Quantifying the Correlation Between Capacity Utilization and Electrolyte Dosage for Ultrahigh‐Energy‐Density 769 Wh Kg −1 Rechargeable Lithium Metal Batteries

ABSTRACT The pursuit of high‐energy‐density lithium metal batteries requires simultaneous optimization of electrode architecture, electrolyte formulation, and interfacial stability. Here, we establish a fundamental parameter g(σ e , D e ) that quantifies the relationship between electrolyte dosage and capacity utilization in ultra‐thick electrodes (>100.0 µm), enabling precise determination of the minimal electrolyte requirement (1.1 g Ah −1 ). Through systematic investigation of electrolyte compatibility with high‐loading cathodes (> 10.0 mAh cm −2 ) at high voltages (4.8 V), we develop an optimized formulation that forms stable interfaces while suppressing parasitic reactions. By integrating these advances—including a lightweight lithium metal anode—we demonstrate a 54.2 Ah pouch cell achieving 769 Wh kg −1 , representing a 150% improvement over conventional lithium‐ion batteries. This work provides both theoretical and practical frameworks for engineering next‐generation batteries through electrolyte minimization and interface stabilization.