An all-climate
battery that rapidly self-heats battery materials and electrochemical
interfaces in cold
environments. Image: Chao-Yang Wang / Penn State
(January 21, 2016) A
lithium-ion battery that self heats if the temperature is below 32 degrees
Fahrenheit has multiple applications, but may have the most impact on relieving
winter "range anxiety" for electric vehicle owners, according to a
team of researchers from Penn State and EC Power, State College.
"It is a long standing problem that batteries do not
perform well at subzero temperatures," said Chao-Yang Wang, William E.
Diefenderfer Chair of mechanical engineering, professor of chemical engineering
and professor of materials science and engineering and director,
Electrochemical Engine Center.
"This may not be an issue for phones and laptops, but is a huge
barrier for electric vehicles, drones, outdoor robots and space applications."
Conventional batteries at below freezing temperatures suffer
severe power loss, which leads to slow charging in cold weather, restricted
regenerative breaking and reduction of vehicle cruise range by as much as 40
percent, the researchers said in today's (Jan. 20) issue of Nature. These problems require larger and more
expensive battery packs to compensate for the cold sapping of energy.
"We don't want electric cars to lose 40 to 50 percent
of their cruise range in frigid weather as reported by the American Automobile
Association and we don't want the cold weather to exacerbate range
anxiety," said Wang. "In cold
winters, range anxiety is the last thing we need."
The researchers, relying on previous patents by EC Power,
developed the all-climate battery to weigh only 1.5 percent more and cost only
0.04 percent of the base battery. They
also designed it to go from -4 to 32 degrees Fahrenheit within 20 seconds and from
-22 to 32 degrees Fahrenheit in 30 seconds and consume only 3.8 percent and 5.5
percent of the cell's capacity. This is
far less than the 40 percent loss in conventional lithium ion batteries.