JP5958119B2 - Positive electrode composition for non-aqueous electrolyte secondary battery - Google Patents
Positive electrode composition for non-aqueous electrolyte secondary battery Download PDFInfo
- Publication number
- JP5958119B2 JP5958119B2 JP2012144594A JP2012144594A JP5958119B2 JP 5958119 B2 JP5958119 B2 JP 5958119B2 JP 2012144594 A JP2012144594 A JP 2012144594A JP 2012144594 A JP2012144594 A JP 2012144594A JP 5958119 B2 JP5958119 B2 JP 5958119B2
- Authority
- JP
- Japan
- Prior art keywords
- active material
- positive electrode
- electrode composition
- discharge capacity
- transition metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Description
本発明は、リチウムイオン二次電池等の非水電解液二次電池用正極組成物に関する。本発明は特に、非水電解液二次電池の放電特性及び出力特性を向上させることができる正極組成物に関する。 The present invention relates to a positive electrode composition for a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In particular, the present invention relates to a positive electrode composition capable of improving the discharge characteristics and output characteristics of a non-aqueous electrolyte secondary battery.
近年、ビデオカメラ、携帯電話、ノートパソコン等の携帯機器の普及及び小型化が進み、その電源用にリチウムイオン二次電池等の非水電解液二次電池が用いられるようになってきている。更に、最近の環境問題への対応から、電気自動車等の動力用電池としても注目されている。 In recent years, portable devices such as video cameras, mobile phones, and notebook personal computers have become widespread and downsized, and non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries have been used for power supplies. Furthermore, it has been attracting attention as a power battery for electric vehicles and the like due to recent environmental problems.
リチウム二次電池用の正極活物質としては、ＬｉＣｏＯ２（コバルト酸リチウム）が４Ｖ級の二次電池を構成できるものとして一般的に広く採用されている。ＬｉＣｏＯ２を正極活物質として用いた場合、放電容量が約１６０ｍＡ／ｇで実用化されている。 As a positive electrode active material for a lithium secondary battery, LiCoO 2 (lithium cobaltate) is generally widely used as a material capable of constituting a 4V class secondary battery. When LiCoO 2 is used as the positive electrode active material, it has been put to practical use with a discharge capacity of about 160 mA / g.
しかし、ＬｉＣｏＯ２の原料であるコバルトは希少資源であり且つ偏在しているため、コストが高く原料供給について不安が生じる。 However, since cobalt, which is a raw material for LiCoO 2 , is a rare resource and is unevenly distributed, the cost is high and anxiety about supply of the raw material occurs.
こうした事情に応じ、ＬｉＮｉＯ２（ニッケル酸リチウム）も検討されている。ＬｉＮｉＯ２は実用的には４Ｖ級で放電容量約２００ｍＡ／ｇの二次電池を実現可能であるが、充放電時の正極活物質の結晶構造の安定性に難がある。 In response to such circumstances, LiNiO 2 (lithium nickelate) has also been studied. LiNiO 2 is practically capable of realizing a secondary battery with a 4 V class discharge capacity of about 200 mA / g, but it is difficult to stabilize the crystal structure of the positive electrode active material during charge and discharge.
そこでＬｉＮｉＯ２のニッケル原子を他元素で置換し、結晶構造の安定性を向上させつつＬｉＣｏＯ２並みの放電容量を低コストで実現する研究もなされている。例えばＬｉＮｉ０．５Ｍｎ０．５Ｏ２等のニッケルマンガン酸リチウムでは約１６０ｍＡ／ｇの放電容量が得られている。 Therefore, research has been conducted to replace the nickel atom of LiNiO 2 with another element to improve the stability of the crystal structure and realize a discharge capacity similar to LiCoO 2 at a low cost. For example, a lithium nickel manganate such as LiNi 0.5 Mn 0.5 O 2 has a discharge capacity of about 160 mA / g.
特許文献１には、リチウム遷移金属複合酸化物と、Ｖ２Ｏ５等の添加物とを有する正極を用いることにより、チタン含有金属複合酸化物を負極とする非水電解質電池における正極規制の放電終了が防止され、サイクル特性が向上することが記載されている。添加物として用いられているのは、充電状態の正極活物質である。 Patent Document 1 discloses a positive electrode regulation discharge in a non-aqueous electrolyte battery using a titanium-containing metal composite oxide as a negative electrode by using a positive electrode having a lithium transition metal composite oxide and an additive such as V 2 O 5. It is described that termination is prevented and cycle characteristics are improved. A positive electrode active material in a charged state is used as an additive.
特許文献２には、非水電解質二次電池の正極に含まれるリチウムニッケル複合酸化物粒子の表面をＶ２Ｏ５で覆うことにより、正極と電解液との界面における電解液の分解反応が抑制され、サイクル特性が向上することが記載されている。特許文献２において、Ｖ２Ｏ５による表面被覆は、リチウムニッケル複合酸化物粒子とＶ２Ｏ５とを混合し、その混合物を６８０〜７２０℃に加熱することで達成される。 In Patent Document 2, the surface of the lithium nickel composite oxide particles contained in the positive electrode of the nonaqueous electrolyte secondary battery is covered with V 2 O 5 to suppress the decomposition reaction of the electrolytic solution at the interface between the positive electrode and the electrolytic solution. It is described that the cycle characteristics are improved. In Patent Document 2, the surface coating with V 2 O 5 is mixed with a V 2 O 5 lithium nickel complex oxide particles, is accomplished by heating the mixture to six hundred and eighty to seven hundred and twenty ° C..
ニッケルマンガン酸リチウムは、希少なコバルトを用いないのでニッケルコバルトマンガン酸リチウムと比べてコスト面で有利であるが、放電容量や出力特性の面で不利になる傾向にある。そのため、コストと放電容量及び出力特性との両立ができないという問題があった。 Since nickel nickel manganate does not use rare cobalt, it is advantageous in terms of cost as compared with nickel cobalt lithium manganate, but tends to be disadvantageous in terms of discharge capacity and output characteristics. Therefore, there is a problem that it is impossible to achieve both cost, discharge capacity, and output characteristics.
本発明はこのような事情に鑑みなされたものであり、ニッケルマンガン酸リチウムを含む非水電解液二次電池用正極組成物であって、電池の放電容量及び出力特性を向上させることができ、コストと電池性能とを両立させることができる正極組成物を提供することを目的とする。 The present invention has been made in view of such circumstances, and is a positive electrode composition for a non-aqueous electrolyte secondary battery containing lithium nickel manganate, which can improve the discharge capacity and output characteristics of the battery, It aims at providing the positive electrode composition which can make cost and battery performance compatible.
上記目的を達成するために本発明者らは鋭意検討を重ね、特定組成のニッケルマンガン酸リチウムと、リチウムイオンを挿入脱離可能な特定の遷移金属酸化物とを含む正極組成物を正極に用いた場合に、ニッケルマンガン酸リチウムを単独で用いた場合と比較して、非水電解液二次電池の放電容量及び出力特性が向上することを見出し、本発明を完成するに至った。 In order to achieve the above object, the present inventors have intensively studied, and used a positive electrode composition containing lithium nickel manganate having a specific composition and a specific transition metal oxide capable of inserting and releasing lithium ions as a positive electrode. In this case, it was found that the discharge capacity and output characteristics of the nonaqueous electrolyte secondary battery were improved as compared with the case where lithium nickel manganate was used alone, and the present invention was completed.
