Conformal graphene cage encapsulated battery electrode materials and methods of forming thereof

Patent metadata

Field	Value
Publication number	US-2016365573-A1
Application number	US-201615178366-A
Country	US
Kind code	A1
Filing date	Jun 9, 2016
Priority date	Jun 12, 2015
Publication date	Dec 15, 2016
Grant date	—

Abstract

A conformal graphene-encapsulated battery electrode material is formed by: (1) coating a battery electrode material with a metal catalyst to form a metal catalyst-coated battery electrode material; (2) growing graphene on the metal catalyst-coated battery electrode material to form a graphene cage encapsulating the metal catalyst-coated battery electrode material; and (3) at least partially removing the metal catalyst to form a void inside the graphene cage.

First claim

What is claimed is:

1 . A method of forming a conformal graphene-encapsulated material, comprising:
coating a battery electrode material with a metal catalyst to form a metal catalyst-coated battery electrode material; growing graphene on the metal catalyst-coated battery electrode material to form a graphene cage encapsulating the metal catalyst-coated battery electrode material; and at least partially removing the metal catalyst to form a void inside the graphene cage.

2 . The method of claim 1 , wherein the metal catalyst is nickel.

3 . The method of claim 1 , wherein coating the battery electrode material with the metal catalyst includes performing electroless deposition of the metal catalyst on the battery electrode material.

4 . The method of claim 1 , wherein growing the graphene includes exposing the metal catalyst-coated battery electrode material to a carbon-containing source, followed by performing carburization and annealing.

5 . The method of claim 4 , wherein annealing is performed at a temperature in the range of 200° C. to 600° C.

6 . The method of claim 1 , wherein removing the metal catalyst is through the graphene cage.

7 . The method of claim 1 , wherein removing the metal catalyst is via an etchant.

8 . The method of claim 1 , wherein the battery electrode material includes silicon.

9 . The method of claim 1 , wherein the battery electrode material is provided as at least one particle having a dimension in the range of 200 nm to 10 μm.

10 . A conformal graphene-encapsulated material comprising:
a graphene cage defining an internal volume; and a battery electrode material disposed within the internal volume, wherein the battery electrode material occupies less than 100% of the internal volume to define a void.

11 . The conformal graphene-encapsulated material of claim 10 , wherein the battery electrode material includes at least one of silicon, silicon monoxide, silicon dioxide, tin, or tin oxide.

12 . The conformal graphene-encapsulated material of claim 10 , wherein the graphene cage has a dimension in the range of 1 μm to 10 μm.

13 . The conformal graphene-encapsulated material of claim 10 , wherein a wall of the graphene cage includes two or more graphene layers.

14 . The conformal graphene-encapsulated material of claim 10 , wherein the graphene cage is a monolithic encapsulating structure.

15 . The conformal graphene-encapsulated material of claim 10 , wherein a surface atomic concentration ratio of an element included in the battery electrode material relative to carbon is 1/20 or less.

16 . A battery electrode comprising the conformal graphene-encapsulated material of claim 10 .

17 . A battery comprising:
an anode; a cathode; and an electrolyte disposed between the anode and the cathode, wherein at least one of the anode or the cathode includes the conformal graphene-encapsulated material of claim 10 .

Assignees

• Univ Leland Stanford Junior

Inventors

• Li Yuzhang
• Yan Kai
• Lu Zhenda
• Cui Yi

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title