Lithium-ion rechargeable battery

Abstract

This invention provides a lithium-ion secondary battery that can suppress the generation of gas due to the decomposition of the electrolyte compared to conventional batteries. [Solution] The device comprises a positive electrode portion, a negative electrode portion, and an electrolyte. The positive electrode portion includes positive electrode particles containing lithium-containing oxide on at least one surface as a positive electrode active material. The electrolyte comprises a first additive and a second additive. The first additive is a radical chain inhibitor, and the second additive is an organic compound having unsaturated bonds.

Claims

1. It includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode portion includes positive electrode particles containing lithium-containing oxide on at least one surface as the positive electrode active material. The electrolyte comprises a first additive and a second additive. The first additive is a radical chain inhibitor, The second additive is an organic compound having an unsaturated bond, in a lithium-ion secondary battery.

2. The lithium-ion secondary battery according to claim 1, wherein the first additive is a phenolic antioxidant.

3. The lithium-ion secondary battery according to claim 1, wherein the electrolyte contains a cyclic carbonate as a solvent.

4. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the operating potential of the positive electrode is 4.3V or higher relative to the oxidation-reduction potential of lithium.

5. The positive electrode particles have a core-shell structure having a first shell layer containing the lithium-containing oxide on the surface of the first core portion. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the lithium-containing oxide contains phosphorus.

6. The lithium-ion secondary battery according to claim 5, wherein the first core portion is composed of lithium nickel manganese oxide.

7. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the electrolyte contains the first additive in an amount of 0.01% or more and 0.5% or less relative to the weight of the electrolyte.

8. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the operating potential of the negative electrode is 0.5V or more and 2.5V or less relative to the oxidation-reduction potential of lithium.

9. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the second additive comprises a cyclic siloxane bond as the main chain, and comprises an unsaturated hydrocarbon group as the side chain of the silicon atom of the cyclic siloxane bond, which is either unsubstituted or has some hydrogen atoms substituted with other atoms.

10. The lithium-ion secondary battery according to any one of claims 1 to 3, wherein the electrolyte contains the second additive in an amount of 0.1% or more and 20% or less relative to the weight of the electrolyte.

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