NONAQUEOUS ELECTROLYTE BATTERY

摘要

A nonaqueous electrolyte battery is provided with which it is possible to flatten voltage characteristics and thereby guarantee safety during a battery malfunction. A lithium ion secondary battery (20) has an electrode group (6) in which positive and negative pole plates are wound. The nonaqueous electrolyte is an EC and DMC mixed solvent to which LiBF4 is added. The positive pole plate is obtained by forming a positive pole mix layer (W2), which comprises a positive pole active substance, at both surfaces of an aluminum foil (W1). A lithium-manganese-magnesium compound oxide having a spinel crystal structure is used for the positive pole active substance. A flame retarder layer (W6) comprising a phosphazene compound is formed at the surface of the positive pole mix layer (W2). The negative pole plate is obtained by forming a negative pole mix layer (W4), which comprises a negative pole active substance, at both surfaces of a rolled copper foil (W3). A graphite material obtained by coating the surface of graphite with pyrolytic carbon is used for the negative pole active substance. The phosphazene compound provides flame resistance, and the voltage characteristics are flattened by the graphite material.