This solid-state battery technology is still a long way from being commercial—Solid Power plans to ramp up production of enough material to produce 800,000 cars a year by 2028—but if it proves practical, batteries could greatly improve the performance of electric vehicles.
However, in the future, Solid Power will not manufacture or sell complete batteries. Instead, it will supply solid electrolyte to other battery makers, says CEO Doug Campbell.
Electrolyte shuttles are charged inside the battery as it charges or releases energy. The lithium-ion batteries that power electric vehicles today use a liquid electrolyte; Solid-state batteries use a solid electrolyte layer that sits between the other layers of the battery to distill charge.
This approach opens up new possibilities for battery chemistry. In particular, lithium metal and silicon based chemistries are unstable or unsafe when combined with a liquid electrolyte in a cell, but could theoretically be used if the solid is substituted instead.
The result will be a battery that can store more energy in a smaller space, meaning cars can go farther before running out of power. Solid Power batteries could eventually improve the energy density of lithium-ion batteries by about half, Campbell says, so a car that used to go 350 miles before it needed to be recharged could have more than 500 miles of range.
Campbell adds that avoiding fluids will also make it easier to create safer cages. While lithium-ion batteries have been designed with protection to ensure they don’t catch fire or explode, removing the liquid will in turn eliminate the need for these costly add-ons. Multi-cell batteries can be denser because their internal temperature control and safety systems require less space.
The concept of extracting liquid electrolytes from battery cells is not new, says Lei Cheng, chemist and battery researcher in the materials department of the Argonne National Laboratory. However, for many years much of the research on solid batteries has focused on the use of organic polymers such as polyethylene oxide.