Pune lab develops batteries that can get fully charged in half an hour

IISER team explains the applications of coin-sized battery. (Express Photo)

IMAGINE a battery installed in your future electric car which can be charged to its full capacity in just half an hour. With most vehicle manufacturing companies in th e world shifting gears towards developing electric vehicles, the need for efficient batteries which can not only store charge for longer time durations but also charge itself completely in the shortest span of time, will be required.

A team of scientists, led by R Vaidhyanathan of city-based Indian Institute of Science, Education and Research (IISER), have developed a battery material of unique configuration suiting the next generation lithium-ion (li-ion) battery. Experts here have designed Covalent Organic Nanosheets (CON) that can be chemically structured and manipulated as per the battery requirement, so much so that it has shown specific capacity of 720 mAh/gm using few milligrams of this organic material when tested in a coin cell battery.

“The material, which is rich in oxygen and nitrogen functionalities, when tested in a half cell circuit, was found to offer very high specific capacity than what is presently available using graphite in these batteries,” said Vaidhyanathan. He added, “If this can be scaled up in kilograms, then this material can find place in larger batteries used in electric vehicles too.”

Graphite, due to its inherent chemical composition, cannot offer a specific capacity higher than 370mAh/g. However, a study published recently in Advanced Energy Materials journal has shown promising results that can have applications in electronic wearables, vehicles, industrial batteries and also in power grids, that require high charge storage capacities. According to Dhanya Putthusseri, another team member, if these batteries are installed in vehicles, it can better the mileage per charge, thereby improving the overall efficiency.

The Indian government is among the frontrunners globally to plan the induction of e-vehicles and is hopeful of rolling out e-cars by 2020 in major Indian cities. Taking a lead, Brihanmumbai Electric Supply and Transport (BEST) earlier this month introduced four e-buses to its existing fleet of public buses in Mumbai. Indian car makers are also tying up with car pooling companies to launch e-taxis as the country.

“With higher energy density supported to the battery, we found that the output in the form of specific capacity was over 700 mAh/g. This literally means that once the battery is charged, it can be used for even long distance drives without any interruptions,” said the young scientist. The team, comprising Satishchandra Ogale, Putthuseri, Sattwick Halder, Kingshuk Roy, tested the shelf life of the battery which, they claim, show highest performance until three years, if the battery is charged at the rate of once every day.

According to senior physicist Ogale, batteries have now become an inevitable device of our lives for which research on low dimensional materials in order to develop advanced batteries are on globally. “The future batteries will not just have to be cost-effective, they will also need to weigh less, have high stability in storing charge and also possess high safety standards,” said Ogale.