Seed-Derived Activated Carbons for Sustainable Supercapacitors: Structure-Performance Relationships and Emerging Opportunities

The search for sustainable and low-cost electrode materials has accelerated interest in biomass-derived activated carbons for electrochemical supercapacitors.Seeds and seed-processing residues form a particularly promising precursor class because they combine renewable carbon, naturally evolved microstructures and, in many cases, protein-or oxygen-rich chemistry that can influence heteroatom content after carbonisation.This mini-review critically examines seed-derived activated carbons with emphasis on synthesis, activation chemistry, pore development, surface functionality and the relationships between material structure and electrochemical response.Recent examples from Lapsi, jackfruit, lotus, Eucalyptus, date, Terminalia chebula, peach, Zanthoxylum armatum, Chaenomeles cathayensis, mango and Albizia lebbeck seeds show that well-engineered carbons can deliver gravimetric capacitances above 300 𝐹𝑔 !" under laboratory three-electrode conditions, together with strong rate capability and long cycling life.The literature also shows that Brunauer-Emmett-Teller surface area alone is not a sufficient predictor of performance: accessible microporosity, mesoporous transport pathways, pore-size/electrolyte matching, electrical conductivity and surface functional groups act jointly.Particular attention is given to Mucuna urens(bull-eye), whose high carbohydrate and protein content provides a plausible carbon and heteroatom-rich precursor.Current searches reveal very limited peer-reviewed electrochemical literature on M. urens-derived supercapacitor carbons, although recent work has begun to examine its conversion to high-surface-area activated carbon.The review therefore identifies M. urens as an emerging research opportunity and proposes a precursor-toperformance framework for its systematic study.Key needs for the field include greener activation, standardised electrochemical reporting, realistic mass loading, two-electrode device validation, reproducibility, life-cycle assessment and scale-up.