Cross‐Linked Polyamide‐Integrated Argyrodite Li 6 PS 5 Cl for All‐Solid‐State Lithium Metal Batteries

Lithium dendrite growth has become a significant barrier to realizing high-performance all-solid-state lithium metal batteries. Herein, an effective approach is presented to address this challenge through interphase engineering by using a cross-linked polyamide (negative electrostatic potential) that is chemically anchored to the surface of Li₆PS₅Cl (positive electrostatic potential). This method improves contact between electrolyte particles and strategically modifies the local electronic structure at the grain boundary. This innovation effectively suppresses lithium dendrite formation and enhances the overall interface stability. As a result, the critical current density of the Li₆PS₅Cl sulfide electrolyte is dramatically boosted from 0.4 to 1.6 mA cm^-2, representing a remarkable fourfold improvement. Moreover, Li-Li symmetric batteries demonstrate exceptional stability, enduring over 10,000 h of consistent Li⁺ deposition/stripping at a high areal capacity of 3 mAh cm^-2. Impressively Li-LiNi_0.89Mn_0.055Co_0.055O₂ full cells exhibited outstanding cycle stability and rate performance, maintaining over 80% capacity retention after 750 cycles at a demanding 1C rate. Pouch cells produced using dry-process electrodes demonstrate strong potential for commercialization. The interphase engineering strategy offers a promising solution to the persistent challenge of dendrite growth, enabling the full realization of sulfide electrolytes' capabilities in next-generation battery technologies.