In situ growth of oxometallate-based coordination polymer decorated Ti₃C₂T_x MXene with enhanced water-assisted proton channels for flexible all-solid-state supercapacitor

As promising electrode material contender for supercapacitors, MXene has high conductivity, abundant surface functional groups, and large surface area. However, the self-restacking of MXene leads to poor ion-accessible surface area and restricted ion transport routes. Water-assisted proton channels contained by Polyoxometallate-based coordination polymer (POMCP) can improve the efficiency of ion transport between MXene layers, which is conducive to enhancing the storage capacity and rate performance. Herein, [PW₁₂O₄₀]@[Cu₆O(TZI)₃(H₂O)₆]₄·OH·31H₂O (CuCP) decorated Ti₃C₂T_x (CuCP/MX) was synthesized by in-situ hydrothermal method. Attribute to the extended interlayer space and enhanced ion transport efficiency, CuCP/MX exhibits excellent electrochemical energy storage properties. It is worth revealing that when assembling into an all-solid-state supercapacitor device (SC), excellent specific capacitance (380 mF/cm²) and energy density (68.4 μWh/cm² at 540 μW/cm²) were exhibited. CuCP/MX is a considerable electrode material for supercapacitors for flexible electronic devices.