Substances 0.000 description 1
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- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/198—Graphene oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G31/00—Compounds of vanadium
- C01G31/02—Oxides
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/40—Nickelates
- C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
- C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
- C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
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- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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Definitions
- the invention relates to a nickel-cobalt lithium manganate cathode material and a preparation method, in particular to a vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate cathode material and a preparation method.
- CN109888257A discloses a graphene-coated modified lithium-ion battery positive electrode material and a preparation method. After mixing graphene-Mn/lithium manganese iron phosphate slurry, ternary material slurry and polyvinylidene fluoride, ultrasonic stirring , and then, the mixed liquid is coated on the surface of the aluminum foil and dried to prepare a ternary positive electrode.
- graphite oxide needs to be added to deionized water, and then graphene-Mn/lithium iron manganese phosphate slurry is obtained by adding potassium permanganate and lithium iron phosphate.
- the control conditions are relatively strict, and It needs to be processed for many times, and the purity of the obtained graphene is low, which is not effective for the subsequent graphene coating of the ternary material.
- CN110311136A discloses a method for coating ternary positive electrode material of lithium ion battery with graphene, which is to use graphene slurry to mix with positive electrode active material, although this method can disperse graphene more uniformly among the particles of ternary positive electrode material , but the ternary material is exposed to the liquid phase environment for a long time during the operation process, which has a great impact on the structure of the ternary material itself, and is difficult to achieve in industrial production.
- CN 109980219A discloses a full-gradient nickel-cobalt-manganese positive electrode material, a ruthenium oxide coating material and a preparation method thereof.
- a ruthenium-containing compound is generated in an ammonia atmosphere to coat the surface of the full-gradient nickel-cobalt-manganese positive electrode material.
- the surface hydroxide coating is further decomposed into ruthenium oxide after re-sintering. This method involves a wet chemical reaction.
- the structure of the nickel-cobalt-manganese cathode material is prone to change in a wet environment.
- the ruthenium oxide used for the coating is expensive, and is generally difficult to be widely used in industrial production.
- the technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and to provide a kind of high lithium ion and electron conductivity in the charging and discharging process, and good structural stability, thermal stability, rate performance and long cycle stability. , a highly reversible charge-discharge reaction of vanadium pentoxide/rGO-coated nickel cobalt lithium manganate cathode material.
- the further technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and to provide a vanadium pentoxide/rGO package which is simple and controllable, has a short technological process, good coating effect and low cost, and is suitable for industrial production.
- the invention discloses a preparation method of a nickel-coated cobalt lithium manganate cathode material.
- vanadium pentoxide/rGO coats nickel cobalt lithium manganate positive electrode material, and the positive electrode material is formed by vanadium pentoxide/rGO coat nickel cobalt lithium manganate Spherical core-shell structure particles; the mass ratio of the vanadium pentoxide/rGO to lithium nickel cobalt manganate is 0.01-0.05:1; the chemical formula of the lithium nickel cobalt manganate is LiNi x Co y Mn (1-xy) O 2 , wherein 0.75 ⁇ x ⁇ 0.85 (more preferably 0.80 ⁇ x ⁇ 0.84), 0.05 ⁇ y ⁇ 0.15 (more preferably 0.08 ⁇ y ⁇ 0.12), 1-xy>0; the vanadium pentoxide/rGO composite material The overall coating layer is formed by anchoring vanadium pentoxide between rGO layers, and the mass ratio of vanadium pentoxide to rGO is 1-3:1.
- the biggest disadvantage of high-nickel materials is the poor structural stability and high-temperature performance, and the surface particles are prone to the following phenomena: the phase transition process of layered structure-spinel structure-inactive rock, resulting in capacity and cycle performance degradation.
- Vanadium pentoxide and rGO are used as ionic conductors and electronic conductors, respectively.
- the electrochemical performance will be improved to varying degrees.
- the ionic conductivity during charging and discharging can be improved, and the ionic conductivity caused by the cycle can be overcome.
- the problem of poor ionic conductivity during the phase transition process is unfavorable.
- the coating of electronic conductor rGO can ensure the rapid deintercalation reaction during cycling, especially under the condition of high rate, the electrochemical performance of the material can be significantly improved after coating with rGO.
- the present invention innovatively proposes that the ion conductor and electronic conductor vanadium pentoxide/rGO composite material coat the positive electrode material, so that it can play a synergistic contribution role in the cycle process. During the cycling process, the material can not only improve the cycle stability, but also ensure the rapid de-intercalation reaction of the layered structure material, showing excellent electrochemical performance.
- the surface coating can improve the ion mobility or electronic conductivity of the material, inhibit the phase transition, increase the stability of the material structure, reduce the dissolution of transition metals in the active material, and can also remove HF, It is conducive to the formation of a solid electrolyte interface film (SEI) on the electrode surface, reducing the electrode resistance and the occurrence of side reactions and heat generation during cycling, thereby significantly improving the cycle life, rate capability, reversible capacity and first Coulombic efficiency of the material.
- SEI solid electrolyte interface film
- rGO in the present invention is an abbreviation of reduced graphene oxide.
- the nickel-cobalt lithium manganate is a full gradient material, the content of nickel gradually decreases from the center to the surface of nickel-cobalt lithium manganate, and the content of manganese gradually increases from the center to the surface of nickel-cobalt lithium manganate, The content of cobalt element is uniformly distributed in the nickel cobalt lithium manganate.
- the average particle size of the vanadium pentoxide/rGO-coated nickel cobalt lithium manganate cathode material is 4-8 ⁇ m.
- the precursors have good morphology and uniform dispersion.
- the average thickness of the vanadium pentoxide/rGO is 3-6 nm.
- the coating layer should not be too thick, and an excessively thick coating layer will affect the first charge-discharge efficiency of the positive electrode material.
- the preparation method of vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate positive electrode material comprises the following steps:
- step (3) after the full gradient nickel cobalt manganese hydroxide precursor obtained in step (2) is mixed and ground with a lithium source, two-stage sintering is performed in an oxidizing atmosphere, and cooled to room temperature to obtain a full gradient nickel cobalt manganese lithium material. ;
- step (3) after rotating and stirring the vanadium pentoxide/rGO composite material obtained in step (1) and the full gradient nickel-cobalt-manganate material obtained in step (3), drying to obtain vanadium pentoxide/rGO coated nickel-cobalt-manganese Lithium oxide cathode material.
- the mass-to-volume ratio (g/g/L) of the graphene oxide, the vanadium source and the organic solvent is 0.1-0.4:0.7-1.0:1. If the graphene oxide is too much and the vanadium source is too small, it mainly reflects the coating effect of the electronic conductor. If the graphene oxide is too small and the vanadium source is too much, the ionic conductor function is mainly reflected. Synergistic coating of ionic and electronic conductors. If the amount of the organic solvent is too small, the vanadium source cannot be completely dissolved and dispersed. If the amount of the organic solvent is too much, the proportion will be out of balance and the solvent will be wasted.
- the vanadium source is one or more of vanadyl acetylacetonate, vanadium acetylacetonate or ammonium metavanadate, etc.
- the organic solvent is N-N dimethylformamide or the like.
- the frequency of the ultrasonic dispersion is 1.5-2.5 kHz, and the time is 0.5-1.0 h.
- the ultrasonic dispersion is mainly for the uniform dispersion of the vanadium source in the organic solvent and uniform attachment to the rGO surface after diffusion. If the ultrasonic dispersion time is too long, the structure of rGO will be damaged and resources will be wasted. If the ultrasonic dispersion time is too short, it is difficult to achieve the effect of uniform dispersion.
- the stirring speed of the solvothermal reaction is 300-500 r/min, the temperature is 150-250°C, and the time is 12-24 h.
- the low-temperature reduction reaction of graphene oxide mainly occurs, and a solvothermal reaction at a certain temperature and time in an organic solvent can obtain rGO with a complete structure, and the dispersed vanadium source will not be affected under this condition. If the temperature is too high or the time is too long, the vanadium source will change, and the structure of rGO will be destroyed. If the temperature is too low or the time is too short, it is difficult to obtain satisfactory rGO.
- step (1) the stirring and cooling can make the dispersion of the vanadium pentoxide/rGO composite material uniform and consistent.
- the centrifugal washing is to use deionized water and anhydrous ethanol to successively cross-centrifuge and wash the precipitate for ⁇ 6 times.
- the drying is freeze-drying.
- the composites after solvothermal reaction were lyophilized to remove the solvent.
- the vacuum degree of the freeze-drying is 80-100 Pa, the temperature is -40--50°C, and the time is 24-40 h.
- the sintering is carried out at a rate of 1-10° C./min (more preferably 3-7° C./min) to raise the temperature to 300-500° C., and sintering for 1-3 hours.
- the oxidative decomposition reaction of the vanadium source mainly occurred, and the generated vanadium pentoxide could be more uniformly and firmly anchored on the surface of the rGO layer.
- the sintering temperature is too low, the decomposition reaction of the vanadium source will be incomplete.
- the sintering temperature is too high, the composites will be separated; if the sintering time is too short, the decomposed vanadium pentoxide will not be evenly distributed in the rGO layer.
- the feeding rate of the low nickel content nickel-cobalt-manganese solution is 30-70 mL/h (more preferably 40-60 mL/h).
- the feeding rate of the mixed solution is 80-120 mL/h (more preferably 90-110 mL/h).
- the feeding speed is too fast, it will lead to a large range of pH variation, making it difficult for the precipitant to effectively precipitate metal ions, which is not conducive to controlling the formation and growth of crystal nuclei during the reaction process. If the feeding speed is too slow, the particles are easy to agglomerate , and is not conducive to improving production efficiency.
- the total molar concentration of nickel, cobalt and manganese ions is 0.3-3.0 mol/L (more preferably 1.5-2.5 mol/L), nickel, The molar ratio of cobalt and manganese is 3 ⁇ 8:1:0 ⁇ 2. If the total molar concentration of nickel, cobalt and manganese ions is too low, the precipitation time will be longer, which is not conducive to improving production efficiency. The settling effect is not good.
- the total molar concentration of nickel, cobalt and manganese ions is 0.3-4.0 mol/L (more preferably 1.5-2.5 mol/L) , the molar ratio of nickel, cobalt and manganese is 8-9:0.5-1.0:0-1. If the total molar concentration of nickel, cobalt and manganese ions is too low, the precipitation time will be longer, which is not conducive to improving production efficiency. The settling effect is not good.
- the nickel content of the low nickel content nickel cobalt manganese solution is lower than the nickel content of the high nickel content nickel cobalt or nickel cobalt manganese solution.
- the volume ratio of ammonia solution, hydroxide precipitant solution, low nickel content nickel cobalt manganese solution and high nickel content nickel cobalt or nickel cobalt manganese solution in the reactor is 0.1 ⁇ 10:1 ⁇ 2:1:1 (more preferably 1:2:1:1). Under the feeding ratio, the initiation of coprecipitation reaction and the control of material gradient are more favorable.
- the molar concentration of the ammonia solution is 1.0-7.0 mol/L (more preferably 1.5-4.5 mol/L). If the molar concentration of the ammonia solution is too low, it is difficult for the metal ions to be completely complexed, and if the molar concentration of the ammonia solution is too high, it is unfavorable for the metal ions to form hydroxide precipitation.
- the concentration of ammonia water in the reaction system is adjusted with ammonia water to maintain at 1.0-7.0 mol/L (more preferably 1.5-4.5 mol/L).
- the mass concentration of the ammonia water used to adjust the ammonia water concentration of the reaction system is 25-28%.
- the pH value of the reaction system is adjusted to be maintained at 10-12 with a hydroxide precipitant solution. At the pH value, it is more favorable to control the particle growth rate not to be too fast or too slow.
- the molar concentration of the hydroxide precipitant solution is 1.0-7.0 mol/L (more preferably 4.0-6.0 mol/L). If the molar concentration of the hydroxide precipitant solution is too high or too low, the pH value of the reaction process cannot be accurately controlled, thereby affecting the morphology of the precursor material.
- the low nickel content nickel cobalt manganese solution and the high nickel content nickel cobalt manganese solution are mixed solutions of soluble nickel salt, soluble cobalt salt and soluble manganese salt, and the high nickel content nickel cobalt solution It is a mixed solution of soluble nickel salt and soluble cobalt salt.
- the soluble nickel salt is one or more of nickel sulfate, nickel nitrate, nickel acetate or nickel chloride, and hydrates thereof.
- the soluble cobalt salt is one or more of cobalt sulfate, cobalt nitrate, cobalt acetate or cobalt chloride, and hydrates thereof.
- the soluble manganese salt is one or more of manganese sulfate, manganese nitrate, manganese acetate or manganese chloride, and hydrates thereof.
- the hydroxide precipitation agent is one or more of sodium hydroxide, potassium hydroxide or lithium hydroxide, and hydrates thereof.
- the protective atmosphere is a nitrogen atmosphere and/or an argon atmosphere.
- the stirring speed of the co-precipitation reaction is 800-1200 r/min, the temperature is 30-70° C. (more preferably 40-60° C.), and the time is 30-50 h. If the stirring speed is too slow, the primary particles are prone to agglomeration, and if the stirring speed is too fast, the grown crystals are prone to breakage; within the temperature range, it is more conducive to the growth of crystals; the reaction time is determined by the content of the raw materials and the feeding speed. Decide.
- the aging temperature is 30-70° C. (more preferably 40-60° C.), and the time is 8-24 h.
- the aging process can replace the sulfate and other anions inside the material, and is beneficial to the uniformity of the particle surface. If the aging time is too short, it is difficult to ensure the ion exchange of anions, which will also affect the subsequent washing process. If the aging time is too long, it is not conducive to the uniformity of production application and material surface.
- the aging temperature is consistent with the co-precipitation reaction temperature, which is conducive to the uniform dispersion of the material without agglomeration, and ensures the uniform growth of primary particles into secondary particles.
- the washing is to cross-wash the filtrate with deionized water and ethanol for ⁇ 6 times respectively.
- the drying temperature is 80-100° C., and the drying time is 12-24 h. If the temperature is too low or the time is too short, the material will be difficult to dry. If the temperature is too high or the time is too long, there will be other side reactions on the surface of the material, which will affect the performance of the material, and if the cycle is too long, it is not conducive to industrial production.
- the molar ratio of the sum of moles of nickel, cobalt and manganese elements in the full gradient nickel-cobalt-manganese hydroxide precursor and the lithium element in the lithium source is 1:1.04-1.11.
- the lithium source is lithium hydroxide and/or lithium carbonate or the like.
- the oxidizing atmosphere is an air atmosphere and/or an oxygen atmosphere or the like.
- the two-stage sintering refers to: first, the temperature is raised to 350-550° C. at a rate of 1-10° C./min (more preferably 3-7° C./min), and then sintered for 2-8 hours (more preferably 3-7° C./min). After preferably 3-6h), the temperature is raised to 550-1000°C (more preferably 600-900°C) at a rate of 1-10°C/min (more preferably 3-7°C/min), and sintered for 8-20h.
- the decomposition reaction of the full gradient precursor and the lithium source mainly occurs.
- the compound reaction between the full gradient precursor and the oxide decomposed by the lithium source mainly occurs in an oxygen atmosphere. If the sintering temperature is too high or the time is too long, the material is easy to agglomerate, and it is difficult to release the capacity during the charging and discharging process. If the sintering temperature is too low or the time is too short, it is difficult to form the desired morphology and affect the electrochemical performance. If the heating rate is too fast, it is difficult to ensure that the material reacts sufficiently, and if the heating rate is too slow, it is not conducive to industrial production.
- the mass ratio of the vanadium pentoxide/rGO composite material to the nickel cobalt lithium manganate material is 0.01-0.05:1. If there are too many vanadium pentoxide/rGO composite materials, the coating layer will be too thick, which will have a negative impact on the capacity of the positive electrode material, and the cost will be too high; if the vanadium pentoxide/rGO composite material is too small, it will be difficult to achieve coating effect, and waste of raw materials.
- the rotational speed of the rotating stirring is 250-400 r/min, and the time is 8-12 h. It is easier to meet the coating requirements of the material at the said rotational speed. If the time is too long, it will damage the material structure and easily cause the material to harden. If the time is too short, it is not conducive to achieve the coating effect.
- the rotational agitation can be achieved without adding ball milling beads in the ball mill.
- the drying temperature is 80-120° C., and the drying time is 2-3 hours.
- the nitrogen, argon or oxygen used in the present invention are all high-purity gases with a purity of ⁇ 99.99%.
