Interface coating via mechano-fusion for improved SiOx anode performance in all-solid-state battery

All-solid-state batteries (ASSBs) have garnered increasing attention owing to their enhanced safety and the ability to deliver high energy density. Among various anode candidates for ASSBs, silicon oxide (SiO x ) is notable due to its mitigated volume change during cycling and improved durability compared to pure silicon. Nonetheless, the electrochemical performance is often hindered by insufficient contact at the interface between active components and sulfide-type solid electrolytes (SEs), largely resulting from void formation during conventional mixing processes. To overcome this limitation, we employed a mechano-fusion (MF) technique to prepare SiO x –SE composite structures. In this approach, ductile Li 6 PS 5 Cl was conformally coated onto the surface of SiO x particles via high-shear mechanical compression in the absence of solvents and binders. This method enhances interfacial adhesion, minimizes void generation, and facilitates continuous ion transport within the electrode. Compared with conventionally ball-milled electrodes, those fabricated using MF exhibited superior capacity retention (27.56 % vs. 58.61 %) and better performance under high-rate conditions, indicating enhanced cycling durability. These findings demonstrate that the MF process offers a robust interfacial engineering strategy for ASSBs and suggests its potential for scalable application in high-performance solid-state anodes. • Mechano-fusion was applied to enhance interface contact in SiO x -based ASSBs. • Dense SE coating on SiO x improved ionic conductivity and reduced polarization. • Coexistence of SE and carbon layers balanced ionic and electronic conduction. • MF process improved long-term cycling and high-rate performance in ASSBs.