RECHARGEABLE BATTERY WITH NONAQUEOUS ELECTROLYTE

摘要

This invention provides a rechargeable battery with nonaqueous electrolyte, comprising a positive electrode comprising a composite lithium oxide-containing positive electrode composite and a positive electrode current collector for supporting this positive electrode composite, a negative electrode containing a material, which can store and release lithium, a separator comprising a polyolefin resin, a nonaqueous electrolyte, and a heat-resistant insulating layer interposed between the positive electrode and the negative electrode. The estimated heat generation rate of the positive electrode composite at 200°C is not more than 50 W/kg. The estimated heat generation rate is determined by determining the relationship between an absolute temperature T and a heat generation rate V of the positive electrode composite with an accelerated rate calorimeter or an uncontrollable reaction measuring device (ARC), plotting the relationship between the reciprocal of the absolute temperature T as X axis and the logarithm of the heat generation rate V as Y axis according to the Arrhenius theorem, determining an approximate straight line matched with the plot present in the heat generation region of T < 200°C (473 K), and extrapolating the approximate straight line to the temperature axis of T = 200°C (473 K).