- the vanadium pentoxide/rGO coated nickel-cobalt lithium manganate cathode material of the present invention has no impurity-phase formation, and the secondary particles have a spherical core-shell structure with an average particle size of 4-8 ⁇ m.
- the battery assembled by the vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material of the present invention has a discharge specific capacity of up to 199mAh/g at current densities of 0.1C (20mAh/g), 5C, and 10C, respectively.
- the positive electrode material can maintain structural stability during the charge-discharge process, and the charge-discharge reaction is highly reversible; at a charge-discharge voltage of 2.7-4.3V and a current density of 1C, the first discharge ratio
- the capacity can be as high as 191.3mAh/g, and after 100 cycles, the discharge specific capacity can still reach 168.2mAh/g, and the retention rate can be as high as 87.92%. Good cycle stability;
- the method of the invention is simple and controllable, has short technological process, good coating effect and low cost, and is suitable for industrial production.
- Example 1 is the XRD pattern of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention
- Example 2 is a SEM image of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention
- Example 3 is a TEM image of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention
- Fig. 4 is the element line scan result of the focused ion beam section of the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) of Example 1 of the present invention
- Fig. 5 shows the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material coated with vanadium pentoxide/rGO in Example 1 of the present invention and the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) in Example 1 of the present invention (for XPS diagram of scale 1);
- Example 6 is a rate curve diagram of a battery assembled by vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Example 1 of the present invention
- Example 7 is a discharge cycle curve diagram of a battery assembled by vanadium pentoxide/rGO coated with LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Example 1 of the present invention
- FIG. 9 is a discharge cycle curve diagram of a battery assembled with a full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Comparative Example 1 of the present invention.
- FIG. 10 is a TEM image of the fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material covered by the comparative example 2rGO of the present invention.
- FIG. 11 is a discharge cycle curve diagram of a battery assembled with a full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by 2rGO in Comparative Example of the present invention.
- the purity of high-purity nitrogen, high-purity argon, and high-purity oxygen used in the embodiment of the present invention are all 99.99%; the graphene oxide used in the embodiment of the present invention is purchased from Sigma-Aldrich; The raw materials or chemical reagents, unless otherwise specified, are obtained through conventional commercial channels.
- Example 1 Vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material
- the positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.84 Co 0.11 Mn 0.05 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.84 Co 0.11 Mn 0.05 O 2 is 0.03:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an integral coating layer, and the mass ratio of vanadium pentoxide to rGO is 1:1; the LiNi 0.84 Co 0.11 Mn 0.05 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 high , the content of cobalt element is uniformly distributed in LiNi 0.84 Co 0.11 Mn 0.05 O 2 ; The average thickness
- the ratio is 7:1:2) with a feeding rate of 50mL/h, pumped into a 2L high nickel content nickel-cobalt solution (a mixed solution of nickel sulfate and cobalt sulfate, wherein the total molar concentration of Ni and Co ions is 2.0mol/ L, the molar ratio of Ni, Co ions is 9:1) in the container, stir to form a mixed solution, at the same time, this mixed solution is pumped into a 2L, 2mol/L ammonia solution with a feeding speed of 100mL/h.
- a 2L high nickel content nickel-cobalt solution a mixed solution of nickel sulfate and cobalt sulfate, wherein the total molar concentration of Ni and Co ions is 2.0mol/ L, the molar ratio of Ni, Co ions is 9:1 in the container, stir to form a mixed solution, at the same time, this mixed solution is pumped into a 2L, 2mol/L ammonia solution with a feeding speed
- the ammonia concentration of the reaction system was regulated at 2 mol/L with 25% ammonia water of mass concentration, and the pH value of the reaction system was adjusted to 11.45 with 4L, 5mol/L sodium hydroxide precipitant solution, and a high-purity solution was introduced.
- the pH value of the reaction system was adjusted to 11.45 with 4L, 5mol/L sodium hydroxide precipitant solution, and a high-purity solution was introduced.
- Under a nitrogen atmosphere at 1000 r/min, 50 °C, heating and stirring for 42 h and co-precipitation reaction, at 50 °C, stirring and aging for 16 h, filtering, and deionized water and ethanol were used to cross-wash the filtrate 6 times, respectively.
- drying for 20h to obtain the full gradient nickel-cobalt-manganese hydroxide precursor;
- step (3) after mixing and grinding 1.0g of the full gradient nickel-cobalt-manganese hydroxide precursor (Ni 8.404mmol, Co 1.0805mmol, Mn 0.5155mmol) obtained in step (2) and 0.463487g (11.0485mmol) lithium hydroxide monohydrate,
- the temperature was first heated to 450°C at a rate of 5°C/min, after sintering for 4 hours, and then heated to 750°C at a rate of 5°C/min, sintered for 12 hours, two-stage sintering was performed, and cooled to room temperature to obtain Full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material;
- step (1) 0.03 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) were rotated and stirred for 10 h at 300 r/min. After drying at 100°C for 2 hours, a LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
- the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated .
- the morphology of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material coated with vanadium pentoxide/rGO according to the embodiment of the present invention better inherits the morphology of the fully gradient nickel cobalt lithium manganate, and the secondary particles It is a spherical core-shell structure with an average particle size of 6 ⁇ m, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
- the surface of the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in the embodiment of the present invention is coated with a layer of vanadium pentoxide/rGO composite material, vanadium pentoxide/rGO The average thickness is 5 nm.
- the content of nickel element gradually decreases from the center of LiNi 0.84 Co 0.11 Mn 0.05 O 2 to the surface, and the content of manganese element decreases gradually.
- the content of cobalt increases gradually from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 , and the content of cobalt is uniformly distributed in LiNi 0.84 Co 0.11 Mn 0.05 O 2 , indicating that it is a gradient polycrystalline agglomerate.
- the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by vanadium pentoxide/rGO in the present invention compared with the full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3), undergoes dioxygen pentoxide After vanadium/rGO coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
- Battery assembly Weigh 0.80g of the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material of the embodiment of the present invention, add 0.1g acetylene black as a conductive agent and 0.1g PVDF polyvinylidene fluoride as a binder, And use N-methylpyrrolidone as a solvent to mix and grind to form a positive electrode material; apply the obtained positive electrode material on the surface of aluminum foil to make a pole piece; in a closed glove box filled with argon, use the pole piece as the positive electrode and the metal lithium sheet as the negative electrode , microporous polypropylene film as separator, 1mol/L LiPF 6 /EC:DMC (volume ratio 1:1) as electrolyte, assembled into CR2025 button battery, and tested the charge-discharge performance.
- the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO according to the embodiment of the present invention under the current densities of 0.1C (20mAh/g), 5C, and 10C,
- the specific discharge capacities are 199mAh/g, 164.2mAh/g, and 146.5mAh/g, respectively, indicating that the cathode material can maintain structural stability during the charge-discharge process, and the charge-discharge reaction is highly reversible.
- the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, before At the current density of 3 cycles), the first discharge specific capacity can be as high as 199mAh/g, and the first discharge specific capacity at a current density of 200mA/g is 191.3mAh/g. After 100 cycles, the discharge specific capacity can still reach 168.2mAh/g.
- the capacity retention rate can be as high as 87.92%, indicating that the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material covered by vanadium pentoxide/rGO in the embodiment of the present invention has better cycle stability.
- Example 2 Vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material
- the positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.83 Co 0.1 Mn 0.07 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.83 Co 0.1 Mn 0.07 O 2 is 0.02:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an overall coating layer, and the mass ratio of vanadium pentoxide to rGO is 1.5:1; the LiNi 0.83 Co 0.1 Mn 0.07 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 high, the content of cobalt element is uniformly distributed in LiNi 0.83 Co 0.1 Mn 0.07 O 2 ; the average
- step (3) After mixing and grinding 1.0 g of the full-gradient nickel-cobalt-manganese hydroxide precursor (Ni 9.1 mmol, Co 1.1 mmol, Mn 0.78 mmol) obtained in step (2) and 0.4258 g (5.762 mmol) of lithium carbonate, the high-purity In an oxygen atmosphere, the temperature was first heated to 400°C at a rate of 3°C/min, after sintering for 5 hours, and then heated to 700°C at a rate of 3°C/min, sintered for 10 hours, two-stage sintering was performed, and cooled to room temperature to obtain a full gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material;
- step (1) 0.02 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full-gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material obtained in step (3) were rotated and stirred at 250 r/min for 12 h. After drying at 120°C for 2 hours, a LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
- the vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated.
- the morphology of the LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention better inherits the morphology of the full gradient nickel cobalt lithium manganate, and the secondary particles are spherical.
- the core-shell structure has an average particle size of 5 ⁇ m, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
- the surface of the vanadium pentoxide/rGO-coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is covered with a layer of vanadium pentoxide/rGO composite material, and the average thickness of the vanadium pentoxide/rGO is 4nm.
- the content of nickel element in the LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention gradually decreased from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 , and the content of manganese element
- the content of cobalt element is uniformly distributed in LiNi 0.83 Co 0.1 Mn 0.07 O 2 from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 gradually increasing.
- the present invention implements vanadium pentoxide/rGO coating LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material relative to step (3) full gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material, through vanadium pentoxide/rGO coating After coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
- the battery assembled by vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention has a specific discharge capacity at current densities of 0.1C (20mAh/g), 5C, and 10C. They are 196.3 mAh/g, 158.2 mAh/g, and 143.1 mAh/g, respectively, indicating that the positive electrode material can keep the structure stable during the charging and discharging process, and the charging and discharging reaction is highly reversible.
- the battery assembled with the LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, the first 3 turns)
- the first discharge specific capacity can be as high as 196.3mAh/g
- the first discharge specific capacity at 200mA/g is 189.6mAh/g
- the discharge specific capacity can still reach 159.2mAh/g
- the capacity retention rate can be as high as 83.97%, indicating that the vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material in the embodiment of the present invention has better cycle stability.
- the positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.82 Co 0.11 Mn 0.07 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.82 Co 0.11 Mn 0.07 O 2 is 0.04:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an overall coating layer, and the mass ratio of vanadium pentoxide to rGO is 2:1; the LiNi 0.82 Co 0.11 Mn 0.07 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 high, the content of cobalt element is uniformly distributed in LiNi 0.82 Co 0.11 Mn 0.07 O 2 ; the average particle size
- Ni, Co, and Mn 2L of low nickel content nickel-cobalt-manganese solution (a mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the total molar concentration of Ni, Co, and Mn ions is 2.0 mol/L, and the molar concentration of Ni, Co, and Mn is 2.0 mol/L).
- the ratio is 7:1.5:1.5) at a feeding rate of 55mL/h, pumped into 2L high nickel content nickel-cobalt-manganese solution (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the total of Ni, Co, Mn ions is The molar concentration is 2.0mol/L, and the molar ratio of Ni, Co, Mn ions is 9:0.5:0.5), stirring to form a mixed solution.
- the ammonia concentration of the reaction system is regulated at 2mol/L with the ammonia solution of 25% mass concentration, and the reaction system is adjusted with 4L, 5mol/L sodium hydroxide precipitant solution.
- the pH value of the solution reached 11.50, and the high-purity argon atmosphere was introduced.
- the co-precipitation reaction was carried out at 55 ° C.
- step (3) After mixing and grinding 1.0 g of the full gradient nickel-cobalt-manganese hydroxide precursor (Ni 8.72 mmol, Co 1.18 mmol, Mn 0.67 mmol) obtained in step (2) and 0.4661 g (11.11 mmol) of lithium hydroxide monohydrate, In a high-purity oxygen atmosphere, the temperature was first heated to 500°C at a rate of 7°C/min, after sintering for 3 hours, and then heated to 800°C at a rate of 7°C/min, sintered for 14 hours, and two-stage sintering was performed, and cooled to room temperature to obtain Full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material;
- step (1) 0.04 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material obtained in step (3) were rotated and stirred at 350 r/min for 8 h, After drying at 80°C for 3 hours, a LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
- the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated.
- the morphology of the LiNi 0.82 Co 0.11 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention better inherits the morphology of the full gradient nickel cobalt lithium manganate, and the secondary particles are spherical.
- the core-shell structure has an average particle size of 7 ⁇ m, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
- the surface of the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is coated with a layer of vanadium pentoxide/rGO composite material, and the average thickness of the vanadium pentoxide/rGO is 6nm.
- the content of nickel element in the LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention gradually decreased from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 , and the content of manganese element
- the content of cobalt element is uniformly distributed in LiNi 0.82 Co 0.11 Mn 0.07 O 2 from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 gradually increasing.
- the present invention implements the vanadium pentoxide/rGO coating LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material relative to the step (3) full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material, through the vanadium pentoxide/rGO coating After coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
- the battery assembled by vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention has a specific discharge capacity at current densities of 0.1C (20mAh/g), 5C, and 10C. They are 197.2mAh/g, 159.4mAh/g, and 145mAh/g, respectively, indicating that the positive electrode material can maintain structural stability during the charging and discharging process, and the charging and discharging reaction is highly reversible.
- the battery assembled with the LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material covered by vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, the first 3 turns)
- the first discharge specific capacity can reach 197.2mAh/g under the current density of 200mA/g, and the first discharge specific capacity is 187.6mAh/g at the current density of 200mA/g.
- the discharge specific capacity can still reach 158.4mAh/g.
- the capacity retention rate can be as high as 84.43%, indicating that the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 cathode material in the embodiment of the present invention has better cycle stability.
- Comparative example 1 full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material
- This comparative example is the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) of Example 1.
- the secondary particle size distribution of the fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material of this comparative example is uniform and spherical, with an average particle size of 6 ⁇ m.
- the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in this comparative example has a charge-discharge voltage of 2.7 to 4.3V and a current density of 0.1C (20mA/g), 5C, and 10C.
- the capacities are 205.4mAh/g, 145.5mAh/g, 121.6mAh/g, respectively.
- the discharge specific capacity of LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material is basically unchanged at low current density, while the discharge ratio at 10C current density is basically unchanged. The capacity dropped significantly, indicating that the charge-discharge reaction of the uncoated positive electrode material was poor in reversibility.
- the first discharge specific capacity can be as high as 205.4mAh/g, the first discharge specific capacity at a current density of 200mA/g is 198.8mAh/g, after 100 cycles, the discharge specific capacity is only 151.2mAh/g, and the capacity retention rate is only 76.06 %, indicating that the full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material of this comparative example has poor cycle stability before being coated with vanadium pentoxide/rGO.
- step (2) 0.01g graphene oxide and 1.0g full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (2) were rotated and stirred at 300 r/min for 10 hours, and then dried at 100° C. for 2 hours to obtain rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material.
- the rGO-coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material of this comparative example has a reduced graphene oxide coating layer with an average thickness of 5 nm on the surface of the material.
- the battery assembled with LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by rGO in this comparative example has a charge-discharge voltage of 2.7-4.3V and a current density of 0.1C (20mA/g), 5C, and 10C.
- the discharge specific capacities are 196.7mAh/g, 153.6mAh/g, and 132.3mAh/g, respectively.
- the discharge specific capacity of the cathode material under the condition of low current density is basically unchanged, while the discharge specific capacity at 10C current density Although the capacity has increased compared to the uncoated cathode material, it is still not good, indicating that the charge-discharge reaction reversibility of the cathode material only coated with rGO is still poor.
- the battery assembled with LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material covered by rGO in this comparative example has a charge-discharge voltage of 2.7-4.3V and a current of 0.1C (20mA/g, the first 3 turns).
- the first discharge specific capacity of the assembled battery is 196.7mAh/g
- the first discharge specific capacity under the current density is 200mA/g is 189.8mAh/g.
- the discharge specific capacity remains at 151.4mAh/g
- the capacity retention rate is 79.77%, indicating that the cycling stability of the cathode material only coated with rGO is still poor.
Abstract
A vanadium pentoxide/rGO-coated lithium nickel cobalt manganese oxide positive electrode material and a preparation method therefor. The positive electrode material is spherical core-shell-structure particles formed by coating lithium nickel cobalt manganese oxide with vanadium pentoxide/rGO, wherein the mass ratio of the vanadium pentoxide/RGO to the lithium nickel cobalt manganese oxide is 0.01-0.05 : 1; the chemical formula of the lithium nickel cobalt manganese oxide is LiNi xCoyMn(1-x-y)O2, with 0.75≤x≤0.85, 0.05≤y≤0.15, and 1-x-y＞0; and the vanadium pentoxide/rGO composite material involves an integral coating layer formed by anchoring vanadium pentoxide between rGO layers, with the mass ratio of vanadium pentoxide to rGO being 1-3 : 1. Further disclosed is a method for preparing the vanadium pentoxide/rGO-coated lithium nickel cobalt manganese oxide positive electrode material. The positive electrode material of the present invention has a high lithium ion and electron conductivity and good electrochemical properties; and the method of the present invention is simple and controllable, has low costs, and is suitable for industrial production.
