EC Power’s All-Climate Battery
This type of battery, adopted by BMW among others, will be used in runabout vehicles at the next Winter Olympics in Beijing. Its self-heating feature means it can perform well in sub-zero conditions, unlike most Li-ion batteries. One report says it’s ‘only 1.5 percent heavier and costs 0.04 percent more than a conventional lithium-ion battery’.
A lithium-ion battery that is safe, has high power and can last for 1 million miles has been developed by a team in Penn State’s Battery and Energy Storage Technology (BEST) Center, reports TechXplore.
Electric vehicle batteries typically require a tradeoff between safety and energy density. If the battery has high energy and power density, which is required for uphill driving or merging on the freeway, then there is a chance the battery can catch fire or explode in the wrong conditions.
But materials that have low energy/power density, and therefore high safety, tend to have poor performance. There is no material that satisfies both. For that reason, battery engineers opt for performance over safety.
“In this work we decided we were going to take a totally different approach,” said Chao-Yang Wang, professor of mechanical, chemical and materials science and engineering, and William E. Diefenderfer Chair in Mechanical Engineering, Penn State. “We divided our strategy into two steps. First we wanted to build a highly stable battery with highly stable materials.”
Their second step was to introduce instant heating. About four years ago, Wang developed a self-heating battery to overcome the problem of poor performance in cold climates.
The battery uses an electric current to heat up in seconds compared to the hours an external heater required. By heating the battery from room temperature to around 140 degrees Fahrenheit—60 degrees Celsius—the battery gets an instant boost in reactivity because the law of kinetics is that reactivity increases exponentially with temperature.
“With these two steps I can get high safety when the battery is not being used and high power when it is,” he said.
The self-heating battery, called the All Climate battery, has been adopted by several car companies, including BMW, and was chosen to power a fleet of 10,000 vehicles that will be used to ferry people between venues at the next Winter Olympics in Beijing.
Full article here.
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March 5, 2020 at 05:03AM
Iowa Climate Science Education 