<p>The growing demand for sustainable, high-performance energy storage has heightened interest in biomass-derived activated carbons (BDACs) as electrode materials for supercapacitors. This review summarizes diverse biomass precursors and evaluates major synthesis routes, including physical/chemical activation, hydrothermal, microwave-assisted, and template methods, and highlights how processing controls pore structure, surface chemistry, and graphitization. Key structural features and their links to electrochemical performance are compared, including surface area, porosity, functional groups, capacitance, energy/power density, and cycling stability. The review also outlines challenges such as precursor variability and scalability, as well as future opportunities, including advanced activation, heteroatom doping, composites, and green synthesis.</p> Graphical abstract <p></p>