A Multifunctional Electrolyte Additive With Solvation Structure Regulation and Electrode/Electrolyte Interface Manipulation Enabling High‐Performance Li‐Ion Batteries in Wide Temperature Range

Improving the tolerance of Li‐ion batteries (LIBs) to extreme temperatures and climates worldwide is vital to their global uptake. However, LIBs call for more strict requirements for the key components when operated in a wide temperature range, especially synchronously desirable interfacial kinetics and thermal stability. Here, a novel multifunctional electrolyte additive, N‐tert‐butyl‐2‐thiophenesulfonamide (NTSA), to fabricate stable LIBs under wide‐temperature conditions, is reported. The Li‐ion solvation structure in the electrolyte is regulated and involves less coordinated solvents (particularly fluoroethylene carbonate), leading to superior Li+ transportation. The effective NTSA additive is preferentially decomposed to form a uniform electrode/electrolyte interface with abundant multiphase inorganic LiF, Li3N, and LiS species simultaneously on the cathode and anode surface. The resulting inorganic‐rich interface can not only boost the interfacial Li‐ion transfer kinetics at low temperatures but also protect the active material and enhance the thermal stability of the interface and LIB devices at high temperatures. By adopting the NTSA‐containing electrolyte, LiCoO2||ω‐Li3V2O5 LIBs can be stably cycled in a wide temperature range between −30 °C and 80 °C, delivering a high capacity of ≈100.1 mAh g−1 (0.2 A g−1) at −20 °C and high capacity retention of 94.5% after 200 cycles (0.5 A g−1) at 55 °C.