Future of Quasi Solid Electrolytes in Long Range Fire-Proof EV Lithium Batteries

India has achieved a significant milestone in the advancement of electric vehicles (EVs). Despite the fact that several studies and discoveries in the modern era have led to new battery technologies, lithium-ion battery continues to be a focal point in the field of EVs. To increase the safety of lithium-ion batteries, our research team, led by Dr. Helen Annal Therese, Department of Chemistry, SRMIST, developed a quasi-solid electrolyte. We work on biodegradable polymer host materials with a ceramic filler, that provides better safety and comparable performance to the liquid electrolyte. Electrolytes, being a major component of battery systems are the vital reason for flammability and unanticipated fire accidents. Explosions are primarily caused by the chemistry of organic solvents in electrolytes and thermal runaway, a phenomenon that causes battery cells to heat up uncontrollably.

Researchers and industrialists are resolute in their efforts to resolve this issue by substituting the flammable liquid electrolyte with a solid electrolyte, calling it a solid-state battery. Solid electrolytes have been the subject of several studies and reports, but the true concern is the trade-off between battery safety and performance. While the scientific world waits for a perfect solid electrolyte to replace liquid electrolytes, the intermediary between the two is known as a quasi-solid electrolyte, having the advantages of both liquid and solid electrolytes, which can be a game changer for EVs.

As a researcher in battery technology, I would, like any other individual, give serious consideration to the electric vehicle's safety features before deciding to purchase one. This uncertainty made us craft a precise problem statement. Despite several findings in this field, more research focussed on commercial output is needed. When it pertains to commercialization, some significant hurdles are safety, cost, and performance. Using low-cost alternatives and an efficient electrospinning technology, we created a safe replacement for liquid electrolytes in lithium-ion batteries. Our preliminary results showcase better battery performance with an extended life span when compared to conventional liquid electrolytes. In addition, it is estimated that electrolyte and separator materials make up 18-22% of the trash that is produced by lithium-ion batteries. We use raw materials that are non-toxic and environmentally friendly. We believe that even a tiny contribution to society can have a great influence.

Based on our findings we believe that our quasi-solid polymer electrolyte has the potential standards to reach industries as a replacement to liquid electrolytes. The main advantage of quasi-solid batteries is that they can be produced in conventional lithium-ion battery production lines. Though these quasi-solid batteries provide better performances when compared to solid-state batteries, they still need to acquire the energy density of conventional lithium-ion batteries. Furthermore, we are conducting temperature-dependent performance trials of the quasi-solid electrolyte under extreme temperatures, as the liquid electrolyte freezes at very low temperatures making it difficult to achieve good battery performance. However, validating the performance, cost, and longevity of quasi-solid batteries is a prerequisite to producing these batteries on a large scale. The exact operation of these batteries in relation to uneven roadways is still a matter that needs further investigation.

Several Chinese EV manufacturers have already shown interest in developing and using this type of quasi-solid batteries in EVs. The Indian government has also initiated several projects and made major contributions to the field of quasi-solid electrolytes through its industry-focused research agenda, particularly the e-mobility R&D road map for India. Being a more relevant need of the hour, more research and findings on quasi-solid batteries as an alternative to conventional lithium-ion batteries can pave the way for commercialization and provide a breakthrough in the field of EVs in India.

About the author  

Jenny Johnson, Research scholar, pursuing Ph.D. in battery technology, under the guidance of Dr. Helen Annal Therese, Department of Chemistry, SRMIST.