A ΒιΆΉΣ³»΄«Γ½ researcher has developed technology that could prevent electric vehicle fires, like those caused by saltwater flooding from Hurricane Ian.
The technology, an aqueous battery, replaces the volatile and highly flammable organic solvents found in electric vehicle lithium-ion batteries with saltwater to create a battery that is safer, faster charging, just as powerful and wonβt short circuit during flooding.
The work is detailed in a new study in .
βDuring Hurricane Ian, a lot of electric cars caught fire after they were soaked in floodwater,β says Yang Yang, an associate professor in ΒιΆΉΣ³»΄«Γ½βs NanoScience Technology Center who led the research. βThat is because the saltwater corrodes the battery and causes a short circuit, which ignites the flammable solvents and other components. Our battery uses saltwater as an electrolyte, eliminating the highly volatile solvents.β
Also key to the batteryβs design is its novel, nano-engineering that allows the battery to overcome limitations of previous aqueous batteries, such as slow charging times and poor stability.
The ΒιΆΉΣ³»΄«Γ½-designed battery is fast charging, reaching full charge in three minutes, compared to the hours it takes lithium-ion batteries.
Yang is an expert in developing materials for renewable energy devices such as batteries with improved safety.
Saltwater Electrical Vehicle Fires
The issue of electric vehicle fires after saltwater flooding surfaced during Hurricane Sandy in 2012 and Hurricane Isaias in 2020.
As a result, the U.S. Fire Administration and the National Highway Traffic Safety Administration have issued special guidance for responding to electric vehicle fires caused by saltwater flooding.
The fires require copious amounts of water to douse, with the International Association of Fire Chiefs recommending firefighters secure a continuous and sustainable water supply of 3,000 to 8,000 gallons.
At least 12 electric vehicle fires were reported in Collier and Lee counties in Florida after Hurricane Ian, where many cars were submerged at least partially in saltwater, according to the US. Fire Administration.
Designing the Battery
Previous aqueous battery designs have suffered from low energy output, instability, the growth of harmful metallic structures called dendrites on the negative electrode and corrosion.
By using saltwater as the batteryβs liquid electrolyte, the ΒιΆΉΣ³»΄«Γ½ researchers were able to use naturally occurring metal ions found in the saltwater, such as sodium, potassium, calcium and magnesium, to create a dual-cation battery that stores more energy. This implementation allowed them to overcome the sluggishness of previous single-cation aqueous battery designs.
To solve problems with instability, dendrite growth and corrosion, the researchers engineered a forest-like 3D zinc-copper anode containing a thin zinc-oxide protective layer on top.
The novel, nano-engineered surface, which looks like a birds-eye-view of a forest, allows the researchers to precisely control electrochemical reactions, thereby increasing the batteryβs stability and quick charging ability.
Furthermore, the zinc-oxide layer prevented dendritic growth of zinc, which was confirmed using optical microscopy.
βThese batteries using the novel materials developed in my lab will remain safe even if they are used improperly or are flooded in saltwater,β Yang says. βOur work can help improve electric vehicle technology and continue to advance it as reliable and safe form of travel.β
Licensing and Acknowledgements
The patent-pending technology is available for through ΒιΆΉΣ³»΄«Γ½βs Office of Technology Transfer.
The research was supported with funding from the U.S. National Science Foundation and American Chemical Society Petroleum Research Fund.
Yang holds joint appointments in ΒιΆΉΣ³»΄«Γ½βs NanoScience Technology Center and theΒ Department of Materials Science and Engineering, which is part of the universityβsΒ College of Engineering and Computer Science. He is a member of ΒιΆΉΣ³»΄«Γ½βsΒ Renewable Energy and Chemical Transformation (REACT) Cluster. He also holds a secondary joint-appointment in ΒιΆΉΣ³»΄«Γ½βsΒ Department of Chemistry and The Stephen W. Hawking Center for Microgravity Research and Education. Before joining ΒιΆΉΣ³»΄«Γ½ in 2015, he was a postdoctoral fellow at Rice University and an Alexander von Humboldt Fellow at the University of Erlangen-Nuremberg in Germany. He received his doctorate in materials science from Tsinghua University in China.
Study title: Three-dimensional Zn-based Alloys for Dendrite-free Aqueous Zn Battery in Dual-cation Electrolytes
