MXene Electrodes for All Strain-Free Solid-State Batteries.

All-solid-state batteries with nonflammable inorganic solid electrolytes are the key to addressing the safety issues of lithium-ion batteries with flammable organic liquid electrolytes. However, conventional electrode materials suffer from substantial volume changes during Li (de)intercalation, leading to mechanical failure of interfaces between electrode materials and solid electrolytes and then severe performance degradation. In this study, we report strain-free charge storage via the interfaces between transition metal carbides (MXenes) and solid electrolytes, where MXene shows negligible structural changes during Li (de)intercalation. scanning electron transmission microscopy with electron energy-loss spectroscopy reveals the pillar effect of trapped Li in the interlayer spaces of MXene to achieve the strain-free features. An all strain-free solid-state battery, which consists of a strain-free TiCT negative electrode and a strain-free disordered rocksalt LiTiVO positive electrode, demonstrates long-term stable operation while preserving the interfacial contact between electrode materials and solid electrolytes.