Carbon electrode and lithium ion hybrid capacitor comprising same
View Patent ↗A carbon material is described, having utility for fabricating an electrode of an electrochemical energy device, wherein the carbon material includes a particulate carbon having a particle size d 50 in a range of from 1 to 15 μm, a bulk density in a range of from 0.3 g/cc to 1.2 g/cc, a surface area as measured by nitrogen BET surface area determination at 25° C. that does not exceed 10 m 2 /g, and an impurity content of less than 3000 ppm by weight, based on weight of the carbon material. Such carbon material may be utilized in amorphous or graphitic form in an electrode of an electrochemical energy device, such as a negative electrode of a lithium-ion battery or a lithium-ion hybrid capacitor.
1. A carbon material having utility for fabricating a negative anode of an electrochemical energy device, said carbon material comprising a particulate carbon having a particle size d 50 in a range of from 1 to 15 μm, a bulk density in a range of from 0.3 g/cc to 0.9 g/cc, a surface area as measured by nitrogen BET surface area determination at 25° C. that does not exceed 10 m 2 /g, and a total content of elements present, as determined by PIXE elemental analysis, of less than 3000 ppm by weight, based on weight of the carbon material.
2. The carbon material of claim 1 , wherein the particle size d 50 is in a range of from 2 to 10 μm.
3. The carbon material of claim 1 , wherein the bulk density is in a range of from 0.3 g/cc to 0.7 g/cc.
4. The carbon material of claim 1 , wherein the surface area of the particulate carbon is in a range of from 2.5 to 10 m 2 /g.
5. The carbon material of claim 1 , wherein the particulate carbon contains at least 98% carbon, less than 0.05% for silicon, less than 2% for sulfur, less than 0.05% for calcium, less than 0.8% for vanadium, less than 400 ppm for iron, less than 250 ppm for nickel, less than 20 ppm for copper, and less than 10 ppm for zinc, wherein all percentages and parts per million are by weight, based on total weight of the carbon material, and subject to the limitation that the total content of elements present, as determined by PIXE elemental analysis, is less than 3000 ppm by weight, based on total weight of the carbon material.
6. The carbon material of claim 1 , in an amorphous form.
7. The carbon material of claim 1 , in a graphitized form.
8. The carbon material of claim 1 , wherein the particulate carbon is a carbonized particulate carbon of a material selected from the group consisting of synthetic polymeric materials, petroleum-based materials, petroleum-derived materials, carbohydrates, and combinations, blends, and mixtures of the foregoing.
9. The carbon material of claim 1 , wherein the total content of elements present is below 1000 ppm by weight, based on total weight of the carbon material.
10. The carbon material of claim 1 , wherein the total content of elements present is in a range of from 0.5 to 5 ppm by weight, based on total weight of the carbon material.
11. An electrode having utility in an electrochemical energy device, said electrode comprising the carbon material of claim 1 .
12. The electrode of claim 11 , which after 100,000 charging/discharging cycles retains a capacitance that is within 5% of initial capacitance of the negative electrode prior to initiation of said cycles, and an equivalent series resistance value that is not more than 20% of the initial equivalent series resistance value of the negative electrode prior to initiation of said cycles.
13. An electrochemical energy device comprising the electrode according to claim 11 .
14. The electrochemical energy device of claim 13 , wherein the electrode after 100,000 charging/discharging cycles retains a capacitance that is within 5% of initial capacitance of the negative electrode prior to initiation of said cycles, and an electrical resistance value that is not more than 20% of the initial equivalent series resistance value of the negative electrode prior to initiation of said cycles.
15. The electrochemical energy device of claim 13 , comprising a lithium ion electrochemical energy device.
16. The carbon material of claim 1 , wherein the particle size d50 is in a range of from 4 to 6 μm, the bulk density is in a range of from 0.5 g/cc to 0.7 g/cc, and the surface area as measured by nitrogen BET surface area determination at 25° C. is in a range of from 2.5 to 10 m 2 /g.
17. A method of making a carbon material comprising:
carbonizing a carbonizable precursor material in an inert gas environment to thermally convert the precursor to the carbon material,
wherein said carbon material comprises a particulate carbon having a particle size d 50 in a range of from 1 to 15 μm, a bulk density in a range of from 0.3 g/cc to 0.9 g/cc, a surface area as measured by nitrogen BET surface area determination at 25° C. that does not exceed 10 m 2 /g, and a total content of elements present, as determined by PIXE elemental analysis, of less than 3000 ppm by weight, based on weight of the carbon material.
18. The method of claim 17 , wherein the carbonizable precursor material has a hydrogen-to-carbon molar ratio (H/C) in a range of from 0.5 to 0.7.
19. The method of claim 17 , wherein the carbonizable precursor material is selected from the group consisting of synthetic polymeric materials, petroleum-based materials, petroleum-derived materials, carbohydrates, and combinations, blends, and mixtures thereof.
20. The method of claim 17 , wherein the carbonizable precursor material is shaped into an electrode preform prior to said carbonizing.