# US 12,113,184 B2 · Thin-film reference electrodes, electrochemical devices including thin-film reference electrodes, and methods of making thin-film reference electrodes

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

- Number: US 12,113,184 B2
- Document ID: US12113184B2
- Status: Granted
- Kind: B2
- Application number: 17/752,185
- Filed: 2022-05-24
- Published: 2022-09-08
- Granted: 2024-10-08
- Earliest claimed: 2019-09-20
- Assignees: GM Global Technology Operations LLC
- Applicants: GM Global Technology Operations LLC
- Inventors: Jing Gao; Brian J. Koch; Zhe Li; Alfred Zhang; Gayatri V. Dadheech
- Web page: https://patentgrep.com/patent/US12113184B2

## CPC

- H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569)
- B05D 1/005: {Spin coating}
- H01M 50/105: Pouches or flexible bags
- H01M 50/109: of button or coin shape
- H01M 50/417: Polyolefins
- H01M 50/569: Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals (battery terminal connectors with integrated measuring arrangements G01R31/364)
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A method of making a reference electrode assembly for an electrochemical cell according to various aspects of the present disclosure includes providing a subassembly including a separator layer and a current collector layer coupled to the separator layer. The method further includes providing an electrode ink including an electroactive material, a binder, and a solvent. The method further includes creating a reference electrode precursor by applying an electroactive precursor layer to the current collector layer. The electroactive precursor layer covers greater than or equal to about 90% of a superficial surface area of a surface of the current collector layer. The electroactive precursor layer includes the electrode ink. The method further includes creating the reference electrode assembly by drying the electroactive precursor layer to remove at least a portion of the solvent, thereby forming an electroactive layer. The electroactive layer is solid and porous.

## Claims

### Claim 1

A method of making a reference electrode assembly for an electrochemical cell, the method comprising:
providing a subassembly comprising a separator layer and a current collector layer coupled to the separator layer, the separator layer being porous and electrically insulating, the current collector layer being electrically conductive;
providing an electrode ink comprising an electroactive material, a binder, and a solvent;
creating a reference electrode precursor by spin-coating an electroactive precursor layer directly to a surface of the current collector layer of the subassembly, the electroactive precursor layer covering an area of greater than or equal to about 70% of the entire superficial surface of the surface of the current collector layer, the electroactive precursor layer comprising the electrode ink; and
creating the reference electrode assembly by drying the electroactive precursor layer to remove at least a portion of the solvent, thereby forming an electroactive layer, the electroactive layer being solid and porous, the electroactive layer defining a thickness of greater than or equal to about 0.2 micrometers to less than or equal to about 1 micrometers and a first porosity of greater than or equal to about 40% to less than or equal to about 60%.

### Claim 2 (depends on 1)

The method of claim 1, wherein the electroactive precursor layer covers greater than or equal to about 80% of the superficial surface area.

### Claim 3 (depends on 1)

The method of claim 1, wherein the electroactive precursor layer covers greater than or equal to about 90% of the superficial surface area.

### Claim 4 (depends on 1)

The method of claim 1, wherein the electroactive precursor layer covers the entire superficial surface area.

### Claim 5 (depends on 1)

The method of claim 1, wherein the spin-coating is performed at a rotational speed of greater than or equal to about 500 RPM to less than or equal to about 3,000 RPM.

### Claim 6 (depends on 1)

The method of claim 1, wherein the spin-coating is performed at a rotational speed of greater than or equal to about 500 RPM to less than or equal to about 2,000 RPM.

### Claim 7 (depends on 1)

The method of claim 1, wherein the electroactive layer defines the thickness of greater than or equal to about 0.5 μm.

### Claim 8 (depends on 1)

The method of claim 1, wherein the first porosity of the electroactive layer is greater than or equal to about a second porosity of the separator layer.

### Claim 9 (depends on 1)

The method of claim 1, wherein the providing the subassembly comprises sputtering the current collector layer onto the separator layer.

### Claim 10 (depends on 1)

The method of claim 1, wherein the current collector layer defines a thickness of greater than or equal to about 25 nanometers to less than or equal to about 100 nanometers.

### Claim 11 (depends on 1)

The method of claim 1, wherein the providing the electrode ink comprises preparing the electrode ink by admixing the electroactive material, the binder, and the solvent.

### Claim 12 (depends on 11)

The method of claim 11, wherein the solvent is present in an amount greater than or equal to about 80% by weight to less than or equal to about 99% by weight.

### Claim 13 (depends on 11)

The method of claim 11, wherein the electroactive material is in a form of a plurality of particles.

### Claim 14 (depends on 1)

The method of claim 1, further comprising:
applying a mask layer to a region of the surface after providing the subassembly and prior to the creating the reference electrode precursor; and
removing the mask layer after the creating the reference electrode precursor.

### Claim 15 (depends on 14)

The method of claim 14, wherein the removing creates a tab.

### Claim 16 (depends on 1)

The method of claim 1, further comprising creating a tab by removing a portion of the electrode ink in a region of the surface by applying a solvent to the electrode ink.

### Claim 17 (depends on 16)

The method of claim 16, wherein the solvent comprises water.

### Claim 18 (depends on 1)

The method of claim 1, further comprising:
collecting excess electrode ink resulting from spin-coating.

### Claim 19 (depends on 1)

The method of claim 1, wherein the drying is performed at ambient temperature.

### Claim 20 (depends on 1)

The method of claim 1, wherein the drying is performed concurrently with the spin-coating.