# US 11,909,041 B2 · Method to produce cathode materials for Li-ion batteries

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- Number: US 11,909,041 B2
- Document ID: US11909041B2
- Status: Granted
- Kind: B2
- Application number: 16/976,788
- Filed: 2019-04-03
- Published: 2021-01-14
- Granted: 2024-02-20
- Earliest claimed: 2018-04-04
- Assignees: Tesla, Inc.
- Applicants: Tesla, Inc.
- Inventors: Feng Zou; Yang Liu
- Web page: https://patentgrep.com/patent/US11909041B2

## CPC

- C01G 53/42: containing alkali metals, e.g. LiNiO2
- C01G 53/82: Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- C01P 2002/52: containing elements as dopants
- C01P 2002/54: one element only
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2004/03: obtained by SEM
- C01P 2004/32: Spheres
- C01P 2004/51: Particles with a specific particle size distribution
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2006/11: Powder tap density
- C01P 2006/40: Electric properties
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

This invention provides an environmental friendly method for the production of high capacity cathode materials for use in Li-ion batteries. Traditional methods for producing lithium mixed metal oxide cathode materials typically generate large amounts of effluent which effluent must be treated prior to discharge. The present process uses mixed metals as raw materials, in a wet chemical reaction with an oxidant, in order to make high-quality metal hydroxide precursors which can be used to prepare high-quality cathode materials after lithiation. As a key feature, in the precursor preparation process, the bulk of the aqueous solution used for the wet chemical reaction can be recycled back to the reactor, so that the total process has little or no effluent generated during production of the cathode precursor material.

## Claims

### Claim 1

A process to produce a lithium mixed metal oxide cathode active material for use in lithium ion batteries comprising:
in a precursor preparation step, adding solid metal particles of selected metals to a reaction system containing a mixture comprising the solid metal particles, an aqueous solution, and at least one oxidant, under alkaline conditions to form a slurry comprising a precursor product and unreacted metals, wherein the selected metals are selected from the group consisting of nickel, manganese, cobalt, aluminum, and magnesium;
in a recycling step, separating the unreacted metals from the slurry to form a first solution and collected unreacted metals, separating the precursor product from the first solution to form a second solution and a collected precursor product, and recycling the collected unreacted metals and the second solution directly to the reaction system; and
in a lithiation step, mixing the collected precursor product with lithium-containing compounds to produce a final mixture, and calcining the final mixture to obtain a lithium mixed metal oxide cathode active material;
wherein the mixture of the precursor preparation step further comprises seed metal hydroxide particles.

### Claim 2 (depends on 1)

The process of claim 1, wherein the precursor preparation step is performed at a pH in a range of between 7.5 to 13, and a temperature in a range of between 20° C. to the boiling point of the slurry.

### Claim 3 (depends on 2)

The process of claim 2, wherein the precursor preparation step further comprises adding at least one of sulfuric acid, nitric acid, acetic acid, lithium hydroxide or oxide, sodium hydroxide, sodium oxide, potassium hydroxide, potassium oxide, and ammonia to the mixture.

### Claim 4 (depends on 1)

The process of claim 1, wherein the aqueous solution further comprises dissolved salts.

### Claim 5 (depends on 1)

The process of claim 1, wherein the aqueous solution further comprises a complexing agent.

### Claim 6 (depends on 1)

The process of claim 1, wherein the oxidant is selected from the group consisting of air, oxygen, metal nitrates, nitric acid, and combinations thereof.

### Claim 7 (depends on 1)

The process of claim 1, wherein the oxidant comprises oxygen.

### Claim 8 (depends on 1)

The process of claim 1, wherein the reaction system comprises at least one agitated tank.

### Claim 9 (depends on 1)

The process of claim 1, wherein the precursor preparation step is performed under steady state conditions and continuous operation.

### Claim 10 (depends on 9)

The process of claim 9, wherein each individual metal element of the selected metals is added continuously at the same ratio to produce the precursor product with a uniform element distribution in each particle of the precursor product.

### Claim 11 (depends on 1)

The process of claim 1, wherein at least 90% of the second solution is directly recycled to the reaction system.

### Claim 12 (depends on 1)

The process of claim 1, wherein solid particles with the same or similar compositions as the precursor product, and a smaller particle size than the precursor product, are introduced into the reaction system during the precursor preparation step.

### Claim 13 (depends on 1)

The process of claim 1, wherein an artificial solution with the same or similar composition as the aqueous solution is used in the precursor preparation step until a suitable second solution is generated from the recycling step and recycled to the reaction system.

### Claim 14 (depends on 1)

The process of claim 1, further comprising drying the collected precursor product.

### Claim 15 (depends on 14)

The process of claim 14, wherein the lithium mixed metal oxide cathode active material is subjected to a size reduction operation.

### Claim 16 (depends on 1)

The process of claim 1, wherein the lithium-containing compounds are selected from lithium hydroxide and lithium carbonate.

### Claim 17 (depends on 1)

The process of claim 1, wherein the final mixture is calcined at a temperature of from 600° C. to 1100° C.

### Claim 18 (depends on 1)

The process of claim 1, wherein the lithium mixed metal oxide cathode active material is subjected to a further treatment selected from washing, coating, and combinations thereof.

### Claim 19 (depends on 1)

The process of claim 1, wherein the seed metal hydroxide particles comprise at least one ionic metal selected from the group consisting of nickel, manganese, cobalt, aluminum, magnesium, zirconium, yttrium, titanium, vanadium and molybdenum.

### Claim 20

A process to produce a lithium mixed metal oxide cathode active material for use in lithium ion batteries comprising:
in a precursor preparation step, adding solid metal particles of selected metals to a reaction system containing a mixture comprising the solid metal particles, an aqueous solution, and at least one oxidant, under alkaline conditions to form a slurry comprising a precursor product and unreacted metals, wherein the selected metals are selected from the group consisting of nickel, manganese, cobalt, aluminum, and magnesium;
in a recycling step, separating the unreacted metals from the slurry to form a first solution and collected unreacted metals, separating the precursor product from the first solution to form a second solution and a collected precursor product, and recycling the collected unreacted metals and the second solution directly to the reaction system; and
in a lithiation step, mixing the collected precursor product with lithium-containing compounds to produce a final mixture, and calcining the final mixture to obtain a lithium mixed metal oxide cathode active material;
wherein solid particles with the same or similar compositions as the precursor product, and a smaller particle size than the precursor product, are introduced into the reaction system during the precursor preparation step.