Pseudocapacitance Through MXene/Solid Electrolyte Interface

All-solid-state energy storage devices with non-flammable inorganic solid electrolytes are a key technology for addressing the safety issues of lithium-ion batteries with flammable organic liquid electrolytes. However, conventional electrode materials suffer from substantial volume change during lithium-ion (de)intercalation, leading to the failure of the interface between the electrode materials and solid electrolytes and then severe performance degradation. In this work, we report pseudocapacitance through a strain-free interface between a solid electrolyte and a transition-metal carbide nanosheet (MXene), where MXene electrodes show negligible structural changes during lithium-ion (de)intercalation. As a proof of concept, we demonstrate the stable operation of an all-solid-state hybrid capacitor (Ti3C2Tx|Li3PS4 glass|LiCoO2).