本発明の非水電解液二次電池用正極組成物は、
一般式ＬｉａＮｉｂＭｎ１−ｂＭｃＯ２（但し１＜ａ＜１．２、０．５≦ｂ＜１、０≦ｃ≦０．０２、ＭはＷ、Ｎｂ、Ｚｒ及びＴｉからなる群より選ばれる少なくとも１種の元素）で表されるリチウム遷移金属複合酸化物と、
リチウムイオンの挿入脱離が可能であり、且つ１種類の遷移金属元素と酸素元素とからなる単純遷移金属酸化物とを含むことを特徴とする。
The positive electrode composition for a non-aqueous electrolyte secondary battery of the present invention is
Formula Li a Ni b Mn 1-b M c O 2 ( where 1 <a <1.2,0.5 ≦ b < 1,0 ≦ c ≦ 0.02, M is W, Nb, from Zr and Ti Lithium transition metal composite oxide represented by at least one element selected from the group consisting of:
Lithium ion insertion / extraction is possible, and a simple transition metal oxide composed of one kind of transition metal element and oxygen element is included.
前記リチウム遷移金属複合酸化物及び前記単純遷移金属酸化物は、それぞれ実質的に独立した粒子として存在していることが好ましい。 The lithium transition metal composite oxide and the simple transition metal oxide are preferably present as substantially independent particles.
前記リチウム遷移金属複合酸化物に対する前記単純遷移金属酸化物中の遷移金属元素の割合は、好ましくは１０ｍｏｌ％以下であり、より好ましくは２ｍｏｌ％〜１０ｍｏｌ％である。 The ratio of the transition metal element in the simple transition metal oxide to the lithium transition metal composite oxide is preferably 10 mol% or less, more preferably 2 mol% to 10 mol%.
前記単純遷移金属酸化物は、好ましくは酸化バナジウム、酸化マンガン、酸化コバルト、酸化ニッケル及び酸化鉄からなる群より選択される少なくとも１種であり、より好ましくは酸化バナジウムである。前記酸化バナジウムは、五酸化バナジウムであることが好ましい。 The simple transition metal oxide is preferably at least one selected from the group consisting of vanadium oxide, manganese oxide, cobalt oxide, nickel oxide and iron oxide, more preferably vanadium oxide. The vanadium oxide is preferably vanadium pentoxide.
本発明の正極組成物は上記の特徴を備えているため、ニッケルマンガン酸リチウムを単独で使用する場合と比較して、電池の放電容量および出力特性を向上させることができる。このため、本発明の正極組成物は、コストと電池性能とを両立させることができる。
本発明の正極組成物は、特に、非水電解液二次電池の初期放電容量及び低温出力特性を向上させるのに有用である。
更に、本発明の正極組成物は、非水電解液二次電池の初期効率を向上させることも可能である。
Since the positive electrode composition of the present invention has the above characteristics, the discharge capacity and output characteristics of the battery can be improved as compared with the case where lithium nickel manganate is used alone. For this reason, the positive electrode composition of the present invention can achieve both cost and battery performance.
The positive electrode composition of the present invention is particularly useful for improving the initial discharge capacity and low-temperature output characteristics of a nonaqueous electrolyte secondary battery.
Furthermore, the positive electrode composition of the present invention can also improve the initial efficiency of the nonaqueous electrolyte secondary battery.
上記構成と効果との関係は、特定の理論にとらわれるものではないが凡そ以下の通りであると推測される。
本発明の正極組成物は、ニッケルマンガン酸リチウム（以下、活物質Ｉとも称する）及びリチウムイオンの挿入脱離が可能であり、且つ1種類の遷移金属元素と酸素元素とからなる単純遷移金属化合物（以下、活物質ＩＩとも称する）の２種類の異なる正極活物質を含むものである。活物質ＩＩは活物質Ｉと比較して電気抵抗が小さいので、放電時に活物質ＩＩに流れる単位質量当たりの電流は、活物質Ｉに流れる単位質量当たりの電流と比較して大きい。このため、正極に流れる電流が等しい場合、本発明の正極組成物を用いた二次電池において放電時に活物質Ｉに流れる電流は、活物質Ｉのみからなる正極組成物を用いた場合に活物質Ｉに流れる電流と比較して小さくなる。放電時に活物質Ｉに流れる電流が小さくなると、活物質Ｉは実質的に低レートで放電していることになり、その結果、本発明の正極組成物における活物質Ｉの放電容量は、活物質Ｉのみからなる正極組成物における活物質Ｉの放電容量よりも大きくなる。このように活物質Ｉの放電容量が大きくなることにより、正極組成物全体として放電容量が大きくなる。更に、本発明の正極組成物を用いることにより、上述のように放電容量が増加するので、初期放電容量もまた増加し、その結果、初期効率も向上し得る。
The relationship between the configuration and the effect is not limited to a specific theory, but is estimated to be as follows.
The positive electrode composition of the present invention is a simple transition metal compound which can insert and desorb lithium nickel manganate (hereinafter also referred to as active material I) and lithium ions, and which comprises one kind of transition metal element and oxygen element (Hereinafter also referred to as active material II) of two different types of positive electrode active materials. Since the active material II has a smaller electrical resistance than the active material I, the current per unit mass flowing through the active material II during discharge is larger than the current per unit mass flowing through the active material I. For this reason, when the current flowing through the positive electrode is equal, the current flowing through the active material I during discharge in the secondary battery using the positive electrode composition of the present invention is the active material when using the positive electrode composition consisting only of the active material I. It becomes smaller than the current flowing through I. When the current flowing through the active material I during discharge decreases, the active material I is discharged at a substantially low rate. As a result, the discharge capacity of the active material I in the positive electrode composition of the present invention is It becomes larger than the discharge capacity of the active material I in the positive electrode composition comprising only I. Thus, when the discharge capacity of the active material I increases, the discharge capacity of the positive electrode composition as a whole increases. Furthermore, since the discharge capacity is increased as described above by using the positive electrode composition of the present invention, the initial discharge capacity is also increased, and as a result, the initial efficiency can be improved.
また、上述のように放電時に活物質Ｉに流れる電流が緩和されること、および活物質ＩＩが高出力特性を有することにより、本発明の正極組成物を用いた非水電解液二次電池は優れた出力特性を有する。 In addition, as described above, the non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention is reduced because the current flowing through the active material I during discharge is relaxed and the active material II has high output characteristics. Excellent output characteristics.
以下、本発明の実施の形態及び実施例について詳細に説明する。但し、本発明はこれら実施の形態及び実施例に限定されるものではない。 Hereinafter, embodiments and examples of the present invention will be described in detail. However, the present invention is not limited to these embodiments and examples.
