Subzero startup of electrochemical power sources using alternating current

Subzero startup constitutes a lingering obstacle impeding the diffusion of battery and fuel cell electric vehicles in cold regions. Both being electrochemical energy devices, lithium-ion battery (LIB) and polymer electrolyte fuel cell (PEFC) share many commonalities in their cold startup problems, tasks and principle behind startup techniques. Subzero startup of LIB and PEFC using alternating current (AC) is receiving increasing attention for its high efficiency, low degradation and superb reliability. To catch the wider attention in the research community and promote the development of this technique, we herein address the AC startup of LIB and PEFC in a single review and in a same framework. After a brief introduction to low temperature performance problem, subzero startup techniques for LIB and PEFC are classified based on a new criterion, i.e. the nature of the heat generation, instead of the location of heat generation. Then, the principle, development and implementation of AC startup are outlined. For the startup of LIB, the Li deposition criterion, the validation and variations in battery, and the comparison with the direct current techniques are elaborated. For the startup of PEFC, the validation in cell, the extension to stack, and the comparison with the air restriction self-heating technique are elaborated. Finally, the common challenges and special requirements for starting up LIB and PEFC are discussed, and the remaining issues and directions for further research are highlighted.