Description
本发明涉及一种镍钴锰酸锂正极材料及制备方法，具体涉及一种五氧化二钒/rGO包覆镍钴锰酸锂正极材料及制备方法。The invention relates to a nickel-cobalt lithium manganate cathode material and a preparation method, in particular to a vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate cathode material and a preparation method.
随着新能源汽车的发展，锂离子动力电池作为最热门的电动车动力电池而备受关注。相对发展成熟稳定的商业石墨负极，针对于高容量、长寿命、低成本、安全环保的正极材料的研发显得尤为迫切。三元材料拥有较高的比容量、能量密度和功率密度以及比较稳定的性能，从而成为商业正极的热门材料。但是，三元材料的电化学性能、热稳定性、结构稳定性还需进一步提高，尤其是在高温以及高电位测试环境下，随着镍含量的提高，这些问题显得尤为突出。因此，对三元材料的改性十分重要。With the development of new energy vehicles, lithium-ion power batteries have attracted much attention as the most popular electric vehicle power batteries. Compared with the mature and stable commercial graphite anode, the research and development of cathode materials with high capacity, long life, low cost, safety and environmental protection is particularly urgent. Ternary materials have high specific capacity, energy density, power density, and relatively stable performance, making them popular materials for commercial cathodes. However, the electrochemical properties, thermal stability, and structural stability of ternary materials need to be further improved, especially in high temperature and high potential test environments. With the increase of nickel content, these problems are particularly prominent. Therefore, the modification of ternary materials is very important.
CN109888257A公开了一种石墨烯包覆改性锂离子电池正极材料及制备方法，是将石墨烯-Mn/磷酸锰铁锂浆料、三元材料浆料、聚偏氟乙烯进行混合后，超声波搅拌，然后，将混合液体涂覆在铝箔表面烘干，制备三元正极极片。但是，该方法中需要将氧化石墨加入去离子水中，再通过加入高锰酸钾和磷酸铁锂获得石墨烯-Mn/磷酸锰铁锂浆料，在实际操作过程中，控制条件比较严格，且需要经过多次处理，所得石墨烯的纯度较低，这对后续石墨烯包覆三元材料的效果不佳。CN109888257A discloses a graphene-coated modified lithium-ion battery positive electrode material and a preparation method. After mixing graphene-Mn/lithium manganese iron phosphate slurry, ternary material slurry and polyvinylidene fluoride, ultrasonic stirring , and then, the mixed liquid is coated on the surface of the aluminum foil and dried to prepare a ternary positive electrode. However, in this method, graphite oxide needs to be added to deionized water, and then graphene-Mn/lithium iron manganese phosphate slurry is obtained by adding potassium permanganate and lithium iron phosphate. In the actual operation process, the control conditions are relatively strict, and It needs to be processed for many times, and the purity of the obtained graphene is low, which is not effective for the subsequent graphene coating of the ternary material.
CN110311136A公开了一种石墨烯包覆锂离子电池三元正极材料的方法，是采用石墨烯浆料与正极活性物质混合，尽管该方法可将石墨烯更加均匀的分散于三元正极材料颗粒之间，但在操作过程三元材料长期暴露在液相环境，这对三元材料自身的结构造成较大的影响，并且在工业生产中难以实现。CN110311136A discloses a method for coating ternary positive electrode material of lithium ion battery with graphene, which is to use graphene slurry to mix with positive electrode active material, although this method can disperse graphene more uniformly among the particles of ternary positive electrode material , but the ternary material is exposed to the liquid phase environment for a long time during the operation process, which has a great impact on the structure of the ternary material itself, and is difficult to achieve in industrial production.
CN 109980219A公开了一种全梯度镍钴锰正极材料、氧化钌包覆材料及其制备方法，是将含钌化合物在氨的气氛下生成氢氧化钌包覆在全梯度镍钴锰正极材料表面，通过再次烧结后表面氢氧化物包覆层进一步分解成氧化钌。该方法涉及湿法化学反应，但是，镍钴锰正极材料在湿法环境中结构容易发生变化，此外，该方法所选用的包覆物氧化钌价格昂贵，一般在工业生产中难以广泛推广使用。CN 109980219A discloses a full-gradient nickel-cobalt-manganese positive electrode material, a ruthenium oxide coating material and a preparation method thereof. A ruthenium-containing compound is generated in an ammonia atmosphere to coat the surface of the full-gradient nickel-cobalt-manganese positive electrode material. The surface hydroxide coating is further decomposed into ruthenium oxide after re-sintering. This method involves a wet chemical reaction. However, the structure of the nickel-cobalt-manganese cathode material is prone to change in a wet environment. In addition, the ruthenium oxide used for the coating is expensive, and is generally difficult to be widely used in industrial production.
发明内容SUMMARY OF THE INVENTION
本发明所要解决的技术问题是，克服现有技术存在的上述缺陷，提供一种在充放电过程中锂离子和电子导电率高，结构稳定性、热稳定性、倍率性能以及长循环稳定性好，充放电反应高度可逆的五氧化二钒/rGO包覆镍钴锰酸锂正极材料。The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and to provide a kind of high lithium ion and electron conductivity in the charging and discharging process, and good structural stability, thermal stability, rate performance and long cycle stability. , a highly reversible charge-discharge reaction of vanadium pentoxide/rGO-coated nickel cobalt lithium manganate cathode material.
本发明进一步要解决的技术问题是，克服现有技术存在的上述缺陷，提供一种简单可控，工艺流程短，包覆效果好，成本低，适宜于工业化生产的五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法。The further technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and to provide a vanadium pentoxide/rGO package which is simple and controllable, has a short technological process, good coating effect and low cost, and is suitable for industrial production. The invention discloses a preparation method of a nickel-coated cobalt lithium manganate cathode material.
本发明解决其技术问题所采用的技术方案如下：五氧化二钒/rGO包覆镍钴锰酸锂正极材料，所述正极材料是由五氧化二钒/rGO包覆镍钴锰酸锂形成的球形核壳结构颗粒；所述五氧化二钒/rGO与镍钴锰酸锂的质量比为0.01～0.05:1；所述镍钴锰酸锂的化学式为LiNi
xCo
yMn
(1-x-y)O
2，其中0.75≤x≤0.85(更优选0.80≤x≤0.84)，0.05≤y≤0.15(更优选0.08≤y≤0.12)，1-x-y＞0；所述五氧化二钒/rGO复合材料由五氧化二钒在rGO层间锚定形成整体包覆层，五氧化二钒与rGO的质量比为1～3:1。高镍材料最大的缺点是结构稳定性和高温性能较差，其表面颗粒极易发生如下现象：层状结构-尖晶石结构-非活性岩石的相变过程，引起容量、循环性能衰减。五氧化二钒和rGO分别作为离子导体和电子导体，包覆正极材料后会不同程度的改善电化学性能，五氧化二钒离子导体包覆后可提高充放电过程离子导电性，克服因循环引起不利相变过程离子导电性变差的问题，再者，电子导体rGO包覆可以保证在循环过程快速脱嵌反应，尤其在大倍率条件下，经过rGO包覆可明显提升材料电化学性能。本发明创新性的提出离子导体和电子导体五氧化二钒/rGO复合材料包覆正极材料，使其在循环过程中发挥协同贡献作用，经过适量的五氧化二钒/rGO复合材料包覆后正极材料在循环过程中，既能提高循环稳定性，也保证了层状结构材料的快速脱嵌反应，表现出优异的电化学性能。本发明通过选择合适的包覆材料使表面涂层能提高材料的离子迁移率或电子导电率，抑制相变，增加材料结构的稳定性，减少活性物质中过渡金属的溶解，还可除去HF，有利于电极表面形成固体电解质界面膜(SEI)，减少电极电阻和循环过程中副反应发生及热生成，从而显著改善材料的循环寿命、倍率性能、可逆容量和首次库仑效率。
The technical solution adopted by the present invention to solve the technical problem is as follows: vanadium pentoxide/rGO coats nickel cobalt lithium manganate positive electrode material, and the positive electrode material is formed by vanadium pentoxide/rGO coat nickel cobalt lithium manganate Spherical core-shell structure particles; the mass ratio of the vanadium pentoxide/rGO to lithium nickel cobalt manganate is 0.01-0.05:1; the chemical formula of the lithium nickel cobalt manganate is LiNi x Co y Mn (1-xy) O 2 , wherein 0.75≤x≤0.85 (more preferably 0.80≤x≤0.84), 0.05≤y≤0.15 (more preferably 0.08≤y≤0.12), 1-xy>0; the vanadium pentoxide/rGO composite material The overall coating layer is formed by anchoring vanadium pentoxide between rGO layers, and the mass ratio of vanadium pentoxide to rGO is 1-3:1. The biggest disadvantage of high-nickel materials is the poor structural stability and high-temperature performance, and the surface particles are prone to the following phenomena: the phase transition process of layered structure-spinel structure-inactive rock, resulting in capacity and cycle performance degradation. Vanadium pentoxide and rGO are used as ionic conductors and electronic conductors, respectively. After coating the cathode material, the electrochemical performance will be improved to varying degrees. After coating with vanadium pentoxide ionic conductors, the ionic conductivity during charging and discharging can be improved, and the ionic conductivity caused by the cycle can be overcome. The problem of poor ionic conductivity during the phase transition process is unfavorable. Furthermore, the coating of electronic conductor rGO can ensure the rapid deintercalation reaction during cycling, especially under the condition of high rate, the electrochemical performance of the material can be significantly improved after coating with rGO. The present invention innovatively proposes that the ion conductor and electronic conductor vanadium pentoxide/rGO composite material coat the positive electrode material, so that it can play a synergistic contribution role in the cycle process. During the cycling process, the material can not only improve the cycle stability, but also ensure the rapid de-intercalation reaction of the layered structure material, showing excellent electrochemical performance. In the present invention, by selecting a suitable coating material, the surface coating can improve the ion mobility or electronic conductivity of the material, inhibit the phase transition, increase the stability of the material structure, reduce the dissolution of transition metals in the active material, and can also remove HF, It is conducive to the formation of a solid electrolyte interface film (SEI) on the electrode surface, reducing the electrode resistance and the occurrence of side reactions and heat generation during cycling, thereby significantly improving the cycle life, rate capability, reversible capacity and first Coulombic efficiency of the material.
本发明中的rGO是还原氧化石墨烯的简称。rGO in the present invention is an abbreviation of reduced graphene oxide.
优选地，所述镍钴锰酸锂为全梯度材料，镍元素的含量从镍钴锰酸锂的中心至表面逐渐降低，锰元素的含量从镍钴锰酸锂的中心至表面逐渐升高，钴元素的含量在镍钴锰酸锂中均匀分布。Preferably, the nickel-cobalt lithium manganate is a full gradient material, the content of nickel gradually decreases from the center to the surface of nickel-cobalt lithium manganate, and the content of manganese gradually increases from the center to the surface of nickel-cobalt lithium manganate, The content of cobalt element is uniformly distributed in the nickel cobalt lithium manganate.
优选地，所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的平均粒径为4～8μm。当五氧化二钒/rGO包覆镍钴锰酸锂正极材料的二次颗粒达到此粒径时，前驱体形貌较好，分散均匀。Preferably, the average particle size of the vanadium pentoxide/rGO-coated nickel cobalt lithium manganate cathode material is 4-8 μm. When the secondary particles of the vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate cathode material reach this particle size, the precursors have good morphology and uniform dispersion.
优选地，所述五氧化二钒/rGO的平均厚度为3～6nm。包覆层不宜过厚，过厚的包覆层会影响正极材料的首次充放电效率。Preferably, the average thickness of the vanadium pentoxide/rGO is 3-6 nm. The coating layer should not be too thick, and an excessively thick coating layer will affect the first charge-discharge efficiency of the positive electrode material.
本发明进一步解决其技术问题所采用的技术方案如下：五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，包括以下步骤：The technical solution adopted by the present invention to further solve the technical problem is as follows: the preparation method of vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate positive electrode material comprises the following steps:
(1)将氧化石墨烯和钒源加入有机溶剂中超声分散，进行溶剂热反应后，搅拌冷却，离心洗涤，干燥，烧结，冷却，得五氧化二钒/rGO复合材料；(1) adding graphene oxide and a vanadium source into an organic solvent for ultrasonic dispersion, after performing a solvothermal reaction, stirring and cooling, centrifugal washing, drying, sintering, and cooling to obtain a vanadium pentoxide/rGO composite material;
(2)将低镍含量镍钴锰溶液泵入装有高镍含量镍钴或镍钴锰溶液的容器中，搅拌形成混合溶液，与此同时，将该混合溶液泵入装有氨水溶液的反应釜中，并同时用氨水调节反应体系的氨水浓度，用氢氧化物沉淀剂溶液调节反应体系的pH值，通入保护气氛下，加热搅拌并进行共沉淀反应后，搅拌陈化，过滤，洗涤，干燥，得全梯度镍钴锰氢氧化物前驱体；(2) low nickel content nickel cobalt manganese solution is pumped into the container that high nickel content nickel cobalt or nickel cobalt manganese solution is housed, stir to form mixed solution, meanwhile, this mixed solution is pumped into the reaction that ammonia solution is housed In the kettle, simultaneously adjust the ammonia concentration of the reaction system with ammonia water, adjust the pH value of the reaction system with hydroxide precipitant solution, pass into the protective atmosphere, heat and stir and carry out co-precipitation reaction, stir and age, filter, wash , and dried to obtain a full gradient nickel-cobalt-manganese hydroxide precursor;
(3)将步骤(2)所得全梯度镍钴锰氢氧化物前驱体与锂源混合研磨后，在氧化气氛下，进行两段式烧结，冷却至室温，得全梯度镍钴锰酸锂材料；(3) after the full gradient nickel cobalt manganese hydroxide precursor obtained in step (2) is mixed and ground with a lithium source, two-stage sintering is performed in an oxidizing atmosphere, and cooled to room temperature to obtain a full gradient nickel cobalt manganese lithium material. ;
(4)将步骤(1)所得五氧化二钒/rGO复合材料和步骤(3)所得全梯度镍钴锰酸锂材料转动搅拌后，烘干，得五氧化二钒/rGO包覆镍钴锰酸锂正极材料。(4) after rotating and stirring the vanadium pentoxide/rGO composite material obtained in step (1) and the full gradient nickel-cobalt-manganate material obtained in step (3), drying to obtain vanadium pentoxide/rGO coated nickel-cobalt-manganese Lithium oxide cathode material.
优选地，步骤(1)中，所述氧化石墨烯、钒源与有机溶剂的质量体积比(g/g/L)为0.1～0.4:0.7～1.0:1。若氧化石墨烯过多而钒源过少，则主要体现了电子导体包覆作用，若氧化石墨烯过少而钒源过多，则主要体现离子导体作用，在所述范围内，更能体现离子导体和电子导体的协同包覆作用。若有机溶剂用量过少，则钒源不能完全溶解分散，若有机溶剂用量过多，则会造成比例失调，且浪费溶剂。Preferably, in step (1), the mass-to-volume ratio (g/g/L) of the graphene oxide, the vanadium source and the organic solvent is 0.1-0.4:0.7-1.0:1. If the graphene oxide is too much and the vanadium source is too small, it mainly reflects the coating effect of the electronic conductor. If the graphene oxide is too small and the vanadium source is too much, the ionic conductor function is mainly reflected. Synergistic coating of ionic and electronic conductors. If the amount of the organic solvent is too small, the vanadium source cannot be completely dissolved and dispersed. If the amount of the organic solvent is too much, the proportion will be out of balance and the solvent will be wasted.
优选地，步骤(1)中，所述钒源为乙酰丙酮氧钒、乙酰丙酮钒或偏钒酸铵等中的一种或几种。Preferably, in step (1), the vanadium source is one or more of vanadyl acetylacetonate, vanadium acetylacetonate or ammonium metavanadate, etc.
优选地，步骤(1)中，所述有机溶剂为N-N二甲基甲酰胺等。Preferably, in step (1), the organic solvent is N-N dimethylformamide or the like.
