Safe Lithium Batteries Get a Boost

A team of researchers in the Department of Chemical and Biomolecular Engineering at the University of Maryland has made a breakthrough in next-generation lithium batteries. The team has developed less flammable electrolytes to enhance the performance and safety of lithium-ion metal batteries.

This is a significant development for the environment involving less use of fossil fuels. But what about its importance for all those electric vehicles and portable electronic devices? Today, while electric vehicles (EVs) are increasingly becoming popular, many customers avoid them, citing the poor cold-weather performance of the batteries. Also, imagine customers demanding better batteries because the ones on their smartphones don’t last long enough. The answers to these fears and concerns lie in the new battery design, which can operate under extreme temperature conditions, and have faster charging, greater range and longer lifespan.

The transdisciplinary and multi-institutional research team led by Chunsheng Wang, a professor in the Department of Chemical and Biomolecular Engineering at the University of Maryland also included Robert Franklin and Frances Riggs Wright, Distinguished Chair in the Department of Chemical & Biomolecular Engineering (CHBE) at the University of Maryland, and UMD Director of the Center for Research in Extreme Batteries, all of whom have long been committed to improving the energy density and safety of batteries, especially in the field of electrolytes, and have achieved a series of innovative results, with the preliminary work proposing non- flammable solid-state Li metal batteries (Nature Energy, 2023), non-aqueous (Nature, 2023) and aqueous (Nature Sustainability, 2023) electrolytes.

As researchers keep pushing the boundaries of battery design, one of the more breakthrough technologies studied is solid-state lithium metal batteries, which use a solid electrolyte material rather than a typical liquid. One new finding is to design solid-state electrolytes that can suppress the branch-like projections of metal known as dendrites. Dendrites are formed on the battery electrodes, and they are a problem because they can shorten the life of battery cells and create short circuits, raising concerns about battery safety.

The researchers led by Chunsheng Wang have found a way to prevent the formation of such dendrites, creating the potential to obtain high-powered batteries and solve their reliability problems. Their findings are described in the journal Nature Energy, which identified a new parameter known as a Critical Interphase Overpotential (CIOP) used to design solid-state electrolytes for Li-dendrite suppression.

“As the CIOP is an intrinsic property of the interphase, it could be used to design interphases for Li-dendrite suppression. The CIOP concept can also be used in other solid-state metal batteries, which also feature SEIs," said Dr. Hongli Wan, a postdoctoral research associate in the Department of Chemical and Biomolecular Engineering at UMD and the first author of the Nature Energy paper.

In another groundbreaking research, Nature journal published a study titled “Electrolyte design for Li-ion batteries under extreme operating conditions" by Professor Chunsheng Wang. Chunsheng and his collaborators developed a class of soft solvating electrolytes that allows for fast recharging and operation of lithium batteries under a wide temperature variation.

“Our finding provides a practical drop-in solution for the Li-ion batteries towards next-generation EVs to meet the energy density, fast-charging, wide temperature operation (−60 °C to +60 °C), and safety requirements,” said Dr. Jijian Xu, the first author of the team’s Nature paper and a visiting Assistant Research Scientist in the Department of Chemical and Biomolecular Engineering at UMD.

In another work published in Nature Sustainability, “All-temperature zinc batteries with high-entropy aqueous electrolyte," the team developed a high-entropy electrolyte design that improved both the battery’s stability over existing models, as well as improved the battery’s operational performance over a wider range of temperatures.

“We were able to achieve both a wide electrochemical stability window, better than water-in-salt electrolytes and an exceptional operating temperature range from −80 °C to +80 °C,” explained Chongyin Yang, former UMD Postdoctoral Research Associate and lead researcher on the paper.
The fundamental challenge in modern society to improve energy storage systems and increase battery life and safety has become ever more crucial as we increasingly depend on battery energy for everything from portable devices to electric vehicles. As researchers push the boundaries of battery design, the mass production of their technologies will significantly impact society. If the battery design technologies are mass-produced, electric vehicles will undercut the prices of those that are fossil–fuel–powered. Also, the increasing use of electric cars will reduce the harmful carbon emissions produced by fossil-fuel-powered automobiles. That is the future with safe and long-lasting rechargeable lithium batteries operating under extreme temperatures.

For additional information:
Wan, H., Wang, Z., Liu, S. et al. Critical interphase overpotential as a lithium dendrite-suppression criterion for all-solid-state lithium battery design. Nat Energy (2023). https://www.nature.com/articles/s41560-023-01231-w

Xu, J., Zhang, J., Pollard, T.P. et al. Electrolyte design for Li-ion batteries under extreme operating conditions. Nature (2023). https://doi.org/10.1038/s41586-022-05627-8

Yang, C., Xia, J., Cui, C. et al. All-temperature zinc batteries with high-entropy aqueous electrolyte. Nat Sustain (2023).https://doi.org/10.1038/s41893-022-01028-x
https://chbe.umd.edu/news/story/new-electrolyte-design-could-be-the-answer-for-safer-rechargeable-batteries-even-in-extreme-cold

https://chbe.umd.edu/news/story/new-sustainable-zinc-battery-design-could-address-future-energy-needs

Published March 23, 2023