NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery arranged so that a pressure-type current interrupt mechanism works early with reliability.SOLUTION: A nonaqueous electrolyte secondary battery comprises: a pressure-type current interrupt device mechanism disposed in a conducting path, and serving to cut off the conducting path when an internal pressure exceeds an operation pressure; a nonaqueous electrolyte; and a positive electrode mixture layer. The nonaqueous electrolyte includes a gas generating agent which generates gas in an overcharge region. The positive electrode mixture layer includes: first positive electrode active material particles including lithium iron phosphate; and second positive electrode active material particles including a lithium nickel complex oxide. Of the total mass of the first and second positive electrode active material particles, the first positive electrode active material particles account for 5-20 mass%.