优选地，步骤(1)中，所述超声分散的频率为1.5～2.5kHz，时间为0.5～1.0h。超声分散主要是为了钒源在有机溶剂中均匀分散，并在扩散后均匀附着在rGO表面。若超声分散的时间过长，则会使rGO的结构破坏并造成资源浪费，若超声分散的时间过短，则难以达到均匀分散的效果。Preferably, in step (1), the frequency of the ultrasonic dispersion is 1.5-2.5 kHz, and the time is 0.5-1.0 h. The ultrasonic dispersion is mainly for the uniform dispersion of the vanadium source in the organic solvent and uniform attachment to the rGO surface after diffusion. If the ultrasonic dispersion time is too long, the structure of rGO will be damaged and resources will be wasted. If the ultrasonic dispersion time is too short, it is difficult to achieve the effect of uniform dispersion.
优选地，步骤(1)中，所述溶剂热反应的搅拌速度为300～500r/min，温度为150～250℃，时间为12～24h。在溶剂热反应过程主要发生氧化石墨烯的低温还原反应，在有机溶剂中通过一定温度和时间的溶剂热反应，得到结构完整的rGO，且在该条件下分散的钒源不会受到影响。若温度过高或时间过长，则会引起钒源的变化，同时rGO的结构会发生破坏，若温度过低或时间过短，则难以获得满意的rGO。Preferably, in step (1), the stirring speed of the solvothermal reaction is 300-500 r/min, the temperature is 150-250°C, and the time is 12-24 h. In the solvothermal reaction process, the low-temperature reduction reaction of graphene oxide mainly occurs, and a solvothermal reaction at a certain temperature and time in an organic solvent can obtain rGO with a complete structure, and the dispersed vanadium source will not be affected under this condition. If the temperature is too high or the time is too long, the vanadium source will change, and the structure of rGO will be destroyed. If the temperature is too low or the time is too short, it is difficult to obtain satisfactory rGO.
步骤(1)中，所述搅拌冷却可使五氧化二钒/rGO复合材料的分散均匀且一致性好。In step (1), the stirring and cooling can make the dispersion of the vanadium pentoxide/rGO composite material uniform and consistent.
优选地，步骤(1)中，所述离心洗涤是用去离子水和无水乙醇分别先后交叉离心洗涤沉淀物≥6次。Preferably, in step (1), the centrifugal washing is to use deionized water and anhydrous ethanol to successively cross-centrifuge and wash the precipitate for ≥ 6 times.
优选地，步骤(1)中，所述干燥为冷冻干燥。为了更好的保持rGO的形貌，溶剂热反应 后的复合材料采用冷冻干燥的方式去除溶剂。Preferably, in step (1), the drying is freeze-drying. In order to better preserve the morphology of rGO, the composites after solvothermal reaction were lyophilized to remove the solvent.
优选地，所述冷冻干燥的真空度为80～100Pa，温度为-40～-50℃，时间为24～40h。Preferably, the vacuum degree of the freeze-drying is 80-100 Pa, the temperature is -40--50°C, and the time is 24-40 h.
优选地，步骤(1)中，所述烧结是以速率1～10℃/min(更优选3～7℃/min)升温至300～500℃，烧结1～3h。在烧结过程中，主要发生钒源的氧化分解反应，生成的五氧化二钒能更加均匀牢固的锚定在rGO层表面。若烧结温度过低，则钒源分解反应不彻底，若烧结温度过高，反而会使复合材料分离；若烧结时间过短，则分解的五氧化二钒未能均匀分布在rGO层。Preferably, in step (1), the sintering is carried out at a rate of 1-10° C./min (more preferably 3-7° C./min) to raise the temperature to 300-500° C., and sintering for 1-3 hours. During the sintering process, the oxidative decomposition reaction of the vanadium source mainly occurred, and the generated vanadium pentoxide could be more uniformly and firmly anchored on the surface of the rGO layer. If the sintering temperature is too low, the decomposition reaction of the vanadium source will be incomplete. If the sintering temperature is too high, the composites will be separated; if the sintering time is too short, the decomposed vanadium pentoxide will not be evenly distributed in the rGO layer.
优选地，步骤(2)中，所述低镍含量镍钴锰溶液的加料速度为30～70mL/h(更优选40～60mL/h)。Preferably, in step (2), the feeding rate of the low nickel content nickel-cobalt-manganese solution is 30-70 mL/h (more preferably 40-60 mL/h).
优选地，步骤(2)中，所述混合溶液的加料速度为80～120mL/h(更优选90～110mL/h)。Preferably, in step (2), the feeding rate of the mixed solution is 80-120 mL/h (more preferably 90-110 mL/h).
若加料速度过快，则会导致pH变化范围较大，使得沉淀剂难以对金属离子进行有效的沉淀，不利于控制反应过程晶核的形成及其生长，若加料速度过慢，则颗粒容易团聚，同时也不利于提高生产效率。If the feeding speed is too fast, it will lead to a large range of pH variation, making it difficult for the precipitant to effectively precipitate metal ions, which is not conducive to controlling the formation and growth of crystal nuclei during the reaction process. If the feeding speed is too slow, the particles are easy to agglomerate , and is not conducive to improving production efficiency.
优选地，步骤(2)中，所述低镍含量镍钴锰溶液中，镍、钴、锰离子的总摩尔浓度为0.3～3.0mol/L(更优选1.5～2.5mol/L)，镍、钴、锰的摩尔比为3～8:1:0～2。若镍、钴、锰离子的总摩尔浓度过低，则沉淀时间较长，不利于提高生产效率，若镍、钴、锰离子的总摩尔浓度过高，则不利于控制反应过程的pH值，沉降效果不佳。Preferably, in step (2), in the low nickel content nickel cobalt manganese solution, the total molar concentration of nickel, cobalt and manganese ions is 0.3-3.0 mol/L (more preferably 1.5-2.5 mol/L), nickel, The molar ratio of cobalt and manganese is 3～8:1:0～2. If the total molar concentration of nickel, cobalt and manganese ions is too low, the precipitation time will be longer, which is not conducive to improving production efficiency. The settling effect is not good.
优选地，步骤(2)中，所述高镍含量镍钴或镍钴锰溶液中，镍、钴、锰离子的总摩尔浓度为0.3～4.0mol/L(更优选1.5～2.5mol/L)，镍、钴、锰的摩尔比为8～9:0.5～1.0:0～1。若镍、钴、锰离子的总摩尔浓度过低，则沉淀时间较长，不利于提高生产效率，若镍、钴、锰离子的总摩尔浓度过高，则不利于控制反应过程的pH值，沉降效果不佳。Preferably, in step (2), in the high nickel content nickel-cobalt or nickel-cobalt-manganese solution, the total molar concentration of nickel, cobalt and manganese ions is 0.3-4.0 mol/L (more preferably 1.5-2.5 mol/L) , the molar ratio of nickel, cobalt and manganese is 8-9:0.5-1.0:0-1. If the total molar concentration of nickel, cobalt and manganese ions is too low, the precipitation time will be longer, which is not conducive to improving production efficiency. The settling effect is not good.
优选地，步骤(2)中，在同一反应体系中，低镍含量镍钴锰溶液的镍含量低于高镍含量镍钴或镍钴锰溶液的镍含量。Preferably, in step (2), in the same reaction system, the nickel content of the low nickel content nickel cobalt manganese solution is lower than the nickel content of the high nickel content nickel cobalt or nickel cobalt manganese solution.
优选地，步骤(2)中，反应釜中氨水溶液、氢氧化物沉淀剂溶液、低镍含量镍钴锰溶液与高镍含量镍钴或镍钴锰溶液的体积比为0.1～10:1～2:1:1(更优选1:2:1:1)。在所述加料比例下，更有利于共沉淀反应的开始和材料梯度的控制。Preferably, in step (2), the volume ratio of ammonia solution, hydroxide precipitant solution, low nickel content nickel cobalt manganese solution and high nickel content nickel cobalt or nickel cobalt manganese solution in the reactor is 0.1～10:1～ 2:1:1 (more preferably 1:2:1:1). Under the feeding ratio, the initiation of coprecipitation reaction and the control of material gradient are more favorable.
优选地，步骤(2)中，所述氨水溶液的摩尔浓度为1.0～7.0mol/L(更优选1.5～4.5mol/L)。若氨水溶液的摩尔浓度过低，则金属离子难以完全络合，若氨水溶液的摩尔浓度过高，则不利于金属离子形成氢氧化物沉淀。Preferably, in step (2), the molar concentration of the ammonia solution is 1.0-7.0 mol/L (more preferably 1.5-4.5 mol/L). If the molar concentration of the ammonia solution is too low, it is difficult for the metal ions to be completely complexed, and if the molar concentration of the ammonia solution is too high, it is unfavorable for the metal ions to form hydroxide precipitation.
优选地，步骤(2)中，用氨水调节反应体系氨水浓度保持在1.0～7.0mol/L(更优选1.5～4.5mol/L)。Preferably, in step (2), the concentration of ammonia water in the reaction system is adjusted with ammonia water to maintain at 1.0-7.0 mol/L (more preferably 1.5-4.5 mol/L).
优选地，步骤(2)中，用于调节反应体系氨水浓度的氨水的质量浓度为25～28％。Preferably, in step (2), the mass concentration of the ammonia water used to adjust the ammonia water concentration of the reaction system is 25-28%.
优选地，步骤(2)中，用氢氧化物沉淀剂溶液调节反应体系的pH值保持在10～12。在所述pH值下，更有利于控制颗粒生长速度不会过快或过慢。Preferably, in step (2), the pH value of the reaction system is adjusted to be maintained at 10-12 with a hydroxide precipitant solution. At the pH value, it is more favorable to control the particle growth rate not to be too fast or too slow.
优选地，步骤(2)中，所述氢氧化物沉淀剂溶液的摩尔浓度为1.0～7.0mol/L(更优选4.0～6.0mol/L)。若氢氧化物沉淀剂溶液的摩尔浓度过高或过低，都不能准确的控制反应过程的pH值，从而对前驱体材料的形貌造成影响。Preferably, in step (2), the molar concentration of the hydroxide precipitant solution is 1.0-7.0 mol/L (more preferably 4.0-6.0 mol/L). If the molar concentration of the hydroxide precipitant solution is too high or too low, the pH value of the reaction process cannot be accurately controlled, thereby affecting the morphology of the precursor material.
优选地，步骤(2)中，所述低镍含量镍钴锰溶液和高镍含量镍钴锰溶液为可溶性镍盐、可溶性钴盐和可溶性锰盐的混合溶液，所述高镍含量镍钴溶液为可溶性镍盐和可溶性钴盐的混合溶液。Preferably, in step (2), the low nickel content nickel cobalt manganese solution and the high nickel content nickel cobalt manganese solution are mixed solutions of soluble nickel salt, soluble cobalt salt and soluble manganese salt, and the high nickel content nickel cobalt solution It is a mixed solution of soluble nickel salt and soluble cobalt salt.
优选地，步骤(2)中，所述可溶性镍盐为硫酸镍、硝酸镍、乙酸镍或氯化镍，及其水合物等中的一种或几种。Preferably, in step (2), the soluble nickel salt is one or more of nickel sulfate, nickel nitrate, nickel acetate or nickel chloride, and hydrates thereof.
优选地，步骤(2)中，所述可溶性钴盐为硫酸钴、硝酸钴、乙酸钴或氯化钴，及其水合物等中的一种或几种。Preferably, in step (2), the soluble cobalt salt is one or more of cobalt sulfate, cobalt nitrate, cobalt acetate or cobalt chloride, and hydrates thereof.
优选地，步骤(2)中，所述可溶性锰盐为硫酸锰、硝酸锰、乙酸锰或氯化锰，及其水合物等中的一种或几种。Preferably, in step (2), the soluble manganese salt is one or more of manganese sulfate, manganese nitrate, manganese acetate or manganese chloride, and hydrates thereof.
优选地，步骤(2)中，所述氢氧化物沉淀剂为氢氧化钠、氢氧化钾或氢氧化锂，及其水合物等中的一种或几种。Preferably, in step (2), the hydroxide precipitation agent is one or more of sodium hydroxide, potassium hydroxide or lithium hydroxide, and hydrates thereof.
优选地，步骤(2)中，所述保护气氛为氮气气氛和/或氩气气氛。Preferably, in step (2), the protective atmosphere is a nitrogen atmosphere and/or an argon atmosphere.
优选地，步骤(2)中，所述共沉淀反应的搅拌速度为800～1200r/min，温度为30～70℃(更优选40～60℃)，时间为30～50h。若搅拌速度过慢，则一次颗粒容易发生团聚，若搅拌速度过快，则生长的晶体容易发生破碎；在所述温度范围内，更有利于晶体的生长；反应时间由原料含量与加料速度共同决定。Preferably, in step (2), the stirring speed of the co-precipitation reaction is 800-1200 r/min, the temperature is 30-70° C. (more preferably 40-60° C.), and the time is 30-50 h. If the stirring speed is too slow, the primary particles are prone to agglomeration, and if the stirring speed is too fast, the grown crystals are prone to breakage; within the temperature range, it is more conducive to the growth of crystals; the reaction time is determined by the content of the raw materials and the feeding speed. Decide.
优选地，步骤(2)中，所述陈化的温度为30～70℃(更优选40～60℃)，时间为8～24h。所述陈化过程能够置换出材料内部的硫酸根等阴离子，并有利于颗粒表面的均一性。若陈化时间过短，则难以确保阴离子的离子交换，对后续洗涤过程也有影响，若陈化时间过长，则不利于生产应用及材料表面的均匀性。所述陈化温度与共沉淀反应温度保持一致，这有利于材料均匀分散不团聚，并保证一次颗粒均匀生长成二次颗粒。Preferably, in step (2), the aging temperature is 30-70° C. (more preferably 40-60° C.), and the time is 8-24 h. The aging process can replace the sulfate and other anions inside the material, and is beneficial to the uniformity of the particle surface. If the aging time is too short, it is difficult to ensure the ion exchange of anions, which will also affect the subsequent washing process. If the aging time is too long, it is not conducive to the uniformity of production application and material surface. The aging temperature is consistent with the co-precipitation reaction temperature, which is conducive to the uniform dispersion of the material without agglomeration, and ensures the uniform growth of primary particles into secondary particles.
优选地，步骤(2)中，所述洗涤为用去离子水与乙醇分别先后交叉洗涤过滤物≥6次。Preferably, in step (2), the washing is to cross-wash the filtrate with deionized water and ethanol for ≥6 times respectively.
优选地，步骤(2)中，所述干燥的温度为80～100℃，时间为12～24h。若温度过低或时间过短，则材料难以干燥，若温度过高或时间过长，则材料表面会有其它副反应，影响材料性能，并且周期过长不利于工业化生产。Preferably, in step (2), the drying temperature is 80-100° C., and the drying time is 12-24 h. If the temperature is too low or the time is too short, the material will be difficult to dry. If the temperature is too high or the time is too long, there will be other side reactions on the surface of the material, which will affect the performance of the material, and if the cycle is too long, it is not conducive to industrial production.
优选地，步骤(3)中，所述全梯度镍钴锰氢氧化物前驱体中镍、钴、锰元素摩尔数总和 与锂源中锂元素的摩尔比为1:1.04～1.11。Preferably, in step (3), the molar ratio of the sum of moles of nickel, cobalt and manganese elements in the full gradient nickel-cobalt-manganese hydroxide precursor and the lithium element in the lithium source is 1:1.04-1.11.
优选地，步骤(3)中，所述锂源为氢氧化锂和/或碳酸锂等。Preferably, in step (3), the lithium source is lithium hydroxide and/or lithium carbonate or the like.
优选地，步骤(3)中，所述氧化气氛为空气气氛和/或氧气气氛等。Preferably, in step (3), the oxidizing atmosphere is an air atmosphere and/or an oxygen atmosphere or the like.
优选地，步骤(3)中，所述两段式烧结是指：先以速率1～10℃/min(更优选3～7℃/min)升温至350～550℃，烧结2～8h(更优选3～6h)后，再以速率1～10℃/min(更优选3～7℃/min)升温至550～1000℃(更优选600～900℃)下，烧结8～20h。第一段烧结过程中，主要发生全梯度前驱体和锂源的分解反应，在第二段烧结过程下，主要发生全梯度前驱体与锂源分解的氧化物在氧气气氛下的化合反应。若烧结温度过高或时间过长，则材料容易结块，充放电过程难以释放容量，若煅烧温度过低或时间过短，则难以形成所需形貌，影响电化学性能。若升温速率过快，则难以保证材料反应充分，若升温速率过慢，则不利于工业化生产。Preferably, in step (3), the two-stage sintering refers to: first, the temperature is raised to 350-550° C. at a rate of 1-10° C./min (more preferably 3-7° C./min), and then sintered for 2-8 hours (more preferably 3-7° C./min). After preferably 3-6h), the temperature is raised to 550-1000°C (more preferably 600-900°C) at a rate of 1-10°C/min (more preferably 3-7°C/min), and sintered for 8-20h. During the first stage sintering process, the decomposition reaction of the full gradient precursor and the lithium source mainly occurs. In the second stage sintering process, the compound reaction between the full gradient precursor and the oxide decomposed by the lithium source mainly occurs in an oxygen atmosphere. If the sintering temperature is too high or the time is too long, the material is easy to agglomerate, and it is difficult to release the capacity during the charging and discharging process. If the sintering temperature is too low or the time is too short, it is difficult to form the desired morphology and affect the electrochemical performance. If the heating rate is too fast, it is difficult to ensure that the material reacts sufficiently, and if the heating rate is too slow, it is not conducive to industrial production.