本発明の非水電解液二次電池用正極組成物は、一般式ＬｉａＮｉｂＭｎ１−ｂＭｃＯ２（但し１＜ａ＜１．２、０．５≦ｂ＜１、０≦ｃ≦０．０２、ＭはＷ、Ｎｂ、Ｚｒ及びＴｉからなる群より選ばれる少なくとも１種の元素）で表されるリチウム遷移金属複合酸化物（活物質Ｉ）と、リチウムイオンの挿入脱離が可能であり、且つ１種類の遷移金属元素と酸素元素とからなる単純遷移金属酸化物（活物質ＩＩ）とを含む。 Non-aqueous electrolyte secondary battery positive electrode composition of the present invention have the general formula Li a Ni b Mn 1-b M c O 2 ( where 1 <a <1.2,0.5 ≦ b < 1,0 ≦ c ≦ 0.02, M is at least one element selected from the group consisting of W, Nb, Zr and Ti) and lithium ion insertion / desorption of lithium ion (active material I) And a simple transition metal oxide (active material II) composed of one kind of transition metal element and oxygen element.
本発明の正極組成物における活物質Ｉは、遷移金属としてニッケル及びマンガンを含み、且つコバルトを含有しないニッケルマンガン酸リチウムである。なお、本明細書において、「ニッケルマンガン酸リチウム」は、ニッケルマンガン酸リチウムのニッケルサイト及び／又はマンガンサイトを微量の他の元素で置換したものも含む。ａの値は大きいほど充放電容量及び出力特性が向上するが、大きすぎると活物質Ｉを使用可能な形態で得ることが困難になる。ａの値が１＜ａ＜１．２の範囲内であると、充放電容量及び出力特性が向上し、且つ活物質Ｉを使用可能な形態で得ることができる。ａの値のより好ましい範囲は１．１０＜ａ＜１．１８である。ｂの値は大きいほど出力特性が向上するが、同時に活物質Ｉの合成が困難になり、未反応のリチウム化合物が生成し易くなる。ｂの値が０．５≦ｂ＜１の範囲内であると、出力特性が向上し、且つ活物質Ｉの合成が容易であり、未反応のリチウム化合物の生成が抑制される。ｂの値のより好ましい範囲は０．５＜ｂ＜０．７である。ニッケルサイト及びマンガンサイトは２ｍｏｌ％程度までであれば他の元素で置換してもよい。従って、ｃの値は０≦ｃ≦０．０２の範囲内である。置換元素ＭがＷ、Ｎｂ、Ｚｒ及びＴｉからなる群より選ばれる少なくとも１種であることが、出力特性の向上の点で好ましい。 The active material I in the positive electrode composition of the present invention is lithium nickel manganate that contains nickel and manganese as transition metals and does not contain cobalt. In the present specification, “lithium nickel manganate” includes those obtained by substituting nickel sites and / or manganese sites of lithium nickel manganate with trace amounts of other elements. The charge / discharge capacity and output characteristics improve as the value of a increases, but if it is too large, it becomes difficult to obtain the active material I in a usable form. When the value of a is in the range of 1 <a <1.2, the charge / discharge capacity and output characteristics are improved, and the active material I can be obtained in a usable form. A more preferable range of the value of a is 1.10 <a <1.18. As the value of b is increased, the output characteristics are improved, but at the same time, the synthesis of the active material I becomes difficult and an unreacted lithium compound is easily generated. When the value of b is in the range of 0.5 ≦ b <1, the output characteristics are improved, the synthesis of the active material I is easy, and the formation of unreacted lithium compounds is suppressed. A more preferable range of the value of b is 0.5 <b <0.7. The nickel site and the manganese site may be substituted with other elements as long as they are up to about 2 mol%. Therefore, the value of c is in the range of 0 ≦ c ≦ 0.02. The substitution element M is preferably at least one selected from the group consisting of W, Nb, Zr and Ti from the viewpoint of improving output characteristics.
上述のニッケルマンガン酸リチウム以外のリチウム遷移金属複合酸化物、例えばニッケルコバルトマンガン酸リチウムを活物質Ｉとして使用した場合には、本発明の効果を得ることはできない。 When a lithium transition metal composite oxide other than the above-described lithium nickel manganate, for example, nickel cobalt lithium manganate is used as the active material I, the effect of the present invention cannot be obtained.
本発明の正極組成物における活物質ＩＩは、リチウムイオンの挿入脱離が可能であり、且つ１種類の遷移金属元素と酸素元素とからなる単純遷移金属酸化物である。活物質ＩＩは、活物質Ｉと共に存在することで活物質Ｉの放電容量の増加に寄与する。なお、本明細書において、「単純遷移金属酸化物」は、１種類の遷移金属元素と酸素元素とからなる遷移金属酸化物を意味し、一般式ＬｘＯｙ（Ｌは遷移金属元素、ｘ及びｙは任意の整数）で表される。本発明において用いられる活物質ＩＩとして、例えば、Ｖ２Ｏ５等の酸化バナジウム、ＭｎＯ２等の酸化マンガン、ＣｏＯ２等の酸化コバルト、ＮｉＯ２等の酸化ニッケル、ＦｅＯ等の酸化鉄が挙げられる。
リチウムイオンの挿入脱離が可能である遷移金属酸化物としては、上述のような単純遷移金属酸化物の他に、例えば、ＦｅＰＯ４等のリン酸鉄、Ｆｅ４（Ｐ２Ｏ７）３等の二リン酸鉄及びＦｅ２（ＳＯ４）３等の硫酸鉄も存在している。本発明者らは、このような遷移金属のオキソ酸塩あるいは複酸化物を活物質ＩＩの代わりに使用した場合には本発明の効果を得ることができず、上述のような単純遷移金属酸化物を活物質ＩＩとして使用した場合にのみ、本発明の効果を得ることができることを見出した。
The active material II in the positive electrode composition of the present invention is a simple transition metal oxide that can insert and desorb lithium ions and is composed of one transition metal element and an oxygen element. The active material II contributes to an increase in the discharge capacity of the active material I by being present together with the active material I. In this specification, “simple transition metal oxide” means a transition metal oxide composed of one kind of transition metal element and an oxygen element, and is represented by the general formula L x O y (L is a transition metal element, x And y is an arbitrary integer). Examples of the active material II used in the present invention include vanadium oxide such as V 2 O 5 , manganese oxide such as MnO 2 , cobalt oxide such as CoO 2 , nickel oxide such as NiO 2 , and iron oxide such as FeO. .
Examples of the transition metal oxide capable of inserting and removing lithium ions include, in addition to the simple transition metal oxide as described above, for example, iron phosphate such as FePO 4 , Fe 4 (P 2 O 7 ) 3, and the like. There are also iron sulfates such as iron diphosphate and Fe 2 (SO 4 ) 3 . The inventors of the present invention cannot obtain the effects of the present invention when such transition metal oxoacid salt or double oxide is used instead of the active material II. It has been found that the effects of the present invention can be obtained only when a product is used as the active material II.
活物質ＩＩの代わりに遷移金属のオキソ酸塩または複酸化物を用いた場合に本発明の効果が得られない理由としては、特定の理論に限定されるものではないが、以下のことが推測される。
本発明において使用される活物質ＩＩ（単純遷移金属酸化物）は活物質Ｉと比較して電気抵抗が小さいので、放電時に活物質ＩＩに流れる単位質量当たりの電流は、活物質Ｉに流れる単位質量当たりの電流と比較して大きい。このため、本発明の正極組成物を用いると、放電時に活物質Ｉに流れる電流を小さくすることができ、正極組成物全体の放電容量を大きくすることができる。
遷移金属酸化物の複酸化物やオキソ酸塩は一般に、活物質ＩＩと比較して電気抵抗が大きい傾向にある。そのため、活物質ＩＩの代わりにこのような複酸化物またはオキソ酸塩を用いた場合、放電時に活物質Ｉに流れる電流を小さくすることができず、従って、活物質Ｉの放電容量および正極組成物自体の放電容量を大きくすることができないと考えられる。
The reason why the effect of the present invention cannot be obtained when transition metal oxoacid salt or double oxide is used instead of active material II is not limited to a specific theory, but the following is presumed. Is done.
