EV battery breakthrough removes cold charging bottleneck

Electric cars are becoming more popular, but many face issues with degraded performance in cold weather. When temperatures drop, charging slows down, and the driving range is drastically reduced as well. Researchers from the University of Michigan and Arbor Battery Innovations have found a promising solution that could ease these issues. They developed an experimental lithium-ion battery that performs well in sub-zero temperatures, allowing for fast charging and reliable driving range.

The key innovation is a special "3D electrode architecture" that helps the battery handle extreme cold better. Typically, very low temperatures slow down the movement of electrons in EV batteries, which leads to longer charging times and reduced driving distance.

To address this issue, the researchers focused on the anode, where lithium ions are stored during charging. They used lasers to change the graphite in the anode, creating pathways that allow lithium ions to move and deposit faster. While this sped up charging, it also created a new challenge: lithium plating. This occurs when lithium builds up on the anode's surface instead of being absorbed, which can hurt battery performance and safety.

The research team solved the plating problem by applying a very thin coating, about 20 nanometers thick, to the battery. This coating, made from lithium borate-carbonate, stops lithium from plating. As a result, the battery can charge quickly at a rate of 6C, meaning it can be fully charged in just 10 minutes, even at -10 degrees Celsius (14 degrees Fahrenheit). The researchers found that the battery's performance remained strong after 100 charge cycles in these cold conditions.

Neil Dasgupta, a mechanical engineering professor at the University of Michigan and co-author of the study, stated that this new technology could be added to current battery manufacturing processes without major changes.

Modern electric cars already use battery preconditioning and heat pumps to help with cold weather. However, these methods do not always work perfectly, and many EV owners notice a drop in range during very cold weather. If this new battery technology can be successfully produced for electric vehicles, it could help potential buyers, especially in areas with harsh winter conditions.

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