# US 12,218,319 B2 · Method of preparing secondary battery

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- Number: US 12,218,319 B2
- Document ID: US12218319B2
- Status: Granted
- Kind: B2
- Application number: 17/773,690
- Filed: 2021-01-19
- Published: 2022-12-01
- Granted: 2025-02-04
- Earliest claimed: 2020-01-20
- Assignees: LG Energy Solution, Ltd.
- Applicants: LG Energy Solution, Ltd.
- Inventors: Dong Jun Lee; Sa Rah Kim; Dong Hui Kim; Kwang Ho Yoo
- Web page: https://patentgrep.com/patent/US12218319B2

## CPC

- H01M 10/0436: {Small-sized flat cells or batteries for portable equipment}
- H01M 10/446: {Initial charging measures}
- H01M 4/044: {Activating, forming or electrochemical attack of the supporting material}
- H01M 4/0447: {of complete cells or cells stacks}
- H01M 4/0459: {Electrochemical doping, intercalation, occlusion or alloying}
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/139: Processes of manufacture
- H01M 4/1395: of electrodes based on metals, Si or alloys
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)}
- H01M 4/667: {in the form of layers, e.g. coatings}
- H01M 10/0413: {Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes}
- H01M 10/049: {Processes for forming or storing electrodes in the battery container}
- 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 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- 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 of preparing a secondary battery which includes pre-lithiating an electrode assembly which includes an electrode structure including a plurality of electrodes and a plurality of separators, and a metal substrate. The plurality of electrodes and the plurality of separators are alternatingly stacked. The metal substrate is present on an outermost surface of the electrode structure in a direction in which the electrode and the separator are stacked. Each positive electrode and negative electrode are spaced apart from each other with one separator of the plurality of separators disposed therebetween. The pre-lithiating includes applying a first current by electrically connecting one of the plurality of positive electrodes and one of the plurality of negative electrodes, and applying a second current by electrically connecting the metal substrate and one of the plurality of positive electrodes, after applying the first current.

## Claims

### Claim 1

A method of preparing a secondary battery, the method comprising:
pre-lithiating an electrode assembly comprising an electrode structure comprising a plurality of electrodes and a plurality of separators; and a metal substrate,
wherein the plurality of electrodes and the plurality of separators are alternatingly stacked,
wherein the metal substrate is present on an outermost surface of the electrode structure in a direction in which the electrodes and the separators are stacked,
wherein the plurality of electrodes comprises negative electrodes, each comprising negative electrode active material layer, and positive electrodes, each comprising positive electrode active material layer, wherein each positive electrode and negative electrode are spaced apart from each other with one separator of the plurality of separators disposed therebetween,
wherein the pre-lithiating comprises:
applying a first current by electrically connecting one of the plurality of positive electrodes one of the plurality of negative electrodes; and
applying a second current by electrically connecting the metal substrate and one of the plurality of positive electrodes, after applying the first current.

### Claim 2 (depends on 1)

The method of claim 1, wherein an amount of the first current is in a range of 0.001 C to 1.000 C.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first step is performed from a state of charge (SOC) of 1% to an SOC of 50%.

### Claim 4 (depends on 1)

The method of claim 1, wherein,
the second current is applied in a constant current and constant voltage mode, and
an amount of the current applied in the constant current mode is in a range of 0.0001 C to 0.1 C.

### Claim 5 (depends on 1)

The method of claim 1, wherein the plurality of electrodes comprise holes penetrating the individual electrodes.

### Claim 6 (depends on 5)

The method of claim 5, wherein a ratio of an area of a surface of each individual electrode to an area occupied by openings of holes on the surface of each individual electrode is in a range of 99.9:0.1 to 80:20.

### Claim 7 (depends on 5)

The method of claim 5, wherein an opening of each hole has a diameter of 1 μm to 100 μm.

### Claim 8 (depends on 1)

The method of claim 1, wherein the negative electrode active material layer comprises a negative electrode active material, and
wherein the negative electrode active material comprises silicon.

### Claim 9 (depends on 1)

The method of claim 1, wherein the metal substrate comprises a lithium layer.

### Claim 10 (depends on 9)

The method of claim 9, wherein the lithium layer has a thickness of 2.5 μm to 300 μm.