Biomass‐derived carbons are eco‐friendly and sustainable materials, making them ideal for supercapacitors due to their high surface area, excellent conductivity, cost‐effectiveness, and environmental benefits. This review provides valuable insights into biomass‐derived carbon and modified carbon for supercapacitors, integrating both experimental results and theoretical calculations. This review begins by discussing the origins of biomass‐derived carbon in supercapacitors, including plant‐based, food waste‐derived, animal‐origin, and microorganism‐generated sources. Then, this review presents strategies to improve the performance of biomass‐derived carbon in supercapacitors, including heteroatom doping, surface functionalization, and hybrid composite construction. Furthermore, this review analyzes the functions of biomass‐derived carbon in supercapacitors both in its pure form and as modified materials. The review also explores composites derived from biomass‐based carbon, including carbon/MXenes, carbon/MOFs, carbon/graphene, carbon/conductive polymers, carbon/transition metal oxides, and carbon/hydroxides, providing a thorough investigation. Most importantly, this review offers an innovative summary and analysis of the role of biomass‐derived carbon in supercapacitors through theoretical calculations, concentrating on four key aspects: energy band structure, density of states, electron cloud density, and adsorption energy. Finally, the review concludes the future research directions for biomass carbon‐based supercapacitors, including the discovery of novel biomass materials, tailoring surface functional groups, fabricating high‐performance composite materials, exploring ion transfer mechanisms, and enhancing practical applications. In summary, this review offers a thorough exploration of the sources, functions, and mechanisms of biomass‐derived carbon in supercapacitors, providing valuable insights for future research.

Molybdenum disulfide (MoS₂) after the few-layer (FL) processing draws attention to its attractive characteristics, such as broadening interlayer spacing, increasing active sites, and promoting purity of the metallic phase. Notwithstanding, the poor stability and easy aggregation of FL-MoS₂ limit its potential for development in the field of electrochemistry. Herein, a nanocomposite between FL-MoS₂ and reduced graphene oxide (rGO) is successfully constructed via the one-pot hydrothermal method. Furthermore, the FL-MoS₂@rGO composite with a stable structure is obtained by regulating the amount of rGO. The excellent supercapacitor capacitances of FL-MoS₂ after building heterostructure composites with rGO are displayed, owing to the synergistic effects occurring in heterostructure. The optimal sample of FL-MoS₂@rGO-2 possesses a specific capacitance of 346.1 F g⁻¹ at 1 A g⁻¹ and a rate ability of 57.2%. Moreover, the capacitance of FL-MoS₂@rGO-2 remains 99.1% after 10,000 cyclic charges and discharges. More importantly, the theoretical calculations confirm the source of extra specific capacitance and raise conductivity in FL-MoS₂@rGO. Also, a FL-MoS₂@rGO-2//AC flexible asymmetric supercapacitor device is successfully fabricated, which presents the superior energy density and power density of 84.31 µWh cm⁻² at 700 µW cm⁻², and 51.42 µWh cm⁻² at 3500 µW cm⁻². This work verifies the potential of the heterostructure composite constructed by FL-MoS₂ in energy storage of electrochemical application.

2D nickel phthalocyanine based MOFs (NiPc-MOFs) with excellent conductivity were synthesized through a solvothermal approach.