Heating-cooperative Charging of Lithium-ion Batteries at Low Temperatures

The charging of lithium-ion batteries (LIBs) is remarkably slowed down at sub-zero environment due to the declined activity of electrochemical processes. This has been a major barrier of the further popularity of electric vehicles especially at cold regions. Motivated by this, this paper proposes a heating-cooperative charging strategy for lithium-ion batteries at low-temperature scenarios. An experimental-validated electro-thermal model is built to explain the coupling mechanism of heating and charging at low-temperatures conditions. On this premise, a multi-objective optimization problem is formulated regarding charging rapidity and energy loss. The dynamic programming (DP)-based solution virtually gives rise to a heating-cooperative charging strategy. Results show that the proposed strategy can adaptively regulate the heating/charging switching mode and the associated current magnitude to ensure the high-efficiency fast charging.