Since the active material II (simple transition metal oxide) used in the present invention has a smaller electric resistance than the active material I, the current per unit mass flowing through the active material II during discharge is a unit flowing through the active material I. Large compared to the current per mass. For this reason, if the positive electrode composition of this invention is used, the electric current which flows into the active material I at the time of discharge can be made small, and the discharge capacity of the whole positive electrode composition can be enlarged.
Generally, transition metal oxide double oxides and oxoacid salts tend to have higher electrical resistance than the active material II. Therefore, when such a double oxide or oxo acid salt is used instead of the active material II, the current flowing through the active material I during discharge cannot be reduced, and therefore the discharge capacity and the positive electrode composition of the active material I cannot be reduced. It is considered that the discharge capacity of the object itself cannot be increased.
本発明の正極組成物を用いた非水電解液二次電池は、上述のように放電容量が増加するので、初期放電容量もまた増加し、その結果、初期効率も向上し得る。
また、上述のように放電時に活物質Ｉに流れる電流が緩和されること、および活物質ＩＩが高出力特性を有することにより、本発明の正極組成物を用いた非水電解液二次電池は優れた出力特性を有する。
Since the discharge capacity of the non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention increases as described above, the initial discharge capacity also increases, and as a result, the initial efficiency can be improved.
In addition, as described above, the non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention is reduced because the current flowing through the active material I during discharge is relaxed and the active material II has high output characteristics. Excellent output characteristics.
ＶＯ、Ｖ２Ｏ３、Ｖ２Ｏ４およびＶ２Ｏ５等の酸化バナジウムは、作動電圧がニッケルマンガン酸リチウムのそれに近いので、活物質ＩＩとして好適に用いることができる。また、酸化バナジウムは一般に高い放電容量を有するので、酸化バナジウムを活物質ＩＩとして使用すると、放電容量がより増加し、出力特性がより向上するので好ましい。更に、五酸化バナジウム（Ｖ２Ｏ５）は優れた負荷特性を有するので、Ｖ２Ｏ５を活物質ＩＩとして使用すると、放電容量だけでなく負荷特性も向上するので好ましい。 Vanadium oxides such as VO, V 2 O 3 , V 2 O 4, and V 2 O 5 can be preferably used as the active material II because the operating voltage is close to that of lithium nickel manganate. Further, since vanadium oxide generally has a high discharge capacity, it is preferable to use vanadium oxide as the active material II because the discharge capacity is further increased and the output characteristics are further improved. Furthermore, since vanadium pentoxide (V 2 O 5 ) has excellent load characteristics, it is preferable to use V 2 O 5 as the active material II because not only the discharge capacity but also the load characteristics are improved.
本発明の正極組成物において、活物質Ｉ及び活物質ＩＩは、それぞれ実質的に独立した粒子として存在していることが好ましい。
本明細書において、活物質Ｉ及び活物質ＩＩがそれぞれ「実質的に独立した粒子として存在している」とは、活物質Ｉの粒子と、活物質ＩＩの粒子とが、物理的又は化学的結合によって一体化されていないことを意味する。
活物質Ｉおよび活物質ＩＩの内、一方の活物質が他方の活物質で被覆される等、両者が一体化されていると、活物質Ｉから活物質ＩＩへのリチウムイオンの移動がおこり、その結果、電気的に不活性なリチウム化合物が生成される可能性がある。活物質Ｉと活物質ＩＩとがそれぞれ独立した粒子として存在していると、そのようなリチウムイオンの移動およびリチウム化合物の生成を抑制することができる。更に、活物質Ｉ及び活物質ＩＩは、正極組成物において全体として均一に分布していると、電池特性がより向上するので好ましい。
In the positive electrode composition of the present invention, the active material I and the active material II are preferably present as substantially independent particles.
In the present specification, each of the active material I and the active material II is “substantially independent particles” means that the particles of the active material I and the particles of the active material II are physically or chemically It means that they are not integrated by bonding.
When both of the active materials I and II are integrated, such as one active material is coated with the other active material, lithium ions move from the active material I to the active material II, As a result, an electrically inactive lithium compound may be generated. When the active material I and the active material II exist as independent particles, such migration of lithium ions and generation of lithium compounds can be suppressed. Furthermore, it is preferable that the active material I and the active material II are uniformly distributed as a whole in the positive electrode composition because battery characteristics are further improved.
正極組成物中の活物質ＩＩの量が多すぎると、負荷特性を向上させる効果が小さくなる虞がある。また、活物質ＩＩは初期充電に関与しないので、活物質ＩＩの量が多すぎると、初期充電容量が減少し、且つ初期放電容量が増加する傾向にある。そのため、初期効率が１００％を超えて、二次電池全体に何らかの不利益をもたらすこともあり得る。従って、正極組成物中の活物質ＩＩの量を適宜調節することが好ましい。本発明の正極組成物における活物質ＩＩの含有量は、リチウム遷移金属複合酸化物（活物質Ｉ）に対する単純遷移金属酸化物（活物質ＩＩ）中の遷移金属元素の割合が１０ｍｏｌ％以下となるような量であれば、負荷特性を向上させる効果が高く、且つ初期効率を１００％未満とすることができるので好ましい。活物質Ｉに対する活物質ＩＩ中の遷移金属元素の割合は、より好ましくは２ｍｏｌ％〜１０ｍｏｌ％である。 If the amount of the active material II in the positive electrode composition is too large, the effect of improving the load characteristics may be reduced. In addition, since the active material II does not participate in the initial charge, if the amount of the active material II is too large, the initial charge capacity tends to decrease and the initial discharge capacity tends to increase. Therefore, the initial efficiency may exceed 100%, which may cause some disadvantage for the entire secondary battery. Therefore, it is preferable to appropriately adjust the amount of the active material II in the positive electrode composition. The content of the active material II in the positive electrode composition of the present invention is such that the ratio of the transition metal element in the simple transition metal oxide (active material II) to the lithium transition metal composite oxide (active material I) is 10 mol% or less. Such an amount is preferable because the effect of improving the load characteristics is high and the initial efficiency can be less than 100%. The ratio of the transition metal element in the active material II to the active material I is more preferably 2 mol% to 10 mol%.
次に本発明の正極組成物の作製方法について説明する。
本発明の活物質Ｉ及び活物質ＩＩは、公知の手法を用いて適宜作製することができるが、市販品を用いてもよい。
本発明の正極組成物は、活物質Ｉと活物質ＩＩとを混合することによって得られる。混合手法は、極端な分布の偏りがない程度に混合することができるものであればよく、例えば、活物質Ｉ及びＩＩを袋に入れて手作業で混合する程度で十分である。ミキサー等を用いて混合を行ってもよいが、活物質Ｉと活物質ＩＩとが固着又は融着したり、活物質Ｉ又は活物質ＩＩの何れか一方が他方を被覆したりすることがないように、混合時間やミキサーの回転速度等を適切に調節することが好ましい。
Next, a method for producing the positive electrode composition of the present invention will be described.
