Patent ID: 7261979

Claim:
A method of charging a lithium secondary cell, comprising: (a) providing a lithium secondary cell, comprising: a lithium-containing positive electrode in electronic contact with a positive electrode current collector, said current collector in electrical connection with an external circuit; a negative electrode in electronic contact with a negative electrode current collector, said current collector in electrical connection with an external circuit; a separator positioned between and in ionic contact with the cathode and the anode; and an electrolyte in ionic contact with the positive and negative electrodes, wherein the charge capacity per unit area of the positive and negative electrodes each are at least 0.75 mA-h/cm 2 ; and wherein the total area specific impedance for the cell and the relative area specific impedances for the positive and negative electrodes are such that, during charging at greater than or equal to 4C, the negative electrode potential is above the potential of metallic lithium; and (b) charging the cell at a C-rate of at least 4C, wherein at least 95% state of charge is obtained in less than 15 minutes.