# US 11,890,659 B2 · Production of metal-based thin foils

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- Number: US 11,890,659 B2
- Document ID: US11890659B2
- Status: Granted
- Kind: B2
- Application number: 16/406,266
- Filed: 2019-05-08
- Published: 2019-08-29
- Granted: 2024-02-06
- Earliest claimed: 2016-11-09
- Assignees: Bayerische Motoren Werke Aktiengesellschaft
- Applicants: Bayerische Motoren Werke Aktiengesellschaft
- Inventors: Dave Andre; Byron Konstantinos Antonopoulos; Saskia Schneider; Dennis Schuenemann; Barbara Stiaszny; Sandra Zugmann
- Web page: https://patentgrep.com/patent/US11890659B2

## CPC

- B21B 1/40: for rolling foils which present special problems, e.g. because of thinness
- B21C 23/002: {Extruding materials of special alloys so far as the composition of the alloy requires or permits special extruding methods of sequences}
- B21C 23/06: Making sheets
- B21C 35/023: {Work treatment directly following extrusion, e.g. further deformation or surface treatment (B21C35/03 takes precedence; gas treatment B21C23/009)}
- C22F 1/16: of other metals or alloys based thereon
- H01M 4/0435: {Rolling or calendering}
- H01M 4/38: of elements or alloys
- H01M 4/405: {Alloys based on lithium}
- H01M 10/00: Secondary cells; Manufacture thereof
- H01M 10/04: Construction or manufacture in general (H01M10/058, H01M10/12, H01M10/28, H01M10/38 take precedence)
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- B21B: ROLLING OF METAL (auxiliary operations used in connection with metal-working operations covered in B21, see B21C; bending by rolling B21D; manufacture of particular objects, e.g. screws, wheels, rings, barrels, balls, by rolling B21H; pressure welding by means of a rolling mill B23K20/04)
- B21C: MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass, C23F17/00)
- 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
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A method for producing metal-based thin foils is provided, which includes the steps of extruding a metal through an extruder to form a preliminary foil, cooling the preliminary foil in a coolant bath, and rolling the preliminary foil in a rolling system containing at least two rollers to form a metal-based thin foil.

## Claims

### Claim 1

A process for the production of thin metal-based foils, comprising the acts of:
providing an extruder, a coolant bath, and a rolling system comprising at least two rollers;
extruding a metal through the extruder to form a preliminary foil, wherein the preliminary foil has a thickness from 100 to 150 μm;
cooling the preliminary foil in the coolant bath containing liquid nitrogen at a temperature between 63 K and 77 K; and
then rolling the preliminary foil at least once in the rolling system comprising at least two rollers to form a thin metal-based foil with a thickness from 5 to 80 μm, wherein during rolling, the preliminary foil is kept below its tear threshold by increasing the temperature of the center of the foil,
wherein the rolling system is cooled by the same coolant used in the coolant bath, and wherein the rolling system is not immersed in the coolant bath.

### Claim 2 (depends on 1)

The process according to claim 1, wherein the thin metal-based foil is a foil selected from the group consisting of an alkali metal, an alkaline earth metal, an alloy of alkali metal and an alloy of alkaline earth metal.

### Claim 3 (depends on 2)

The process according to claim 2, wherein the thin metal-based foil is a lithium-based foil.