The active material I and the active material II of the present invention can be appropriately prepared using a known method, but commercially available products may be used.
The positive electrode composition of the present invention is obtained by mixing the active material I and the active material II. Any mixing technique may be used as long as it can be mixed to such an extent that there is no extreme distribution bias. For example, it is sufficient that the active materials I and II are manually mixed in a bag. Mixing may be performed using a mixer or the like, but active material I and active material II are not fixed or fused, and either active material I or active material II does not cover the other. Thus, it is preferable to appropriately adjust the mixing time, the rotation speed of the mixer, and the like.
以下、実施例にてより具体的な例を説明する。 Hereinafter, more specific examples will be described in Examples.
炭酸リチウム０．５８ｍｏｌ及び中央粒径４μｍのニッケルマンガン複合酸化物（Ｎｉ／Ｍｎ＝６／４（モル比））１．００ｍｏｌを混合し、大気雰囲気中８９０℃で９時間焼成した。焼成後焼成品を解砕、粉砕し、＃２２０メッシュの乾式篩（目開き約７０μｍ）に通し、組成Ｌｉ１．１６Ｎｉ０．６０Ｍｎ０．４０Ｏ２のニッケルマンガン酸リチウム粒子（中央粒径４μｍ）を得た。このニッケルマンガン酸リチウム粒子を実施例１の活物質Ｉとして使用した。 0.58 mol of lithium carbonate and 1.00 mol of nickel manganese composite oxide (Ni / Mn = 6/4 (molar ratio)) having a median particle size of 4 μm were mixed and fired at 890 ° C. for 9 hours in the air atmosphere. After firing, the fired product is crushed and pulverized, passed through a # 220 mesh dry sieve (mesh size of about 70 μm), and nickel manganate particles (center particles) of composition Li 1.16 Ni 0.60 Mn 0.40 O 2 4 μm in diameter) was obtained. The lithium nickel manganate particles were used as the active material I of Example 1.
中央粒径０．５μｍのＶ２Ｏ５粒子を実施例１の活物質ＩＩとして使用した。活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中の遷移金属元素（バナジウム）の割合が０．５ｍｏｌ％となるように袋に入れ、袋内で撹拌・混合し、実施例１の正極組成物を得た。 V 2 O 5 particles having a median particle size of 0.5 μm were used as the active material II of Example 1. The active material I and the active material II are put in a bag so that the ratio of the transition metal element (vanadium) in the active material II to the active material I is 0.5 mol%, and stirred and mixed in the bag. A positive electrode composition was obtained.
活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が２．０ｍｏｌ％となるように混合した以外は実施例１と同様の手順で、実施例２の正極組成物を得た。 The positive electrode composition of Example 2 was prepared in the same manner as in Example 1 except that active material I and active material II were mixed so that the ratio of vanadium in active material II to active material I was 2.0 mol%. Got.
活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が５．０ｍｏｌ％となるように混合した以外は実施例１と同様の手順で、実施例３の正極組成物を得た。 The positive electrode composition of Example 3 was prepared in the same manner as in Example 1 except that active material I and active material II were mixed so that the ratio of vanadium in active material II to active material I was 5.0 mol%. Got.
活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が１０ｍｏｌ％となるように混合した以外は実施例１と同様の手順で、実施例４の正極組成物を得た。 A positive electrode composition of Example 4 was obtained in the same procedure as Example 1 except that active material I and active material II were mixed so that the ratio of vanadium in active material II to active material I was 10 mol%. It was.
［比較例１］
実施例１の活物質Ｉのみを比較例１の正極組成物として使用した。
[Comparative Example 1]
Only the active material I of Example 1 was used as the positive electrode composition of Comparative Example 1.
［比較例２］
中央粒径０．５μｍのＦｅ２（ＳＯ４）３粒子を活物質ＩＩとして使用し、活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中の鉄の割合が５．０ｍｏｌ％となるように混合した以外は実施例１と同様の手順で、比較例２の正極組成物を得た。
[Comparative Example 2]
Fe 2 (SO 4 ) 3 particles having a median particle size of 0.5 μm are used as the active material II, and the active material I and the active material II have a ratio of iron in the active material II to the active material I of 5.0 mol%. A positive electrode composition of Comparative Example 2 was obtained in the same procedure as in Example 1 except that mixing was performed.
［比較例３］
実施例１の活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が５．０ｍｏｌ％となるように袋に入れ、袋内で均一に分散混合した後、ミキサーで攪拌した。得られた混合物を５８０℃で熱処理し、ニッケルマンガン酸リチウム粒子の表面がＶ２Ｏ５粒子で被覆された比較例３の正極組成物を得た。
[Comparative Example 3]
The active material I and the active material II of Example 1 are put in a bag so that the ratio of vanadium in the active material II to the active material I is 5.0 mol%, and uniformly dispersed and mixed in the bag. Stir. The obtained mixture was heat-treated at 580 ° C. to obtain a positive electrode composition of Comparative Example 3 in which the surfaces of lithium nickel manganate particles were coated with V 2 O 5 particles.
［比較例４］
炭酸リチウム０．５８ｍｏｌ及び中央粒径６μｍのニッケルコバルトマンガン複合酸化物（Ｎｉ／Ｃｏ／Ｍｎ＝５／２／３（モル比））１．００ｍｏｌを混合し、大気雰囲気中８８０℃で９時間焼成した。焼成後焼成品を解砕、粉砕し、＃２２０メッシュの乾式篩（目開き約７０μｍ）に通し、組成Ｌｉ１．１６Ｎｉ０．５０Ｃｏ０．２０Ｍｎ０．３０Ｏ２のニッケルコバルトマンガン酸リチウム粒子（中央粒径４μｍ）を得た。これを比較例４の活物質Ｉとして使用した。
[Comparative Example 4]
0.58 mol of lithium carbonate and 1.00 mol of nickel cobalt manganese composite oxide (Ni / Co / Mn = 5/2/3 (molar ratio)) with a median particle size of 6 μm are mixed and fired at 880 ° C. for 9 hours in an air atmosphere. did. After firing, the fired product is crushed and pulverized, passed through a # 220 mesh dry sieve (aperture approximately 70 μm), and nickel cobalt manganate having a composition of Li 1.16 Ni 0.50 Co 0.20 Mn 0.30 O 2 Lithium particles (median particle size 4 μm) were obtained. This was used as the active material I of Comparative Example 4.
中央粒径０．５μｍのＶ２Ｏ５粒子を活物質ＩＩとして使用した。活物質Ｉ及び活物質ＩＩを、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が５．０ｍｏｌ％となるように袋内で撹拌・混合し、比較例４の正極組成物を得た。 V 2 O 5 particles having a median particle size of 0.5 μm were used as the active material II. The active material I and the active material II were stirred and mixed in the bag so that the ratio of vanadium in the active material II to the active material I was 5.0 mol%, whereby a positive electrode composition of Comparative Example 4 was obtained.
［比較例５］
比較例４の活物質Ｉのみを比較例５の正極組成物として使用した。
[Comparative Example 5]
Only the active material I of Comparative Example 4 was used as the positive electrode composition of Comparative Example 5.
