Electrode material for secondary batteries and manufacturing method thereof, and secondary battery
Provided is an electrode material for secondary batteries, including a porous carbon material being derived from a plant and having an average particle size of less than 4 μm.
1. An electrode material for secondary batteries, the electrode material comprising: a porous carbon material being derived from a plant and having an average particle size of less than 4 μm, wherein the porous carbon material comprises first pores having a first pore size of 50 nm or less and a first cumulative pore volume of 0.7 cm 3 /g and second pores having a second pore size of 50 nm to 200 nm and a second cumulative pore volume of more than 0.1 cm 3 /g, and the porous carbon material comprises micropores having a pore size of 0.8 nm to 1 nm.
2. The electrode material according to claim 1 , wherein the porous carbon material has a value of a specific surface area using a nitrogen BET method of 10 m 2 /g or more, and a volume of pores using a BJH method of 0.7 cm 3 /g or more.
3. The electrode material according to claim 1 , wherein the porous carbon material is obtained from a plant-derived material having a silicon content of 5% by mass or more by carbonizing, treating with acid or alkali, and pulverizing the plant-derived material.
4. The electrode material according to claim 1 , wherein the porous carbon material comprises a silicon content of not more than 1% by mass.
5. The electrode material of claim 1 , wherein a specific surface area of the porous carbon material is 400 m 2 /g or more.
6. The electrode material of claim 1 , wherein a volume of pores of the porous carbon material is more than 1 cm 3 /g.
7. A secondary battery comprising: an electrode including a porous carbon material being derived from a plant and having an average particle size of less than 4 μm, wherein the porous carbon material comprises first pores having a first pore size of 50 nm or less and a first cumulative pore volume of 0.7 cm 3 /g and second pores having a second pore size of 50 nm to 200 nm and a second cumulative pore volume of more than 0.1 cm 3 /g, and the porous carbon material comprises micropores having a pore size of 0.8 nm to 1 nm.
8. The secondary battery according to claim 7 , wherein a positive electrode is constituted by the electrode.
9. The secondary battery according to claim 7 , wherein the secondary battery is a lithium-sulfur secondary battery, and wherein the electrode carries sulfur or a sulfur compound.
10. A manufacturing method of an electrode material for secondary batteries, the method comprising: after carbonizing a plant-derived material at 400° C. to 1400° C., performing treatment with acid or alkali on the carbonized material, and then pulverizing the treated material, to obtain the electrode material for secondary batteries including a porous carbon material having an average particle size of less than 4 μm, wherein the porous carbon material comprises first pores having a first pore size of 50 nm or less and a first cumulative pore volume of 0.7 cm 3 /g and second pores having a second pore size of 50 nm to 200 nm and a second cumulative pore volume of more than 0.1 cm 3 /g, and the porous carbon material comprises micropores having a pore size of 0.8 nm to 1 nm.
11. The manufacturing method of an electrode material for secondary batteries according to claim 10 , further comprising: performing, after the pulverizing, heat treatment at a temperature exceeding a temperature during the carbonizing.
12. The manufacturing method of an electrode material for secondary batteries according to claim 10 , wherein the treatment with acid or alkali causes silicon components in the carbonized plant-derived material to be removed.
13. The manufacturing method of an electrode material for secondary batteries according to claim 10 , wherein the plant-derived material has a silicon content of 5% by mass or more.