Stepwise segmented charging technique for lithium-ion battery to induce thermal management by low-temperature internal heating

The severe deterioration of performance for the lithium-ion battery(LIB) at low temperatures adversely restricts the feasibility and applicability of LIB for electric vehicle(EV) applications. Therefore preheating batteries to proper temperature is an essential function of an effective battery management system to improve the low temperature performance. A novel internal heating strategy applying stepwise sequences of charging current pulses and constant discharging current amplitude is proposed, based on the first order RC equivalent circuit model and the temperature-rise model of LIB. In view of the developed preheating method, a preheating simulation model of charging current step-growth is established and simulated, and then the method is experimentally validated for rapidity and feasibility. Ultimately, the preheated battery is charged and the capacity charged is 2.30 times larger comparing with non-preheated battery.