New Lithium-Metal Battery Could Double the Range of EVs

The key variable for every electric vehicle is energy density – the higher the watt-hours per kilogram (Wh/kg), the longer the electric range and the more EVs become functionally similar to internal combustion engines. And a team at the U.S. Department of Energy’s Pacific Northwest National Laboratory has created a new type of lithium-metal battery with an exceptionally high number of cycles (and the archetypical energy density for that sort of battery).

Typically, lithium-metal batteries store far more energy than their lithium-ion cousins, but the lifetime of the former was a tiny fraction of the latter – four years ago, a lithium-metal battery could last about 50 cycles, while lithium-ion variants can persevere for at least 1,000 cycles.

But the gap is closing – the scientists at the PNNL used thin strips of lithium (about 20 microns wide) to create a lithium-metal battery that lasts about 600 cycles and with an absurd energy density of 350 Wh/kg. And the team is aiming even higher – they intend to reach at least 500 Wh/kg, hence the DOE’s multi-institutional Innovation Center for Battery500 Consortium (emphasis mine).

For reference, the average energy density of lithium-ion batteries is around 50-260 Wh/kg, with most modern ones hovering around 200-250 Wh/kg. Needless to say, doubling that amount would dramatically change our conception of an EV’s range, maybe even solving the mythical “range anxiety.”

And the team is getting close to their titular goal, though much work remains.

“The Battery500 Consortium has made great progress in increasing the energy density and extending the cycle life,” said Distinguished Professor M. Stanley Whittingham of Binghamton University, the 2019 Nobel Prize laureate in chemistry. “But much more needs to be done. In particular, there are safety issues with lithium-metal batteries that must be addressed. That’s something that the Battery500 team is working hard to resolve.”

Read more about this development here.