LITHIUM SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a lithium secondary battery of a superior power characteristic, especially at room temperature to lower temperatures. SOLUTION: The lithium secondary battery is constituted so that a graphite material carbon fiber is used as a negative electrode active material wherein a specific surface area is not less than 10 m2/g and not more than 20 m2/g, and the average fiber diameter is not less than 0.1 μm and not more than 0.3 μm. By using carbon fibers in an appropriate range wherein a density of the active material at the negative electrode can be enhanced and wherein an electrical conduction property in the negative electrode can be kept high while making use of a merit that the specific surface area is large, this becomes the lithium secondary battery having a large discharge capacity and a superior power characteristic.