NONAQUEOUS ELECTROLYTE BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery capable of flattening voltage characteristics and securing safety at the time of battery abnormality.

SOLUTION: A lithium ion secondary battery 20 is provided with an electrode group 6 around which positive and negative electrode plates are wound. A nonaqueous electrolyte includes a mixed solvent of EC and DMC with LiBF4added. In the positive electrode plates, positive electrode mixture layers W2 including a positive active material are formed at both sides of an aluminium foil W1. The positive active material uses a lithium manganese magnesium complex oxide with a spinel crystal structure. The positive electrode mixture layers W2 have flame-resistant agent layers W6 including a phosphazene compound formed on the surfaces. In the negative electrode plates, negative electrode mixture layers W4 including an negative active material are formed at both sides of a rolled copper foil W3. The negative active material uses a graphite material with the graphite surface coated with pyrolytic carbon. The phosphazene compound exhibits fire-resistant performance, and voltage characteristics are flattened by the graphite material.

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