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Promising shorter charge times and more energy for longer range travel, the technology was developed by engineers at Pennsylvania State University.
“The need for smaller, faster-charging batteries is greater than ever,” said Professor Chao-Yang Wang, lead author on the study. “There are simply not enough batteries and critical raw materials, especially those produced domestically, to meet anticipated demand.”
California, which is the largest automotive market in the US, recently joined countries such as the UK by announcing a ban on new petrol and diesel cars. “By 2035, the largest auto market in the United States will effectively retire the internal combustion engine,” the research announcement said.
If new car sales are going to shift to battery-powered EVs, Wang said, they will need to overcome two major drawbacks – they are too slow to recharge and too large to be efficient and affordable. Instead of taking a few minutes at the petrol station, some EVs can take all day to recharge depending on the battery.
“Our fast-charging technology works for most energy-dense batteries and will open a new possibility to downsize EV batteries from 150 to 50 kWh without causing drivers to feel range anxiety,” said Wang, whose lab partnered with start up EC Power to develop the technology. “The smaller, faster-charging batteries will dramatically cut down battery cost and usage of critical raw materials such as cobalt, graphite and lithium, enabling mass adoption of affordable electric cars.”
The technology relies on internal thermal modulation, an active method of temperature control to demand the best performance possible from the battery, Wang said.
Batteries operate most efficiently when they are hot, but not too hot. Keeping batteries consistently at just the right temperature has been a major challenge for battery engineers. Historically, they have relied on external, bulky heating and cooling systems to regulate battery temperature, which respond slowly and waste a lot of energy, the researchers said.
Wang and his team decided to instead regulate the temperature from inside the battery. The team developed a new battery structure that adds an ultrathin nickel foil as the fourth component alongside the anode, electrolyte and cathode. Acting as a stimulus, the nickel foil self-regulates the battery’s temperature and reactivity, which allows for 10-minute fast charging on “just about any EV battery”, Wang claimed.
“True fast-charging batteries would have immediate impact,” the researchers said. “Since there are not enough raw minerals for every internal combustion engine car to be replaced by a 150 kWh-equipped EV, fast charging is imperative for EVs to go mainstream.”
EC Power is working to manufacture and commercialise the fast-charging battery.
The work, which was published in Nature, was supported by the US Department of Energy, the US Department of Defence, the US Air Force and the William E Diefenderfer Endowment.
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