# US 2021/0242498 A1 · Lithium ion secondary battery

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- Number: US 2021/0242498 A1
- Document ID: US20210242498A1
- Status: Published application
- Kind: A1
- Application number: 17/052,811
- Filed: 2019-08-29
- Published: 2021-08-05
- Earliest claimed: 2018-08-31
- Assignees: Contemporary Amperex Technology Co., Limited
- Applicants: Contemporary Amperex Technology Co., Limited
- Inventors: Zhiqiang LI; Changlong HAN
- Web page: https://patentgrep.com/patent/US20210242498A1

## CPC

- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 10/0567: characterised by the additives
- H01M 4/0404: {by coating on electrode collectors}
- H01M 4/364: {as mixtures}
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 4/623: {fluorinated polymers}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0568: characterised by the solutes
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- H01M 2004/028: {Positive electrodes}
- H01M 2300/0028: characterised by the solvent
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present application discloses a lithium ion secondary battery comprising a positive electrode plate, a negative electrode plate, a separator and an electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode film provided on at least one surface of the positive electrode current collector, and the positive electrode film comprises a first positive electrode active material represented by chemical formula Li1+xNiaCobMe1−a−bO2−yAy and a second positive electrode active material represented by chemical formula Li1+zMncN2−cO4−dBd; the positive electrode plate has a resistivity r of 3500 Ω·m or less; and the electrolyte comprises a fluorine-containing lithium salt type additive. The lithium ion secondary battery provided by the present application is capable of satisfying high safety performance, high-temperature storage performance and cycle performance simultaneously.

## Claims

### Claim 1

A lithium ion secondary battery comprising a positive electrode plate, a negative electrode plate, a separator and an electrolyte, wherein
the positive electrode plate comprises a positive electrode current collector and a positive electrode film provided on at least one surface of the positive electrode current collector, and the positive electrode film comprises a first positive electrode active material represented by chemical formula (1) and a second positive electrode active material represented by chemical formula (2),
Li1+xNiaCobMe1−a−bO2−yAy chemical formula (1)
Li1+zMncN2−cO4−dBd chemical formula (2)
in the chemical formula (1), −0.1≤x≤0.2, 0<a<1, 0<b<1, 0≤a+b<1, 0<y<0.2, Me comprises one or more of Mn, Fe, Cr, Ti, Zn, V, Al, Zr and Ce, and A comprises one or more of S, N, F, Cl, Br and I,
in the chemical formula (2), −0.1≤z≤0.2, 0<c≤2, 0≤d<1, N comprises one or more of Ni, Fe, Cr, Ti, Zn, V, Al, Mg, Zr and Ce, and B comprises one or more of S, N, F, Cl, Br and I;
the positive electrode plate has a resistivity r of 3500 n-m or less; and,
the electrolyte comprises a fluorine-containing lithium salt type additive.

### Claim 2 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the resistivity of the positive electrode plate is 2500 Ω·m or less.

### Claim 3 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein in the chemical formula (1), 0.5≤a<1, 0<b<0.5, 0.7≤a+b<1, 0≤y<0.1, M is one or both of Mn and Al, and A is one or both of S and F.

### Claim 4 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the fluorine-containing lithium salt type additive is one or more of a compound represented by chemical formula (3) and a compound represented by chemical formula (4),
in the chemical formula (3), R is one or more of F, Cl, Br, and I, and R comprises F, M is P or B, when M is P, n+2m=6, and m is 1 or 2, and when M is B, n+2m=4, and m is 0 or 1,
in the chemical formula (4), G is one or more of F, Cl, Br and I, and G comprises F, E is P or B, when E is P, x+2y=6, and y is 1 or 2, and when E is B, x+2y=4, and y is 0 or 1.

### Claim 5 (depends on 4)

The lithium ion secondary battery according to claim 4, wherein the fluorine-containing lithium salt type additive is one or more of lithium difluorophosphate LiPO2F2, lithium difluorooxalate phosphate LiDFOP, lithium tetrafluoroborate LiBF4, and lithium difluorooxalate borate LiDFOB.

### Claim 6 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the fluorine-containing lithium salt type additive is present in the electrolyte in a weight percentage u of 0.005 wt %˜3 wt %.

### Claim 7 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the positive electrode film comprises manganese element in a weight v of 1.1×10−3 g/cm2˜9.1×10−3 g/cm2 per unit area.

### Claim 8 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the positive electrode plate and the electrolyte in the lithium ion secondary battery satisfy the following formula (11)
0.005
⁢
≤
u
1
⁢
0
⁢
0
⁢
v
≤
2
⁢
7
.
5
formula
⁢
⁢
(
11
)
in which v is weight of manganese element contained in the positive electrode film per unit area, in g/cm2; and u is weight percentage of fluorine-containing lithium salt type additive in the electrolyte, in wt %.

### Claim 9 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the electrolyte further contains a negative electrode film-forming enhancer; and
the negative electrode film-forming enhancer is one or more of cyclic carbonates with unsaturated bonds in side chains, fluorine-containing cyclic carbonates and cyclic sulfonates.

### Claim 10 (depends on 9)

The lithium ion secondary battery according to claim 9, wherein the negative electrode film-forming enhancer is present in the electrolyte in a weight percentage of 0.005 wt %-6 wt %.

### Claim 11 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the positive electrode plate and the electrolyte in the lithium ion secondary battery satisfy the following formula (21),
Li1+zMncN2−cO4−dBd chemical formula (2)
in which, r is resistivity of the positive electrode plate in Ω·m; and s1 is ionic conductivity of the electrolyte at 25° C. in mS/cm.

### Claim 12 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the resistivity of the positive electrode plate is 1200 Ω·m or less.

### Claim 13 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the fluorine-containing lithium salt type additive is present in the electrolyte in a weight percentage u of 0.1 wt %˜2 wt %.

### Claim 14 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the positive electrode film comprises manganese element in a weight v of 1.1×10−3 g/cm2˜8.2×10−3 g/cm2 per unit area.

### Claim 15 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the positive electrode plate and the electrolyte in the lithium ion secondary battery satisfy the following formula (12)
0
.
0
⁢
1
≤
u
1
⁢
0
⁢
0
⁢
v
≤
2
⁢
0
.
0
formula
⁢
⁢
(
12
)
in which v is weight of manganese element contained in the positive electrode film per unit area, in g/cm2; and u is weight percentage of fluorine-containing lithium salt type additive in the electrolyte, in wt %.

### Claim 16 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the electrolyte further contains a negative electrode film-forming enhancer; and
the negative electrode film-forming enhancer is one or more of vinyl ethylene carbonate VEC, methylene methanedisulfonate MMDS, difluoroethylene carbonate DFEC, trifluoromethyl ethylene carbonate TFPC, and 1-propene-1,3-sultone PST.

### Claim 17 (depends on 9)

The lithium ion secondary battery according to claim 9, wherein the negative electrode film-forming enhancer is present in the electrolyte in a weight percentage of 0.01 wt %-5 wt %.

### Claim 18 (depends on 9)

The lithium ion secondary battery according to claim 9, wherein the negative electrode film-forming enhancer is present in the electrolyte in a weight percentage of 0.1 wt %-2 wt %.

### Claim 19 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein
the positive electrode plate and the electrolyte in the lithium ion secondary battery satisfy the following formula (22),
−0.5≤ln r−s1≤1.5 formula (22)
in which, r is resistivity of the positive electrode plate in Ω·m; and s1 is ionic conductivity of the electrolyte at 25° C. in mS/cm.