优选地，步骤(4)中，所述五氧化二钒/rGO复合材料与镍钴锰酸锂材料的质量比为0.01～0.05:1。若五氧化二钒/rGO复合材料过多，则包覆层太厚，对正极材料的容量会造成负面影响，并且成本太高；若五氧化二钒/rGO复合材料过少，难以达到包覆效果，且造成原料的浪费。Preferably, in step (4), the mass ratio of the vanadium pentoxide/rGO composite material to the nickel cobalt lithium manganate material is 0.01-0.05:1. If there are too many vanadium pentoxide/rGO composite materials, the coating layer will be too thick, which will have a negative impact on the capacity of the positive electrode material, and the cost will be too high; if the vanadium pentoxide/rGO composite material is too small, it will be difficult to achieve coating effect, and waste of raw materials.
优选地，步骤(4)中，所述转动搅拌的转速为250～400r/min，时间为8～12h。在所述转速下更易达到材料的包覆要求，若时间过长，则会对材料结构造成破坏，并且容易引起材料板结，若时间过短，则不利于达到包覆效果。所述转动搅拌可在球磨机中不加球磨珠实现。Preferably, in step (4), the rotational speed of the rotating stirring is 250-400 r/min, and the time is 8-12 h. It is easier to meet the coating requirements of the material at the said rotational speed. If the time is too long, it will damage the material structure and easily cause the material to harden. If the time is too short, it is not conducive to achieve the coating effect. The rotational agitation can be achieved without adding ball milling beads in the ball mill.
优选地，步骤(4)中，所述烘干的温度为80～120℃，时间为2～3h。Preferably, in step (4), the drying temperature is 80-120° C., and the drying time is 2-3 hours.
本发明所使用的氮气、氩气或氧气均为纯度≥99.99％的高纯气体。The nitrogen, argon or oxygen used in the present invention are all high-purity gases with a purity of ≥99.99%.
本发明的有益效果如下：The beneficial effects of the present invention are as follows:
(1)本发明五氧化二钒/rGO包覆镍钴锰酸锂正极材料无杂相生成，二次颗粒为类球形核壳结构，平均粒径为4～8μm，在二次颗粒表面形成了一层五氧化二钒/rGO复合薄膜，五氧化二钒/rGO的平均厚度为3～6nm，镍钴锰酸锂中的镍元素的含量从镍钴锰酸锂的中心至表面逐渐降低，锰元素的含量从镍钴锰酸锂的中心至表面逐渐升高，钴元素的含量在镍钴锰酸锂中均匀分布，说明其为梯度多晶团聚体；(1) The vanadium pentoxide/rGO coated nickel-cobalt lithium manganate cathode material of the present invention has no impurity-phase formation, and the secondary particles have a spherical core-shell structure with an average particle size of 4-8 μm. A layer of vanadium pentoxide/rGO composite film, the average thickness of vanadium pentoxide/rGO is 3-6 nm, the content of nickel element in nickel-cobalt lithium manganate gradually decreases from the center to the surface of nickel-cobalt lithium manganate, manganese The content of the element gradually increases from the center to the surface of the nickel-cobalt lithium manganate, and the content of the cobalt element is uniformly distributed in the nickel-cobalt lithium manganate, indicating that it is a gradient polycrystalline agglomerate;
(2)本发明五氧化二钒/rGO包覆镍钴锰酸锂正极材料所组装的电池，在0.1C(20mAh/g)、5C、10C的电流密度下，放电比容量分别高达199mAh/g、164.2mAh/g、146.5mAh/g，说明该正极材料在充放电过程中能够保持结构的稳定，充放电反应高度可逆；在2.7～4.3V充放电电压，1C的电流密度下，首次放电比容量可高达191.3mAh/g，循环100圈后，放电比容量仍可达168.2mAh/g，保持率可高达87.92％，说明本发明五氧化二钒/rGO包覆镍钴锰酸锂正极材料的循环稳定性较好；(2) The battery assembled by the vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material of the present invention has a discharge specific capacity of up to 199mAh/g at current densities of 0.1C (20mAh/g), 5C, and 10C, respectively. , 164.2mAh/g, 146.5mAh/g, indicating that the positive electrode material can maintain structural stability during the charge-discharge process, and the charge-discharge reaction is highly reversible; at a charge-discharge voltage of 2.7-4.3V and a current density of 1C, the first discharge ratio The capacity can be as high as 191.3mAh/g, and after 100 cycles, the discharge specific capacity can still reach 168.2mAh/g, and the retention rate can be as high as 87.92%. Good cycle stability;
(3)本发明方法简单可控，工艺流程短，包覆效果好，成本低，适宜于工业化生产。(3) The method of the invention is simple and controllable, has short technological process, good coating effect and low cost, and is suitable for industrial production.
图1是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的XRD图；
1 is the XRD pattern of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention;
图2是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的SEM图；
2 is a SEM image of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention;
图3是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的TEM图；
3 is a TEM image of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in Example 1 of the present invention;
图4是本发明实施例1步骤(3)所得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料的聚焦离子束切面元素线扫结果；
Fig. 4 is the element line scan result of the focused ion beam section of the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) of Example 1 of the present invention;
图5是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料和本发明实施例1步骤(3)所得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料(对比例1)的XPS图；
Fig. 5 shows the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material coated with vanadium pentoxide/rGO in Example 1 of the present invention and the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) in Example 1 of the present invention (for XPS diagram of scale 1);
图6是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池的倍率曲线图；
6 is a rate curve diagram of a battery assembled by vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Example 1 of the present invention;
图7是本发明实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池的放电循环曲线图；
7 is a discharge cycle curve diagram of a battery assembled by vanadium pentoxide/rGO coated with LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Example 1 of the present invention;
图8是本发明对比例1全梯度LiNi
0.84Co
0.11Mn
0.05O
2正极材料的SEM图；
8 is a SEM image of the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Comparative Example 1 of the present invention;
图9是本发明对比例1全梯度LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池的放电循环曲线图；
9 is a discharge cycle curve diagram of a battery assembled with a full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in Comparative Example 1 of the present invention;
图10是本发明对比例2rGO包覆全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料的TEM图；
FIG. 10 is a TEM image of the fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material covered by the comparative example 2rGO of the present invention;
图11是本发明对比例2rGO包覆全梯度LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池的放电循环曲线图。
FIG. 11 is a discharge cycle curve diagram of a battery assembled with a full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by 2rGO in Comparative Example of the present invention.
下面结合实施例和附图对本发明作进一步说明。The present invention will be further described below with reference to the embodiments and accompanying drawings.
本发明实施例所使用的高纯氮气、高纯氩气、高纯氧气的纯度均为99.99％；本发明实施例所使用的氧化石墨烯购于西格玛-奥德里奇；本发明实施例所使用的原料或化学试剂，如无特殊说明，均通过常规商业途径获得。The purity of high-purity nitrogen, high-purity argon, and high-purity oxygen used in the embodiment of the present invention are all 99.99%; the graphene oxide used in the embodiment of the present invention is purchased from Sigma-Aldrich; The raw materials or chemical reagents, unless otherwise specified, are obtained through conventional commercial channels.
实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料
Example 1 Vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material
所述正极材料是由五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2形成的球形核壳结构颗粒；所述五氧化二钒/rGO与LiNi
0.84Co
0.11Mn
0.05O
2的质量比为0.03:1；所述五氧化二钒/rGO复合材料由五氧化二钒在rGO层间锚定形成整体包覆层，五氧化二钒与rGO的质量比为1:1；所述LiNi
0.84Co
0.11Mn
0.05O
2为全梯度材料，镍元素的含量从LiNi
0.84Co
0.11Mn
0.05O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.84Co
0.11Mn
0.05O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.84Co
0.11Mn
0.05O
2中均匀分布；所述五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的平均粒径为6μm；所述五氧化二钒/rGO的平均厚度为5nm。
The positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.84 Co 0.11 Mn 0.05 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.84 Co 0.11 Mn 0.05 O 2 is 0.03:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an integral coating layer, and the mass ratio of vanadium pentoxide to rGO is 1:1; the LiNi 0.84 Co 0.11 Mn 0.05 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 high , the content of cobalt element is uniformly distributed in LiNi 0.84 Co 0.11 Mn 0.05 O 2 ; The average thickness of vanadium/rGO is 5 nm.
实施例1五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的制备方法
Example 1 Preparation method of vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material
(1)将0.02g氧化石墨烯和0.0583g乙酰丙酮氧钒加入装有60mL N-N二甲基甲酰胺的圆底烧瓶中，在2kHz下，超声分散0.8h，在400r/min、200℃下，进行溶剂热反应20h后，搅拌冷却，用去离子水和无水乙醇分别先后交叉离心洗涤沉淀物6次，在100Pa、-45℃下，冷冻干燥30h，以速率5℃/min升温至400℃，烧结2h，冷却，得五氧化二钒/rGO复合材料；(1) Add 0.02g graphene oxide and 0.0583g vanadyl acetylacetonate into a round-bottomed flask containing 60mL of NN dimethylformamide, at 2kHz, ultrasonically disperse for 0.8h, at 400r/min and 200°C, After solvothermal reaction for 20h, the mixture was stirred and cooled, and the precipitate was washed 6 times with deionized water and anhydrous ethanol by cross-centrifugation, respectively, freeze-dried at 100Pa, -45°C for 30h, and heated to 400°C at a rate of 5°C/min. , sintered for 2h, cooled to obtain vanadium pentoxide/rGO composite;
(2)将2L低镍含量镍钴锰溶液(硫酸镍、硫酸钴和硫酸锰的混合溶液，其中，Ni、Co、Mn离子的总摩尔浓度为2.0mol/L，Ni、Co、Mn的摩尔比为7:1:2)以加料速度50mL/h，泵入装有2L高镍含量镍钴溶液(硫酸镍和硫酸钴的混合溶液，其中，Ni、Co离子的总摩尔浓度为2.0mol/L，Ni、Co离子的摩尔比为9:1)的容器中，搅拌形成混合溶液，与此同时，将该混合溶液以加料速度100mL/h，泵入装有2L、2mol/L氨水溶液的反应釜中，并同时用质量浓度25％的氨水调节反应体系的氨水浓度保持在2mol/L，用4L、5mol/L氢氧化钠沉淀剂溶液调节反应体系的pH值至11.45，通入高纯氮气气氛下，在1000r/min、50℃下，加热搅拌并进行共沉淀反应42h后，在50℃下，搅拌陈化16h，过滤，用去离子水与乙醇分别先后交叉洗涤过滤物6次，在90℃下，干燥20h，得全梯度镍钴锰氢氧化物前驱体；(2) 2L of low nickel content nickel-cobalt-manganese solution (mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate, wherein, the total molar concentration of Ni, Co, Mn ions is 2.0mol/L, and the molar concentration of Ni, Co, Mn is 2.0 mol/L. The ratio is 7:1:2) with a feeding rate of 50mL/h, pumped into a 2L high nickel content nickel-cobalt solution (a mixed solution of nickel sulfate and cobalt sulfate, wherein the total molar concentration of Ni and Co ions is 2.0mol/ L, the molar ratio of Ni, Co ions is 9:1) in the container, stir to form a mixed solution, at the same time, this mixed solution is pumped into a 2L, 2mol/L ammonia solution with a feeding speed of 100mL/h. In the reaction kettle, the ammonia concentration of the reaction system was regulated at 2 mol/L with 25% ammonia water of mass concentration, and the pH value of the reaction system was adjusted to 11.45 with 4L, 5mol/L sodium hydroxide precipitant solution, and a high-purity solution was introduced. Under a nitrogen atmosphere, at 1000 r/min, 50 °C, heating and stirring for 42 h and co-precipitation reaction, at 50 °C, stirring and aging for 16 h, filtering, and deionized water and ethanol were used to cross-wash the filtrate 6 times, respectively. At 90°C, drying for 20h to obtain the full gradient nickel-cobalt-manganese hydroxide precursor;
(3)将1.0g步骤(2)所得全梯度镍钴锰氢氧化物前驱体(Ni 8.404mmol、Co 1.0805mmol、Mn 0.5155mmol)与0.463487g(11.0485mmol)一水合氢氧化锂混合研磨后，在高纯氧气气氛下，先以速率5℃/min升温至450℃，烧结4h后，再以速率5℃/min升温至750℃下，烧结12h，进行两段式烧结，冷却至室温，得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料；
(3) after mixing and grinding 1.0g of the full gradient nickel-cobalt-manganese hydroxide precursor (Ni 8.404mmol, Co 1.0805mmol, Mn 0.5155mmol) obtained in step (2) and 0.463487g (11.0485mmol) lithium hydroxide monohydrate, In a high-purity oxygen atmosphere, the temperature was first heated to 450°C at a rate of 5°C/min, after sintering for 4 hours, and then heated to 750°C at a rate of 5°C/min, sintered for 12 hours, two-stage sintering was performed, and cooled to room temperature to obtain Full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material;
(4)将0.03g步骤(1)所得五氧化二钒/rGO复合材料和步骤(3)所得1.0g全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料，在300r/min下，转动搅拌10h后，在100℃下，烘干2h，得五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料。
(4) 0.03 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) were rotated and stirred for 10 h at 300 r/min. After drying at 100°C for 2 hours, a LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
如图1所示，本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料与PDF卡片上LiNiO
2(PDF#85-1966)的特征峰符合，无杂相生成。
As shown in Figure 1, the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated .
如图2所示，本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的形貌较好的继承了全梯度镍钴锰酸锂的形貌，二次颗粒为类球核壳结构，平均粒径为6μm，在二次颗粒表面形成了一层五氧化二钒/rGO复合薄膜。
As shown in FIG. 2 , the morphology of the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material coated with vanadium pentoxide/rGO according to the embodiment of the present invention better inherits the morphology of the fully gradient nickel cobalt lithium manganate, and the secondary particles It is a spherical core-shell structure with an average particle size of 6 μm, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
如图3所示，本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的表面包覆了一层五氧化二钒/rGO复合材料，五氧化二钒/rGO的平均厚度为5nm。
As shown in FIG. 3 , the surface of the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in the embodiment of the present invention is coated with a layer of vanadium pentoxide/rGO composite material, vanadium pentoxide/rGO The average thickness is 5 nm.
如图4所示，本发明实施例步骤(3)所得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料中，镍元素的含量从LiNi
0.84Co
0.11Mn
0.05O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.84Co
0.11Mn
0.05O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.84Co
0.11Mn
0.05O
2中均匀分布，说明其为梯度多晶 团聚体。
As shown in FIG. 4 , in the fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) of the embodiment of the present invention, the content of nickel element gradually decreases from the center of LiNi 0.84 Co 0.11 Mn 0.05 O 2 to the surface, and the content of manganese element decreases gradually. The content of cobalt increases gradually from the center to the surface of LiNi 0.84 Co 0.11 Mn 0.05 O 2 , and the content of cobalt is uniformly distributed in LiNi 0.84 Co 0.11 Mn 0.05 O 2 , indicating that it is a gradient polycrystalline agglomerate.
