High-performance all-solid-state flexible carbon/TiO2 micro-supercapacitors with photo-rechargeable capability

Abstract

A high-performance all-solid-state flexible interdigitated carbon/TiO₂ micro-supercapacitor (MSC) with photo-rechargeable capability was prepared by combining a laser direct writing technique with electrophoretic deposition of TiO₂ nanoparticles. The carbon/TiO₂ MSC shows the same excellent capacitive performance as the pure carbon MSC, such as high specific capacitance up to 27.3 mF cm⁻² at a typical current density of 0.05 mA cm⁻², excellent cycling stability, long-time stability, and mechanical stability. Under UV light irradiation, the carbon/TiO₂ MSC can be charged to above 100 mV, and still maintain 60 mV after 10 photo-charging cycles, demonstrating its photo-rechargeable capability. What's more, after 10 photo-charging cycles, the carbon/TiO₂ MSC shows no capacitive performance degradation, which can be attributed to the high structural stability of the carbon/TiO₂ MSC under UV light irradiation.