Lithium secondary battery

摘要

A lithium secondary battery including an internal electrode body contained in a battery case including a positive electrode, a negative electrode and a separator made of porous polymer, the positive electrode and the negative electrode are wound or laminated. A working volume ratio of the positive active material and the negative active material obtained by the positive active material weight being divided by the negative active material weight is within the range from 40% to 90% of the theoretical working volume ratio. The lithium secondary battery has high safety as well as high energy density by controlling the working volume of an electrode active material and the dispersion of the distribution of the working volume and in particular is preferably used for a drive motor of an electric vehicle.