# US 2025/0219143 A1 · Electrolyte for sodium secondary battery, sodium secondary battery, and electrical apparatus

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- Number: US 2025/0219143 A1
- Document ID: US20250219143A1
- Status: Published application
- Kind: A1
- Application number: 19/084,804
- Filed: 2025-03-20
- Published: 2025-07-03
- Earliest claimed: 2023-01-16
- Assignees: Contemporary Amperex Technology (Honk Kong) Limited
- Applicants: Contemporary Amperex Technology (Honk Kong) Limited
- Inventors: Xiaolong Li; Bingkun Guo; Xinxin Zhang; Ben Liu; Shigang Chen; Shikang Yao; Qicheng Zhou; Jiadian Lan; Wenguang Lin
- Web page: https://patentgrep.com/patent/US20250219143A1

## CPC

- H01M 10/0567: characterised by the additives
- H01M 4/366: {as layered products}
- H01M 4/381: {Alkaline or alkaline earth metals elements (H01M4/40 takes precedence)}
- H01M 4/625: {Carbon or graphite}
- H01M 4/663: {containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres}
- H01M 4/667: {in the form of layers, e.g. coatings}
- H01M 10/054: Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
- H01M 10/0568: characterised by the solutes
- H01M 10/0569: characterised by the solvents
- H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)}
- H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)}
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- H01M 2300/0025: Organic electrolyte
- 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

This application provides an electrolyte for a sodium secondary battery, a sodium secondary battery, and an electrical apparatus. An electrolyte for a sodium secondary battery is provided, where the electrolyte includes an additive, and the additive includes a fluorinated ether compound. In this application, through the addition of an additive, including a fluorinated ether compound, in the electrolyte, the high-temperature cycling performance of the battery can be improved, the high-temperature gas generation phenomenon of the battery can be alleviated, and the electrochemical performance and safety performance of the battery can be improved.

## Claims

### Claim 1

An electrolyte for a sodium secondary battery, wherein the electrolyte comprises an additive, wherein the additive comprises a fluorinated ether compound.

### Claim 2 (depends on 1)

The electrolyte according to claim 1, wherein the fluorinated ether compound comprises one or more of compounds represented by formula I:
wherein
R1 and R2 are each independently selected from fluorine-substituted or unsubstituted C1-C6 alkyl groups, and at least one of R1 or R2 contains a fluorine atom.

### Claim 3 (depends on 1)

The electrolyte according to claim 1, wherein the fluorinated ether compound comprises one or more of 1,1,2,2-tetrafluoroethyl methyl ether, 2,2,3,3-tetrafluoropropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, bis-(2,2,2-trifluoroethyl) ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, methyl nonafluorobutyl ether, bis-(1,1,2,2-tetrafluoroethyl) ether, difluoromethyl-2,2,2-trifluoroethyl ether, 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane, 1,1,2,3,3,3-pentafluoropropyl-2,2,2-trifluoroethyl ether, 2,2,3,3-tetrafluoropropyl difluoromethyl ether, 2,2,3,3-tetrafluoro-1-methoxypropane, 1,1,2,3,3,3-pentafluoropropyl ethyl ether, 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,3,3,3-hexafluoropropyl methyl ether, ethyl perfluorobutyl ether, ethyl nonafluorobutyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, 1,1,2,3,3,3-pentafluoropropyl-2,2,2-trifluoroethyl ether, 2,2,3,3,3-pentafluoropropyl difluoromethyl ether, or 2,2,2-trifluoroethyl ethyl ether, or one or more of bis-(2,2,2-trifluoroethyl) ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, methyl nonafluorobutyl ether, ethyl perfluorobutyl ether, or ethyl nonafluorobutyl ether.

### Claim 4 (depends on 1)

The electrolyte according to claim 1, wherein, based on a total mass of the electrolyte, a mass percentage of the additive is 0.2%-10%, or 0.5%-6.5%.

### Claim 5 (depends on 1)

The electrolyte according to claim 1, wherein the electrolyte further comprises a sodium salt and an ether solvent, and based on a total mass of the electrolyte, a mass percentage of the sodium salt is 3%-40%, or 5%-30%.

### Claim 6 (depends on 5)

The electrolyte according to claim 5, wherein the sodium salt comprises one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium hexafluoroarsenate, or sodium trifluoroacetate.

### Claim 7 (depends on 5)

The electrolyte according to claim 5, wherein the ether solvent comprises one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetrahydrofuran, or methyltetrahydrofuran, or one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, or ethylene glycol diethyl ether.

### Claim 8 (depends on 1)

The electrolyte according to claim 1, wherein the electrolyte further comprises a lithium salt.

### Claim 9 (depends on 8)

The electrolyte according to claim 8, wherein the lithium salt comprises one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium trifluoroacetate, lithium tetraphenylborate, lithium trifluoromethylsulfonate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethylsulfonyl)imide.

### Claim 10

A sodium secondary battery, wherein the sodium secondary battery comprises an electrolyte, wherein the electrolyte comprises an additive, and wherein the additive comprises a fluorinated ether compound.

### Claim 11 (depends on 10)

The sodium secondary battery according to claim 10, wherein the sodium secondary battery comprises a negative electrode plate, the negative electrode plate comprising a negative electrode current collector and a primer coating formed on at least one side of the negative electrode current collector, and
the sodium secondary battery satisfies following relational expression: 0.3≤Z-0.01 X≤6, wherein
X g/m2 is a surface density of the primer coating, and Z % is a mass percentage of the additive based on a total mass of the electrolyte.

### Claim 12 (depends on 10)

The sodium secondary battery according to claim 10, wherein the sodium secondary battery comprises the negative electrode plate, a negative electrode plate comprising a negative electrode current collector and a primer coating formed on at least one side of the negative electrode current collector, and the electrolyte comprises a lithium salt, and
the sodium secondary battery satisfies following relational expression: 0.84≤Y-0.01 X≤5.84, wherein
X g/m2 is a surface density of the primer coating, and Y % is a mass percentage of the lithium salt based on a total mass of the electrolyte.

### Claim 13 (depends on 11)

The sodium secondary battery according to claim 11, wherein the surface density of the primer coating is 5 g/m2-50 g/m2.

### Claim 14 (depends on 11)

The sodium secondary battery according to claim 11, wherein the primer coating is one or more of carbon coating, alloy coating, or metal oxide coating, or carbon coating.

### Claim 15 (depends on 11)

The sodium secondary battery according to claim 11, wherein the primer coating contains one or more of super conductive carbon black, Ketjen black, acetylene black, carbon nanotubes, or graphene.

### Claim 16 (depends on 10)

The sodium secondary battery according to claim 10, wherein the sodium secondary battery is a sodium metal battery with no negative electrode.

### Claim 17

An electrical apparatus, characterized by comprising a sodium secondary battery, wherein the sodium secondary battery comprises an electrolyte, wherein the electrolyte comprises an additive, and wherein the additive comprises a fluorinated ether compound.