A Photo-rechargeable Supercapacitor using CsPbBr₃-Activated Carbon Composite

The need for renewable and sustainable energy resources is increasing exponentially. Due to their high specific power, capacitance, and cyclic stability Supercapacitors (SC) emerge a promising alternative for renewable energy storage device and have drawn tremendous attention over the past decade. Hybrid halide perovskite materials, exhibiting mixed electronic-ionic conductivity and outstanding optical properties, hold great promise as potential candidates for advancing this field. In the current study, CsPbBr₃ nanoparticles were synthesized using the hot injection method under a nitrogen gas environment, and their potential for Photo-rechargeable Supercapacitor applications was explored. To enhance the energy and power density of the CsPbBr₃ supercapacitors, composites of CsPbBr₃ and Activated carbon (AC) were fabricated. The AC was prepared through the solvothermal method, followed by activation using KOH at 750 ºC in an argon atmosphere. The CsPbBr₃-AC composites were synthesized by introducing the desired amount of AC (powder) into a three-neck flask containing all the necessary precursors, using the similar reaction conditions used for the synthesis of pristine CsPbBr₃. Detailed structural and spectroscopic characterizations were performed, confirming the formation of CsPbBr₃-AC composites. Supercapacitors were realized using CsPbBr₃-AC composites as the working electrode, Platinum as the counter electrode, and Ag/AgCl as the reference electrode. Electrochemical measurements were carried out using cyclic voltammetry (CV) and galvanostatic charging/discharging (GCD) under both dark and illuminated conditions. These devices exhibited high capacitance and excellent capacitive retention, demonstrating their significance in Photo-rechargeable Supercapacitor applications.