Supercapacitor Electrode Materials from Carbon Resources

Supercapacitors bridge the gap between conventional capacitors and batteries by delivering high power density, rapid charge–discharge rates and extended cycle life. Central to their performance are electrode materials derived from carbon resources, which offer tunable porosity, surface chemistry and conductivity. Activated carbons, biochar and coal‐derived carbons provide high specific surface areas and adjustable pore architectures, facilitating the accumulation of electrolyte ions at the electrode–electrolyte interface. Graphene and its derivatives introduce two‐dimensional conductivity and mechanical flexibility, while carbon nanotubes supply one‐dimensional electron pathways. Recent advances spotlight heteroatom doping—most commonly with nitrogen, phosphorus or oxygen—to introduce pseudocapacitive contributions and improve wettability. Three‐dimensional hierarchical structures further optimise ion transport and electron percolation by integrating macro-, meso- and micropores in a single network. Together, these developments have elevated specific capacitances above 300 F g⁻¹, energy densities exceeding 20 Wh kg⁻¹ and cycle stabilities beyond 50 000 cycles, pointing to viable applications in electric vehicles, grid stabilisation and portable electronics. The sustainable sourcing of precursors—from agricultural residues to low-rank coals—aligns energy storage with circular-economy principles and decarbonisation targets.

Research from Nature Portfolio

Recent studies have demonstrated the fabrication of three-dimensional porous carbon aerogels from coal oxide via freeze-drying and calcination. The resulting aerogels exhibit hierarchical porosity, surface areas above 1 300 m² g⁻¹ and a specific capacitance near 260 F g⁻¹, with over 100 % capacitance retention after 50 000 cycles. In a complementary approach, hybrid electrodes integrating carbon nanotubes with nitrogen-doped activated carbon achieved free, in-situ growth of multi-walled and bamboo-like nanotubes on biomass-derived substrates. This design provides intertwined electron pathways and abundant pyridinic-N sites, leading to enhanced rate capability and stability under high current densities.

Supercapacitor Electrode Materials from Carbon Resources publication trend

The graph below shows the total number of articles in supercapacitor electrode materials from carbon resources across all publications each year (not limited to Nature Index journals).

Technical terms

Specific capacitance: The amount of electric charge stored per unit mass of electrode material, expressed in farads per gram (F g⁻¹).

Energy density: The energy stored per unit mass or volume of the device, typically expressed in watt-hours per kilogram (Wh kg⁻¹).

Power density: The rate at which energy can be delivered per unit mass, usually measured in watts per kilogram (W kg⁻¹).

Activated carbon: Carbon material treated to develop high surface area and tailored pore structure for efficient ion adsorption.

Biochar: Carbonaceous solid produced from biomass pyrolysis, used as a low-cost, sustainable precursor for porous electrodes.

Graphene oxide: Oxidised form of graphene containing oxygen functional groups, offering high surface area and tunable chemistry.

Heteroatom doping: Introduction of non-carbon elements (such as N, P or O) into the carbon lattice to add pseudocapacitance and improve conductivity.

3D hierarchical porosity: A multiscale pore network combining macro-, meso- and micropores to optimise ion transport, storage and electron pathways.

References

1. Coal-based 3D hierarchical porous carbon aerogels for high performance and super-long life supercapacitors. Scientific Reports (2020).
2. Porous Doped Carbons from Anthracite for High-Performance Supercapacitors. Applied Sciences (2020).
3. Reduced Graphene Oxide Derived from Low-Grade Coal for High-Performance Flexible Supercapacitors with Ultrahigh Cyclability. Nanomaterials (2022).
4. 3D hierarchical porous hybrid nanostructure of carbon nanotubes and N-doped activated carbon. Scientific Reports (2020).