Hard carbon composite for alkali metal-ion batteries
A method is provided for fabricating a graphene-doped, carbohydrate-derived hard carbon (G-HC) composite material for alkali metal-ion batteries. The method provides graphene oxide (GO) dispersed in an aqueous solution. A carbohydrate is dissolved into the aqueous solution and subsequently the water is removed to create a precipitate. In one aspect, the carbohydrate is sucrose. The precipitate is dehydrated and exposed to a thermal treatment of less than 1200 degrees C. to carbonize the carbohydrate. The result is the formation of a graphene-doped, carbohydrate-derived hard carbon (G-HC) composite. Typically, the G-HC composite is made up of graphene in the range of 0.1 and 20% by weight (wt %), and HC in the range of 80 to 99.9 wt %. The G-HC composite has a specific surface area of less than 10 square meters per gram (m 2 /g). A G-HC composite suitable for use in alkali metal-ion batteries electrodes is also provided.
1. A method for fabricating a graphene-doped, carbohydrate-derived hard carbon composite material for alkali metal-ion batteries, the method comprising:
providing graphene oxide (GO) dispersed in an aqueous solution;
dissolving a carbohydrate into the aqueous solution;
removing water to create a precipitate;
dehydrating the precipitate;
exposing the precipitate to a thermal treatment; and,
forming a graphene-doped carbohydrate-derived hard carbon (G-HC) composite.
2. The method of claim 1 wherein forming the G-HC composite includes forming a G-HC composite comprising graphene in a range of 0.1 and 20% by weight (wt %) and HC in a range of 80 to 99.9 wt %.
3. The method of claim 1 further comprising:
in response to the thermal treatment, carbonizing the carbohydrate.
4. The method of claim 1 wherein adding the carbohydrate to the aqueous solution includes adding sucrose to the aqueous solution.
5. The method of claim 1 wherein exposing the precipitate to the thermal treatment includes exposing the precipitate to a temperature of less than 1200 degrees Centigrade (C).
6. The method of claim 5 wherein exposing the precipitate to the thermal treatment includes performing the thermal treatment in an inert gas environment using a gas selected from a group consisting of nitrogen and argon.
7. The method of claim 1 wherein forming the G-HC composite includes the G-HC composite having a specific surface area (SSA) of less than 10 square meters per gram (m 2 /g).
8. The method of claim 1 wherein dispersing the GO into the aqueous solution includes performing a process selected from a group consisting of sonication and stirring.
9. The method of claim 1 wherein dehydrating the precipitate includes heating at a temperature of less than 250 degrees C.
10. A graphene-doped, carbohydrate-derived hard carbon composite battery electrode, the battery electrode comprising:
a current collector;
carbonaceous materials overlying the current collector comprising:
a graphene-doped, carbohydrate-derived hard carbon (G-HC) composite; and,
a binder material.
11. The battery electrode of claim 10 wherein the ratio of G-HC composite to the carbonaceous materials is in a range of 70 to 100% by weight (wt %).
12. The battery electrode of claim 10 wherein the carbonaceous materials further comprise a conductive carbon additive.
13. The battery electrode of claim 12 wherein the ratio of conductive carbon additive in the carbonaceous materials is in a range of 0 to 30 wt %.
14. The battery electrode of claim 10 wherein the ratio of binder material to the carbonaceous materials is in a range of 3 to 20 wt %.
15. The battery electrode of claim 10 wherein the binder material includes a polymer.
16. The battery electrode of claim 10 wherein the G-HC composite is a graphene-doped, sucrose-derived hard carbon composite.
17. The battery electrode of claim 10 wherein the G-HC composite has a specific surface area (SSA) of less than 10 square meters per gram (m 2 /g).
18. A composite material for use as an alkali metal-ion battery electrode, the composite material comprising:
graphene-doped, carbohydrate-derived hard carbon composite.
19. The composite material of claim 18 wherein the graphene-doped, carbohydrate-derived hard carbon composite is a graphene-doped sucrose-derived hard carbon composite.
20. The composite material of claim 18 wherein the G-HC composite has a specific surface area (SSA) of less than 10 square meters per gram (m 2 /g).