Chelating Solvent Mediated Solvation Structure Enables High‐Rate Operation of Ah‐Level Li‐Ion Batteries in Nonflammable Phosphate Electrolyte
Mengchuang Liu, Wei Liu, Ziqi Zeng, Fenfen Ma, Yuanke Wu, Kuijie Li, Wei Zhong, Xin Chen, Shijie Cheng, Jia Xie
Abstract
Abstract Highly flammable carbonate electrolytes induce significant safety risk for lithium‐ion batteries (LIBs), raising concerns about their suitability for large‐scale applications. In contrast, non‐flammable phosphate electrolytes offer a potential solution, yet the untamed strong interaction of Li + ‐phosphates and inefficient Li + diffusion result in sluggish reaction kinetics, which restricts the operation of Ah‐level LIBs to rates below 0.2C. Herein, a chelating solvent‐mediated ion‐solvent coordinated structure is designed to modulate Li + ‐phosphates interaction. This innovative approach enables a high‐efficiency pseduo‐structrural diffusion, similar to that observed in high concentration electrolytes, while maintaining a standard concentration of 1 mol L −1 and achieving high Li⁺ conductivity. The operating rate of Ah‐level graphite|LiFePO 4 cells is increased from 0.2C to 2C, with 1 Ah and 25 Ah cells retaining 73.9% and 71.0% capacity after 1000 and 600 cycles, respectively. Additionally, the maximum temperature of 25 Ah cells during nail penetration is significantly reduced from 338.9 to 200 °C. This strategy provides promising tuition for developing advanced electrolytes.