Highly Efficient Solid-State Supercapacitor with Porous Electrode Material

Herein, a flexible solid-state supercapacitor (FSC) with a high level of efficiency with porous electrode material derived from mahogany fruit shell waste (MS) is reported. The mahogany-fruit-shell-derived activated carbon (MSAC) is produced using chemical activation, followed by carbonization at various carbonization temperatures (500, 600, 700, and 800 & DEG;C) and activation ratios (MS:KOH = 1:1, 1:2, and 1:3). The high-performance MSAC has an intricate porous structure with a surface area of 1072 m(2) g(-1). It exhibits a specific capacitance of 267 F g(-1) and outstanding capacitance retention of 97% even after 10 000 charge-discharge cycles. The MSAC-based FSCs are constructed utilizing a gel polymer electrolyte (poly(vinyl alcohol)|sodium sulfate), and their performance is compared with that of conventional supercapacitor systems. The MSAC-based FSC shows a very high specific capacitance of 121 F g(-1), which is remarkably superior to previously reported FSCs. Additionally, as-prepared FSC exhibits wide electrochemical window, flexibility, ease of handling, safety, along with a high capacitance retention of 78% after 2000 charging-discharging cycles. These exceptional capacitive properties, such as its extended cycle life and excellent rate capability, suggest that it is a potential alternative for a range of next-generation energy storage applications.