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 degrees 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.