如图5所示，本发明实施五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料相对于步骤(3)所得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料，经过五氧化二钒/rGO包覆后，在XPS全谱图中可以看到钒的特征峰。
As shown in FIG. 5 , the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by vanadium pentoxide/rGO in the present invention, compared with the full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3), undergoes dioxygen pentoxide After vanadium/rGO coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
电池组装：称取0.80g本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料，加入0.1g乙炔黑作导电剂和0.1gPVDF聚偏氟乙烯作粘结剂，并以N-甲基吡咯烷酮作为溶剂混合研磨形成正极材料；将所得正极材料涂于铝箔表面制成极片；在充满氩气的密闭手套箱中，以该极片为正极，金属锂片为负极，微孔聚丙烯膜作为隔膜，1mol/L LiPF
6/EC:DMC(体积比1:1)为电解液，组装成CR2025的扣式电池，并进行充放电性能测试。
Battery assembly: Weigh 0.80g of the vanadium pentoxide/rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material of the embodiment of the present invention, add 0.1g acetylene black as a conductive agent and 0.1g PVDF polyvinylidene fluoride as a binder, And use N-methylpyrrolidone as a solvent to mix and grind to form a positive electrode material; apply the obtained positive electrode material on the surface of aluminum foil to make a pole piece; in a closed glove box filled with argon, use the pole piece as the positive electrode and the metal lithium sheet as the negative electrode , microporous polypropylene film as separator, 1mol/L LiPF 6 /EC:DMC (volume ratio 1:1) as electrolyte, assembled into CR2025 button battery, and tested the charge-discharge performance.
如图6所示，本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池，在0.1C(20mAh/g)、5C、10C的电流密度下，放电比容量分别为199mAh/g、164.2mAh/g、146.5mAh/g，说明该正极材料在充放电过程中能够保持结构的稳定，充放电反应高度可逆。
As shown in FIG. 6 , the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO according to the embodiment of the present invention, under the current densities of 0.1C (20mAh/g), 5C, and 10C, The specific discharge capacities are 199mAh/g, 164.2mAh/g, and 146.5mAh/g, respectively, indicating that the cathode material can maintain structural stability during the charge-discharge process, and the charge-discharge reaction is highly reversible.
如图7所示，本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池，在2.7～4.3V充放电电压，0.1C(20mA/g，前3圈)的电流密度下，首次放电比容量可高达199mAh/g，电流密度为200mA/g下的首次放电比容量为191.3mAh/g，循环100圈后，放电比容量仍可达168.2mAh/g，容量保持率可高达87.92％，说明本发明实施例五氧化二钒/rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料的循环稳定性较好。
As shown in FIG. 7 , the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, before At the current density of 3 cycles), the first discharge specific capacity can be as high as 199mAh/g, and the first discharge specific capacity at a current density of 200mA/g is 191.3mAh/g. After 100 cycles, the discharge specific capacity can still reach 168.2mAh/g. g, the capacity retention rate can be as high as 87.92%, indicating that the LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material covered by vanadium pentoxide/rGO in the embodiment of the present invention has better cycle stability.
实施例2五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料
Example 2 Vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material
所述正极材料是由五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2形成的球形核壳结构颗粒；所述五氧化二钒/rGO与LiNi
0.83Co
0.1Mn
0.07O
2的质量比为0.02:1；所述五氧化二钒/rGO复合材料由五氧化二钒在rGO层间锚定形成整体包覆层，五氧化二钒与rGO的质量比为1.5:1；所述LiNi
0.83Co
0.1Mn
0.07O
2为全梯度材料，镍元素的含量从LiNi
0.83Co
0.1Mn
0.07O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.83Co
0.1Mn
0.07O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.83Co
0.1Mn
0.07O
2中均匀分布；所述五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料的平均粒径为5μm；所述五氧化二钒/rGO的平均厚度为4nm。
The positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.83 Co 0.1 Mn 0.07 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.83 Co 0.1 Mn 0.07 O 2 is 0.02:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an overall coating layer, and the mass ratio of vanadium pentoxide to rGO is 1.5:1; the LiNi 0.83 Co 0.1 Mn 0.07 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 high, the content of cobalt element is uniformly distributed in LiNi 0.83 Co 0.1 Mn 0.07 O 2 ; the average particle size of the LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material coated with vanadium pentoxide/rGO is 5 μm; the pentoxide The average thickness of vanadium/rGO is 4 nm.
实施例2五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料的制备方法
Example 2 Preparation method of vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material
(1)将0.01g氧化石墨烯和0.0438g乙酰丙酮氧钒加入装有60mL N-N二甲基甲酰胺的圆底烧瓶中，在2kHz下，超声分散0.5h，在500r/min、180℃下，进行溶剂热反应16h后，搅拌冷却，用去离子水和无水乙醇分别先后交叉离心洗涤沉淀物6次，在90Pa、-50℃下，冷冻干燥24h，以速率3℃/min升温至350℃，烧结2.5h，冷却，得五氧化二钒/rGO复合材料；(1) Add 0.01g graphene oxide and 0.0438g vanadyl acetylacetonate into a round-bottomed flask containing 60mL of NN dimethylformamide, at 2kHz, ultrasonically disperse for 0.5h, at 500r/min and 180°C, After solvothermal reaction for 16 h, the mixture was stirred and cooled, and the precipitate was washed with deionized water and absolute ethanol by cross-centrifugation for 6 times, freeze-dried at 90 Pa, -50 °C for 24 h, and heated to 350 °C at a rate of 3 °C/min. , sintered for 2.5h, cooled to obtain vanadium pentoxide/rGO composite;
(2)将2L低镍含量镍钴锰溶液(硝酸镍、硝酸钴和硝酸锰的混合溶液，其中，Ni、Co、 Mn离子的总摩尔浓度为2.0mol/L，Ni、Co、Mn的摩尔比为7:1.5:1.5)以加料速度45mL/h，泵入装有2L高镍含量镍钴锰溶液(硝酸镍、硝酸钴和硝酸锰的混合溶液，其中，Ni、Co、Mn离子的总摩尔浓度为2.0mol/L，Ni、Co、Mn离子的摩尔比为9:0.5:0.5)的容器中，搅拌形成混合溶液，与此同时，将该混合溶液以加料速度90mL/h，泵入装有2L、2mol/L氨水溶液的反应釜中，并同时用质量浓度25％的氨水调节反应体系的氨水浓度保持在2mol/L，用4L、5mol/L氢氧化钾沉淀剂溶液调节反应体系的pH值至11.30，通入高纯氮气气氛下，在1100r/min、45℃下，加热搅拌并进行共沉淀反应36h后，在45℃下，搅拌陈化20h，过滤，用去离子水与乙醇分别先后交叉洗涤过滤物6次，在80℃下，干燥24h，得全梯度镍钴锰氢氧化物前驱体；(2) 2L low nickel content nickel-cobalt-manganese solution (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein, the total molar concentration of Ni, Co, Mn ions is 2.0mol/L, the molar concentration of Ni, Co, Mn is 2.0 mol/L; The ratio is 7:1.5:1.5) at a feeding rate of 45mL/h, pumped into 2L high nickel content nickel-cobalt-manganese solution (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the total of Ni, Co, Mn ions is The molar concentration is 2.0mol/L, and the molar ratio of Ni, Co, Mn ions is 9:0.5:0.5), stirring to form a mixed solution, at the same time, the mixed solution is pumped at a feeding speed of 90mL/h In the reactor of 2L, 2mol/L ammonia solution is housed, and the ammonia concentration that regulates reaction system with the ammoniacal liquor of mass concentration 25% remains at 2mol/L simultaneously, regulates the reaction system with 4L, 5mol/L potassium hydroxide precipitant solution The pH value of the solution reached 11.30, and the high-purity nitrogen atmosphere was introduced. After heating and stirring at 1100 r/min and 45 ° C for 36 h, the co-precipitation reaction was carried out, and then at 45 ° C, stirring and aging for 20 h. The filtrate was cross-washed 6 times with ethanol, and dried at 80 °C for 24 h to obtain the full-gradient nickel-cobalt-manganese hydroxide precursor;
(3)将1.0g步骤(2)所得全梯度镍钴锰氢氧化物前驱体(Ni 9.1mmol、Co 1.1mmol、Mn0.78mmol)与0.4258g(5.762mmol)碳酸锂混合研磨后，在高纯氧气气氛下，先以速率3℃/min升温至400℃，烧结5h后，再以速率3℃/min升温至700℃下，烧结10h，进行两段式烧结，冷却至室温，得全梯度LiNi
0.83Co
0.1Mn
0.07O
2材料；
(3) After mixing and grinding 1.0 g of the full-gradient nickel-cobalt-manganese hydroxide precursor (Ni 9.1 mmol, Co 1.1 mmol, Mn 0.78 mmol) obtained in step (2) and 0.4258 g (5.762 mmol) of lithium carbonate, the high-purity In an oxygen atmosphere, the temperature was first heated to 400°C at a rate of 3°C/min, after sintering for 5 hours, and then heated to 700°C at a rate of 3°C/min, sintered for 10 hours, two-stage sintering was performed, and cooled to room temperature to obtain a full gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material;
(4)将0.02g步骤(1)所得五氧化二钒/rGO复合材料和步骤(3)所得1.0g全梯度LiNi
0.83Co
0.1Mn
0.07O
2材料，在250r/min下，转动搅拌12h后，在120℃下，烘干2h，得五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料。
(4) 0.02 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full-gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material obtained in step (3) were rotated and stirred at 250 r/min for 12 h. After drying at 120°C for 2 hours, a LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料与PDF卡片上LiNiO
2(PDF#85-1966)的特征峰符合，无杂相生成。
After testing, the vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料的形貌较好的继承了全梯度镍钴锰酸锂的形貌，二次颗粒为类球形核壳结构，平均粒径为5μm，在二次颗粒表面形成了一层五氧化二钒/rGO复合薄膜。
After testing, the morphology of the LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention better inherits the morphology of the full gradient nickel cobalt lithium manganate, and the secondary particles are spherical. The core-shell structure has an average particle size of 5 μm, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料的表面包覆了一层五氧化二钒/rGO复合材料，五氧化二钒/rGO的平均厚度为4nm。
After testing, the surface of the vanadium pentoxide/rGO-coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is covered with a layer of vanadium pentoxide/rGO composite material, and the average thickness of the vanadium pentoxide/rGO is 4nm.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料中镍元素的含量从LiNi
0.83Co
0.1Mn
0.07O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.83Co
0.1Mn
0.07O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.83Co
0.1Mn
0.07O
2中均匀分布。
After testing, the content of nickel element in the LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention gradually decreased from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 , and the content of manganese element The content of cobalt element is uniformly distributed in LiNi 0.83 Co 0.1 Mn 0.07 O 2 from the center to the surface of LiNi 0.83 Co 0.1 Mn 0.07 O 2 gradually increasing.
经检测，本发明实施五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料相对于步骤(3)全梯度LiNi
0.83Co
0.1Mn
0.07O
2材料，经过五氧化二钒/rGO包覆后，在XPS全谱图中可以看到钒的特征峰。
After testing, the present invention implements vanadium pentoxide/rGO coating LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material relative to step (3) full gradient LiNi 0.83 Co 0.1 Mn 0.07 O 2 material, through vanadium pentoxide/rGO coating After coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
电池组装：同实施例1。Battery assembly: same as Example 1.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料所组装的电池，在0.1C(20mAh/g)、5C、10C的电流密度下，放电比容量分别为196.3mAh/g、158.2mAh/g、 143.1mAh/g，说明该正极材料在充放电过程中能够保持结构的稳定，充放电反应高度可逆。
After testing, the battery assembled by vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention has a specific discharge capacity at current densities of 0.1C (20mAh/g), 5C, and 10C. They are 196.3 mAh/g, 158.2 mAh/g, and 143.1 mAh/g, respectively, indicating that the positive electrode material can keep the structure stable during the charging and discharging process, and the charging and discharging reaction is highly reversible.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料所组装的电池，在2.7～4.3V充放电电压，0.1C(20mA/g，前3圈)的电流密度下，首次放电比容量可高达196.3mAh/g，电流密度为200mA/g下的首次放电比容量为189.6mAh/g，循环100圈后，放电比容量仍可达159.2mAh/g，容量保持率可高达83.97％，说明本发明实施例五氧化二钒/rGO包覆LiNi
0.83Co
0.1Mn
0.07O
2正极材料的循环稳定性较好。
After testing, the battery assembled with the LiNi 0.83 Co 0.1 Mn 0.07 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, the first 3 turns) At the same current density, the first discharge specific capacity can be as high as 196.3mAh/g, the first discharge specific capacity at 200mA/g is 189.6mAh/g, and after 100 cycles, the discharge specific capacity can still reach 159.2mAh/g, The capacity retention rate can be as high as 83.97%, indicating that the vanadium pentoxide/rGO coated LiNi 0.83 Co 0.1 Mn 0.07 O 2 cathode material in the embodiment of the present invention has better cycle stability.
实施例3五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料
Example 3 Vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material
所述正极材料是由五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2形成的球形核壳结构颗粒；所述五氧化二钒/rGO与LiNi
0.82Co
0.11Mn
0.07O
2的质量比为0.04:1；所述五氧化二钒/rGO复合材料由五氧化二钒在rGO层间锚定形成整体包覆层，五氧化二钒与rGO的质量比为2:1；所述LiNi
0.82Co
0.11Mn
0.07O
2为全梯度材料，镍元素的含量从LiNi
0.82Co
0.11Mn
0.07O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.82Co
0.11Mn
0.07O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.82Co
0.11Mn
0.07O
2中均匀分布；所述五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料的平均粒径为7μm；所述五氧化二钒/rGO的平均厚度为6nm。
The positive electrode material is a spherical core-shell structure particle formed by coating LiNi 0.82 Co 0.11 Mn 0.07 O 2 with vanadium pentoxide/rGO; the mass ratio of the vanadium pentoxide/rGO to LiNi 0.82 Co 0.11 Mn 0.07 O 2 is 0.04:1; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an overall coating layer, and the mass ratio of vanadium pentoxide to rGO is 2:1; the LiNi 0.82 Co 0.11 Mn 0.07 O 2 is a full gradient material, the content of nickel gradually decreases from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 , and the content of manganese gradually increases from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 high, the content of cobalt element is uniformly distributed in LiNi 0.82 Co 0.11 Mn 0.07 O 2 ; the average particle size of the LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material covered by the vanadium pentoxide/rGO is 7 μm; the pentoxide The average thickness of vanadium/rGO is 6 nm.
