Stabilization the Electrode/Electrolyte Interphase by Reconstructing the Solvation Structure of Eutectic‐Based Polymer Electrolyte
Man Guo, Shilun Gao, Yingli Wang, Kai Liu, Jinshi Zhao, Zixuan Zhang, Yiheng Li, Chunliang Li, Lianqi Zhang
Abstract
Abstract The development of Quasi solid polymer electrolyte (QSPE) is recognized as a promising approach to achieving lithium (Li) batteries simultaneously with high energy‐density and high safety. However, the electrolytes capable of forming a stable solid electrolyte interphase/cathode electrolyte interphase (SEI/CEI) layer remain a major challenge. Herein, a novel eutectic‐based QSPE consisting of succinonitrile, Li bis(trifluoromethanesulfonyl)imide, and a rationally designed polymer network is developed. By adjusting the eutectic components in QSPEs, the Li + solvation structures can be well reconstructed, which induces the formation of an inorganic‐rich SEI/CEI layer simultaneously. As a result, the assembled Li|QSPE‐3|LiFePO 4 (LFP) cell exhibits a high‐capacity retention of 99% over 700 cycles at 0.5C, and a cell with a high mass loading LFP cathode (≈3.53 mAh cm −2 ) can stably cycle for 150 cycles at 25 °C (capacity retention 88.3%). It is found that the restricted solvation structure can induce the formation of LiF and Li 3 N‐rich SEI/CEI on the electrode surface, thus inhibiting Li dendrite growth. This study provides a new strategy for the design of QSPEs with a stabilized electrode/electrolyte interface protection layer for Li metal batteries.