Secondary battery
A secondary battery includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode active material layer that includes a positive electrode active material, a fluorine-based binder having a melting point from 152° C. to 166° C., a conductive assistant having a specific surface area from 1000 m 2 /g to 1500 m 2 /g, and a vinylpyrrolidone-based polymer.
1. A secondary battery comprising:
a positive electrode including a positive electrode active material layer;
a negative electrode; and
an electrolyte,
wherein the positive electrode active material layer includes a positive electrode active material, a homopolymer of polyvinylidene difluoride having a melting point from 152° C. to 166° C., a conductive assistant having a specific surface area from 1000 m 2 /g to 1500 m 2 /g, and a vinylpyrrolidone-based polymer,
a content of the homopolymer of the polyvinylidene difluoride in the positive electrode active material layer is 0.7 mass % or more and 4.0 mass % or less,
a content of the conductive assistant in the positive electrode active material layer is 0.2 mass % or more and 5 mass % or less, and
a content of the vinylpyrrolidone-based polymer in the positive electrode active material layer is from 0.01 mass % to 0.2 mass %.
2. The secondary battery according to claim 1 , wherein the conductive assistant has a granular shape.
3. The secondary battery according to claim 1 , wherein the positive electrode active material includes a lithium transition metal oxide having a layered rock salt structure.
4. The secondary battery according to claim 1 further comprising a separator, wherein the separator is provided between the positive electrode and the negative electrode.
5. The secondary battery according to claim 4 , wherein the separator includes a porous film.
6. The secondary battery according to claim 1 , wherein the positive electrode further includes a positive electrode current collector.
7. The secondary battery according to claim 6 , wherein the positive electrode current collector includes at least one of aluminum foil, nickel foil and a stainless steel foil.
8. An electronic device comprising:
a secondary battery according to claim 1 , and
an electronic circuit that is electrically connected to the secondary battery.
9. The secondary battery according to claim 1 , wherein the homopolymer of polyvinylidene difluoride has the melting point from 152° C. to 160° C., and wherein the conductive assistant has the specific surface area from 1250 m 2 /g to 1500 m 2 /g.
10. The secondary battery according to claim 9 , wherein the conductive assistant includes a carbon material having a granular shape.