Etching and surface self-assembly of Ni-MOF/MXene hybrids for excellent flexible Pseudocapacitance

In order to meet the demand for portable and wearable electronic devices in contemporary society, there has been the focus on flexible supercapacitors (FSSCs). In this study, MXene and Ni-MOF were self-assembled to create MXene-NPO flexible electrodes through the process of phosphorylation achieved through in situ etching. The composite electrodes exhibited excellent specific capacitance of 1406 F g⁻¹ (1 A g⁻¹), with the capacitance retention of 94.7% after 20,000 cycles. Furthermore, the electrochemical performance of the assembled MXene-NPO//AC flexible device (with energy density and power density of 118 Wh kg⁻¹ and 799.7 W kg⁻¹) was found to remain stable under different bending angles. The shape of the CV curve was not significantly distorted. The capacitance retention of the flexible device remained at 95.1% after 1000 charge/discharge cycles when folded at 90°. This work offers insights into the development of future flexible energy storage devices.