Scientists have developed a new sunlight-powered supercapacitor that can both capture and store solar energy in a single integrated device, a breakthrough that could support clean, low-cost and self-sustaining power solutions for everyday use, the Ministry of Science & Technology said in a press release.
The device, known as a photo-capacitor, has been developed by researchers at the Centre for Nano and Soft Matter Sciences (CeNS) in Bengaluru, an autonomous institute under the Department of Science and Technology of the Government of India. It combines the functions of a solar panel and an energy storage unit into one integrated system.
Researchers said the development could help improve power supply for portable electronics, wearable devices and systems operating in areas without access to the electricity grid. By using sunlight directly and storing the energy at the same time, the device reduces the need for separate components and complex control systems.
At present, most solar power systems depend on two different units — one to capture sunlight and another to store energy. These systems also need extra electronic components to manage differences in power flow between the two units. Scientists said this increases cost, energy loss and overall size, making such systems less suitable for small and independent devices.
The new device overcomes these limitations by combining energy capture and storage into a single unit. It converts sunlight into electrical energy and stores it for later use, helping simplify the system and reduce energy losses during operation.
Scientists said the innovation marks a step forward in the development of efficient and environmentally friendly energy storage technologies.
Under the guidance of Dr. Kavita Pandey, innovated with the help of binder-free use of nickel-cobalt oxide (NiCo2O4) nanowires, which have been uniformly grown on nickel foam using a simple in situ hydrothermal process.
These nanowires, only a few nanometres in diameter and several micrometres long, form a highly porous and conductive 3D network that efficiently absorbs sunlight and stores electrical charge. This unique architecture allowed the material to act simultaneously as a solar energy harvester and a supercapacitor electrode.
When tested, the NiCo2O4 electrode exhibited a remarkable 54% increase in capacitance under illumination, rising from 570 to 880 mF cm-2 at a current density of 15 mA cm-2. This exceptional performance stems from the efficient generation and transfer of light-induced charge carriers within the nanowire network. Even after 10,000 charge-discharge cycles, the electrode retained 85% of its original capacity, demonstrating its long-term stability, an essential feature for practical applications.
