Temperature-adaptive EC-free electrolyte for practical high-safety and high-voltage lithium-ion batteries

Next-generation lithium-ion batteries require electrolytes compatible with high-safety and high-voltage operation. However, the commercial ethylene carbonate (EC)-based electrolyte remains constrained by serious parasitic reaction and poor oxidation stability. Although EC-free electrolyte shows great potential, it cannot completely solve the “cross-talk” reaction issue under thermal abuse. Herein, we propose a temperature-adaptive interface regulation strategy via acrylamide-based EC-free electrolyte. During normal cycling, the designed electrolyte can form robust inorganic-rich interface to maintain efficient operation. When thermal abuse occurs (>80 °C), a thermally stable interface via adaptive crosslinking solidify can effectively suppressing “cross-talk” reaction. Under both conditions before and after thermal abuse, practical Ah-level LiNi₀.₈Co₀.₁Mn₀.₁O₂|Graphite/SiO pouch cells with the designed electrolyte achieve capacity retention rate exceeding 80% after 400 cycles under 4.5 V. Moreover, thermal runaway (TR) triggering temperature of pouch cell can be effectively improved from 188.3 °C to 247.1 °C, and the self-heat generation time before TR can be significantly extended by more than double. This work provides valuable insights for the academic and industrial sectors in developing the next generation of high-performance batteries.