Authors: Mingao Chen, Shu Zhang, Xuesong Ge, Zhilin Yang, Gaohao Sun, Aobing Du, Jingwen Zhao, Shengting Li, Ju Xiao, Hongliang Li, Guanglei Cui
Published: 2025-03-17
Source: Full article
AbstractThe electrolyte and its interfacial chemistry are crucial for the development of high‐temperature magnesium metal batteries. Here, a robust in situ cross‐linked gel polymer electrolyte (MgB@CGPE) and its derived Mg3N2‐rich (Mg3N2 and related Mg─N─H complexes) interphase are obtained by a multifunctional diamine additive. The Mg3N2‐rich interphase exhibits low magnesium ion migration activation energy and can effectively inhibit the continuous decomposition of electrolyte at the interface under elevated temperatures. Moreover, the MgB@CGPE can enable reversible magnesium deposition and dissolution over a wide temperature range of 30–180 °C. The assembled Mo6S8//MgB@CGPE//Mg cells demonstrate stable cycling over 200 cycles at 150 °C with 80% capacity retention. Additionally, these cells also address crucial mechanical and thermal safety concerns, indicating their potential for use under extreme conditions. This work presents a universal and practical strategy for designing polymer electrolytes that operate at elevated temperatures.