This study presents a novel, eco-friendly method to fabricate hierarchical porous lignin/cellulose-based carbon materials (LCs) for energy storage applications. The method uses cellulose nanofibrils as a scaffold and template, which helps in the formation of a hierarchical porous structure. By varying the cellulose content, the specific surface area and graphitization degree of the LCs can be controlled. The resulting bio-based carbon material, LC30, has a high specific surface area of 1770 m²/g and exhibits a high specific capacitance of 216.2 F/g at a current density of 0.5 A/g. The supercapacitor based on LC30 demonstrates an outstanding energy density of 12.3 Wh/kg at a power density of 50 W/kg. The material's sustainable raw materials, simple and harmless preparation process, and excellent electrochemical performance make it a promising candidate for supercapacitor electrodes. The study highlights the challenges in using lignin as a carbon precursor due to its tendency to agglomerate and the use of corrosive and non-recyclable reagents in traditional pyrolysis methods. The proposed method overcomes these issues by utilizing cellulose nanofibrils to create a hierarchical porous structure, which enhances the electrochemical performance of the resulting carbon material. The preparation process does not involve activation or acid treatment, and no expensive or harmful chemicals are used, making it a simple, low-cost, and eco-friendly method for producing porous biomass-based carbon materials. This approach offers a promising solution for the development of advanced energy storage devices.This study presents a novel, eco-friendly method to fabricate hierarchical porous lignin/cellulose-based carbon materials (LCs) for energy storage applications. The method uses cellulose nanofibrils as a scaffold and template, which helps in the formation of a hierarchical porous structure. By varying the cellulose content, the specific surface area and graphitization degree of the LCs can be controlled. The resulting bio-based carbon material, LC30, has a high specific surface area of 1770 m²/g and exhibits a high specific capacitance of 216.2 F/g at a current density of 0.5 A/g. The supercapacitor based on LC30 demonstrates an outstanding energy density of 12.3 Wh/kg at a power density of 50 W/kg. The material's sustainable raw materials, simple and harmless preparation process, and excellent electrochemical performance make it a promising candidate for supercapacitor electrodes. The study highlights the challenges in using lignin as a carbon precursor due to its tendency to agglomerate and the use of corrosive and non-recyclable reagents in traditional pyrolysis methods. The proposed method overcomes these issues by utilizing cellulose nanofibrils to create a hierarchical porous structure, which enhances the electrochemical performance of the resulting carbon material. The preparation process does not involve activation or acid treatment, and no expensive or harmful chemicals are used, making it a simple, low-cost, and eco-friendly method for producing porous biomass-based carbon materials. This approach offers a promising solution for the development of advanced energy storage devices.