# US 12,002,957 B2 · ε-VOPO4 cathode for lithium ion batteries

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- Number: US 12,002,957 B2
- Document ID: US12002957B2
- Status: Granted
- Kind: B2
- Application number: 18/354,493
- Filed: 2023-07-18
- Published: 2023-11-09
- Granted: 2024-06-04
- Earliest claimed: 2018-03-05
- Assignees: The Research Foundation for The State University of New York
- Applicants: The Research Foundation for The State University of New York
- Inventors: Carrie Siu; M. Stanley Whittingham
- Web page: https://patentgrep.com/patent/US12002957B2

## CPC

- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- C01B 25/372: {of titanium, vanadium, zirconium, niobium, hafnium or tantalum}
- H01M 4/136: Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
- H01M 4/1397: of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
- H01M 4/623: {fluorinated polymers}
- H01M 4/625: {Carbon or graphite}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2002/90: Other crystal-structural characteristics not specified above
- C01P 2004/03: obtained by SEM
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- 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

The epsilon polymorph of vanadyl phosphate, ε-VOPO4, made from the solvothermally synthesized H2VOPO4, is a high density cathode material for lithium-ion batteries optimized to reversibly intercalate two Li-ions to reach the full theoretical capacity at least 50 cycles with a coulombic efficiency of 98%. This material adopts a stable 3D tunnel structure and can extract two Li-ions per vanadium ion, giving a theoretical capacity of 305 mAh/g, with an upper charge/discharge plateau at around 4.0 V, and one lower at around 2.5 V.

## Claims

### Claim 1

A lithium battery, comprising:
a cathode formed with ε-VOPO4, particles and electrically conductive carbon particles, on a current collector, wherein the ε-VOPO4 has a dual lithium ion exchange characteristic, having a capacity of at least 275 mAh/g at a discharge rate of C/20;
a lithium metal anode; and
an electrolyte adapted to operate at a charging voltage of at least 4.5 V.

### Claim 2

A lithium battery, comprising:
a cathode comprising a mixture of ε-VOPO4, electrically conductive carbon, and a binder, on a current collector, the ε-VOPO4 having a capacity of at least 275 mAh/g and a capacity of at least 125 mAh/g while maintaining a voltage exceeding 3.7 V, at a discharge rate of C/20;
an anode comprising lithium metal;
electrolyte; and
a solid electrolyte interphase.

### Claim 3

A battery, comprising:
a cathode comprising ε-VOPO4, having a capacity of at least 90% of a theoretical capacity value of 305 mAh/g at a discharge rate of C/20, bound with conductive particles;
an anode; and
an electrolyte.

### Claim 4 (depends on 3)

The battery according to claim 3, further comprising a lithium salt in the electrolyte, wherein the anode comprises lithium metal, and the cathode comprises lithiated ε-VOPO4.

### Claim 5 (depends on 3)

The battery according to claim 3, further comprising a lithium salt in the electrolyte, wherein the anode comprises a source of lithium ions, and the cathode comprises ε-VOPO4 configured to intercalate about two lithium ions per vanadium.

### Claim 6 (depends on 3)

The battery according to claim 3, wherein the ε-VOPO4 is solvothermally or hydrothermally generated.

### Claim 7 (depends on 3)

The battery according to claim 3, wherein the conductive particles comprise carbon particles.

### Claim 8 (depends on 3)

The battery according to claim 3, wherein the conductive particles comprise graphene nanoplatelets or carbon nanotubes.

### Claim 9 (depends on 3)

The battery according to claim 3, wherein the cathode comprises at least 75% by weight ε-VOPO4, at least 5% by weight graphene nanoplatelets, and at least 5% by weight of a binder.

### Claim 10 (depends on 3)

The battery according to claim 3, wherein the conductive particles comprise graphene, and the cathode comprises between 5% and 15% by weight of the graphene.

### Claim 11 (depends on 3)

The battery according to claim 3, wherein the ε-VOPO4 comprises a vanadium which is adapted to undergo a change in oxidation state of two between a charged state and a discharged state.

### Claim 12 (depends on 11)

The battery according to claim 11, wherein the battery has a discharge profile having voltage plateaus at about 2.1 V, 2.25 V, 2.5 V, and 3.9 V.

### Claim 13 (depends on 11)

The battery according to claim 11, wherein the ε-VOPO4 has a capacity of at least 290 mAh/g at a discharge rate of C/20.

### Claim 14 (depends on 11)

The battery according to claim 11, wherein the ε-VOPO4 has a capacity of 305 mAh/g at a discharge rate of C/20.

### Claim 15 (depends on 11)

The battery according to claim 11, wherein the ε-VOPO4 has a capacity of about 125 mAh/g while maintaining a voltage exceeding 3.7 V at a discharge rate of C/20.

### Claim 16 (depends on 11)

The battery according to claim 11, wherein the ε-VOPO4 has an energy capacity of at least 850 mWh/g.

### Claim 17 (depends on 11)

The battery according to claim 11, wherein the cathode has at least two states, comprising:
a first state in which at least 80 mol % of vanadium of the ε-VOPO4 is oxidized in a first oxidation state and associated with two lithium ions per vanadium, and
a second state in which at least 80 mol % of the ε-VOPO4 is oxidized in a second oxidation state which differs by two from the first oxidation state.

### Claim 18 (depends on 3)

The battery according to claim 3, wherein the anode comprises a carbonaceous material having intercalated lithium ions.

### Claim 19 (depends on 3)

The battery according to claim 3, wherein the electrolyte has an operating window comprising 4.5 V.

### Claim 20 (depends on 3)

The battery according to claim 3, wherein the electrolyte comprises a solid electrolyte.