［電池特性の評価］
以下の要領で評価用の二次電池を作製し、各種評価に用いた。
[Evaluation of battery characteristics]
Secondary batteries for evaluation were produced in the following manner and used for various evaluations.
［電池抵抗評価用二次電池の作製］
正極組成物の粉末９０重量％、導電剤となる炭素粉末５重量％、及びポリフッ化ビニリデン（ＰＶＤＦ）のノルマルメチルピロリドン（ＮＭＰ）溶液（ＰＶＤＦ量として５重量％）５重量％を混練してペーストを調製し、これをアルミニウム箔からなる集電体に塗布し乾燥させ、圧延して正極板とした。
[Preparation of secondary battery for battery resistance evaluation]
A paste prepared by kneading 90% by weight of the positive electrode composition powder, 5% by weight of carbon powder as a conductive agent, and 5% by weight of a normal methylpyrrolidone (NMP) solution of polyvinylidene fluoride (PVDF) (5% by weight as PVDF). Was applied to a current collector made of aluminum foil, dried, and rolled to obtain a positive electrode plate.
負極活物質として黒鉛材料を用いた。負極活物質の粉末９７．５重量％、カルボキシメチルセルロース（ＣＭＣ）１．５重量％、及びスチレンブタジエンゴム（ＳＢＲ）１．０重量％を水に分散し、混練してペーストを調製し、これを銅箔からなる集電体に塗布し乾燥させ、圧延して負極板とした。 A graphite material was used as the negative electrode active material. A paste of 97.5% by weight of negative electrode active material powder, 1.5% by weight of carboxymethylcellulose (CMC) and 1.0% by weight of styrene butadiene rubber (SBR) was dispersed in water and kneaded to prepare a paste. It apply | coated to the electrical power collector which consists of copper foil, it was made to dry and it rolled and it was set as the negative electrode plate.
エチレンカーボネート（ＥＣ）とメチルエチルカーボネート（ＭＥＣ）とを体積比３：７で混合して混合溶媒を調製した。得られた混合溶媒に電解質として六フッ化リン酸リチウム（ＬｉＰＦ６）を溶解し、濃度１ｍｏｌ／ｌの非水電解液を調製した。 Ethylene carbonate (EC) and methyl ethyl carbonate (MEC) were mixed at a volume ratio of 3: 7 to prepare a mixed solvent. Lithium hexafluorophosphate (LiPF 6 ) was dissolved as an electrolyte in the obtained mixed solvent to prepare a nonaqueous electrolytic solution having a concentration of 1 mol / l.
セパレータとして多孔性ポリエチレンフィルムを用いた。 A porous polyethylene film was used as a separator.
正極板及び負極板にリード電極を取り付け、正極、セパレータ、負極の順に重ねた。これらをラミネートパックに収納し、電解液を注入してラミネートパックを封止し、ラミネート型二次電池を得た。これを電池抵抗の評価に用いた。 Lead electrodes were attached to the positive electrode plate and the negative electrode plate, and the positive electrode, the separator, and the negative electrode were stacked in this order. These were accommodated in a laminate pack, and an electrolyte solution was injected to seal the laminate pack to obtain a laminate type secondary battery. This was used for evaluation of battery resistance.
［充放電容量評価用二次電池の作製］
負極活物質として金属リチウムを用いた。金属リチウムを薄いシート状に成型して負極板とした。正極板、セパレータ及び電解液は電池抵抗評価用二次電池と同じものを用いた。
[Production of secondary battery for charge / discharge capacity evaluation]
Metallic lithium was used as the negative electrode active material. Metal lithium was molded into a thin sheet to form a negative electrode plate. The positive electrode plate, separator, and electrolytic solution used were the same as those for the secondary battery for battery resistance evaluation.
正極板にリード電極を取り付け、負極、セパレータ、正極を順に容器に収納した。負極はステンレス製の容器底部に電気的に接続し、容器底部を負極端子とした。セパレータはテフロン（登録商標）製の容器側部によって固定した。正極のリード電極の先端は容器外部に導出し、正極端子とした。正極及び負極の端子は、容器側部によって電気的に絶縁されていた。収納後電解液を注入し、ステンレス製の容器蓋部によって封止し、密閉型の試験電池を得た。これを充放電容量の評価に用いた。 A lead electrode was attached to the positive electrode plate, and the negative electrode, the separator, and the positive electrode were sequentially accommodated in the container. The negative electrode was electrically connected to the bottom of the stainless steel container, and the container bottom was used as the negative electrode terminal. The separator was fixed by the side of the container made of Teflon (registered trademark). The tip of the positive lead electrode was led out of the container and used as a positive terminal. The positive and negative terminals were electrically insulated by the container side. After storage, the electrolyte was poured and sealed with a stainless steel container lid to obtain a sealed test battery. This was used for evaluation of charge / discharge capacity.
［電池抵抗の測定］
電池抵抗評価用二次電池を用いて、以下の要領で電流及び電圧を測定し、電池抵抗を求めた。
[Measurement of battery resistance]
Using a secondary battery for battery resistance evaluation, current and voltage were measured in the following manner to obtain battery resistance.
測定温度−２５℃において、満充電電圧を４．２Ｖとして充電深度５０％まで定電流充電し、その後特定の電流値でパルス放電を行った。パルスは１０秒印加後開放１０分で放電のみ行った。パルス放電の電流値ｉは０．０４Ａ、０．０６Ａ、０．０８Ａ及び０．１０Ａとした。電流値ｉをグラフ横軸に、パルス放電１０秒後の電圧値Ｖをグラフ縦軸にそれぞれプロットし、ｉ−Ｖプロットにおいて直線線形が保たれる電流範囲で傾きの絶対値を求め、電池抵抗Ｒ（−２５℃）とした。Ｒ（−２５℃）の値が小さいほど、低温出力特性が高いことを意味する。 At a measurement temperature of −25 ° C., a full charge voltage was set to 4.2 V, and constant current charging was performed to a charge depth of 50%, and then pulse discharge was performed at a specific current value. The pulse was discharged only for 10 minutes after the application for 10 seconds. The pulse discharge current value i was 0.04 A, 0.06 A, 0.08 A, and 0.10 A. The current value i is plotted on the horizontal axis of the graph, the voltage value V after 10 seconds of pulse discharge is plotted on the vertical axis of the graph, and the absolute value of the slope is obtained in the current range in which linear linearity is maintained in the i-V plot. R (−25 ° C.). A smaller value of R (−25 ° C.) means higher low temperature output characteristics.
次に、充放電容量評価用二次電池を用いて、以下の要領で初期充放電容量及び負荷放電容量を測定した。 Next, using the secondary battery for charge / discharge capacity evaluation, the initial charge / discharge capacity and the load discharge capacity were measured in the following manner.
