JPWO2021217587A5

JPWO2021217587A5 -

Info

Publication number: JPWO2021217587A5
Application number: JP2022532654A
Authority: JP
Publication date: 2023-03-16

Claims

負極集電体と、第１の負極フィルム層及び第２の負極フィルム層を含む負極フィルム層とを含む負極シートを備え、
前記第１の負極フィルム層は、負極集電体の少なくとも一つの表面に設けられ、且つ天然黒鉛を含む第１の負極活物質を含み、
前記第２の負極フィルム層は、第１の負極フィルム層上に設けられ、且つ人造黒鉛を含む第２の負極活物質を含み、
前記第２の負極活物質は、二次粒子を含み、且つ前記第２の負極活物質における前記二次粒子の数量割合はＳ２≧２０％である、二次電池。 A negative electrode sheet including a negative electrode current collector and a negative electrode film layer including a first negative film layer and a second negative film layer,
The first negative electrode film layer is provided on at least one surface of the negative electrode current collector and includes a first negative electrode active material containing natural graphite,
The second negative electrode film layer is provided on the first negative electrode film layer and contains a second negative electrode active material containing artificial graphite,
The secondary battery, wherein the second negative electrode active material contains secondary particles, and the secondary particles have a quantity ratio of S2≧20% in the second negative electrode active material.

前記第２の負極活物質における前記二次粒子の数量割合は、Ｓ２≧５０％である、請求項１に記載の二次電池。 2. The secondary battery according to claim 1, wherein the secondary particles have a numerical ratio of S2≧50% in the second negative electrode active material.

前記第１の負極活物質は、一次粒子を含み、第１の負極活物質における前記一次粒子の数量割合は、Ｓ１≧８０％であり、好ましくは、９０％≦Ｓ１≦１００％である、請求項１又は２に記載の二次電池。 The first negative electrode active material contains primary particles, and the number ratio of the primary particles in the first negative electrode active material is S1≧80%, preferably 90%≦S1≦100%. Item 3. The secondary battery according to Item 1 or 2.

前記第１の負極活物質における前記天然黒鉛の質量割合は、≧６０％であり、好ましくは、前記第１の負極活物質における前記天然黒鉛の質量割合は８０％～１００％である、請求項１～３のいずれか一項に記載の二次電池。 The mass ratio of the natural graphite in the first negative electrode active material is ≧60%, and preferably the mass ratio of the natural graphite in the first negative electrode active material is 80% to 100%. 4. The secondary battery according to any one of 1 to 3.

前記第２の負極活物質における前記人造黒鉛の質量割合は、≧９０％であり、好ましくは、前記第２の負極活物質における前記人造黒鉛の質量割合は９５％～１００％である、請求項１～４のいずれか一項に記載の二次電池。 The mass ratio of the artificial graphite in the second negative electrode active material is ≧90%, and preferably the mass ratio of the artificial graphite in the second negative electrode active material is 95% to 100%. 5. The secondary battery according to any one of 1 to 4.

前記第１の負極活物質の体積分布粒径Ｄ_Ｖ５０は、前記第２の負極活物質の体積分布粒径Ｄ_Ｖ５０より大きい、請求項１～５のいずれか一項に記載の二次電池。 The secondary according to any one of claims 1 to 5, wherein the volume distribution particle size D _V 50 of the first negative electrode active material is greater than the volume distribution particle size D _V 50 of the second negative electrode active material. battery.

前記第１の負極活物質の２００００Ｎ圧力での圧縮密度と前記第２の負極活物質の２００００Ｎ圧力での圧縮密度との比は≧０．７８であり、好ましくは、０．８４～０．９８である、請求項１～６のいずれか一項に記載の二次電池。 The ratio of the compression density at 20000N pressure of the first negative electrode active material and the compression density at 20000N pressure of the second negative electrode active material is ≧0.78, preferably 0.84 to 0.98. The secondary battery according to any one of claims 1 to 6, wherein

