Electrode material, electrode, and battery

1. An electrode comprising a plant-derived porous carbon material that catalyzes oxygen reduction at the electrode.

2. The electrode according to claim 1 ,

wherein the plant-derived porous carbon material is a carbonized material treated with at least one of an acid and an alkali.

3. The electrode according to claim 1 , wherein:

the porous carbon material is used for oxygen reduction at a pH of 3 or more and 10 or less when generating electric power;

a specific surface area of the porous carbon material is 100 m 2 /g or more as measured by the nitrogen BET method; and

a pore volume of the porous carbon material is 0.2 cm 3 /g or more as measured by the BJH method and 0.1 cm 3 /g or more as measured by the MP method.

4. The electrode according to claim 1 ,

wherein an oxygen reduction starting potential of the porous carbon material is more noble than 0.15 V as measured versus a Ag/AgCl reference electrode.

5. The electrode according to claim 1 ,

wherein the porous carbon material includes an oxygen reduction catalyst supported thereon, and wherein the plant-derived porous carbon material and the oxygen rejection catalyst each increase a rate of the oxygen reduction.

6. The electrode according to claim 5 ,

wherein the oxygen reduction catalyst is at least one material selected from the group consisting of a noble metal, a transition-metal oxide, a transition-metal porphyrin, phthalocyanine, a porphyrin polymer, a phthalocyanine polymer, perovskite, and a product of pyrolysis of a cobalt salt using polyacrylonitrile.

7. The electrode according to claim 1 ,

wherein the porous carbon material is supported on a supporting member, and wherein the electrode outputs current during the catalysis of the oxygen reduction.

8. The electrode according to claim 1 ,

wherein the electrode is used as a positive electrode of a battery that produces an electric current when the plant-derived porous carbon material catalyzes the oxygen reduction at the electrode.

9. An electrode material comprising a plant-derived porous carbon material that catalyzes oxygen reduction at the electrode material.

10. The electrode material according to claim 9 ,

wherein the porous carbon material is used for oxygen reduction in conjunction with an electrolyte having a pH of 3 or more and 10 or less.

11. The electrode material according to claim 9 , wherein:

a specific surface area of the porous carbon material is 100 m 2 /g or more as measured by the nitrogen BET method; and

a pore volume of the porous carbon material is 0.2 cm 3 /g or more as measured by the BJH method and 0.1 cm 3 /g or more as measured by the MP method.

12. The electrode material according to claim 9 ,

wherein an oxygen reduction starting potential of the porous carbon material is more noble than 0.15 V as measured versus a Ag/AgCl reference electrode.

13. A battery comprising a positive electrode including a plant-derived porous carbon material that catalyzes oxygen reduction at the positive electrode.

14. The battery according to claim 13 ,

wherein the porous carbon material is used for oxygen reduction under a pH-neutral condition.

15. The battery according to claim 13 , wherein:

a specific surface area of the porous carbon material is 100 m 2 /g or more as measured by the nitrogen BET method; and

a pore volume of the porous carbon material is 0.2 cm 3 /g or more as measured by the BJH method and 0.1 cm 3 /g or more as measured by the MP method.

16. The battery according to claim 13 ,

wherein an oxygen reduction starting potential of the positive electrode is more noble than 0.15 V as measured versus a Ag/AgCl reference electrode.

17. The battery according to claim 13 ,

wherein the battery includes an electrolytic solution containing a buffer substance.

18. The battery according to claim 17 ,

wherein the buffer substance has a pK a of 4 or more and 10 or less.

19. The battery according to claim 13 ,

wherein the battery is one of an enzymatic biofuel cell and a microbial fuel cell.