Scientists at University of California, San Diego are exploring designs that can function at extreme temperatures, and they're beginning to make some significant inroads.the team demonstrates a lithium battery that can not only operate at freezing cold and scorching hot temperatures, but may store double the energy of current devices and be friendlier to the environment while it's at it.

Figure 1: A lithium battery can operate both at freezing cold and scorching hot temperatures.

Figure 1 shows thatweak-binding electrolyte was integrated into an experimental lithium battery with a high-density metal anode and a sulfur-based cathode that was able to operate at sub-zero temperatures while retaining much of its capacity.

“In electric vehicles, the battery packs are typically under the floor, close to these hot roads. Also, batteries warm up just from having a current run through during operation. If the batteries cannot tolerate this warmup at high temperature, their performance will quickly degrade.”

In tests, the proof-of-concept batteries retained 87.5 per cent and 115.9 per cent of their energy capacity at -40°C and 50°C, respectively. They also had high Coulombic efficiencies of 98.2 and 98.7 per cent at these temperatures, respectively, which means the batteries can undergo more charge and discharge cycles before they stop working.

The batteries are both cold and heat tolerant thanks to their electrolyte. It is made of a liquid solution of dibutyl ether mixed with a lithium salt. A special feature about dibutyl ether is that its molecules bind weakly to lithium ions. In other words, the electrolyte molecules can easily let go of lithium ions as the battery runs. [2]

In tests, their batteries withstood more than other known lithium-sulfur models, both in high and low temperatures.

“You need a high-temperature operation in areas where the ambient temperature can reach the triple digits, and the roads get even hotter. In electric vehicles, the battery packs are typically under the floor, close to these hot roads,” explained Zheng Chen.

“Also, batteries warm up just from having a current run through during operation. If the batteries cannot tolerate this warmup at high temperature, their performance will quickly degrade.”

The next steps include scaling up the battery chemistry, optimizing it to work at even higher temperatures, and further extending cycle life.

References:

1. https://newatlas.com/energy/energy-dense-lithium-sulfur-battery-extreme-temperatures/
2. https://eandt.theiet.org/content/articles/2022/07/energy-dense-batteries-developed-that-operate-at-extreme-temperatures/
3. https://www.inceptivemind.com/ucsd-energy-dense-batteries-work-well-scorching-sun-freezing-cold/25375/

Cite this article:

Sri Vasagi K (2022), Lithium-Ion Batteries that Function in Extreme Temperatures, Anatechmaz, pp. 360