| abstract |
A lithium ion secondary battery comprising anpositive electrode, a negative electrode, a separator andna nonaqueous electrolyte, wherein the separator consistsnessentially of a porous sheet, the positive electrodenactive material and the negative electrode activenmaterial can be reversibly doped and dedoped such that,nwhere Qp (mAh) is an electric charge necessary forncausing total lithium contained in the positive electrodento be dedoped and Qn (mAh) is an electric chargennecessary for causing lithium to fully dope the negativenelectrode, Qp > Qn, and when the battery is charged at ancharging current Ic (mA) in a range of 0.2Qn/h < Ic <n2Qn/h, in a range of an electric charge for charging Qcn(mAh) of 1 < Qc/Qn < Qp/Qn, doping of the positivenelectrode by lithium is started through lithium particlesnproduced on the negative electrode by charging of thenbattery and is continued up to Qc > Qp. |