Surface modification method for carbonaceous particles

Abstract

The present invention describes a method for surface modification of carbonaceous particles, the method comprising: a step of agglomerating the carbonaceous particles by mixing them with a non-carbonized bio-based binder; a step of heating the carbonaceous particle aggregate to a temperature T at a rate of at least 25°C / min; and a step of carbonizing the carbonaceous particle aggregate at the temperature T in a gaseous environment containing hydrocarbon gas. The present invention also describes a graphite anode material.

Claims

1. A method for surface modification of carbonaceous particles, wherein the method is: The carbonaceous particles are mixed with a non-carbonized bio-based binder to aggregate (aggregate) the carbonaceous particles, The process involves heating the aggregated carbonaceous particles to a temperature T at a rate of at least 25°C / min, The carbonaceous particle aggregate is carbonized at the temperature T in a gaseous environment containing a hydrocarbon-containing gas. A method that includes the following:

2. The method for surface modification of carbonaceous particles according to claim 1, wherein T is at most 950°C, preferably in the range of 750°C to 950°C.

3. The method for surface modification of carbonaceous particles according to claim 1 or 2, further comprising the step of drying the carbonaceous particle aggregate so that the carbonaceous particle aggregate contains at most 1% moisture, preferably at most 0.1% moisture, before heating the carbonaceous particle aggregate.

4. The method for surface modification of carbonaceous particles according to any one of claims 1 to 3, wherein the bio-based binder is selected from one or more lignin and lignosulfonates.

5. The carbonaceous particle surface modification method according to any one of claims 1 to 4, wherein the carbonaceous particle has a maximum D50 of 50 microns.

6. The method for surface modification of carbonaceous particles according to any one of claims 1 to 5, wherein the carbonaceous particles are selected from one or more natural graphite particles and synthetic graphite particles.

7. The method for surface modification of carbonaceous particles according to any one of claims 1 to 6, wherein the hydrocarbon-containing gas is selected from one or more of acetylene, ethylene, ethanol, methane, propane, and propylene.

8. The method for surface modification of carbonaceous particles according to any one of claims 1 to 7, wherein the concentration of the hydrocarbon-containing gas in the gaseous environment is in the range of 1% to 24%, preferably in the range of 10% to 24%.

9. The method for surface modification of carbonaceous particles according to any one of claims 1 to 8, wherein the step of agglomerating the carbonaceous particles with a non-carbonized bio-based binder comprises mixing the carbonaceous particles and the non-carbonized bio-based binder in an aqueous formulation.

10. The method for surface modification of carbonaceous particles according to claim 9, wherein the dry content ratio of the non-carbonized bio-based binder to the graphite particles in the aqueous formulation is in the range of 2.5% by weight to 10% by weight.

11. A method for surface modification of carbonaceous particles according to any one of claims 1 to 10, wherein one or both of the heating step of the carbonaceous particle aggregate and the carbonization step of the carbonaceous particle aggregate are performed in a rotary furnace, a paddle mixer, a heating mixer, or a screw mixer.

12. A method for surface modification of carbonaceous particles according to any one of claims 1 to 11, wherein the carbonization step of the carbonaceous particle aggregate is carried out under parallel flow conditions.

13. The method for surface modification of carbonaceous particles according to any one of claims 1 to 12, wherein the duration of the carbonization step of the carbonaceous particle aggregate in a gaseous environment is at most 45 minutes.

14. A graphite anode material comprising surface-modified carbonaceous particles, wherein the surface-modified carbonaceous particles are 0.85 m ２ A graphite anode material having an SSA BET of less than 0.03% by weight, an oxygen content of less than 0.03% by weight, and a sulfur concentration of less than 0.02% by weight.

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