Challenges and strategies of formulating low‐temperature electrolytes in lithium‐ion batteries

Lithium‐ion batteries (LIBs) have monopolized energy storage markets in modern society. The reliable operation of LIBs at cold condition (<0°C), nevertheless, is inevitably hampered by the sluggish kinetics and parasite reactions, which falls behind the increasing demands for portable electronics and electric vehicles. The electrolyte controls both Li+ transport and interfacial reaction, dictating the low‐temperature performance substantially. Therefore, the rational formulation of electrolytes is significant for realizing superior low‐temperature performance and broadening application niches of LIBs. Herein, we first discuss the kinetic limitations of low‐temperature LIBs, highlighting the importance of electrolyte structure and interfacial chemistry. Then, the advancements for formulating subzero‐temperature electrolyte are summarized with in‐depth discussions about electrolyte formulation, solvation structure, interfacial chemistry, and low‐temperature behaviors. Moreover, some opportunities for lithium metal batteries and the corresponding low‐temperature electrolyte are covered. Finally, the major challenges and future perspectives are outlined for low‐temperature LIBs.