Group IV-VI compound graphene anode with catalyst

1. An electrode for use in a lithium-ion battery, the electrode comprising a group IV-VI compound and a transition metal group VI compound on a three-dimensional graphene network, wherein a major portion of the transition metal group VI compound is provided on top of the group IV-VI compound or in close proximity to it, whereby the transition metal group VI compound contributes to the decomposition of a lithium group VI compound at the surface of the group IV-VI compound,

the group IV-VI compound being represented by a chemical formula MX2, wherein M is selected from tin, germanium and silicon and X is selected from sulphur, oxygen and selenium, the transition metal group VI compound comprising a transition metal and a group VI element, the group VI element being selected from sulphur, oxygen and selenium.

2. The electrode according to claim 1 , wherein a content of the transition metal group VI compound is between 2 and 8 weight percent.

3. The electrode according to claim 1 , wherein a molybdenum group VI compound is provided on a material which comprises the group IV-VI compound on a three-dimensional graphene network.

4. The electrode according to claim 1 , wherein the transition metal group VI compound is provided in a form of nanosheets.

5. The electrode according to claim 4 , wherein the nanosheets of the transition metal group VI compound are provided on larger nanosheets of the group IV-VI compound.

6. The electrode according to claim 1 , wherein a loading of the group IV-VI compound is 0.7-1 mg per cubic centimeter of the three-dimensional graphene network.

7. The electrode according to claim 1 , wherein the three-dimensional graphene forms a binder-free interconnected porous network.

8. The electrode according to claim 1 , wherein the group IV-VI compound is tin disulfide and the transition metal group VI compound is molybdenum disulfide or tungsten disulfide.

9. A lithium-ion battery comprising an electrode according to claim 1 , the lithium-ion battery further comprising a casing with a first terminal and a second terminal, a counter electrode and an electrolyte, the electrolyte containing lithium ions, wherein the electrode, the counter electrode and the electrolyte are provided in the casing, the electrode is connected to a first terminal, the counter electrode is connected to the second terminal, and the electrolyte is in contact with the electrode and with the counter electrode.

10. A method of producing an electrode for a lithium-ion battery, the method comprising:

depositing a carbon compound on a porous metal scaffold by chemical vapor deposition to obtain a three-dimensional graphene;

bringing a group IV compound into contact with the three-dimensional graphene, the group IV compound comprising tin, germanium or silicon;

subjecting the group IV compound and the three-dimensional graphene to a hydrothermal treatment to obtain a group IV-VI compound surface structure on the three-dimensional graphene;

bringing a transition metal group VI compound into contact with the three-dimensional graphene; and

subjecting the transition metal group VI compound and the three-dimensional graphene with the group IV-VI compound surface structure to a hydrothermal treatment to obtain a transition metal group VI compound surface structure on the group IV-VI compound surface structure.

11. The method according to claim 10 , wherein preparation of the three-dimensional graphene comprises:

flowing a mixture of argon and ethanol over a nickel foam;

cooling the reaction product; and

etching away the nickel foam.

12. The method according to item 10 , wherein preparation of the group IV-VI compound on the three-dimensional graphene comprises:

providing a mixture of a group IV tetrachloride, water, thioacetamide and sodium dodecyl sulfate in ethanol,

the group IV tetrachloride being selected from tin tetrachloride, germanium tetrachloride and silicon tetrachloride;

bringing the mixture and the three-dimensional graphene together; and

letting the mixture and the three-dimensional graphene react.

13. The method according to claim 10 , wherein preparation of the transition metal group VI compound on the three-dimensional graphene comprises;

providing a mixture of a group VI amino acid and sodium transition metal compound in water and ethanol, the group VI amino acid being selected from L-cysteine, selenocysteine and serine;

bringing pieces of the three-dimensional graphene with the group IV-VI surface structure and the mixture together; and

letting the three-dimensional graphene with the group IV VI compound surface structure and the mixture react.

14. The method according to claim 10 comprising drying the electrode material at a temperature above 100° C.

15. A method for producing a lithium-ion battery comprising:

producing an electrode according to claim 10 , the method further comprising:

providing a counter electrode and a membrane;

inserting the electrode, the membrane and the counter electrode into a casing of the coin cell;

filling an electrolyte into the casing of the lithium-ion battery; and

closing the casing of the lithium-ion battery.