Toward wide‐temperature electrolyte for lithium–ion batteries

Abstract Lithium–ion battery (LIB) suffers from safety risks and narrow operational temperature range in despite the rapid drop in cost over the past decade. Subjected to the limited materials choices, it is not feasible to modify the cathode and anode to improve the battery's wide‐temperature performance, hence, optimizing the design of the electrolyte system has currently become the most feasible and economical way to broaden the operating temperature range of LIBs. Considering urgent demands for wide‐temperature LIBs and achieved enormously excited results about wide‐temperature electrolytes in recent years, a review about this topic and scope is timely and important at present. In this study, we first examine the physicochemical properties of current commercial electrolytes with emphasis on the variations of key parameters along with the temperature. After that, we give comprehensive overview of the employed strategies for separately improving the electrochemical performance of electrolytes toward low‐temperature, high‐temperature, and wide‐temperature applications. Furthermore, recent progress of ionic liquids and solid‐state electrolytes that are capable of working within wide temperature range is also summarized. We hope this review will provide deep understanding of the design principles of wide‐temperature electrolyte, and inspire more endeavors to conquer the practicability issue of LIBs in extreme environments.