Engineering the solid electrolyte interphase for enhancing high-rate cycling and temperature adaptability of lithium-ion batteries†

In overcoming the barrier of rapid Li⁺ transfer in lithium-ion batteries at extreme temperatures, the desolvation process and interfacial charge transport play critical roles. However, tuning the solvation structure and designing a kinetically stable electrode–electrolyte interface to achieve high-rate charging and discharging remain a challenge. Here, a lithium nonafluoro-1-butanesulfonate (NFSALi) additive is introduced to optimize stability and the robust solid electrolyte interface film (SEI), realizing a rapid Li⁺ transfer process and the structural integrity of electrode materials. The NFSALi-derived thinner, fluorine-rich, and sulfur-containing SEI in nitrile-assisted carbonate electrolytes effectively suppresses the decomposition of valeronitrile solvent during high-rate cycling and wide-temperature operation (−40–55 °C). More importantly, the graphite‖LiNi_0.5Co_0.2Mn_0.3O₂ pouch cell demonstrates a capacity retention of 66.88% after 200 high-rate cycles with 3C charging and 5C discharging under a high-temperature condition of 55 °C. This work provides significant guidance to develop inorganic-rich interfacial chemistry for lithium-ion batteries under extreme operating conditions.