前記第１の負極活物質は、
（１）前記第１の負極活物質の体積分布粒径Ｄ_Ｖ１０は、６μｍ～１１μｍであり、好ましくは７μｍ～８μｍであり、
（２）前記第１の負極活物質の体積分布粒径Ｄ_Ｖ５０は、１１μｍ～２０μｍであり、好ましくは１５μｍ～２０μｍであり、
（３）前記第１の負極活物質の体積分布粒径Ｄ_Ｖ９９は、２４μｍ～３８μｍであり、好ましくは３０μｍ～３８μｍであり、
（４）前記第１の負極活物質の粒度分布（Ｄ_Ｖ９０－Ｄ_Ｖ１０）／Ｄ_Ｖ５０は、０．７～１．５であり、好ましくは０．９～１．３であり、
（５）前記第１の負極活物質の２００００Ｎ圧力での圧縮密度は、１．６ｇ／ｃｍ^３～１．８８ｇ／ｃｍ^３であり、好ましくは１．７０ｇ／ｃｍ^３～１．８５ｇ／ｃｍ^３であり、
（６）前記第１の負極活物質の黒鉛化度は≧９５．５％であり、好ましくは９６．５％～９８．５％であり、前記黒鉛化度は明細書に記載の方法で測定され、
のうちの一つ又は複数をさらに満たす、請求項１～５のいずれか一項に記載の二次電池。 The first negative electrode active material is
(1) the volume distribution particle size D _V 10 of the first negative electrode active material is 6 μm to 11 μm, preferably 7 μm to 8 μm;
(2) the volume distribution particle size D _V 50 of the first negative electrode active material is 11 μm to 20 μm, preferably 15 μm to 20 μm;
(3) the volume distribution particle diameter D _V 99 of the first negative electrode active material is 24 μm to 38 μm, preferably 30 μm to 38 μm;
(4) the particle size distribution (D _V 90 - D _V 10)/D _V 50 of the first negative electrode active material is 0.7 to 1.5, preferably 0.9 to 1.3;
(5) The compression density of the first negative electrode active material at a pressure of 20000 N is 1.6 g/cm ³ to 1.88 g/cm ³ , preferably 1.70 g/cm ³ to 1.85 g/cm ³ . and
(6) The degree of graphitization of the first negative electrode active material is ≧95.5%, preferably 96.5% to 98.5%, and the degree of graphitization is measured by the method described in the specification. is,
The secondary battery according to any one of claims 1 to 5, further satisfying one or more of

前記第２の負極活物質は、
（１）前記第２の負極活物質の体積分布粒径Ｄ_Ｖ１０は、６．２μｍ～９．２μｍであり、好ましくは６．６μｍ～８．８μｍであり、
（２）前記第２の負極活物質の体積分布粒径Ｄ_Ｖ５０は、１１μｍ～１８μｍであり、好ましくは１２μｍ～１６μｍであり、
（３）前記第２の負極活物質の体積分布粒径Ｄ_Ｖ９９は、２９μｍ～４３μｍであり、好ましくは３７μｍ～４１μｍであり、
（４）前記第２の負極活物質の粒度分布（Ｄ_Ｖ９０－Ｄ_Ｖ１０）／Ｄ_Ｖ５０は、０．９～１．６であり、好ましくは１．１～１．４であり、
（５）前記第２の負極活物質の２００００Ｎ圧力での圧縮密度は、１．５８ｇ／ｃｍ^３～１．８２ｇ／ｃｍ^３であり、好ましくは１．６４ｇ／ｃｍ^３～１．７４ｇ／ｃｍ^３であり、
（６）前記第２の負極活物質の黒鉛化度は９２．５％～９６．５％であり、より好ましくは９３．１％～９５．１％であり、前記黒鉛化度は明細書に記載の方法で測定され、
のうちの一つ又は複数をさらに満たす、請求項１～６のいずれか一項に記載の二次電池。 The second negative electrode active material is
(1) the volume distribution particle size D _V 10 of the second negative electrode active material is 6.2 μm to 9.2 μm, preferably 6.6 μm to 8.8 μm;
(2) the volume distribution particle diameter D _V 50 of the second negative electrode active material is 11 μm to 18 μm, preferably 12 μm to 16 μm;
(3) the volume distribution particle size D _V 99 of the second negative electrode active material is 29 μm to 43 μm, preferably 37 μm to 41 μm;
(4) the particle size distribution (D _V 90 - D _V 10)/D _V 50 of the second negative electrode active material is 0.9 to 1.6, preferably 1.1 to 1.4;
(5) The compression density of the second negative electrode active material at a pressure of 20000 N is 1.58 g/cm ³ to 1.82 g/cm ³ , preferably 1.64 g/cm ³ to 1.74 g/cm ³ . and
(6) The degree of graphitization of the second negative electrode active material is 92.5% to 96.5%, more preferably 93.1% to 95.1%, and the degree of graphitization is specified in the specification. Measured by the method described,
The secondary battery according to any one of claims 1 to 6, further satisfying one or more of

