Delocalized electrolyte design enables 600 Wh kg lithium metal pouch cells.

The development of high-energy lithium metal batteries (LMBs) is essential for advances in next-generation energy storage and electric vehicle technologies. Nevertheless, the practical applications of LMBs are constrained by current electrolyte designs that inherently rely on dominant solvation structures, preventing transformative progress in performance optimization. Here, we address this limitation through a delocalized electrolyte design that fosters a more disordered solvation microenvironment, thereby mitigating dynamic barriers and stabilizing interphases. The resulting delocalized electrolyte delivers notable energy densities of 604.2 Wh kg in a 5.5-Ah LiNiCoMnO (Ni90)||Li pouch cell with a lean electrolyte design (1.0 g Ah) and 618.2 Wh kg in a 5.2-Ah Ni90||Li pouch cell with an ultralean electrolyte design (0.9 g Ah), maintaining significant cycle stability over 100 and 90 cycles, respectively. In addition, the 70-104 V NCM811||Li battery pack (3,904 Wh) exhibits a high energy density of 480.9 Wh kg and stable cycling over 25 cycles. These results demonstrate the need to circumvent inherent reliance on dominant solvation structures in electrolyte design to achieve the high-energy Battery600 and scalable Pack480 targets.