Capacitance-Enhanced Microsupercapacitors with a Redox Electrolyte Additive for an All-MXene-Based Flexible Self-Powered Integrated Photodetecting System

Although much effort has been devoted to improving theelectrochemicalperformances of MXene-based metal-ion hybrid microsupercapacitors(MSCs), few works focus on the electrolyte. Therefore, we proposedK(4)Fe(CN)(6) as the redox additive to alter theproperties of the Zn(CF3SO3)(2) gelelectrolyte used in Ti3C2T x -DMAC MXene-based interdigital Zn-ion hybrid MSCs. The electrontransfers between Fe2+ and Fe3+ in K4Fe(CN)(6) can provide an additional Faraday pseudocapacitance,resulting in the high volumetric capacitance (2107.4 F cm(-3) at a scan rate of 5 mV s(-1)) of the MSCs and excellentcycling stability with 88.64% of the original capacity retention after5000 cycles of charge and discharge. Such a superior performance ofMSCs can provide a potential of 0.9 V for the integrated Ti3C2T x -DCTES MXene-based photodetector,which endows the detector with a stable response to 808 nm wavelengthlaser, providing a strong support for flexible self-powered integratedsensing systems.