Rice Straw-Derived Biochar Electrode for Sustainable Energy Storage Applications

In the search for environmentally acceptable and sustainable energy storage solutions, biomass-derived biochar materials are becoming popular in supercapacitor applications. Rice straw is regularly disposed of as agricultural waste, but it is an intriguing biomass precursor for synthesizing activated biochar suitable for supercapacitor electrodes. This study exhibited the utilization of activated biochar synthesized from rice straw through pyrolysis and potassium hydroxide (KOH) activation for supercapacitor applications. Structural examination, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen (N 2 ) adsorption and desorption, showed the activated rice straw-derived biochar‘s distinct crystal structure, morphological structure, pore structure, and surface area. Rice straw-derived biochar revealed an amorphous structure, nanosheet-like or multilayered morphology, and hierarchical pore structure. Electrochemical characterization showed that the activated rice straw-derived biochar has high specific capacitances of 116.48 F/g at 1 A/g and 84.58 F/g at 5 A/g, respectively. The amorphous character, hierarchical pore structure, and nanosheet-like morphology of the rice straw-derived biochar provided favorable properties for effective ion transfer for high electrochemical performance. These findings exhibited the prospects of rice straw as a sustainable and economical biomass precursor to produce excellent electrode material in supercapacitor applications.