［初期充放電容量の測定］
満充電電圧４．３Ｖ、充電負荷０．２Ｃ（１Ｃ：満充電の状態から１時間で放電を終了させる電流値）で定電流定電圧充電し、満充電電圧までに蓄積した電荷を初期充電容量とした。次いで、放電電圧２．７５Ｖ、放電負荷０．２Ｃで定電流放電し、放電電圧までに放出した電荷を初期放電容量とした。初期充電容量に対する初期放電容量の比を初期効率とした。
[Measurement of initial charge / discharge capacity]
Charge at constant current and constant voltage with a full charge voltage of 4.3V and a charge load of 0.2C (1C: current value that completes the discharge in 1 hour from the fully charged state), and the charge accumulated up to the full charge voltage is the initial charge capacity It was. Next, constant current discharge was performed at a discharge voltage of 2.75 V and a discharge load of 0.2 C, and the charge released up to the discharge voltage was defined as the initial discharge capacity. The ratio of the initial discharge capacity to the initial charge capacity was defined as the initial efficiency.
［負荷放電容量の測定］
満充電電圧を４．３Ｖ、放電電圧を２．７５Ｖとし、放電負荷を０．２Ｃ、１Ｃ、３Ｃの順に変化させて、それぞれ充電と放電を行った。３Ｃのときの放電容量を負荷放電容量とした。初期放電容量に対する負荷放電容量の比を負荷効率とした。負荷効率が高いことは、負荷特性が良好であることを意味する。
[Measurement of load discharge capacity]
The full charge voltage was 4.3V, the discharge voltage was 2.75V, the discharge load was changed in the order of 0.2C, 1C, and 3C, and charging and discharging were performed, respectively. The discharge capacity at 3C was taken as the load discharge capacity. The ratio of load discharge capacity to initial discharge capacity was defined as load efficiency. High load efficiency means good load characteristics.
［正極組成物における活物質Ｉの初期放電容量の算出］
正極組成物全体の初期放電容量から活物質ＩＩの初期放電容量を差し引き、活物質Ｉの初期放電容量を算出した。上述の測定条件において、活物質ＩＩの初期放電容量は、正極組成物中の活物質ＩＩの割合によらず一定であると仮定し、Ｖ２Ｏ５の初期放電容量を１５０ｍＡｈ／ｇ、Ｆｅ２（ＳＯ４）２の初期放電容量を１１０ｍＡｈ／ｇとして計算を行った。
[Calculation of initial discharge capacity of active material I in positive electrode composition]
The initial discharge capacity of the active material I was calculated by subtracting the initial discharge capacity of the active material II from the initial discharge capacity of the entire positive electrode composition. Under the measurement conditions described above, the initial discharge capacity of the active material II is assumed to be constant regardless of the ratio of the active material II in the positive electrode composition, and the initial discharge capacity of V 2 O 5 is 150 mAh / g, Fe 2. The calculation was performed with the initial discharge capacity of (SO 4 ) 2 being 110 mAh / g.
実施例１〜４及び比較例１〜５について、正極組成物の詳細を表１に、電池特性を表２に示す。 For Examples 1 to 4 and Comparative Examples 1 to 5, details of the positive electrode composition are shown in Table 1, and battery characteristics are shown in Table 2.
活物質Ｉがニッケルマンガン酸リチウムであり、活物質ＩＩがＶ２Ｏ５である正極組成物を用いた実施例１〜４の二次電池は、ニッケルマンガン酸リチウムのみを含む正極組成物を用いた比較例１の二次電池と比較して、初期充電容量は減少したものの、初期放電容量、初期効率および活物質Ｉの初期放電容量が増加した。実施例１〜４の初期充電容量が比較例１より減少したのは、初期充電に関与しないＶ２Ｏ５が正極組成物中に存在していることに起因する。また、表２より、実施例１〜４の二次電池は、比較例１と比較して負荷特性及び低温出力特性が向上したことがわかる。 The secondary batteries of Examples 1 to 4 using the positive electrode composition in which the active material I is lithium nickel manganate and the active material II is V 2 O 5 use the positive electrode composition containing only lithium nickel manganate. Compared with the secondary battery of Comparative Example 1, the initial charge capacity decreased, but the initial discharge capacity, the initial efficiency, and the initial discharge capacity of the active material I increased. The reason why the initial charge capacities of Examples 1 to 4 decreased from Comparative Example 1 is that V 2 O 5 that is not involved in the initial charge is present in the positive electrode composition. Table 2 also indicates that the secondary batteries of Examples 1 to 4 have improved load characteristics and low temperature output characteristics as compared with Comparative Example 1.
実施例１〜４の二次電池において、活物質ＩＩの含有量が多いほど、初期充電容量が小さくなり、低温出力特性が向上し、初期効率が大きくなった。一方、初期放電容量、負荷効率および活物質Ｉの初期放電容量は、活物質Ｉに対する活物質ＩＩ中のバナジウムの割合が５．０ｍｏｌ％である実施例３において最大の値となった。 In the secondary batteries of Examples 1 to 4, the larger the content of the active material II, the smaller the initial charge capacity, the low temperature output characteristics, and the greater the initial efficiency. On the other hand, the initial discharge capacity, the load efficiency, and the initial discharge capacity of the active material I were the maximum values in Example 3 in which the ratio of vanadium in the active material II to the active material I was 5.0 mol%.
活物質ＩＩとしてＶ２Ｏ５の代わりにオキソ酸塩であるＦｅ２（ＳＯ４）３を用いた比較例２の二次電池は、実施例１〜４の二次電池と比較して、初期充電容量、初期放電容量、負荷効率及び活物質Ｉの初期放電容量が小さくなった。このことより、活物質ＩＩが単純酸化物でない場合には本発明の効果が得られないことがわかる。 The secondary battery of Comparative Example 2 using Fe 2 (SO 4 ) 3 , which is an oxo acid salt instead of V 2 O 5 as the active material II, is more initial than the secondary batteries of Examples 1 to 4. The charge capacity, initial discharge capacity, load efficiency, and initial discharge capacity of the active material I were reduced. This shows that the effect of the present invention cannot be obtained when the active material II is not a simple oxide.
活物質Ｉの表面が活物質ＩＩで被覆されている比較例３の二次電池は、活物質Ｉ及びＩＩがそれぞれ独立して粒子として存在している実施例１〜４の二次電池と比較して、初期充電容量、初期放電容量、初期効率、負荷効率及び活物質Ｉの初期放電容量の値が小さくなり、低温出力特性が低下した。このことより、活物質Ｉおよび活物質ＩＩはそれぞれ実質的に独立した粒子として存在していることが好ましいことがわかる。 The secondary battery of Comparative Example 3 in which the surface of the active material I is coated with the active material II is compared with the secondary batteries of Examples 1 to 4 in which the active materials I and II exist independently as particles. As a result, the initial charge capacity, the initial discharge capacity, the initial efficiency, the load efficiency, and the initial discharge capacity of the active material I decreased, and the low-temperature output characteristics deteriorated. This indicates that the active material I and the active material II are preferably present as substantially independent particles.
活物質Ｉがニッケルコバルトマンガン酸リチウムであり、活物質ＩＩがＶ２Ｏ５である比較例４の二次電池は、ニッケルコバルトマンガン酸リチウムのみを含有する比較例５の二次電池と比較して、初期効率は高いものの、初期充電容量、初期放電容量、負荷効率及び活物質Ｉの初期放電容量の値が小さくなり、低温出力特性が低下した。このことより、ニッケルマンガン酸リチウム以外のリチウム遷移金属複合酸化物を活物質Ｉとして使用した場合には本発明の効果が得られないことがわかる。 The secondary battery of Comparative Example 4 in which the active material I is nickel cobalt lithium manganate and the active material II is V 2 O 5 is compared with the secondary battery of Comparative Example 5 containing only nickel cobalt lithium manganate. Although the initial efficiency was high, the initial charge capacity, the initial discharge capacity, the load efficiency, and the initial discharge capacity of the active material I were decreased, and the low temperature output characteristics were deteriorated. This shows that when the lithium transition metal composite oxide other than lithium nickel manganate is used as the active material I, the effect of the present invention cannot be obtained.