实施例3五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料的制备方法
Example 3 Preparation method of vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material
(1)将0.02g氧化石墨烯和0.0515g偏钒酸铵加入装有60mL N-N二甲基甲酰胺的圆底烧瓶中，在2kHz下，超声分散1.0h，在300r/min、220℃下，进行溶剂热反应24h后，搅拌冷却，用去离子水和无水乙醇分别先后交叉离心洗涤沉淀物7次，在80Pa、-40℃下，冷冻干燥36h，以速率7℃/min升温至450℃，烧结1.5h，冷却，得五氧化二钒/rGO复合材料；(1) Add 0.02g graphene oxide and 0.0515g ammonium metavanadate into a round-bottomed flask containing 60mL of NN dimethylformamide, at 2kHz, ultrasonically disperse for 1.0h, at 300r/min and 220°C, After solvothermal reaction for 24h, the mixture was stirred and cooled, and the precipitate was washed 7 times with deionized water and anhydrous ethanol by cross-centrifugation, freeze-dried at 80Pa and -40°C for 36h, and heated to 450°C at a rate of 7°C/min. , sintered for 1.5h, cooled to obtain vanadium pentoxide/rGO composite;
(2)将2L低镍含量镍钴锰溶液(硝酸镍、硝酸钴和硝酸锰的混合溶液，其中，Ni、Co、Mn离子的总摩尔浓度为2.0mol/L，Ni、Co、Mn的摩尔比为7:1.5:1.5)以加料速度55mL/h，泵入装有2L高镍含量镍钴锰溶液(硝酸镍、硝酸钴和硝酸锰的混合溶液，其中，Ni、Co、Mn离子的总摩尔浓度为2.0mol/L，Ni、Co、Mn离子的摩尔比为9:0.5:0.5)的容器中，搅拌形成混合溶液，与此同时，将该混合溶液以加料速度110mL/h，泵入装有2L、2mol/L氨水溶液的反应釜中，并同时用质量浓度25％的氨水调节反应体系的氨水浓度保持在2mol/L，用4L、5mol/L氢氧化钠沉淀剂溶液调节反应体系的pH值至11.50，通入高纯氩气气氛下，在900r/min、55℃下，加热搅拌并进行共沉淀反应48h后，在55℃下，搅拌陈化12h，过滤，用去离子水与乙醇分别先后交叉洗涤过滤物7次，在100℃下，干燥16h，得全梯度镍钴锰氢氧化物前驱体；(2) 2L of low nickel content nickel-cobalt-manganese solution (a mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the total molar concentration of Ni, Co, and Mn ions is 2.0 mol/L, and the molar concentration of Ni, Co, and Mn is 2.0 mol/L). The ratio is 7:1.5:1.5) at a feeding rate of 55mL/h, pumped into 2L high nickel content nickel-cobalt-manganese solution (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the total of Ni, Co, Mn ions is The molar concentration is 2.0mol/L, and the molar ratio of Ni, Co, Mn ions is 9:0.5:0.5), stirring to form a mixed solution. In the reactor of 2L, 2mol/L aqueous ammonia solution, and at the same time, the ammonia concentration of the reaction system is regulated at 2mol/L with the ammonia solution of 25% mass concentration, and the reaction system is adjusted with 4L, 5mol/L sodium hydroxide precipitant solution. The pH value of the solution reached 11.50, and the high-purity argon atmosphere was introduced. After heating and stirring at 900 r/min and 55 ° C for 48 h, the co-precipitation reaction was carried out at 55 ° C. After stirring and aging for 12 h, filtered and deionized water The filtrate was cross-washed with ethanol for 7 times, and dried at 100 °C for 16 h to obtain the full gradient nickel-cobalt-manganese hydroxide precursor;
(3)将1.0g步骤(2)所得全梯度镍钴锰氢氧化物前驱体(Ni 8.72mmol、Co 1.18mmol、Mn0.67mmol)与0.4661g(11.11mmol)一水合氢氧化锂混合研磨后，在高纯氧气气氛下，先以速率7℃/min升温至500℃，烧结3h后，再以速率7℃/min升温至800℃下，烧结14h，进行 两段式烧结，冷却至室温，得全梯度LiNi
0.82Co
0.11Mn
0.07O
2材料；
(3) After mixing and grinding 1.0 g of the full gradient nickel-cobalt-manganese hydroxide precursor (Ni 8.72 mmol, Co 1.18 mmol, Mn 0.67 mmol) obtained in step (2) and 0.4661 g (11.11 mmol) of lithium hydroxide monohydrate, In a high-purity oxygen atmosphere, the temperature was first heated to 500°C at a rate of 7°C/min, after sintering for 3 hours, and then heated to 800°C at a rate of 7°C/min, sintered for 14 hours, and two-stage sintering was performed, and cooled to room temperature to obtain Full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material;
(4)将0.04g步骤(1)所得五氧化二钒/rGO复合材料和步骤(3)所得1.0g全梯度LiNi
0.82Co
0.11Mn
0.07O
2材料，在350r/min下，转动搅拌8h后，在80℃下，烘干3h，得五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料。
(4) 0.04 g of the vanadium pentoxide/rGO composite material obtained in step (1) and 1.0 g of the full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material obtained in step (3) were rotated and stirred at 350 r/min for 8 h, After drying at 80°C for 3 hours, a LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material was obtained by vanadium pentoxide/rGO coating.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料与PDF卡片上LiNiO
2(PDF#85-1966)的特征峰符合，无杂相生成。
After testing, the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is consistent with the characteristic peaks of LiNiO 2 (PDF#85-1966) on the PDF card, and no impurity is generated.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料的形貌较好的继承了全梯度镍钴锰酸锂的形貌，二次颗粒为类球形核壳结构，平均粒径为7μm，在二次颗粒表面形成了一层五氧化二钒/rGO复合薄膜。
After testing, the morphology of the LiNi 0.82 Co 0.11 Mn 0.07 O 2 cathode material coated with vanadium pentoxide/rGO in the embodiment of the present invention better inherits the morphology of the full gradient nickel cobalt lithium manganate, and the secondary particles are spherical. The core-shell structure has an average particle size of 7 μm, and a layer of vanadium pentoxide/rGO composite film is formed on the surface of the secondary particles.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料的表面包覆了一层五氧化二钒/rGO复合材料，五氧化二钒/rGO的平均厚度为6nm。
After testing, the surface of the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention is coated with a layer of vanadium pentoxide/rGO composite material, and the average thickness of the vanadium pentoxide/rGO is 6nm.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料中镍元素的含量从LiNi
0.82Co
0.11Mn
0.07O
2的中心至表面逐渐降低，锰元素的含量从LiNi
0.82Co
0.11Mn
0.07O
2的中心至表面逐渐升高，钴元素的含量在LiNi
0.82Co
0.11Mn
0.07O
2中均匀分布。
After testing, the content of nickel element in the LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material coated with vanadium pentoxide/rGO in the embodiment of the present invention gradually decreased from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 , and the content of manganese element The content of cobalt element is uniformly distributed in LiNi 0.82 Co 0.11 Mn 0.07 O 2 from the center to the surface of LiNi 0.82 Co 0.11 Mn 0.07 O 2 gradually increasing.
经检测，本发明实施五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料相对于步骤(3)全梯度LiNi
0.82Co
0.11Mn
0.07O
2材料，经过五氧化二钒/rGO包覆后，在XPS全谱图中可以看到钒的特征峰。
After testing, the present invention implements the vanadium pentoxide/rGO coating LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material relative to the step (3) full gradient LiNi 0.82 Co 0.11 Mn 0.07 O 2 material, through the vanadium pentoxide/rGO coating After coating, the characteristic peaks of vanadium can be seen in the XPS full spectrum.
电池组装：同实施例1。Battery assembly: same as Example 1.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料所组装的电池，在0.1C(20mAh/g)、5C、10C的电流密度下，放电比容量分别为197.2mAh/g、159.4mAh/g、145mAh/g，说明该正极材料在充放电过程中能够保持结构的稳定，充放电反应高度可逆。
After testing, the battery assembled by vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material in the embodiment of the present invention has a specific discharge capacity at current densities of 0.1C (20mAh/g), 5C, and 10C. They are 197.2mAh/g, 159.4mAh/g, and 145mAh/g, respectively, indicating that the positive electrode material can maintain structural stability during the charging and discharging process, and the charging and discharging reaction is highly reversible.
经检测，本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料所组装的电池，在2.7～4.3V充放电电压，0.1C(20mA/g，前3圈)的电流密度下，首次放电比容量可高达197.2mAh/g，电流密度为200mA/g下的首次放电比容量为187.6mAh/g，循环100圈后，放电比容量仍可达158.4mAh/g，容量保持率可高达84.43％，说明本发明实施例五氧化二钒/rGO包覆LiNi
0.82Co
0.11Mn
0.07O
2正极材料的循环稳定性较好。
After testing, the battery assembled with the LiNi 0.82 Co 0.11 Mn 0.07 O 2 positive electrode material covered by vanadium pentoxide/rGO in the embodiment of the present invention has a charge-discharge voltage of 2.7-4.3V, 0.1C (20mA/g, the first 3 turns) The first discharge specific capacity can reach 197.2mAh/g under the current density of 200mA/g, and the first discharge specific capacity is 187.6mAh/g at the current density of 200mA/g. After 100 cycles, the discharge specific capacity can still reach 158.4mAh/g. The capacity retention rate can be as high as 84.43%, indicating that the vanadium pentoxide/rGO coated LiNi 0.82 Co 0.11 Mn 0.07 O 2 cathode material in the embodiment of the present invention has better cycle stability.
对比例1全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料
Comparative example 1 full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material
本对比例即为实施例1步骤(3)所得全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料。
This comparative example is the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (3) of Example 1.
如图8所示，本对比例全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料的二次颗粒大小分布均匀，呈类球形，平均粒径为6μm。
As shown in FIG. 8 , the secondary particle size distribution of the fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material of this comparative example is uniform and spherical, with an average particle size of 6 μm.
经检测，本对比例LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池，在充放电电压为2.7～ 4.3V，在0.1C(20mA/g)、5C、10C的电流密度下，放电比容量分别为205.4mAh/g、145.5mAh/g、121.6mAh/g，LiNi
0.84Co
0.11Mn
0.05O
2正极材料在小电流密度条件下的放电比容量基本不变，而在10C电流密度时放电比容量明显下降，说明没有经过包覆的正极材料充放电反应可逆性较差。
After testing, the battery assembled with the LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material in this comparative example has a charge-discharge voltage of 2.7 to 4.3V and a current density of 0.1C (20mA/g), 5C, and 10C. The capacities are 205.4mAh/g, 145.5mAh/g, 121.6mAh/g, respectively. The discharge specific capacity of LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material is basically unchanged at low current density, while the discharge ratio at 10C current density is basically unchanged. The capacity dropped significantly, indicating that the charge-discharge reaction of the uncoated positive electrode material was poor in reversibility.
如图9所示，本对比例全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料所组装的电池，在2.7～4.3V充放电电压，0.1C(20mA/g，前3圈)的电流密度下，首次放电比容量可高达205.4mAh/g，电流密度为200mA/g下的首次放电比容量为198.8mAh/g，循环100圈后，放电比容量仅为151.2mAh/g，容量保持率仅为76.06％，说明本对比例全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料在没有进行五氧化二钒/rGO包覆前的循环稳定性较差。
As shown in Figure 9, the battery assembled with the full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material of this comparative example, under the charge-discharge voltage of 2.7-4.3V and the current density of 0.1C (20mA/g, the first 3 turns), The first discharge specific capacity can be as high as 205.4mAh/g, the first discharge specific capacity at a current density of 200mA/g is 198.8mAh/g, after 100 cycles, the discharge specific capacity is only 151.2mAh/g, and the capacity retention rate is only 76.06 %, indicating that the full-gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material of this comparative example has poor cycle stability before being coated with vanadium pentoxide/rGO.
对比例2 rGO包覆全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料的制备方法
Comparative example 2 Preparation method of rGO-coated fully gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material
(1)同实施例1步骤(2)；(1) step (2) with embodiment 1;
(2)同实施例1步骤(3)；(2) step (3) with embodiment 1;
(3)将0.01g氧化石墨烯和步骤(2)所得1.0g全梯度LiNi
0.84Co
0.11Mn
0.05O
2材料，在300r/min下，转动搅拌10h后，在100℃下，烘干2h，得rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料。
(3) 0.01g graphene oxide and 1.0g full gradient LiNi 0.84 Co 0.11 Mn 0.05 O 2 material obtained in step (2) were rotated and stirred at 300 r/min for 10 hours, and then dried at 100° C. for 2 hours to obtain rGO coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material.
如图10所示，本对比例rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料在材料的表面有一层平均厚度5nm的还原氧化石墨烯包覆层。
As shown in Figure 10, the rGO-coated LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material of this comparative example has a reduced graphene oxide coating layer with an average thickness of 5 nm on the surface of the material.
经检测，本对比例rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池，在充放电电压为2.7～4.3V，在0.1C(20mA/g)、5C、10C的电流密度下，放电比容量分别为196.7mAh/g、153.6mAh/g、132.3mAh/g，经过rGO包覆后正极材料在小电流密度条件下的放电比容量基本不变，而在10C电流密度时放电比容量虽然相对于没有包覆的正极材料有所上升，但仍然不佳，说明仅经过rGO包覆的正极材料充放电反应可逆性仍然较差。
After testing, the battery assembled with LiNi 0.84 Co 0.11 Mn 0.05 O 2 positive electrode material covered by rGO in this comparative example has a charge-discharge voltage of 2.7-4.3V and a current density of 0.1C (20mA/g), 5C, and 10C. , the discharge specific capacities are 196.7mAh/g, 153.6mAh/g, and 132.3mAh/g, respectively. After rGO coating, the discharge specific capacity of the cathode material under the condition of low current density is basically unchanged, while the discharge specific capacity at 10C current density Although the capacity has increased compared to the uncoated cathode material, it is still not good, indicating that the charge-discharge reaction reversibility of the cathode material only coated with rGO is still poor.
如图11所示，本对比例rGO包覆LiNi
0.84Co
0.11Mn
0.05O
2正极材料所组装的电池，在充放电电压为2.7～4.3V，0.1C(20mA/g，前3圈)的电流密度下，所组装电池的首次放电比容量为196.7mAh/g，电流密度为200mA/g下的首次放电比容量为189.8mAh/g，循环100圈后，放电比容量保持在151.4mAh/g，容量保持率为79.77％，说明仅经rGO包覆的正极材料的循环稳定性仍然较差。
As shown in Figure 11, the battery assembled with LiNi 0.84 Co 0.11 Mn 0.05 O 2 cathode material covered by rGO in this comparative example has a charge-discharge voltage of 2.7-4.3V and a current of 0.1C (20mA/g, the first 3 turns). Under the density, the first discharge specific capacity of the assembled battery is 196.7mAh/g, and the first discharge specific capacity under the current density is 200mA/g is 189.8mAh/g. After 100 cycles, the discharge specific capacity remains at 151.4mAh/g, The capacity retention rate is 79.77%, indicating that the cycling stability of the cathode material only coated with rGO is still poor.
Claims (8)
- 一种五氧化二钒/rGO包覆镍钴锰酸锂正极材料，其特征在于：所述正极材料是由五氧化二钒/rGO包覆镍钴锰酸锂形成的球形核壳结构颗粒；所述五氧化二钒/rGO与镍钴锰酸锂的质量比为0.01～0.05:1；所述镍钴锰酸锂的化学式为LiNi xCo yMn (1-x-y)O 2，其中0.75≤x≤0.85，0.05≤y≤0.15，1-x-y＞0；所述五氧化二钒/rGO复合材料由五氧化二钒在rGO层间锚定形成整体包覆层，五氧化二钒与rGO的质量比为1～3:1。 A vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate positive electrode material, characterized in that: the positive electrode material is a spherical core-shell structure particle formed by vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate; The mass ratio of vanadium pentoxide/rGO to lithium nickel cobalt manganate is 0.01 to 0.05:1; the chemical formula of lithium nickel cobalt manganate is LiNi x Co y Mn (1-xy) O 2 , where 0.75≤x ≤0.85, 0.05≤y≤0.15, 1-xy>0; the vanadium pentoxide/rGO composite material is anchored by vanadium pentoxide between the rGO layers to form an overall coating layer, the quality of vanadium pentoxide and rGO The ratio is 1 to 3:1.
- 根据权利要求1所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料，其特征在于：所述镍钴锰酸锂为全梯度材料，镍元素的含量从镍钴锰酸锂的中心至表面逐渐降低，锰元素的含量从镍钴锰酸锂的中心至表面逐渐升高，钴元素的含量在镍钴锰酸锂中均匀分布；所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的平均粒径为4～8μm；所述五氧化二钒/rGO的平均厚度为3～6nm。The vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate cathode material according to claim 1, wherein the nickel-cobalt lithium manganate is a full gradient material, and the content of nickel is from the center of the nickel-cobalt lithium manganate When the surface gradually decreases, the content of manganese element gradually increases from the center of the nickel-cobalt lithium manganese oxide to the surface, and the content of cobalt element is uniformly distributed in the nickel-cobalt lithium manganese oxide; the vanadium pentoxide/rGO is coated with nickel-cobalt-manganese oxide. The average particle size of the lithium oxide positive electrode material is 4-8 μm; the average thickness of the vanadium pentoxide/rGO is 3-6 nm.
- 一种如权利要求1或2所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征在于，包括以下步骤：A preparation method of vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material as claimed in claim 1 or 2, characterized in that, comprising the following steps:(1)将氧化石墨烯和钒源加入有机溶剂中超声分散，进行溶剂热反应后，搅拌冷却，离心洗涤，干燥，烧结，冷却，得五氧化二钒/rGO复合材料；(1) adding graphene oxide and a vanadium source into an organic solvent for ultrasonic dispersion, after performing a solvothermal reaction, stirring and cooling, centrifugal washing, drying, sintering, and cooling to obtain a vanadium pentoxide/rGO composite material;(2)将低镍含量镍钴锰溶液泵入装有高镍含量镍钴或镍钴锰溶液的容器中，搅拌形成混合溶液，与此同时，将该混合溶液泵入装有氨水溶液的反应釜中，并同时用氨水调节反应体系的氨水浓度，用氢氧化物沉淀剂溶液调节反应体系的pH值，通入保护气氛下，加热搅拌并进行共沉淀反应后，搅拌陈化，过滤，洗涤，干燥，得全梯度镍钴锰氢氧化物前驱体；(2) low nickel content nickel cobalt manganese solution is pumped into the container that high nickel content nickel cobalt or nickel cobalt manganese solution is housed, stir to form mixed solution, meanwhile, this mixed solution is pumped into the reaction that ammonia solution is housed In the kettle, simultaneously adjust the ammonia concentration of the reaction system with ammonia water, adjust the pH value of the reaction system with hydroxide precipitant solution, pass into the protective atmosphere, heat and stir and carry out co-precipitation reaction, stir and age, filter, wash , and dried to obtain a full gradient nickel-cobalt-manganese hydroxide precursor;(3)将步骤(2)所得全梯度镍钴锰氢氧化物前驱体与锂源混合研磨后，在氧化气氛下，进行两段式烧结，冷却至室温，得全梯度镍钴锰酸锂材料；(3) after the full gradient nickel cobalt manganese hydroxide precursor obtained in step (2) is mixed and ground with a lithium source, two-stage sintering is performed in an oxidizing atmosphere, and cooled to room temperature to obtain a full gradient nickel cobalt manganese lithium material. ;(4)将步骤(1)所得五氧化二钒/rGO复合材料和步骤(3)所得全梯度镍钴锰酸锂材料转动搅拌后，烘干，得五氧化二钒/rGO包覆镍钴锰酸锂正极材料。(4) after rotating and stirring the vanadium pentoxide/rGO composite material obtained in step (1) and the full gradient nickel-cobalt-manganate material obtained in step (3), drying to obtain vanadium pentoxide/rGO coated nickel-cobalt-manganese Lithium oxide cathode material.
