IIT Delhi study to help develop alternative to lithium-ion batteries

New Delhi, Aug 16: Researchers at the Indian Institutes of Technology (IIT) Delhi on Friday released a new study about sodium-sulphur (RT-Na/S) batteries that will pave the way for developing an alternative to lithium-ion batteries.

The sustainability of lithium-ion batteries has been challenged by the scarcity of electrode materials and the supply chain of other critical components. This has forced battery manufacturers to look for an alternative battery technology.

The room-temperature sodium-sulphur (RT-Na/S) batteries -- with abundant and inexpensive electrode materials in the form of sodium and sulphur -- may prove a potential alternative, said the team of researchers. These rely on a different kind of chemical reaction, which makes them capable of storing much more energy in comparison to lithium-ion batteries.

But these RT-Na/S batteries experience dendrite growth -- branched structures -- on the sodium metal anode. These structures cause the cell to fail prematurely.

The team at the Department of Energy Science and Engineering (DESE), IIT Delhi, has been working to find a possible solution to this dendrite-related problem, which can cause short circuits and degrade the battery's performance over time.

In their research, published in the Journal of Materials Chemistry, the team managed to stabilise room-temperature sodium-sulphur battery technology by employing an iodide-based additive in the organic electrolyte solution.

To prevent the growth of sodium dendrites, the team employed Bismuth iodide (BiI3) as an additive molecule to alter the properties of the electrolyte.

BiI3 reduces the energy required for sodium ions to leave the solvent and enter the electrode, improving the charge transfer kinetics. This results in better battery efficiency and faster charging times, the researchers said.

“This exciting development highlights the importance of innovative research in addressing global energy challenges. By harnessing the power of abundant and safe materials like sodium and sulphur and enhancing their performance with innovative additives like BiI3, we move closer to a future where sustainable energy storage is accessible to all,” said Prof. Vipin Kumar from the Department of Energy Science and Engineering, IIT Delhi.

“Room-temperature sodium-sulphur batteries would be ideal for use in electric vehicles and grid applications,” the researcher added.