Rational Lithium Salt Selection Principle for Designing High-Entropy Electrolytes toward High-Performance Lithium Metal Batteries

High-entropy electrolytes (HEEs), typically formed by mixing over four types of salts or solvents, have attracted considerable attention due to their diverse solvation microenvironments that improve the cyclability of high-energy lithium metal batteries (LMBs). However, knowledge of salt screening is limited beyond merely increasing the number of salts in electrolyte formulations to increase the solvation configurations. Here, we present a new design principle for constructing an HEE (LTFA-LDFN) by selecting lithium salts containing amphiphilic anions with asymmetric Li⁺-chelating capabilities (i.e., trifluoroacetate) together with anions featuring multiple Li⁺ coordination sites (i.e., difluorophosphate and nitrate). The amphiphilic trifluoroacetate, containing both a high donor number and a noncoordinating moiety, competitively coordinates with Li⁺ from poorly soluble lithium difluorophosphate and lithium nitrate, disrupting their inherent three-dimensional cation-anion network and enhancing solubility in carbonate solvents. Molecular dynamics calculations further reveal that LTFA-LDFN supports 64 distinct Li⁺ solvation configurations within the top 80% of all configurations, with 71.2% being anion-dominated─unlike the fully solvent-coordinated configurations in conventional carbonate electrolytes. As quantified using the Boltzmann equation, LTFA-LDFN reached a solvation configurational entropy of up to 6.5 × 10^-23 J K^-1. Such high-entropy solvation characteristics enhance the compatibility of Li||NCM811 cells with carbonate electrolytes, achieving stable cycling for over 1000 cycles with 80.2% capacity retention at room temperature under 1 C and more than 300 cycles with over 80% retention at 60 °C under 2 C. Our findings underscore the significant potential of delicate anion engineering to achieve high-entropy-like configuration diversity, paving a new way for advancements in LMBs and beyond.