| abstract |
A lithium ion secondary battery comprising a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, wherein the separator consists essentially of 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, and when the battery is charged at a charging current Ic (mA) in a range of 0.2Qn/h < Ic < 2Qn/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 started through lithium particles produced on the negative electrode by charging of the battery and is continued up to Qc > Qp. |