Researchers at the University of Michigan have developed a new rechargeable technology for batteries that could drastically extend the range of the electric vehicles or the time between cell phone charges.
The lithium ion battery, the current standard for battery technology, became the norm in the early 1990s, when it was found that such technology was more stable than the rechargeable lithium metal batteries tested in the 1980s.
Those early lithium metal batteries used liquid electrolytes, and in the battery environment, the lithium traveling between the electrodes formed “metal whiskers”, the so-called dendrites that can create a short circuit and cause the batteries to catch fire and even explode.
Now the University of Michigan researchers say that their battery breakthrough—using a ceramic, solid-state electrolyte in lithium metal batteries—solves the short-circuiting and poor durability issues with those batteries, in what could be a game-changer and a roadmap to what could be the next generation of rechargeable batteries.
The current widely used lithium ion batteries use graphite to prevent the forming of the metal whiskers, but energy density and capacity with graphite is much lower than the energy density in lithium metal in a solid-state battery, the scientists say in the research funded by the Advanced Research Project Agency-Energy and the Department of Energy.
Current lithium ion batteries max out with a total energy density at around 600 watt-hours per liter (Wh/L) at the cell level, while solid-state batteries can reach 1,200 Wh/L, according to the researchers.
“It’s not combustible. We make it at over 1,800 degrees Fahrenheit in air. And there’s no liquid, which is what typically fuels the battery fires you see,” said Jeff Sakamoto, a UofM associate professor of mechanical engineering who leads the work.
The new lithium metal battery technology not only prevents fires, but it also dramatically improves charging rates, the researchers say.
“Up until now, the rates at which you could plate lithium would mean you’d have to charge a lithium metal car battery over 20 to 50 hours (for full power),” Sakamoto said. “With this breakthrough, we demonstrated we can charge the battery in 3 hours or less.”