- 根据权利要求3所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征在于：步骤(1)中，所述氧化石墨烯、钒源与有机溶剂的质量体积比(g/g/L)为0.1～0.4:0.7～1.0:1；所述钒源为乙酰丙酮氧钒、乙酰丙酮钒或偏钒酸铵中的一种或几种；所述有机溶剂为N-N二甲基甲酰胺；所述超声分散的频率为1.5～2.5kHz，时间为0.5～1.0h；所述溶剂热反应的搅拌速度为300～500r/min，温度为150～250℃，时间为12～24h；所述离心洗涤是用去离子水和无水乙醇分别先后交叉离心洗涤沉淀物≥6次；所述干燥为冷冻干燥；所述冷冻干燥的真空度为80～100Pa，温度为-40～-50℃，时间为24～40h；所述烧结是以速率1～10℃/min升温至300～500℃，烧结1～3h。The preparation method of the vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material according to claim 3, wherein: in step (1), the mass volume ratio of the graphene oxide, the vanadium source and the organic solvent (g/g/L) is 0.1～0.4:0.7～1.0:1; Described vanadium source is one or more in vanadyl acetylacetonate, vanadium acetylacetonate or ammonium metavanadate; Described organic solvent is NN dimethylformamide; the frequency of the ultrasonic dispersion is 1.5-2.5 kHz, and the time is 0.5-1.0 h; the stirring speed of the solvothermal reaction is 300-500 r/min, the temperature is 150-250 ℃, and the time is 12 ~24h; the centrifugal washing is to use deionized water and anhydrous ethanol to successively cross-centrifuge and wash the precipitate ≥6 times; the drying is freeze-drying; the vacuum degree of the freeze-drying is 80-100Pa, and the temperature is -40 ～-50°C, the time is 24～40h; the sintering is heated at a rate of 1～10°C/min to 300～500°C, and sintered for 1～3h.
- 根据权利要求3或4所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征 在于：步骤(2)中，所述低镍含量镍钴锰溶液的加料速度为30～70mL/h；所述混合溶液的加料速度为80～120mL/h；所述低镍含量镍钴锰溶液中，镍、钴、锰离子的总摩尔浓度为0.3～3.0mol/L，镍、钴、锰的摩尔比为3～8:1:0～2；所述高镍含量镍钴或镍钴锰溶液中，镍、钴、锰离子的总摩尔浓度为0.3～4.0mol/L，镍、钴、锰的摩尔比为8～9:0.5～1.0:0～1；在同一反应体系中，低镍含量镍钴锰溶液的镍含量低于高镍含量镍钴或镍钴锰溶液的镍含量；反应釜中氨水溶液、氢氧化物沉淀剂溶液、低镍含量镍钴锰溶液与高镍含量镍钴或镍钴锰溶液的体积比为0.1～10:1～2:1:1；所述氨水溶液的摩尔浓度为1.0～7.0mol/L；用氨水调节反应体系氨水浓度保持在1.0～7.0mol/L；用于调节反应体系氨水浓度的氨水的质量浓度为25～28％；用氢氧化物沉淀剂溶液调节反应体系的pH值保持在10～12；所述氢氧化物沉淀剂溶液的摩尔浓度为1.0～7.0mol/L；所述低镍含量镍钴锰溶液和高镍含量镍钴锰溶液为可溶性镍盐、可溶性钴盐和可溶性锰盐的混合溶液，所述高镍含量镍钴溶液为可溶性镍盐和可溶性钴盐的混合溶液；所述可溶性镍盐为硫酸镍、硝酸镍、乙酸镍或氯化镍，及其水合物中的一种或几种；所述可溶性钴盐为硫酸钴、硝酸钴、乙酸钴或氯化钴，及其水合物中的一种或几种；所述可溶性锰盐为硫酸锰、硝酸锰、乙酸锰或氯化锰，及其水合物中的一种或几种；所述氢氧化物沉淀剂为氢氧化钠、氢氧化钾或氢氧化锂，及其水合物中的一种或几种。According to the preparation method of the vanadium pentoxide/rGO-coated nickel-cobalt-manganate cathode material according to claim 3 or 4, it is characterized in that: in step (2), the feeding rate of the low-nickel content nickel-cobalt-manganese solution is 30-70mL/h; the feeding rate of the mixed solution is 80-120mL/h; in the low-nickel content nickel-cobalt-manganese solution, the total molar concentration of nickel, cobalt and manganese ions is 0.3-3.0mol/L, and the nickel The molar ratio of cobalt, cobalt and manganese is 3～8:1:0～2; in the high nickel content nickel cobalt or nickel cobalt manganese solution, the total molar concentration of nickel, cobalt and manganese ions is 0.3～4.0mol/L, The molar ratio of nickel, cobalt and manganese is 8~9:0.5~1.0:0~1; in the same reaction system, the nickel content of the low nickel content nickel cobalt manganese solution is lower than that of the high nickel content nickel cobalt or nickel cobalt manganese solution. Nickel content; the volume ratio of ammonia solution, hydroxide precipitant solution, low nickel content nickel cobalt manganese solution and high nickel content nickel cobalt or nickel cobalt manganese solution in the reaction kettle is 0.1～10:1～2:1:1; The molar concentration of the aqueous ammonia solution is 1.0-7.0 mol/L; the ammonia water concentration in the reaction system is adjusted with ammonia water to be maintained at 1.0-7.0 mol/L; the mass concentration of the ammonia water used for adjusting the ammonia water concentration in the reaction system is 25-28%; The pH value of the hydroxide precipitant solution to adjust the reaction system is maintained at 10 to 12; the molar concentration of the hydroxide precipitant solution is 1.0 to 7.0 mol/L; the low nickel content nickel cobalt manganese solution and the high nickel content The nickel-cobalt-manganese solution is a mixed solution of soluble nickel salt, soluble cobalt salt and soluble manganese salt, and the high nickel content nickel-cobalt solution is a mixed solution of soluble nickel salt and soluble cobalt salt; the soluble nickel salt is nickel sulfate, nitric acid One or more of nickel, nickel acetate or nickel chloride, and their hydrates; the soluble cobalt salt is cobalt sulfate, cobalt nitrate, cobalt acetate or cobalt chloride, and one or more of their hydrates The soluble manganese salt is one or more of manganese sulfate, manganese nitrate, manganese acetate or manganese chloride, and hydrates thereof; the hydroxide precipitant is sodium hydroxide, potassium hydroxide or hydrogen Lithium oxide, and one or more of its hydrates.
- 根据权利要求3或4所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征在于：步骤(2)中，所述保护气氛为氮气气氛和/或氩气气氛；所述共沉淀反应的搅拌速度为800～1200r/min，温度为30～70℃，时间为30～50h；所述陈化的温度为30～70℃，时间为8～24h；所述洗涤为用去离子水与乙醇分别先后交叉洗涤过滤物≥6次；所述干燥的温度为80～100℃，时间为12～24h。According to the preparation method of vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material according to claim 3 or 4, it is characterized in that: in step (2), the protective atmosphere is nitrogen atmosphere and/or argon atmosphere ; the stirring speed of the co-precipitation reaction is 800-1200r/min, the temperature is 30-70 ℃, and the time is 30-50 h; the temperature of the aging is 30-70 ℃, and the time is 8-24 h; the washing In order to cross-wash the filtrate with deionized water and ethanol for ≥6 times, the drying temperature is 80-100° C. and the time is 12-24 hours.
- 根据权利要求3或4所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征在于：步骤(3)中，所述全梯度镍钴锰氢氧化物前驱体中镍、钴、锰元素摩尔数总和与锂源中锂元素的摩尔比为1:1.04～1.11；所述锂源为氢氧化锂和/或碳酸锂；所述氧化气氛为空气气氛和/或氧气气氛；所述两段式烧结是指：先以速率1～10℃/min升温至350～550℃，烧结2～8h后，再以速率1～10℃/min升温至550～1000℃下，烧结8～20h。The preparation method of the vanadium pentoxide/rGO coated nickel cobalt lithium manganate cathode material according to claim 3 or 4, characterized in that: in step (3), in the full gradient nickel cobalt manganese hydroxide precursor The molar ratio of the sum of moles of nickel, cobalt and manganese elements to the lithium element in the lithium source is 1:1.04 to 1.11; the lithium source is lithium hydroxide and/or lithium carbonate; the oxidizing atmosphere is air atmosphere and/or oxygen Atmosphere; the two-stage sintering refers to: first heating at a rate of 1-10°C/min to 350-550°C, after sintering for 2-8 hours, and then heating at a rate of 1-10°C/min to 550-1000°C, Sintering for 8-20h.
- 根据权利要求3或4所述五氧化二钒/rGO包覆镍钴锰酸锂正极材料的制备方法，其特征在于：步骤(4)中，所述五氧化二钒/rGO复合材料与镍钴锰酸锂材料的质量比为0.01～0.05:1；所述转动搅拌的转速为250～400r/min，时间为8～12h；所述烘干的温度为80～120℃，时间为2～3h。The preparation method of the vanadium pentoxide/rGO-coated nickel-cobalt lithium manganate cathode material according to claim 3 or 4, characterized in that: in step (4), the vanadium pentoxide/rGO composite material and nickel-cobalt The mass ratio of the lithium manganate material is 0.01-0.05:1; the rotational speed of the rotating stirring is 250-400r/min, and the time is 8-12h; the drying temperature is 80-120°C, and the time is 2-3h .
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Cited By (4)
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| CN114628680A (en) * | 2022-03-14 | 2022-06-14 | 辽宁大学 | Preparation method and application of tridecyloxy hexa-vanadium electrode material for water-based zinc ion battery |
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| CN115947385A (en) * | 2022-09-29 | 2023-04-11 | 宁夏汉尧富锂科技有限责任公司 | Preparation method of low-cobalt and cobalt-free precursor and lithium-poor low-cobalt and cobalt-free cathode material and product thereof |
| CN117374270A (en) * | 2023-12-08 | 2024-01-09 | 湖南德景源科技有限公司 | Production process of lithium nickel cobalt manganese positive electrode material powder |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111785960B (en) * | 2020-09-03 | 2020-11-20 | 中南大学 | Vanadium pentoxide/rGO coated nickel cobalt lithium manganate positive electrode material and preparation method thereof |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120321953A1 (en) * | 2011-06-17 | 2012-12-20 | Nanotek Instruments, Inc. | Graphene-enabled vanadium oxide cathode and lithium cells containing same |
| CN110518202A (en) * | 2019-08-05 | 2019-11-29 | 三峡大学 | A kind of V of self-supporting2O5/ rGO nano-array sodium-ion battery material and preparation method thereof |
| CN111092210A (en) * | 2019-12-30 | 2020-05-01 | 中科廊坊过程工程研究院 | Ternary positive electrode composite material and preparation method and application thereof |
| CN111785960A (en) * | 2020-09-03 | 2020-10-16 | 中南大学 | Vanadium pentoxide/rGO coated nickel cobalt lithium manganate positive electrode material and preparation method thereof |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100324624B1 (en) * | 2000-02-26 | 2002-02-27 | 박호군 | Metal oxide electrodes coated with a porous metal film, a porous metaloxide film or a porous carbon film, its fabrication method and lithium secondary battery using it |
| US20100154206A1 (en) * | 2008-12-19 | 2010-06-24 | Conocophillips Company | Process for making composite lithium powders for batteries |
| KR20120039799A (en) * | 2010-10-18 | 2012-04-26 | 한국전기연구원 | Stable dispersion of reduced graphene oxide and its reduced graphene oxide solution |
| US20130171502A1 (en) * | 2011-12-29 | 2013-07-04 | Guorong Chen | Hybrid electrode and surface-mediated cell-based super-hybrid energy storage device containing same |
| CN103855373B (en) * | 2012-11-30 | 2016-08-24 | 海洋王照明科技股份有限公司 | Vanadic anhydride/graphene composite material and its preparation method and application |
| CN103746100B (en) * | 2014-01-21 | 2015-12-30 | 中国计量学院 | A kind of V 2o 5nano particle/graphene lithium ion battery positive pole material and preparation method thereof |
| CN104600290A (en) * | 2014-12-30 | 2015-05-06 | 深圳市贝特瑞新能源材料股份有限公司 | Nickel-cobalt lithium aluminate composite positive electrode material and preparation method thereof |
| CN108780890B (en) * | 2016-01-25 | 2022-03-18 | 魁北克电力公司 | Core-shell electrode material particles and their use in electrochemical cells |
| CN106129405B (en) * | 2016-08-15 | 2018-11-13 | 哈尔滨工业大学 | A kind of LiFePO4―V2O5- Graphene composite positive poles and preparation method thereof |
| CN107916066B (en) * | 2017-06-21 | 2019-11-29 | 广东华材实业股份有限公司 | Vanadium dioxide composite powder of containing graphene and the preparation method and application thereof |
| US20190115591A1 (en) * | 2017-10-16 | 2019-04-18 | Nanotek Instruments, Inc. | Surface-Stabilized Cathode Active Material Particles, Lithium Secondary Batteries Containing Same, and Method of Manufacturing |
| CN108134077B (en) * | 2017-12-28 | 2020-08-11 | 清远佳致新材料研究院有限公司 | Preparation method of high-voltage lithium ion battery anode material with core-shell structure |
| CN108878859A (en) * | 2018-06-07 | 2018-11-23 | 中航锂电（洛阳）有限公司 | A kind of nickel-cobalt lithium manganate cathode material and preparation method thereof, lithium ion battery |
| CN109860533B (en) * | 2018-12-18 | 2022-03-29 | 廊坊绿色工业技术服务中心 | Composite core-shell structure magnesium ion battery positive electrode material and preparation method and application thereof |
| CN110176593A (en) * | 2019-06-03 | 2019-08-27 | 合肥国轩高科动力能源有限公司 | A kind of preparation method of the nickelic tertiary cathode material of double-coating |
-
2020
- 2020-09-03 CN CN202010916078.3A patent/CN111785960B/en active Active
-
2021
- 2021-07-27 WO PCT/CN2021/108587 patent/WO2022048346A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120321953A1 (en) * | 2011-06-17 | 2012-12-20 | Nanotek Instruments, Inc. | Graphene-enabled vanadium oxide cathode and lithium cells containing same |
| CN110518202A (en) * | 2019-08-05 | 2019-11-29 | 三峡大学 | A kind of V of self-supporting2O5/ rGO nano-array sodium-ion battery material and preparation method thereof |
| CN111092210A (en) * | 2019-12-30 | 2020-05-01 | 中科廊坊过程工程研究院 | Ternary positive electrode composite material and preparation method and application thereof |
| CN111785960A (en) * | 2020-09-03 | 2020-10-16 | 中南大学 | Vanadium pentoxide/rGO coated nickel cobalt lithium manganate positive electrode material and preparation method thereof |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114628680A (en) * | 2022-03-14 | 2022-06-14 | 辽宁大学 | Preparation method and application of tridecyloxy hexa-vanadium electrode material for water-based zinc ion battery |
| CN114744185A (en) * | 2022-03-25 | 2022-07-12 | 湖北亿纬动力有限公司 | Graphene-coated ternary material and preparation method and application thereof |
| CN115947385A (en) * | 2022-09-29 | 2023-04-11 | 宁夏汉尧富锂科技有限责任公司 | Preparation method of low-cobalt and cobalt-free precursor and lithium-poor low-cobalt and cobalt-free cathode material and product thereof |
| CN117374270A (en) * | 2023-12-08 | 2024-01-09 | 湖南德景源科技有限公司 | Production process of lithium nickel cobalt manganese positive electrode material powder |
| CN117374270B (en) * | 2023-12-08 | 2024-03-22 | 湖南德景源科技有限公司 | Production process of lithium nickel cobalt manganese positive electrode material powder |
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