- An experimental lithium-ion battery showed minimal to no susceptibility to sub-zero temperatures.
- Developed by Arbor Battery Innovations and University of Michigan researchers, the cells charged rapidly and lost no range.
- The battery uses a special “3D electrode architecture” that’s less resistant to extreme temperatures.
Frigid weather and electric vehicle batteries aren’t besties. If your electric vehicle takes 20 minutes to charge at a DC charger in summer, it may take several additional minutes when the mercury drops. That’s not only a waste of time, but also keeps buyers away from battery-powered vehicles, especially those who live in regions susceptible to Arctic blasts and the occasional polar vortex.
But researchers are working hard to solve this problem.
A study published in the scientific journal Joule says a special type of electrode can help an EV battery resist extreme temperatures, preserving its range and charging performance. The battery material was developed by scientists at the University of Michigan and battery research firm Arbor Battery Innovations. They claim the battery can charge in 10 minutes at -10 degrees Celsius (14 degrees F.) Even after 100 cycles, degradation was apparently minimal.
When the needle drops to uncomfortable temperatures, movement of electrons in your EV battery slows down rapidly, which means your driving range reduces and charging speeds taper off.
EVs today mitigate this impact to a certain extent with battery preconditioning and heat pumps, but that doesn’t weatherproof the battery. It just minimizes the impact of extreme weather. Battery makers also do their part, usually making the anode thicker to make it more temperature resistant.
Photo by: Tim Stevens/InsideEVs
But Michigan researchers said lithium doesn’t necessarily move freely within thicker anodes and can even cause slower charging and reduced performance. They solved that by blasting laser into the graphite used in anodes so that ions could deposit there faster. But this also caused challenges. Hyper-fast charging speeds can cause lithium plating, where lithium builds on the anode surface instead of being properly absorbed and delivering any meaningful energy.
Plating reduces battery performance, slows down charging speeds and even creates safety risks like short circuits. Michigan researchers prevented plating by coating the battery with a glassy material made using lithium borate-carbonate, about 20 nanometers thick. As a result, the cells charged at a rate of 6C, which means a full charge just took 10 minutes in a subzero climate. For reference, at a rate of 1C, a battery charges in one hour.
This technique can even be adopted without major changes to existing factories, said mechanical engineering and materials science professor Neil Dasgupta, who is also one of the authors of the study.
What we don’t know about this experiment, however, is the size of the battery and the percentage range. It’s unclear if the 10-minute charging time was for a full 0-100% charge or a 20-80% top-up that automakers recommend to EV owners to preserve the long-term health of the battery. The authors of the study did not immediately respond to InsideEVs request for a comment.
Photo by: Polestar
That’s not to say that your EV simply sucks in cold weather. No, most modern EVs have a broader operating range. A Tesla Model 3, for example, has an operating temperature broader than what researchers in this study have claimed for their experiment.
The Model 3’s battery can work between -22F and 140F, according to its user manual. But just because its battery is functional within those temperatures doesn’t mean it’s efficient. We’ve seen dozens of Tesla owners reporting how range plummets when the mercury drops below zero.
The study, on the other hand, says that EV batteries with such advanced chemistries can not only work flawlessly in extreme temperatures, but also charge rapidly without any performance loss or degradation. It sounds brilliant as an experiment and would be even sweeter if we saw it in the real world.
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