Improvement of Lithium-Metal Electrode All-Solid-State Batteries Performance by Shot Peening and Magnetron Sputtering

To enable fast charging in lithium-metal anode all-solid-state batteries, suppressing lithium dendrite formation at the solid electrolyte (SE) interface is critical. Increasing fracture toughness via shot peening (SP) and improving interfacial contact with Au sputtering can inhibit dendrite growth. However, conventional sputtering may reduce toughness due to localized thermal damage. This study investigated magnetron sputtering as a low-damage, plasma-based Au deposition method. SEs with and without SP were fabricated and coated via normal and magnetron sputtering. Critical current density (CCD) and fracture toughness were evaluated. Without SP, CCD improvement was limited regardless of sputtering method due to poor bonding. With SP, CCD was significantly enhanced, and magnetron sputtering yielded higher CCD than conventional sputtering. Fracture toughness tests confirmed that thermal damage from normal sputtering reduced strength, while magnetron sputtering preserved it. These findings demonstrate that combining SP with magnetron sputtering improves SE interfacial properties, enhancing fast-charging capability and cycling stability.