Mumbai: As the number of electric vehicles (EV) users grow around the country, researchers at the Indian Institute of Technology Bombay (IITB) have sought to address a key issue affecting EVs: Overheating of batteries.
An institute research team has claimed to have found a unique solution that could bring down the maximum temperature of Lithium-ion (Li-ion) battery packs and even lower their weight by 57%. The proposed method, for which the team has obtained a patent, will make the batteries more efficient, safer and increase their longevity, said the researchers.
India has been witnessing a steady rise in EV use. In November 2023, the nationwide EV sales reached 1,52,610 units. This marked a significant 26% year-on-year increase compared to November 2022, which recorded 1,21,598 units. As of now 34.54 lakh EVs are registered in the country, with the government estimating the sales to hit 1 crore units per annum by 2030.
Safety concerns
However, these vehicles have also triggered safety concerns as multiple incidents of electric scooters and cars catching fire. The technique developed by IITB researchers involves removing the heat evenly from each battery in the pack, thereby maintaining a uniform temperature across the module.
In the conventional cooling method, batteries are cooled by circulating a fluid across battery surfaces through metal pipes or channels, where the area of contact between the coolant and batteries remains constant. However, this design leads to an uneven removal of heat as the coolant itself keeps getting hotter as it passes through batteries.
Researchers propose different design
To overcome this drawback, the researchers proposed a different design where the contact area between the coolant and batteries gradually increases, which enhances the heat transfer capacity of the fluid. This can simply be achieved by adding and removing a few metal strips, they said.
A computer simulation of this design indicated a reduction of around 70% in the maximum temperature difference in the different regions within the battery module as compared to conventional methods.
“All batteries have an optimum temperature at which they work most efficiently. Too much heat can limit battery performance and, in worst scenarios, cause them to catch fire or explode. Lithium-ion batteries, for example, need an optimal temperature range of around 20–40° C to function correctly,” said Ekta Singh Shrinet, a PhD student at IITB and a part of the research team.
The researchers believe that their new design strategy will have broad applications not just in the electric vehicle industry, but also solar power storage and other devices which rely on battery packs with multiple batteries.
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