In Situ Gel Polymer Electrolyte with Rapid Li+ Transport Channels and Anchored Anion Sites for High‐Current‐Density Lithium‐Ion Batteries

Abstract In situ formed gel polymer electrolytes (GPEs) have advantages in safety and adaptability to current high‐voltage lithium‐ion batteries (LIBs). However, it is challenging for GPEs to achieve stable cycling at high current densities. A flexible framework is proposed for stable in situ GPE, by introducing ─CF 3 groups to the polymer network to establish rapid Li + transport channels, and incorporating secondary amine N─H groups to anchor anion. The obtained GPE exhibits a high ionic conductivity of 2.6 mS cm −1 and a high Li + transference number of 0.67. The assembled Li||NCM811 cell demonstrates excellent rate performance, with a discharging capacity of 112.3 mAh g⁻¹ at 10C, and capacity retention of 87.6% after 260 cycles at 1C. Furthermore, the assembled graphite||NCM811 cell demonstrates excellent long‐term cycling stability with impressive capacity retention of 73.2% after 300 cycles 3C (1.8 mA cm −2 ). This work presents a promising approach to enhancing the cycling stability of GPEs for high‐voltage LIBs at high current density.