A method for embedding sulphur into conductive carbon is provided. Elemental sulphur is dissolved in liquid ammonia to form a sulphur-ammonia solution. Conductive carbon is soaked in the sulphur-ammonia solution to embed the conductive carbon with the dissolved sulphur. The liquid ammonia in the sulphur-ammonia solution can be removed as gaseous ammonia to yield sulphur-embedded conductive carbon. The sulphur-embedded conductive carbon can be used to manufacture sulphur cathodes. Such sulphur cathodes and batteries incorporating such sulphur cathodes are provided.

A method for embedding sulphur into conductive carbon is provided. Elemental sulphur is dissolved in liquid ammonia to form a sulphur-ammonia solution. Conductive carbon is soaked in the sulphur-ammonia solution to embed the conductive carbon with the dissolved sulphur. The liquid ammonia in the sulphur-ammonia solution can be removed as gaseous ammonia to yield sulphur-embedded conductive carbon. The sulphur-embedded conductive carbon can be used to manufacture sulphur cathodes. Such sulphur cathodes and batteries incorporating such sulphur cathodes are provided.

The present invention relates to an all-solid-state battery including: an electrode assembly including a negative electrode, a positive electrode, and a solid electrolyte between the negative electrode and the positive electrode; and a case for accommodating the electrode assembly, wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer including a negative electrode active material and a binder, the negative electrode active material includes a carbon-based material and metal particles, the binder includes a first polymer of a butadiene rubber, and a second polymer selected from carboxy alkyl cellulose (wherein alkyl is a C1 to C6 alkyl), a salt thereof, and a combination thereof, and the first polymer and the second polymer are included in a weight ratio of 1:1 to 6:1.

The present invention relates to an all-solid-state battery including: an electrode assembly including a negative electrode, a positive electrode, and a solid electrolyte between the negative electrode and the positive electrode; and a case for accommodating the electrode assembly, wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer including a negative electrode active material and a binder, the negative electrode active material includes a carbon-based material and metal particles, the binder includes a first polymer of a butadiene rubber, and a second polymer selected from carboxy alkyl cellulose (wherein alkyl is a C1 to C6 alkyl), a salt thereof, and a combination thereof, and the first polymer and the second polymer are included in a weight ratio of 1:1 to 6:1.

A negative electrode including: a negative electrode current collector; and a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material, wherein the negative electrode active material includes natural graphite particles, and has a particle strength of 40 MPa to 200 MPa when being plastically deformed.

A negative electrode including: a negative electrode current collector; and a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material, wherein the negative electrode active material includes natural graphite particles, and has a particle strength of 40 MPa to 200 MPa when being plastically deformed.

Provided is a lithium ion secondary battery including Li.sub.4Ti.sub.5O.sub.12 particles in a negative electrode active material layer and having both high heat generation suppressing performance during overcharging, and high storage stability in a high SOC region. The lithium ion secondary battery herein disclosed includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode has a positive electrode active material layer. The positive electrode active material layer includes Li.sub.3PO.sub.4 as a secondary material. The negative electrode has a negative electrode active material layer. The negative electrode active material layer includes Li.sub.4Ti.sub.5O.sub.12 as a secondary material. The Li.sub.3PO.sub.4 content in the positive electrode active material layer is 0.5 mass % or more and 5.0 mass % or less. The Li.sub.4Ti.sub.5O.sub.12 content in the negative electrode active material layer is 0.5 mass % or more and 5.0 mass % or less.

Provided is a lithium ion secondary battery including Li.sub.4Ti.sub.5O.sub.12 particles in a negative electrode active material layer and having both high heat generation suppressing performance during overcharging, and high storage stability in a high SOC region. The lithium ion secondary battery herein disclosed includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode has a positive electrode active material layer. The positive electrode active material layer includes Li.sub.3PO.sub.4 as a secondary material. The negative electrode has a negative electrode active material layer. The negative electrode active material layer includes Li.sub.4Ti.sub.5O.sub.12 as a secondary material. The Li.sub.3PO.sub.4 content in the positive electrode active material layer is 0.5 mass % or more and 5.0 mass % or less. The Li.sub.4Ti.sub.5O.sub.12 content in the negative electrode active material layer is 0.5 mass % or more and 5.0 mass % or less.

A method for producing a negative electrode active material realizing both of improvement in tolerance against the deposition of lithium and improvement in life performance is provided. A method for producing a negative electrode active material includes the steps of preparing graphite particles having a BET specific surface area of 10.3 m.sup.2/g or larger and 12.2 m.sup.2/g or smaller; and coating at least a part of a surface of the graphite particles with amorphous carbon. In the step of coating, at least the part of the surface of the graphite particles is coated with the amorphous carbon such that a value obtained by subtracting a BET specific surface area of the negative electrode active material from a BET specific surface area of the graphite particles is 6.9 m.sup.2/g or larger and 8.3 m.sup.2/g or smaller.

A method for producing a negative electrode active material realizing both of improvement in tolerance against the deposition of lithium and improvement in life performance is provided. A method for producing a negative electrode active material includes the steps of preparing graphite particles having a BET specific surface area of 10.3 m.sup.2/g or larger and 12.2 m.sup.2/g or smaller; and coating at least a part of a surface of the graphite particles with amorphous carbon. In the step of coating, at least the part of the surface of the graphite particles is coated with the amorphous carbon such that a value obtained by subtracting a BET specific surface area of the negative electrode active material from a BET specific surface area of the graphite particles is 6.9 m.sup.2/g or larger and 8.3 m.sup.2/g or smaller.