Electrochemical Performance of Nickel Oxide Supercapacitor Materials

Nickel oxide (NiO) has emerged as a pivotal pseudocapacitive material in supercapacitor technology, combining high theoretical capacitance with robust cycle stability. Advances in nanostructuring—ranging from hollow microspheres to nanosheets, aerogels and core–shell hybrids—have focused on maximising surface area, optimising ion and electron transport pathways and enhancing electrical conductivity through composite formation or metallic decoration. The resulting electrodes consistently deliver specific capacitances in the range of several hundred to over a thousand farads per gram, while retaining over 80 % of performance after thousands of charge–discharge cycles. Practical implementations include asymmetric and symmetric devices offering energy densities approaching those of lead–acid and nickel–metal hydride batteries, and power densities exceeding 1 000 W kg−1. Sustainable synthesis routes and biomass-derived precursors are increasingly adopted to reduce cost and environmental impact, underscoring the global relevance of NiO for grid-level storage, portable electronics and electric vehicles.

Research from Nature Portfolio

Green synthetic approaches have been demonstrated using plant extracts to produce NiO nanoparticles with exemplary electrochemical performance. A one-step aloe vera-mediated route yields crystalline NiO with specific capacitances up to 462 F g⁻¹ in a three-electrode system and 239 F g⁻¹ in a symmetric two-electrode device, alongside energy densities of 47.8 Wh kg⁻¹ and retention of 89 % after 2 000 cycles. Sustainable carbon-matrix composites derived from bitumen and asphaltene fractions afford nanoporous NiO/C materials combining electric double-layer and faradaic storage, achieving 380 F g⁻¹ at 1 A g⁻¹ and showcasing how crude-oil by-products can be valorised into high-performance supercapacitor electrodes.

Electrochemical Performance of Nickel Oxide Supercapacitor Materials publication trend

The graph below shows the total number of articles in electrochemical performance of nickel oxide supercapacitor materials across all publications each year (not limited to Nature Index journals).

Technical terms

Specific capacitance: The capacitance normalised to electrode mass, indicating charge storage capacity in farads per gram (F g⁻¹).

Pseudocapacitance: Faradaic charge storage arising from reversible surface redox reactions, distinct from non-faradaic electric double-layer capacitance.

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

Power density: The rate of energy delivery per unit mass, expressed in watts per kilogram (W kg⁻¹).

Asymmetric supercapacitor: A device pairing two different electrode materials to extend operating voltage and enhance energy density compared with symmetric configurations.

References

1. Multishelled NiO Hollow Microspheres for High-performance Supercapacitors with Ultrahigh Energy Density and Robust Cycle Life. Scientific Reports (2016).
2. Natural resource-derived NiO nanoparticles via aloe vera for high-performance symmetric supercapacitor. Scientific Reports (2024).
3. Bitumen and asphaltene derived nanoporous carbon and nickel oxide/carbon composites for supercapacitor electrodes. Scientific Reports (2022).
4. NiO/Ni Nanowafer Aerogel Electrodes for High Performance Supercapacitors. Nanomaterials (2022).
5. NiO Pseudocapacitance and Optical Properties: Does The Shape Win?. Materials (2020).