High-performance aqueous zinc-ion hybrid micro-supercapacitors enabled by surface-modified Ti3C2 MXene anode and polar organic molecule intercalated AlxV2O5 cathode

The Ti₃C₂T_x MXene has emerged as an ideal anode material for aqueous Zn-ion hybrid micro-supercapacitors (AZHMSCs) due to its high conductivity, excellent stretchability, and modifiable surface functional groups. However, the interlayer stacking effect and inert –F functional groups limit its ion transport and charge storage capabilities. In this study, a deep alkali treatment strategy is proposed to convert Ti₃C₂T_x MXene nanosheets into m-Ti₃C₂ MXene nanofibers with oxygen-rich surface terminal functional groups. This structure not only alleviates interlayer stacking but also shows enhanced Zn²⁺ adsorption affinity via oxygen groups, resulting in a specific capacitance of 1231.8 mF cm⁻² at 1 mA cm⁻². Meanwhile, the cathode employs polar organic molecules, specifically NMP, intercalated into Al_xV₂O₅. The strong electrostatic interaction between NMP and pre-embedded aluminum ions improves material structural stability (96.05 % capacity retention after 5000 cycles) and enhances specific capacity (327.78 μAh cm⁻² at 0.5 mA cm⁻²). AZHMSCs assembled with these modified electrodes exhibit excellent electrochemical performance: an energy density of 105.15 μWh cm⁻² at a power density of 0.48 mW cm⁻², capacity retention rate of 89.29 % after 3000 cycles, and good bending stability. This study offers a novel approach for electrode design and the construction of high-performance micro-energy storage devices.