A novel dual-current formation process for advanced lithium-ion batteries

A fast formation procedure for lithium-ion batteries has been proposed in which the total charging time is decreased by at least 50%. The procedure consists of a dual-current charging, with a small 0.1 C-current followed by a large 1.0 C-current. Small current helps to grow a solid-electrolyte interphase (SEI), and large current accelerates the charging process. Electrochemical impedance data show that formation affects the anode SEI film. The proposed fast formation procedure retains an effective SEI film as that of a battery with standard formation procedure, in which the active materials of both the anode and cathode are intact, therefore electrochemical performance is unaffected. (c) 2005 The Electrochemical Society.