# US 2019/0355976 A1 · Anodes for sodium-ion batteries

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- Number: US 2019/0355976 A1
- Document ID: US20190355976A1
- Status: Published application
- Kind: A1
- Application number: 16/418,506
- Filed: 2019-05-21
- Published: 2019-11-21
- Earliest claimed: 2018-05-21
- Assignees: University of Southern California
- Applicants: University of Southern California
- Inventors: CHONGWU ZHOU; XUAN CAO; QINGZHOU LIU; YIHANG LIU; YUQIANG MA; CHENFEI SHEN; LIANG CHEN; ANYI ZHANG; PAUL DAVID ASIMOW
- Web page: https://patentgrep.com/patent/US20190355976A1

## CPC

- H01M 4/1393: of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/0404: {by coating on electrode collectors}
- H01M 4/043: {involving compressing or compaction}
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/139: Processes of manufacture
- H01M 4/38: of elements or alloys
- H01M 4/587: for inserting or intercalating light metals
- H01M 4/625: {Carbon or graphite}
- H01M 10/054: Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
- H01M 4/366: {as layered products}
- H01M 2004/027: {Negative 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A method for forming an anode of a sodium ion battery includes a step of heat treating the red phosphorus precursor and reduced graphene oxide powder at a first temperature that vaporizes the red phosphorus precursor such that red phosphorus structures grow on the reduced graphene oxide powder. Another method for forming an anode of a sodium ion battery includes steps of placing a red phosphorus precursor and a graphene oxide precursor in a reaction chamber; establishing a reducing environment in the reaction chamber; and heating the red phosphorus precursor and a graphene oxide precursor to a first temperature that is sufficient temperature to form a composite of red phosphorus and reduced graphene oxide. Characteristically, red phosphorus deposition and graphene oxide reduction are completed simultaneously in a single-step heat treatment. A method for making a black phosphorus-composite for sodium-ion batter anodes is also provided.

## Claims

### Claim 1

A method for forming an anode of a sodium ion battery, the method comprising:
a) placing a red phosphorus precursor and reduced graphene oxide powder into a reaction chamber; and
b) heat treating the red phosphorus precursor and reduced graphene oxide powder under vacuum at a first temperature that vaporizes the red phosphorus precursor such that red phosphorus structures grow on the reduced graphene oxide powder; and
c) cooling down reaction products formed in step b).

### Claim 2 (depends on 1)

The method of claim 1 wherein the red phosphorus structures are nanostructures or microstructures.

### Claim 3 (depends on 1)

The method of claim 1 wherein the red phosphorus structures are nanodots.

### Claim 4 (depends on 1)

The method of claim 1 wherein first temperature is from about 550° C. to 650° C.

### Claim 5 (depends on 1)

The method of claim 1 wherein reduced graphene oxide powder includes reduced graphene oxide powder

### Claim 6

A method for forming an anode of a sodium ion battery, the method comprising:
a) placing a red phosphorus precursor and a graphene oxide precursor in a reaction chamber;
b) establishing a reducing environment in the reaction chamber; and
c) heating the red phosphorus precursor and a graphene oxide precursor to a first temperature that is sufficient temperature to form a composite of red phosphorus and reduced graphene oxide, wherein red phosphorus deposition and graphene oxide reduction are completed simultaneously in a single-step heat treatment.

### Claim 7 (depends on 6)

The method of claim 6 wherein the first temperature is from about 400 to 550° C.

### Claim 8 (depends on 6)

The method of claim 6 wherein the composite of red phosphorus and reduced graphene oxide includes nanostructures or microstructures.

### Claim 9 (depends on 6)

The method of claim 6 wherein the reducing environment includes molecular hydrogen and an inert gas.

### Claim 10 (depends on 6)

The method of claim 6 wherein the red phosphorus precursor and a graphene oxide precursor are arranged in a layered structure.

### Claim 11 (depends on 10)

The method of claim 10 wherein the red phosphorus precursor and a graphene oxide precursor are arranged in a layered structure with a graphene precursor layer interposed between two red phosphorus layers.

### Claim 12 (depends on 6)

The method of claim 6 further comprising maintaining a reaction product of red phosphorus precursor and a graphene oxide precursor at a second temperature to convert white phosphorus to red phosphorus.

### Claim 13

A method for forming an anode of a sodium ion battery, the method comprising:
a) arranging red phosphorus powder and graphene oxide powder in a layered structure having alternating layers of phosphorus powder and graphene oxide;
b) heat treating the layered structure at a first temperature to form a red phosphorus/reduced graphene oxide combination film;
c) placing the red phosphorus/reduced graphene oxide combination film on a substrate; and
d) applying a pressure to the red phosphorus/reduced graphene oxide combination film that is sufficient to convert red phosphorus to black phosphorus such that a black phosphorus/reduced graphene oxide combination film is formed, the pressure being greater than or equal to about 5 GPa.

### Claim 14 (depends on 13)

The method of claim 13 wherein the substrate is a metal sheet or metal foil that is used as a current collector in a battery.

### Claim 15 (depends on 13)

The method of claim 13 wherein a plurality of red phosphorus/reduced graphene oxide combination film are stacked and then subject to the pressure.

### Claim 16 (depends on 13)

The method of claim 13 wherein the pressure is applied with the red phosphorus/reduced graphene oxide combination film being at a second temperature of about 20 to 40 degrees C.

### Claim 17 (depends on 13)

The method of claim 13 wherein the red phosphorus powder includes nanostructures or microstructures.

### Claim 18 (depends on 13)

The method of claim 13 wherein first temperature is from about 450° C. to 650° C.

### Claim 19 (depends on 13)

The method of claim 13 wherein graphene oxide powder includes reduced graphene oxide powder.

### Claim 20 (depends on 13)

The method of claim 13 wherein the pressure is from about 5 to 12 GPa.

### Claim 21 (depends on 13)

The method of claim 13 wherein phosphorus powder layers and graphene oxide layers are formed by filtration.

### Claim 22

A sodium ion battery comprising:
an electrolyte disposed in a container;
a cathode at least partially immersed in the electrolyte; and
an anode at least partially immersed in the electrolyte, wherein the anode includes a component selected from the group consisting of a red phosphorus-reduced graphene oxide composite having red phosphorus nanodots disposed over reduced graphene oxide substrates, a layered black phosphorus graphene composite, a layered black phosphorus graphene composite, and combinations thereof.

### Claim 23 (depends on 22)

The sodium ion battery of claim 22 further comprising a separator disposed between the cathode and the anode.