Interfacial Engineering of Solvent‐Free Cathodes with High Loading for High‐Energy‐Density Lithium Metal Batteries

Abstract Solvent−free dry−film technology has garnered significant attention owing to its capability to enable high mass loading of the electrodes and circumvent pollution and waste resulting from toxic organic solvents. Nevertheless, thick electrodes inherently pose large ion diffusion resistance, thereby hindering the efficient utilization of the active materials. In this study, Li 7 La 3 Zr 2 O 12 (LLZO) solid‐state electrolyte particles are incorporated onto the surface of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathodes, which lowers the activation energy ( E a ) for interfacial lithium ions (Li + ) transfer and enhances the diffusion kinetics of Li + . As a result, ultrahigh loading (54 mg cm −2 ) cathodes are fabricated, demonstrating a remarkable areal capacity of up to 10.4 mAh cm −2 and a high energy density of 473 Wh kg −1 when applied in a lithium metal battery. The interphase properties analysis indicates that the application of LLZO at the solid/liquid interface facilitates the formation of a comprehensive and stable electrode interface layer to fully cover the surface of cathode material, which effectively suppresses side reactions and prevents the particle crack and structure degradation over cycling. These results suggest that the incorporation of LLZO as an additive in dry‐film cathodes holds great promise for sustainable and cost−effective manufacturing of high‐energy‐density lithium metal batteries.