| abstract |
A lithium ion secondary battery including a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, where the separator essentially includes a porous sheet. The positive electrode active material and the negative electrode active material can be reversibly doped and dedoped such that, where Qp (mAh) is an electric charge necessary for causing total lithium contained in the positive electrode to be dedoped and Qn (mAh) is an electric charge necessary for causing lithium to fully dope the negative electrode, Qp>Qn. Further, when the battery is charged at a charging current Ic (mA) in a range of 0.2 Qn/h<Ic<2 Qn/h, in a range of an electric charge for charging Qc (mAh) of 1<Qc/Qn<Qp/Qn, doping of the positive electrode by lithium is initiated by producing lithium particles on the negative electrode by charging of the battery until Qc<QP. |