All-Ti₃C₂T_xMXene Based Flexible On-chip Microsupercapacitor Array

Flexible on-chip microsupercapacitors(MSCs) are highly desired for integrated wearable or portable electronics due to their advantages of small size, high power density, easy integration, long lifespan, high security, and flexibility. The output voltage of MSCs can be improved by designing MSC arrays, which could further expand their application fields. In this work, we proposed a facile laser direct cutting method to prepare an on-chip flexible MSC array using Ti₃C₂T_xMXene as both current collector and electrode materials. The designed MSC in PVA/H₂SO₄ all-solid-state gel electrolyte exhibits a large volume/areal capacitance of 770.72 F/cm³(46.24 mF/cm²) at a scan rate of 20 mV/s, a high energy density of 68.51 mW·h/cm³ at a power density of 6.16 W/cm³, excellent cycling stability with capacitance retention of 98.50% after 10000 charge/discharge cycles. The MSC also shows superior flexibility and stability even after repetition of charge/discharge cycles under the convex and concave bending states. In addition, the assembled MSC array(4 in series) provides a high voltage of 3.2 V, which could easily power a purple light-emitting diode more than 10 min, demonstrating its potential application in integrated portable/wearable devices.