New Delhi: Indian researchers have unveiled a sunlight-powered supercapacitor that can both capture and store energy in a single integrated device, a breakthrough that could simplify power systems for portable, wearable and off-grid technologies.
The device, developed at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru—an autonomous institute under the Department of Science and Technology—combines solar energy harvesting and storage, eliminating the need for separate panels and batteries and the associated power management electronics.
At the heart of the innovation are binder-free nickel–cobalt oxide (NiCo₂O₄) nanowires grown on nickel foam, forming a porous, conductive 3D network that absorbs sunlight and stores charge. In tests, the electrode showed a 54% increase in capacitance under illumination, rising from 570 to 880 mF cm⁻² at a current density of 15 mA cm⁻², and retained about 85% of its capacity even after 10,000 charge–discharge cycles.
To assess real-world use, researchers built an asymmetric photo-supercapacitor that delivered a stable 1.2-volt output and maintained 88% capacitance after 1,000 photo-charging cycles, operating efficiently from indoor light to high-intensity sunlight. The team said the architecture can endure both mechanical and electrochemical stress over prolonged use.
The study, published in Sustainable Energy & Fuels, also used theoretical simulations to explain the performance gains, showing that nickel substitution narrows the band gap and improves charge transport. By integrating harvesting and storage in one architecture, the technology could reduce reliance on conventional batteries and fossil fuels, and help advance self-sustaining, green power systems, the researchers said.