BATTERY WITH IMPROVED CYCLE CHARACTERISTICS, BATTERY PACK, ELECTRONIC APPARATUS, ELECTRICALLY DRIVEN VEHICLE, ELECTRICAL STORAGE DEVICE, AND POWER SYSTEM

摘要

The purpose of the present invention is to provide a battery able to minimize any drop in capacitance resulting from repeated charging and discharging, and a battery pack, electronic device, electric vehicle, electric storage device, and power system using the same. The present invention is a battery in which the area density (mg/cm2) of a positive electrode active material layer is 27 mg/cm2 or greater, and the porous film included in a separator has a configuration satisfying the following formulae: 0.04=Ri=?0.07L?0.09×S+4.99; Ri=t2L/?'; ?'=[{(L×?/100?Rz×0.46/3}/L)]×100; t={(1.216×?'Td×10?4)/L}0.5 [Ri: film resistance (µm), L: film thickness (µm), t: tortuosity, T: air permeability (sec/100 cc), d: pore diameter (nm), Rz: maximum height of surface roughness (total value for front surface and rear surface) (µm), ?: porosity (%), ?': corrected porosity (%), S: area density of positive electrode active material (mg/cm2)]