Electrode particles suitable for batteries
The disclosure relates to a carbon-based electrode material that has been graphitized to hold ions in the electrode of a battery and more particularly include carbide or carbide and nitride surfaces that protect the graphite core. The preferred batteries include metal ion such as lithium ion batteries where the carbon-based electrode is the anode although the carbon-based electrode may also serve in dual ion batteries where both electrodes may comprise the graphitized carbon-based electrodes. The electrodes are more amorphous than conventional graphite electrodes and include a carbide or nitride containing surface treatment.
1. A process of forming graphite anode materials for metal ion batteries comprising:
selecting and sizing carbon precursor material to particles having a desired mean average particle size;
combining the precursor material with a carbide forming element at a ratio of between 0.01% and 10% of the blend; and
graphitizing the combination at a temperature between about 2500° C. and 3000° C. in argon, helium, or nitrogen gas resulting in particles with carbide compounds along the surfaces and graphite cores,
wherein the carbide compound includes a carbide forming element of B and Ce.
2. The process according to claim 1 wherein the carbide forming element is selected from Ti, Y, Zr, Nb, Mo, La, and combinations thereof.
3. The process according to claim 1 wherein the step of selecting and sizing the carbon precursor more particularly comprises sizing the particles to a mean average particle size of about from about 1 to 50 μm.
4. The process according to claim 3 wherein the step of selecting and sizing the carbon precursor more particularly comprises sizing the particles to a mean average particle size of about 3 to about 30 μm.
5. The process according to claim 4 wherein the step of selecting and sizing the carbon precursor more particularly comprises sizing the particles to a mean average particle size of about 3 to about 25 μm.
6. The process according to claim 1 wherein the step of sizing the carbon precursor more particularly comprises milling the carbon precursor.
7. The process according to claim 6 wherein the step of milling comprises milling in one of a ball-mill, knife mill, impact mill and jet mill or combinations thereof.
8. The process according to claim 1 wherein the step of selecting the carbon precursor more particularly comprises selecting the precursor from calcined needle petroleum coke, uncalcined needle petroleum coke, calcined anode petroleum coke, uncalcined anode petroleum coke, calcined coal tar pitch, uncalcined coal tar pitch, and combinations thereof.
9. The process according to claim 1 wherein the step of graphitizing further comprises graphitizing at a temperature between 2750° C. and 2950° C. for a period of time of between 5 minutes and 90 minutes.
10. The process according to claim 9 wherein the step of graphitizing further comprises graphitizing a period of time of between 10 minutes and 45 minutes.
11. The process according to claim 1 wherein the step of combining the precursor material with carbide forming element further comprises the carbide forming element combined at a rate of between 50 ppm and 10% by weight of the carbon precursor.
12. The process according to claim 1 wherein the step of combining the precursor material with carbide forming element further comprises combining the carbide forming element at between 500 ppm and 3% by weight of the carbon precursor.
13. The process according to claim 1 wherein the step of graphitizing the combination of carbide forming materials further comprises graphitizing in a gaseous nitrogen environment where both carbide and nitride compounds are formed at the surface of the particles.
14. The process according to claim 1 wherein the step of graphitizing the combination of carbide forming materials further comprises graphitizing in a gaseous argon, helium or combination of argon and helium.
15. The process according to claim 1 wherein the step of selecting and sizing the carbon precursor material further comprises selecting the carbon precursor material, then calcining the carbon precursor material to increase the carbon content to at least about 92% carbon and then sizing to particles to a mean average particle size of between 3 and 30 μm.
16. The process according to claim 1 wherein the step of selecting and sizing the carbon precursor material further comprises selecting the carbon precursor material, then calcining the carbon precursor material to increase the carbon content to at least about 95% carbon and then sizing to particles to a mean average particle size of between 3 and 30 μm.
17. The process according to claim 1 wherein the step of selecting and sizing the carbon precursor material further comprises selecting the carbon precursor material, then calcining the carbon precursor material to increase the carbon content to at least about 97% carbon and then sizing to a mean average particle size of between 3 and 30 μm.