# US 10,483,544 B2 · Lithium secondary batteries

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- Number: US 10,483,544 B2
- Document ID: US10483544B2
- Status: Granted
- Kind: B2
- Application number: 15/447,708
- Filed: 2017-03-02
- Published: 2017-09-07
- Granted: 2019-11-19
- Earliest claimed: 2016-03-04
- Assignees: SK Innovation Co., Ltd.
- Applicants: SK Innovation Co., Ltd.
- Inventors: Jee Hee Lee; Sang Jin Kim; Hyo Sang Kim; Jung Hwan Kim
- Web page: https://patentgrep.com/patent/US10483544B2

## CPC

- H01M 4/587: for inserting or intercalating light metals
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0569: characterised by the solvents
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- H01M 2300/0028: characterised by the solvent
- H01M 2300/004: Three solvents
- 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

Provided is a lithium secondary battery including an anode containing agglomerate artificial graphite having pores with an average diameter of 80 to 150 nm; and an electrolyte solution having a viscosity of 5.0 cP or less at 25° C. The lithium secondary battery according to the present invention may have excellent life characteristics, high temperature storage characteristics and output characteristics.

## Claims

### Claim 1

A lithium secondary battery comprising: an anode containing agglomerate artificial graphite having pores with an average diameter of 80 to 150 nm; and an electrolyte solution having a viscosity of 5.0 cP or less at 25° C.,
wherein the agglomerate artificial graphite satisfies the following Equation 1:
0.1≤ΔHA/HA≤0.4
wherein HA is an average particle diameter (μm) of the agglomerate artificial graphite; and ΔHA is an average particle diameter variation (μm) of the agglomerate artificial graphite when applying a pressure of 4 mN/cm2,
wherein the electrolyte solution contains a first solvent including ethylmethyl carbonate, diethyl carbonate or a mixed solution thereof and a second solvent including at least one selected from dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC).

### Claim 2 (depends on 1)

The lithium secondary battery of claim 1, wherein the agglomerate artificial graphite has a true density of 2 to 2.5 g/cm3, and a specific surface area of 0.5 to 5 m2/g.

### Claim 3 (depends on 1)

The lithium secondary battery of claim 1, wherein the agglomerate artificial graphite has Lc(002) of 3.355 to 3.361 in which Lc(002) is a crystallite size in a C-axis direction when measuring an X-ray diffraction pattern.

### Claim 4 (depends on 1)

The lithium secondary battery of claim 1, wherein the first solvent contains 55 to 80 vol % of ethylmethyl carbonate based on a total volume of the electrolyte solution.

### Claim 5

A lithium secondary battery comprising: an anode containing agglomerate artificial graphite having pores with an average diameter of 80 to 150 nm; and an electrolyte solution having a viscosity of 5.0 cP or less at 25° C.,
wherein the agglomerate artificial graphite has a true density of 2 to 2.5 g/cm3, and a specific surface area of 0.5 to 5 m2/g,
wherein the electrolyte solution contains a first solvent including ethylmethyl carbonate, diethyl carbonate or a mixed solution thereof, and a second solvent including at least one selected from dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC).

### Claim 6 (depends on 5)

The lithium secondary battery of claim 5, wherein the agglomerate artificial graphite has Lc(002) of 3.355 to 3.361 in which Lc(002) is a crystallite size in a C-axis direction when measuring an X-ray diffraction pattern.

### Claim 7 (depends on 5)

The lithium secondary battery of claim 5, wherein the first solvent contains 55 to 80 vol % of ethylmethyl carbonate based on a total volume of the electrolyte solution.