摘要
This study introduces a novel composite material, U-NiCo-OH@TTBC, comprised of tamarind seed biochar (TTBC) and nickel-cobalt hydroxide, designed for high-performance supercapacitors. This composite exhibits a unique urchin-like structure with a specific surface area of 610 m 2 g −1 , facilitating efficient electron-ion transport and electrolyte diffusion. U-NiCo-OH@TTBC demonstrates an impressive storage capacity of 759 F g −1 at 1 A g −1 , along with a specific capacitance of 158 F g −1 . The symmetric device built with U-NiCo-OH@TTBC boasts power densities ranging from 787 to 7183 W kg −1 and energy densities between 16 and 54 Wh kg −1 . Most notably, the device exhibits exceptional long-term cyclic stability, retaining 92 % of its performance after 10,000 charge-discharge cycles. This work highlights the potential of agricultural waste as sustainable carbon sources and their compatibility with metal hydroxides to create eco-friendly and durable supercapacitor electrodes.