# US 2021/0242550 A1 · System and method for multi-electrolyte activation and refurbishment of electrochemical cells

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0242550 A1
- Document ID: US20210242550A1
- Status: Published application
- Kind: A1
- Application number: 17/130,776
- Filed: 2020-12-22
- Published: 2021-08-05
- Earliest claimed: 2019-12-23
- Assignees: Central Intelligence Agency
- Applicants: Central Intelligence Agency
- Inventors: Stefan C. Bradford; Grant Umeda; Kirakodu S. Nanjundaswamy
- Web page: https://patentgrep.com/patent/US20210242550A1

## CPC

- H01M 4/044: {Activating, forming or electrochemical attack of the supporting material}
- H01M 50/609: Arrangements or processes for filling with liquid, e.g. electrolytes
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0566: Liquid materials
- H01M 10/0569: characterised by the solvents
- H01M 10/058: Construction or manufacture
- H01M 50/691: Arrangements or processes for draining liquids from casings; Cleaning battery or cell casings
- H01M 2300/0045: Room temperature molten salts comprising at least one organic ion
- 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

A method for multi-electrolyte activation or refurbishment of an electrochemical cell uses a first electrolyte to electrochemically decompose electrolyte components onto an electrode surface to create an electrode-electrolyte interphase (EEI). Once the EEI is created, the first electrolyte may be extracted so that a second electrolyte can be introduced into the electrochemical cell. The second electrolyte can interact with the EEI to optimize performance over a broader range of conditions than if the second electrolyte were interacting with the bare electrode. This method also allows for refurbishment of an electrochemical cell. Various structures may be provided on the electrochemical cell itself to facilitate the method.

## Claims

### Claim 1

An activation method for a cell comprising:
introducing a first electrolyte into a cell having one or more electrodes;
conditioning the cell by activating the cell with the first electrolyte to form an electrode-electrolyte interface on one or more of the electrodes in the cell;
removing the first electrolyte from the cell;
introducing a second electrolyte into the cell, where the second electrolyte has a different composition from the first electrolyte; and
activating the cell with the second electrolyte.

### Claim 2 (depends on 1)

The activation method of claim 1, wherein the activation method makes the cell appropriate for use in an extreme condition.

### Claim 3 (depends on 2)

The activation method of claim 2, wherein the activation procedure makes the cell appropriate for use in high temperatures.

### Claim 4 (depends on 3)

The activation method of claim 3, wherein the cell is a liquid electrolyte cell.

### Claim 5 (depends on 4)

The activation method of claim 4, wherein the first electrolyte includes a lithium-ion battery electrolyte.

### Claim 6 (depends on 5)

The activation method of claim 5, wherein the second electrolyte includes an ionic liquid-based electrolyte.

### Claim 7 (depends on 6)

The activation method of claim 6, wherein the second electrolyte includes ethyl methyl carbonate.

### Claim 8 (depends on 6)

The activation method of claim 6, wherein the second electrolyte includes a PMI based ionic liquid.

### Claim 9 (depends on 4)

The activation method of claim 4 further comprising drying the cell prior to the step of introducing the second electrolyte into the cell.

### Claim 10 (depends on 9)

The activation method of claim 9, wherein the cell is vacuum dried.

### Claim 11

A refurbishment method for a cell comprising:
removing an original electrolyte from the cell;
introducing a second electrolyte into the cell; and
activating the cell with the second electrolyte.

### Claim 12 (depends on 11)

The refurbishment method of claim 11, wherein the second electrolyte is different from the original electrolyte.

### Claim 13 (depends on 12)

The refurbishment method of claim 12, wherein the second electrolyte includes the original electrolyte.

### Claim 14

A cell comprising:
a housing;
a cathode and an anode disposed in the housing;
an electrolyte disposed in the housing and in contact with the cathode and the anode;
an electrode-electrolyte interface formed on at least one of the cathode and the anode, wherein the electrode-electrolyte interface is configured to enhance operation of the cell.

### Claim 15 (depends on 14)

The cell of claim 14, wherein the electrode-electrolyte interface is configured to enhance the operation of the cell in an extreme condition.

### Claim 16 (depends on 15)

The cell of claim 15, wherein the extreme condition is high temperatures.

### Claim 17 (depends on 14)

The cell of claim 14, wherein the electrolyte is a liquid electrolyte.

### Claim 18 (depends on 17)

The cell of claim 17 further comprising a pouch structure, wherein the cathode, the anode, and the electrolyte are disposed at least partially within the pouch.

### Claim 19 (depends on 18)

The cell of claim 18, wherein the pouch includes at least one port configured to facilitate removing and replacing the liquid electrolyte.

### Claim 20 (depends on 15)

The claim of claim 15, wherein the electrolyte includes an ionic liquid-based electrolyte.