Solvation-mediated division of labor decouples crosstalk in high-voltage lithium-metal batteries

The practical deployment of high-voltage lithium-metal batteries (LMBs) is restricted by the coupled degradation mechanisms between the anode and cathode. Here, we demonstrate a solvation-mediated division-of-labor strategy through the synergistic pairing of fluoroethylene carbonate (FEC) and lithium difluorophosphate (LiPO₂F₂) that effectively decouples the crosstalk in high-voltage LMBs. By reconfiguring the lithium-ion solvation environment into an anion-enriched regime, the electrolyte promotes the preferential reduction of FEC on the anode and the simultaneous oxidation of LiPO₂F₂ on the cathode. This site-selective interphase engineering suppresses deleterious electrode crosstalk, enabling Li||LiNi_0.6Mn_0.4O₂ cells to retain >80 % capacity for 300 cycles at 1 C and 4.5 V, markedly exceeding the sub-60-cycle stability of baseline cells. This work presents the solvation-mediated division of labor as a generalizable strategy to decouple interfacial crosstalk, offering an actionable framework for high-voltage electrolyte design.