Coordination Topology Design in Anion‐Rich Solvated Electrolytes for High‐Voltage Lithium Metal Batteries

Abstract Electrolytes with anion‐rich solvated structures are promising for high‐voltage lithium metal batteries (LMBs) due to their good interfacial compatibility. Nevertheless, limited Li‐ion transport of these electrolytes has hindered their high‐rate application. Here we demonstrate that Li‐ion transport in anion‐rich solvated electrolytes could be facilitated by designing the coordination topology of anions in the solvation structure. Results show that, for a binary‐anion electrolyte, equal‐molar anions show the most expanded energy level distribution of solvation structures, thus reducing the Li‐ion transport energy barrier, and resulting in a Li‐ion conductivity even higher than that of the commercial carbonate electrolyte at a temperature range from −40 °C to 60 °C. More importantly, we identify a universal principle governing the Li‐ion transport enhancement driven by anion configurations: only the combination of anions with multi‐coordination sites shows facilitation in Li‐ion transport, while the combination of centrosymmetric anions with the mono‐coordination site harms it. The diversified anion‐rich solvated structures also form stable interphases on the electrodes, enabling long‐term cycling of 4.5 V LMBs at a high current density of 3.78 mA cm −2 . Overall, our findings shine new light on developing practical electrolytes for energy‐dense LMBs.