In Scandinavia, electric vehicles must be equipped with a small heater in the battery box, while the heating devices in California are significantly larger than those in Minnesota and Canada.
A team led by Chao-Yang Wang, head of the Electrochemical Engine Research Center at Penn State University, has developed a new type of battery that can prevent energy loss at sub-zero temperatures through self-heating. It operates on the same principle as fast-charging stations, but it can fully charge the battery in 15 minutes even when the ambient temperature drops to -43 degrees Celsius.
This type of battery connects one end of a thin nickel sheet to the negative terminal, while the other end extends outside the battery to form a third terminal. A temperature sensor connected to a switch detects that the ambient temperature has dropped to around 25 degrees Celsius, and then controls the flow of current through the nickel sheet via the switch. The resistivity of the nickel sheet causes it to heat up, supplying heat to the battery from within.
Once the temperature rises above room temperature, the switch on the battery will automatically switch the current to directly charge the battery. Wang claims that this means we don't need to replace the charging station; we can control heating and charging within the battery itself without adjusting the charging device.
In a report published in the Proceedings of the National Academy of Sciences, researchers claim their prototype battery can withstand 4,500 15-minute fast charges at 0 degrees Celsius with only 20% energy loss. This translates to a battery life of 12.5 years. In contrast, a conventional battery with 20% energy loss can only withstand 50 charges.
Researchers say this innovative technology also makes batteries safer. Charging lithium batteries at 10 degrees Celsius causes lithium ions to accumulate on the anode surface, which can lead to risks such as short circuits, heat loss, and fire. Researchers say this unique fast-charging method allows manufacturers to create lighter and safer smaller batteries for electric vehicles.
