Indian Institute of Technology Madras Researchers are developing mechanically-rechargeable zinc-air batteries as an alternative to lithium-ion batteries which are used in electric vehicles

The researchers have filed for patents for this new battery technology, and are collaborating with major industries to develop these zinc-air batteries. They are economical compared to existing lithium-ion batteries and have a longer shelf life. Zinc-air batteries can be used in two-wheeler and three-wheeler EVs

Currently, Indian EV manufacturing firms import lithium-ion batteries mostly from China. Although lithium-ion batteries are widely used, there are several limitations such as limited availability. Further, the diverse requirements of the Indian market cannot be fully met by lithium-ion batteries alone, said a release from IIT Madras.

‘A cost-effective alternative’

Aravind Kumar Chandiran, Assistant Professor, Department of Chemical Engineering, IIT Madras, and his research group have been working towards developing a cost-effective alternative to Lithium-ion batteries. The researchers are mooting separate ‘zinc recharge stations’, similar to petrol stations.

The EV users utilising zinc-air batteries can reach out to these bunks whenever the batteries are drained, similar to the current model of conventional vehicles refuelling at petrol stations. This technology is based on ‘battery swapping’ in which vehicle users can swap used ‘zinc cassettes’ of the battery with fully-charged ‘zinc cassettes’ at these ‘zinc recharge stations,’ the release said.

Akhil Kongara, a Research Scholar, IIT Madras, said, according to the proposed plan, an EV user will only have to spend a few minutes at the ‘zinc recharge stations’ to swap ‘zinc cassettes’.

Zinc is widely available in India and would reduce the import of lithium-ion batteries as it is cheaper.While lithium-ion batteries cost $200 to $250 a KWhr, zinc-air batteries cost around $150 KWhr. With wider usage, the price is expected to come below $100 KWhr. Zinc-air batteries are also water-based and have a longer shelf life. They Zinc-air batteries have good turnaround efficiency, the release said.