前記二次電池は、正極シートを含み、
前記正極シートは、正極集電体と、正極集電体の少なくとも一つの表面に設置され且つ正極活物質を含む正極フィルム層とを含み、
前記正極活物質は、リチウム遷移金属酸化物、オリビン構造のリチウム含有リン酸塩及びそれらのそれぞれの改質化合物のうちの1種類又は複数種類を含み、
好ましくは、前記正極活物質は、式１に示すリチウム遷移金属酸化物及びその改質化合物のうちの1種類又は複数種類を含み、
Ｌｉ_ａＮｉ_ｂＣｏ_ｃＭ_ｄＯ_ｅＡ_ｆ式１
前記式１において、０．８≦ａ≦１．２、０．５≦ｂ＜１、０＜ｃ＜１、０＜ｄ＜１、１≦ｅ≦２、０≦ｆ≦１、ＭはＭｎ、Ａｌ、Ｚｒ、Ｚｎ、Ｃｕ、Ｃｒ、Ｍｇ、Ｆｅ、Ｖ、Ｔｉ及びＢから選択される１種類または複数種類であり、ＡはＮ、Ｆ、Ｓ及びＣｌから選択される１種類または複数種類であることを特徴とする、請求項１～９のいずれか一項に記載の二次電池である。 The secondary battery includes a positive electrode sheet,
The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector and containing a positive electrode active material,
the positive electrode active material comprises one or more of a lithium transition metal oxide, an olivine-structured lithium-containing phosphate, and their respective modification compounds;
Preferably, the positive electrode active material contains one or more of lithium transition metal oxides represented by Formula 1 and modified compounds thereof,
_{LiaNibCocMdOeAf} _Formula ₁ _{_} _{_} _{_}
In Formula 1, 0.8≦a≦1.2, 0.5≦b<1, 0<c<1, 0<d<1, 1≦e≦2, 0≦f≦1, M is Mn , Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A is one or more selected from N, F, S and Cl The secondary battery according to any one of claims 1 to 9, characterized in that

１）負極集電体の少なくとも一つの表面に、天然黒鉛を含む第１の負極活物質を備える第１の負極フィルム層を形成し、
２）前記第１の負極フィルム層に、人造黒鉛と数量割合がＳ２≧２０％である二次粒子とを含む第２の負極活物質を備える第２の負極フィルム層を形成することにより、
二次電池の負極シートを作製する、二次電池の作製方法。 1) forming a first negative electrode film layer comprising a first negative electrode active material containing natural graphite on at least one surface of a negative electrode current collector;
2) forming, on the first negative electrode film layer, a second negative electrode film layer comprising a second negative electrode active material containing artificial graphite and secondary particles having a quantity ratio of S2≧20%,
A method for producing a secondary battery, comprising producing a negative electrode sheet for a secondary battery.

前記第１の負極フィルム層と前記第２の負極フィルム層が同時に塗布される、請求項１１に記載の二次電池の作製方法。 12. The method of making a secondary battery of claim 11, wherein the first anode film layer and the second anode film layer are applied simultaneously.

請求項１～１０のいずれか一項に記載の二次電池又は請求項１１又は１２に記載の方法で作製された二次電池を含む装置。
A device comprising the secondary battery according to any one of claims 1 to 10 or a secondary battery produced by the method according to claim 11 or 12.