Preparation of rGO/PEDOT:PSS composite with high photothermal conversion efficiency for light enhanced quasi-solid-state supercapacitor

The suppression of performance degradation at low temperatures and the improvement of capacity are still important issues that need to be solved for many energy storage devices. Here, we prepared reduced graphene oxide/poly(3,4-ethylenedioxythiophene):poly(sodium styrene sulfonate) composite (rGO/PEDOT:PSS) via a facile hydrothermal reaction, and apply it to a symmetric supercapacitor. On the one hand, the optimized composite exhibits improved electrochemical performance, and its specific capacitance is 50 % higher than that of pure rGO; on the other hand, the optimized composite also exhibits excellent photothermal properties, under the NIR light illumination intensity of 1.05 W cm ⁻² (808 nm), it shows a high photothermal conversion efficiency of 62.0 %. Thus, the photothermal effect enhances the performance of the supercapacitor, and under a low illumination intensity of 0.18 W cm ⁻² , its specific capacitance and energy density could be increased to 1.8 and 1.6 times higher than those in the dark condition, respectively. This study provides new design ideas for the development of next-generation flexible and wearable devices and more smart options for the wide application of light energy.