Functionalized and Customized Electrolyte Enabling NCM811||Gr Pouch Cells Operation at 150°C

ABSTRACT With the expanding applications of lithium‐ion batteries (LIBs), there is a growing demand for high‐performance LIBs with high‐temperature‐resistant, especially in fields such as military or aerospace exploration. However, traditional electrolytes suffer from poor thermal stability and severe side reactions at temperatures above 60°C, failing to meet the practical use under high‐temperature conditions. Here, we propose a high‐temperature‐resistant electrolyte system, i.e., high‐boiling‐point propylene carbonate, as well as dual‐anion engineering to improve interface stability. The anion‐regulated solvation structures achieve perfect compatibility between propylene carbonate and graphite, while the dual‐anion synergy induces the formation of organic/inorganic gradient interphase dominated by C‐F/LiB x O y species under high temperature. The LiNi 0.8 Co 0.1 Mn 0.1 O 2 || graphite pouch cells demonstrate excellent cycling durability and rate capability under extreme conditions, achieving an outstanding lifespan of over 1000 cycles at 100°C, while retaining 55.7% of their rated capacity under a harsh 100°C and 5 C condition. Remarkably, the cells maintain normal electrochemical functionality even at 150°C, underscoring the robustness of the proposed electrolyte design.