IISc supercapacitor to replace batteries in EVs

BENGALURU:  Researchers at the Indian Institute of Science (IISc) have developed a new type of supercapacitor that can replace batteries in streetlights, electric cars and medical devices.

The supercapacitor, developed by researchers from IISc’s Department of Instrumentation and Applied Physics (IAP), is different from others, as it is smaller or ‘ultra-micro’, but capable of storing larger amounts of energy. Hence, the supercapacitor can be easier to use in smaller electronic devices, eliminating the need for batteries, while ensuring that the device stays charged for a longer time.

“Most of these devices are currently powered by batteries. However, over time, these batteries lose their ability to store charge and therefore have a limited shelf-life. Capacitors, on the other hand, can store an electrical charge for much longer, by their design. Supercapacitors, on the other hand, combine the best of both batteries and capacitors -- they can store and release large amounts of energy, and are therefore highly sought-after for next-generation electronic devices,” the researchers said.

Abha Misra, an IAP professor and a corresponding study author, said the supercapacitor used Field Effect Transistors (FETs) instead of metallic electrodes, which are more commonly used, as charge collectors. “Using FET as an electrode for supercapacitors is something new for tuning charge in a capacitor,” she said.

During their tests, they found that the ultra-micro supercapacitor, due to the materials used, was able to increase capacitance (ability to store energy as electricity within the device) to 3,000 per cent. This was compared to a regular supercapacitor, which showed only an 18 per cent increase. The key was the use of molybdenum disulphide (MoS2) and graphene in increasing the mobility of electrons within the supercapacitor.

“In future, we are planning to explore if replacing MoS2 with other materials can increase the capacitance of the supercapacitor even more. The supercapacitor is fully functional and can be deployed in energy-storage devices like electric car batteries or any miniaturised system by on-chip integration. We are also planning to apply for a patent on the supercapacitor,” they said.