Self-heating lithium-ion battery could improve EV range in winter

Credit: Penn State/EC Power/Green Car Reports

Cold weather reduces the range of electric vehicles (EVs). There is a small effect due to running the heater, but the major cause is that batteries become less efficient at converting the chemical energy stored inside them into electricity when they are cold.

Range loss is up to 40%.

Less widely recognised is the negative impact on regenerative braking & increased charging times.

Pennsylvania State University & EC Power researchers may have a solution. It is essentially a resistance-heater inside each individual cell of the battery. Warming the battery consumes less than 6% of battery capacity, depending on temperature. This compares very favourably with the 40% capacity loss from operating a cold battery.

Researchers hope that a similar approach will allow active management of batteries for improved safety, performance, & extended service life.

http://news.psu.edu/story/388410/2016/01/20/research/self-heating-lithium-ion-battery-could-beat-winter-woes

http://www.greencarreports.com/news/1102141_self-heating-lithium-ion-battery-could-cut-winter-range-woes / University Park Pa Pennsylvania State University A lithium-ion lithium ion LiIon battery self heats temperature below 32 degrees Fahrenheit 0 zero defrees Celcius Celsium multiple applications most impact relieving winter range anxiety electric vehicle owners team of researchers Penn State EC Power State College long standing problem batteries do not perform well at subzero temperatures Chao-Yang Wang William E. Diefenderfer Chair mechanical engineering professor of chemical engineering professor materials science and engineering director Electrochemical Engine Center issue for phones laptops huge barrier electric vehicles drones outdoor robots space applications conventional batteries below freezing temperatures suffer severe power loss leads to slow charging cold weather restricted regenerative braking reduction vehicle cruise range as much as 40 percent researchers Nature magazine problems larger more expensive battery packs compensate cold sapping of energy electric cars lose 40 to 50 percent cruise range frigid weather reported American Automobile Association don't want cold weather exacerbate range anxiety cold winters range anxiety researchers previous patents EC Power developed all-climate battery weigh only 1.5 percent more cost only 0.04 percent battery designed -4 to 32 degrees Fahrenheit 20 seconds -22 to 32 degrees Fahrenheit 30 seconds consume only 3.8 percent 5.5 percent cell's capacity far less than 40 percent loss conventional lithium ion batteries all-climate battery uses nickel foil 50-micrometer thickness one end attached negative terminal extending outside cell create third terminal temperature sensor attached switch causes electrons flow through nickel foil complete circuit rapidly heats up nickel foil resistance heating warms inside battery battery 32 degrees Fahrenheit 0 degrees Celsius Celcius switch turns off electric current flows normal manner other materials resistance-heating element nickel low cost works well broaden work new paradigm Smart Battery SmartBattery Professor Wang use similar structures principles actively regulate battery's safety performance life working project Guangsheng Zhang Yongjun Leng research associates mechanical engineering Xiao-Guang Yang postdoctoral Fellow Penn State Terrence Xu Shanhai Ge Yan J, innovation engineers EC Power collaborated research Professor Wang Chief Technology Officer founder startup EC Power EC Power supported project /