The accelerated energy consumption and its impacts on our lives have led to the development of various efficient and sustainable energy storage devices. The bioderived materials are viable, cost-effective, and sustainable and hence a versatile material in fabricating energy storage devices, especially for supercapacitors. Herein a porous 3D honeycomb-like carbon is derived from the biomaterial coconut rachis which was used for the fabrication of electrodes for a supercapacitor with chitosan as the binder. A high surface area of 1,630.67 m2/g and a pore size distribution ranging from 1.5 nm to 5 nm were observed, confirming the material’s suitability for energy storage applications. Electrochemical tests revealed a maximum specific capacitance of 199 F/g at a current density of 0.62 A/g, with stable cycle life retention of 94–95% after 10,000 cycles. The optimized mass loading of the electrodes demonstrated superior performance, highlighting the potential of coconut rachis-derived carbon as an environmentally friendly and cost-effective alternative for supercapacitor applications. These findings suggest that the developed material holds promise for future energy storage systems that prioritize both performance and sustainability.