Engineers at Penn State have created a battery that can overcome one of the major hurdles electric cars face: the weather. They have a designed a new battery that can self-heat, allowing for rapid charging regardless of the outside cold.
Like any other battery, electric vehicle (EV) batteries are affected negatively by the cold. Studies by the Department of Energy have shown that weather can affect plug-in EV batteries by over 25 percent, bringing car ranges down from around 80 miles to 60. The engineers at Penn State have developed a self-heating battery that can provide a 15-minute rapid charge at all temperatures, even when the cold is as low as minus 45 degrees Fahrenheit.
Batteries have both positive and negative terminals. The scientists placed thin nickel foil with one end attached to the negative terminal and the other end creating a third terminal. When a temperature sensor attached to a battery detects that the battery is below room temperature, it then sends electrons flowing through the nickel foil. This heats the battery up until it’s above room temperature again.
When the sensor detects that the battery is above room temperature, that’s the sign that charging that can begin again. Electric current flows into the battery, rapidly charging in a more efficient state.
“One unique feature of our cell is that it will do the heating and then switch to charging automatically. Also, the stations already out there do not have to be changed. Control off heating and charging is within the battery, not the chargers,” says Chao-Yang Wang, director of Penn State’s Electrochemical Engine Center, in a press statement.
All batteries degrade in ability over time. But 4,500 cycles of testing the new cell in increments of 15-minute charging at 32 degrees F showed only a 20 percent capacity loss. Over a car’s entire life, this could provide 280,000 miles of driving and a lifetime of 12.5 years. A conventional battery showed a 20 percent capacity loss after only 50 charges.
“This ubiquitous fast-charging method will also allow manufacturers to use smaller batteries that are lighter and also safer in a vehicle,” says Wang.
As electric cars and trucks become increasingly popular, greater attention is being paid to their batteries and how they function within the environment. Nissan, for example, has begun turning old Leaf batteries into streetlights in Japan.