Selectively fluorinated aromatic lithium salts regulate the solvation structure and interfacial chemistry for all-solid-state batteries

作者：Shuaishuai Yan, Hao Liu, Yang Lu, Qingqing Feng, Hang-Yu Zhou, Yuhao Wu, Wenhui Hou, Yingchun Xia, Haiyu Zhou, Pan Zhou, Xuan Song, Yuqing Ou, Kai Liu · 发表于：Science Advances · 年份：2025 · DOI：10.1126/sciadv.ads4014 · 被引用次数：69 · 研究领域：Medicine

Solid polymer electrolytes suffer from the polymer-dominated Li+ solvation structure, causing unstable electrolyte/electrode interphases and deteriorated battery performance. Here, we design a class of selectively fluorinated aromatic lithium salts (SFALS) as single conducting lithium salts to regulate the solvation structure and interfacial chemistry for all-solid-state lithium metal batteries. By tuning the anionic structure, the Li+-polyether coupling is weakened, and the Li+-anion coordination is enhanced. The hydrogen bonding between the SFALS and polymer matrix induces a special “triad”-type solvation structure, which improves the electrolyte homogeneity and mechanical strength, and promotes the formation of an ultrathin and robust Li2O-rich solid electrolyte interphase. Therefore, the stable cycling of more than 1650 cycles (Coulombic efficiency, 99.8%) for LiFePO4/Li half cells and 580 cycles (97.4% capacity retention) for full cells is achieved. This molecular engineering strategy could inspire further advancements of functional lithium salts for practical application of all-solid-state lithium metal batteries.