# US 8,785,044 B2 · Lithium-iron disulfide cathode formulation having pyrite content and low conductive additives

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- Number: US 8,785,044 B2
- Document ID: US8785044B2
- Status: Granted
- Kind: B2
- Application number: 12/869,244
- Filed: 2010-08-26
- Published: 2011-01-13
- Granted: 2014-07-22
- Earliest claimed: 2008-10-17
- Assignees: Eveready Battery Company, Inc.
- Applicants: Jack W Marple; Weiwei Huang; Michael W Wemple
- Inventors: Jack W Marple; Weiwei Huang; Michael W Wemple
- Web page: https://patentgrep.com/patent/US8785044B2

## CPC

- H01M 4/06: Electrodes for primary cells
- H01M 4/382: {Lithium (H01M4/405 takes precedence)}
- H01M 4/5815: {Sulfides}
- H01M 4/625: {Carbon or graphite}
- H01M 4/405: {Alloys based on lithium}
- H01M 6/164: {by the solvent}
- H01M 50/107: having curved cross-section, e.g. round or elliptic (H01M50/103, H01M50/109, H01M50/11 take precedence)
- H01M 2004/8689: {Positive electrodes}
- H01M 2220/30: Batteries in portable systems, e.g. mobile phone, laptop
- Y02E 60/10: Energy storage using batteries
- Y02E 60/50: Fuel cells
- 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

The invention relates to primary electrochemical cells having a jellyroll electrode assembly that includes a lithium-based negative electrode, a positive electrode with a coating comprising iron disulfide deposited on a current collector and a polymeric separator. More particularly, the invention relates to a cell designs and cathode formulations incorporating specific types of conductors to improve cell performance.

## Claims

### Claim 1

An electrochemical cell comprising:
a cylindrical housing;
a nonaqueous electrolyte including an organic solvent and a spiral wound electrode assembly disposed within the housing;
wherein the spiral wound electrode assembly includes an anode consisting essentially of lithium or a lithium alloy and a cathode mix coated onto a foil current collector at a final solids packing percentage of at least 58% and no more than 63%;
wherein the cathode mix comprises at least 95 wt. % of pyrite, less than 2 wt. % of a binder and less than or equal to 2 wt. % of conductors; and
wherein the conductors include graphite and at least 50 wt. % of acetylene black.

### Claim 2 (depends on 1)

The electrochemical cell according to claim 1, wherein the graphite is mechanically expanded graphite.

### Claim 3 (depends on 1)

The electrochemical cell according to claim 1, wherein the cathode mix consists essentially of 95-98 wt. % pyrite, 1-2 wt. % conductors and less than 2 wt. % of a binder and, optionally, processing aids.

### Claim 4 (depends on 1)

The electrochemical cell according to claim 1, wherein the cathode mix comprises at least 96 wt. % of pyrite.

### Claim 5 (depends on 1)

The electrochemical cell according to claim 1, wherein the solids packing percentage is at least 58% and no more than 60%.

### Claim 6 (depends on 1)

The electrochemical cell according to claim 1, wherein the conductor includes lactonic or phenolic functional groups.

### Claim 7 (depends on 1)

The electrochemical cell according to claim 1, wherein the conductor includes functional groups at a concentration of less than about 50 μg of functional group/g of conductor.

### Claim 8 (depends on 1)

The electrochemical cell according to claim 1, wherein the conductors include at least 55 wt. % of acetylene black.

### Claim 9

An electrochemical cell comprising:
a cylindrical housing;
a nonaqueous electrolyte including an organic solvent and a spiral wound electrode assembly disposed within the housing;
wherein the spiral wound electrode assembly includes an anode consisting essentially of lithium or a lithium alloy and a cathode mix coated onto a foil current collector at a final solids packing percentage of at least 58% and no more than 63%;
wherein the cathode mix comprises at least 95 wt. % of pyrite, less than 2 wt. % of a binder and less than or equal to 2 wt. % of conductors; and
wherein the conductors include graphitized carbon and graphite.

### Claim 10 (depends on 9)

The electrochemical cell according to claim 9, wherein the graphitized carbon comprises at least 50 wt. % of the conductors.

### Claim 11 (depends on 9)

The electrochemical cell according to claim 9, wherein the graphite is mechanically expanded graphite.

### Claim 12 (depends on 9)

The electrochemical cell according to claim 9, wherein the cathode mix is coated to a solids packing percentage between at least 58% and no more than 60%.

### Claim 13 (depends on 9)

The electrochemical cell according to claim 9, wherein the cathode mix comprises at least 96 wt. % of pyrite.

### Claim 14 (depends on 9)

The electrochemical cell according to claim 9, wherein the conductor includes lactonic or phenolic functional groups.

### Claim 15 (depends on 9)

The electrochemical cell according to claim 9, the conductor includes functional groups at a concentration of less than about 50 μg of functional group/g of conductor.

### Claim 16 (depends on 9)

The electrochemical cell according to claim 9, wherein the cathode mix consists essentially of 95-98 wt. % pyrite, 1-2 wt. % conductors and less than 2 wt. % of a binder and, optionally, processing aids.