# US 2022/0037699 A1 · Propylene Carbonate-Based Electrolyte For Lithium Ion Batteries With Silicon-Based Anodes

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- Number: US 2022/0037699 A1
- Document ID: US20220037699A1
- Status: Published application
- Kind: A1
- Application number: 17/130,088
- Filed: 2020-12-22
- Published: 2022-02-03
- Earliest claimed: 2020-07-28
- Assignees: Apple Inc.
- Applicants: Apple Inc.
- Inventors: Hyea Kim; OuJung Kwon; Woo Cheol Shin
- Web page: https://patentgrep.com/patent/US20220037699A1

## CPC

- H01M 10/0569: characterised by the solvents
- H01G 11/60: characterised by the solvent
- H01G 11/62: characterised by the solute, e.g. salts, anions or cations therein
- H01G 11/64: characterised by additives
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 10/052: Li-accumulators
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0567: characterised by the additives
- H01M 10/0568: characterised by the solutes
- H01M 2004/027: {Negative electrodes}
- H01M 2300/0037: Mixture of 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
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An electrochemical cell has an anode comprising a silicon-based active material, a cathode comprising a cathode active material, and an electrolyte having no ethylene carbonate. The electrolyte comprises a solvent, the solvent being 20 wt % to 50 wt % propylene carbonate with the remainder being a linear solvent, a lithium salt, and less than 15 wt % of one or more additives. The silicon-based anode active material has a specific capacity of ≥700 mAh/g.

## Claims

### Claim 1

An electrochemical cell, comprising:
an anode comprising a silicon-based active material having a specific capacity of ≥700 mAh/g;
a cathode comprising a cathode active material; and
an electrolyte comprising:
an ethylene carbonate-free solvent, the ethylene carbonate-free solvent being 20 wt % to 50 wt % propylene carbonate with the remainder being a linear solvent;
a lithium salt; and
less than 15 wt % of one or more additives.

### Claim 2 (depends on 1)

The electrochemical cell of claim 1, wherein the linear solvent is one or a combination of diethyl carbonate, dimethyl carbonate or ethyl methyl carbonate.

### Claim 3 (depends on 1)

The electrochemical cell of claim 1, wherein the linear solvent is one or a combination of propyl propionate or ethyl propionate.

### Claim 4 (depends on 1)

The electrochemical cell of claim 1, wherein the molar concentration of the lithium salt is 0.7 M to 1.5 M.

### Claim 5 (depends on 1)

The electrochemical cell of claim 1, wherein the lithium salt is LiPF6.

### Claim 6 (depends on 5)

The electrochemical cell of claim 5, wherein the lithium salt further includes LiFSI or LiTFSI.

### Claim 7 (depends on 1)

The electrochemical cell of claim 1, wherein the one or more additives is fluoroethylene carbonate.

### Claim 8 (depends on 1)

The electrochemical cell of claim 1, wherein the one or more additives is selected from the group consisting of fluoroethylene carbonate, vinylene carbonate, an oxalate-based additive, and a nitrile-based additive.

### Claim 9 (depends on 1)

The electrochemical cell of claim 1, wherein the ethylene carbonate-free solvent is 30 wt % propylene carbonate and 70 wt % diethyl carbonate.

### Claim 10

An electrochemical cell, comprising:
an anode comprising a silicon-based active material having a specific capacity of ≥700 mAh/g;
a cathode comprising a cathode active material; and
an electrolyte having no ethylene carbonate, the electrolyte comprising:
a solvent, the solvent being 30 wt % propylene carbonate and 70 wt % diethyl carbonate;
1.15 M LiPF6; and
less than 15 wt % of one or more additives.

### Claim 11 (depends on 10)

The electrochemical cell of claim 10, wherein the one or more additives are fluoroethylene carbonate and vinylene carbonate.

### Claim 12

An electrochemical cell, comprising:
an anode comprising a silicon-based active material having a specific capacity of ≥700 mAh/g;
a cathode comprising a cathode active material; and
an electrolyte consisting of:
a solvent, the solvent being 20 wt % to 50 wt % propylene carbonate with the remainder being a linear solvent;
lithium salt selected from the group consisting of LiPF6, LiPF6 and LiFSI, or LiPF6 and LiTFSI, the lithium salt having a molar concentration of 0.7 M to 1.5 M; and
less than 15 wt % of one or more additives.

### Claim 13 (depends on 12)

The electrochemical cell of claim 12, wherein the linear solvent is one or a combination of diethyl carbonate, dimethyl carbonate or ethyl methyl carbonate.

### Claim 14 (depends on 12)

The electrochemical cell of claim 12, wherein the linear solvent is one or a combination of propyl propionate or ethyl propionate.

### Claim 15 (depends on 12)

The electrochemical cell of claim 12, wherein the one or more additives is fluoroethylene carbonate.

### Claim 16 (depends on 12)

The electrochemical cell of claim 12, wherein the one or more additives is selected from the group consisting of fluoroethylene carbonate, vinylene carbonate, an oxalate-based additive, and a nitrile-based additive.

### Claim 17 (depends on 12)

The electrochemical cell of claim 12, wherein the solvent is 30 wt % propylene carbonate and 70 wt % diethyl carbonate.