上述のように、本発明の正極組成物は、コバルトフリーのニッケルマンガン酸リチウムを用いながら、十分な初期放電容量、負荷特性、および低温出力特性を達成することができた。本発明の正極組成物を正極に用いた非水電解液二次電池の初期効率は、ニッケルコバルトマンガン酸リチウムを正極に用いた非水電解液二次電池の初期効率とほぼ同等である。そのため、電池仕様を大幅に変更することなく正極を代替することも可能である。 As described above, the positive electrode composition of the present invention was able to achieve sufficient initial discharge capacity, load characteristics, and low-temperature output characteristics while using cobalt-free lithium nickel manganate. The initial efficiency of the non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention for the positive electrode is substantially equal to the initial efficiency of the non-aqueous electrolyte secondary battery using nickel nickel lithium manganate as the positive electrode. Therefore, it is possible to substitute the positive electrode without significantly changing the battery specification.
本発明の正極組成物を正極に用いた非水電解液二次電池は、コバルトフリーであり、且つ優れた放電容量、出力特性および負荷特性を有する。本発明の正極組成物を正極に用いた非水電解液二次電池は、低温出力特性が特に優れているので、コストと電池性能との両立が厳しく求められる電気自動車等の車載用電池に好適に用いることができる。 The non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention for the positive electrode is cobalt-free and has excellent discharge capacity, output characteristics, and load characteristics. The non-aqueous electrolyte secondary battery using the positive electrode composition of the present invention for the positive electrode is particularly excellent in low-temperature output characteristics, and is therefore suitable for an in-vehicle battery such as an electric vehicle that requires strict balance between cost and battery performance. Can be used.
Claims (2)
前記リチウム遷移金属複合酸化物及び前記五酸化バナジウムが、それぞれ実質的に独立した粒子として存在しており、
前記リチウム遷移金属複合酸化物に対する前記五酸化バナジウム中の遷移金属元素の割合が０．５ｍｏｌ％〜１０ｍｏｌ％である、非水電解液二次電池用正極組成物。 Formula Li a Ni b Mn 1-b M c O 2 ( where 1 <a <1.2,0.5 ≦ b < 1,0 ≦ c ≦ 0.02, M is W, Nb, from Zr and Ti lithium transition metal composite oxide represented by at least one element) selected from the group consisting, viewed contains a vanadium pentoxide,
The lithium transition metal composite oxide and the vanadium pentoxide are present as substantially independent particles,
The positive electrode composition for nonaqueous electrolyte secondary batteries whose ratio of the transition metal element in the said vanadium pentoxide with respect to the said lithium transition metal complex oxide is 0.5 mol%-10 mol% .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012144594A JP5958119B2 (en) | 2012-06-27 | 2012-06-27 | Positive electrode composition for non-aqueous electrolyte secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012144594A JP5958119B2 (en) | 2012-06-27 | 2012-06-27 | Positive electrode composition for non-aqueous electrolyte secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014010912A JP2014010912A (en) | 2014-01-20 |
| JP5958119B2 true JP5958119B2 (en) | 2016-07-27 |
Family
ID=50107458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012144594A Active JP5958119B2 (en) | 2012-06-27 | 2012-06-27 | Positive electrode composition for non-aqueous electrolyte secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5958119B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111434618B (en) | 2020-01-17 | 2022-07-22 | 蜂巢能源科技有限公司 | Cobalt-free layered positive electrode material, preparation method and lithium ion battery |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20060111393A (en) * | 2005-04-22 | 2006-10-27 | 주식회사 엘지화학 | New system of lithium ion battery containing material with high irreversible capacity |
| JP4445447B2 (en) * | 2005-09-15 | 2010-04-07 | 株式会社東芝 | Nonaqueous electrolyte battery and battery pack |
| KR101264332B1 (en) * | 2006-09-20 | 2013-05-14 | 삼성에스디아이 주식회사 | Cathode active material and lithium battery using the same |
| JP5407117B2 (en) * | 2007-06-26 | 2014-02-05 | 日産自動車株式会社 | Lithium ion battery |
| JP5703626B2 (en) * | 2010-08-19 | 2015-04-22 | 日亜化学工業株式会社 | Cathode active material for non-aqueous electrolyte secondary battery |
-
2012
- 2012-06-27 JP JP2012144594A patent/JP5958119B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014010912A (en) | 2014-01-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5382061B2 (en) | Positive electrode composition for non-aqueous electrolyte secondary battery and positive electrode slurry using the positive electrode composition | |
| JP5099168B2 (en) | Lithium ion secondary battery | |
| US10062925B2 (en) | Electrolyte solution for lithium secondary battery and lithium secondary battery | |
| US20110059351A1 (en) | Lithium ion secondary battery | |
| JP5017778B2 (en) | Positive electrode for non-aqueous electrolyte battery and non-aqueous electrolyte battery | |
| JPWO2012035648A1 (en) | Non-aqueous electrolyte secondary battery active material and non-aqueous electrolyte secondary battery | |
| JP2008091236A (en) | Nonaqueous electrolyte secondary battery | |
| US11677065B2 (en) | Cathode active material of lithium secondary battery | |
| CN108717977B (en) | Lithium ion battery with excellent zero-volt storage performance | |
| JP2013131437A (en) | Positive electrode composition for nonaqueous electrolyte secondary battery and method for producing positive electrode slurry for nonaqueous electrolyte secondary battery | |
| JP3579280B2 (en) | Negative electrode for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery provided with this negative electrode | |
| JPWO2011045848A1 (en) | Non-aqueous electrolyte type lithium ion secondary battery | |
| JP2012209064A (en) | Cathode active material and secondary cell using the same | |
| JP2012099316A (en) | Cathode active material for lithium-ion secondary battery, and lithium-ion secondary battery | |
| JP6246682B2 (en) | Lithium ion secondary battery | |
| JP6191351B2 (en) | Positive electrode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using the same | |
| JP2012252951A (en) | Nonaqueous electrolyte secondary battery | |
| JP2018195419A (en) | Positive electrode material for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery arranged by use thereof, and method for manufacturing positive electrode material for nonaqueous electrolyte secondary battery | |
| JP6233101B2 (en) | Cathode active material for non-aqueous electrolyte secondary battery | |
| CN112689916A (en) | Electric storage element | |
| JP2013051170A (en) | Negative electrode active material of nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery | |
| JP5958119B2 (en) | Positive electrode composition for non-aqueous electrolyte secondary battery | |
| JP6273707B2 (en) | Positive electrode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using the same | |
| JP4843833B2 (en) | Method for improving low temperature characteristics of lithium secondary battery | |
| JP5985272B2 (en) | Nonaqueous electrolyte secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20150210 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20151130 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20151201 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20160127 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20160218 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160308 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20160428 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20160524 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160606 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5958119 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |