Anode active material and battery
View Patent ↗A battery capable of obtaining a high capacity and reducing its expansion is provided. A spirally wound electrode body formed through laminating a cathode and an anode with a separator and an electrolyte in between to form a laminate and spirally winding the laminate is included in a package member made of an aluminum laminate film. An anode active material layer includes an agglomerated graphite material in which a plurality of primary particles made of graphite having fine pores are agglomerated so that the orientation planes thereof are not parallel to each other, at least in part, to form secondary particles. In the agglomerated graphite material, the total volume of fine pores with a diameter from 10 nm to 1×10 5 nm inclusive estimated by mercury porosimetry ranges from 0.5 cm 3 /g to 1.5 cm 3 /g inclusive per unit weight.
1. An anode active material comprising:
an agglomerated graphite material in which a plurality of primary particles made of graphite having fine pores are agglomerated so that the orientation planes thereof are not parallel to each other, at least in part, to form secondary particles, and in which the total volume of fine pores with a diameter from 10 nm to 1×10 5 nm inclusive as estimated by mercury porosimetry ranges from 0.5 cm 3 /g to 1.5 cm 3 /g inclusive per unit weight,
wherein the content of the agglomerated graphite material in the anode active material ranges from 3 wt % to 30 wt %.
2. The anode active material according to claim 1 , wherein in the agglomerated graphite material, the total volume of fine pores with a diameter from 10 nm to 2×10 3 nm inclusive as estimated by mercury porosimetry ranges from 0.1 cm 3 /g to 0.3 cm 3 /g inclusive.
3. The anode active material according to claim 1 , wherein when the length of the secondary particle in a major axis direction is represented by A, and the length in a minor axis direction is represented by B, the average of aspect ratio represented by A/B is 4 or less.
4. The anode active material according to claim 1 , wherein a specific surface area of the agglomerated graphite material is 5 m 2 /g or less.
5. A battery comprising:
a cathode;
an anode; and
an electrolyte,
wherein the anode includes an anode active material including an agglomerated graphite material as an anode active material, the agglomerated graphite material in which a plurality of primary particles made of graphite having fine pores are agglomerated so that the orientation planes thereof are not parallel to each other, at least in part, to form secondary particles, and
wherein in the agglomerated graphite material, the total volume of fine pores with a diameter ranging from 10 nm to 1×10 5 nm inclusive as estimated by mercury porosimetry ranges from 0.5 cm 3 /g to 1.5 cm 3 /g inclusive per unit weight, and
wherein the content of the agglomerated graphite material in the anode active material ranges from 3 wt % to 30 wt %.
6. The battery according to claim 5 , wherein the cathode, the anode and the electrolyte are contained in a film-shaped package member.
7. The battery according to claim 5 , wherein in the agglomerated graphite material, the total volume of fine pores with a diameter ranging from 10 nm to 2×10 3 nm inclusive as estimated by mercury porosimetry ranges from 0.1 cm 3 /g to 0.3 cm 3 /g inclusive.
8. The battery according to claim 5 , wherein when the length of the secondary particle in a major axis direction is represented by A, and the length in a minor axis direction is represented by B, the average of aspect ratio represented by A/B is 4 or less.
9. The battery according to claim 5 , wherein the specific surface area of the agglomerated graphite material is 5 m2/g or less.
10. The battery according to claim 5 , wherein the electrolyte includes an electrolyte solution and a polymer including vinylidene fluoride.
11. The battery according to claim 5 , wherein the electrolyte includes an electrolyte solution and a polymer having a structure in which a polymerizable compound having an acrylate group or a methacrylate group is polymerized.
12. The battery according to claim 5 , wherein the electrolyte includes an electrolyte solution and a polymer having a structure in which at least one kind selected from the group consisting of polyvinylacetal and its derivatives is polymerized.
13. The anode active material according to claim 1 , wherein the anode active material includes, in addition to the agglomerated graphite material, an element selected from the group consisting of: a mesocarbon microbead and a natural graphite.
14. The battery according to claim 5 , wherein the anode active material includes, in addition to the agglomerated graphite material, an element selected from the group consisting of: a mesocarbon microbead and a natural graphite.