Analysis and Experiment of Bipolar-Pulse Heating Mehtod for Lithium-ion Batterries

This paper proposes a lithium-ion batteries heating method that generates bipolar current pulses based on the RLC non-oscillating network. The heating performance with different input states is analyzed, including the bipolar pulse heating current, the adjustment range of frequency, and the duty ratio. A prototype is built based on the half-bridge topology with the proposed RLC network to verify the analysis. Experimental results show that the proposed method is able to heat lithium-ion batteries in a low-temperature environment effectively. The self-heating performance is reliable by using the ohmic loss and electrochemical heat without external heating devices. The proposed method is conducive to improve the performance of lithium-ion batteries in a low-temperature environment. Moreover, the heating power can be easily adjusted by varying the duty ratio. The heating current reaches 1.2 C with 50% duty cycle. The measured self-heating temperature of the four series-connected 18650 lithium-ion batteries rises by 13°C, from 2.6°C to 15.6°C.