Solid Power LLC is a Colorado University spinoff company founded for the development and commercialization of an innovative solid-state rechargeable battery. Solid Power was recently awarded a $3.4 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy for the purpose of creating a battery that can improve electric vehicle driving range.
The rechargeable batteries that are standard in today’s electric vehicles—as well as in a host of consumer electronics, such as mobile phones and laptops—are lithium-ion batteries, which generate electricity when lithium ions move back and forth between electrodes in a liquid electrolyte solution.
Engineers and chemists have long known that using lithium metal as the anode in a rechargeable battery—as opposed to the conventional carbon materials that are used as the anode in conventional lithium-ion batteries—can dramatically increase its energy density. But using lithium metal, a highly reactive solid, in conjunction with a liquid electrolyte is extremely hazardous because it increases the chance of a thermal runaway reaction that can result in a fire or an explosion.
The critical innovation added by Lee and Stoldt that allows their solid-state lithium battery to out-perform standard lithium-ion batteries is the construction of the cathode, the part of the battery that attracts the positively charged lithium ions once they’re discharged from the lithium metal. Instead of using a solid mass of material, Lee and Stoldt created a “composite cathode,” essentially small particles of cathode material held together with solid electrolyte and infused with an additive that increases its electrical conductivity. This configuration allows ions and electrons to move more easily within the cathode.
“The real innovation is an all-solid composite cathode that is based upon an iron-sulfur chemistry that we developed at CU,” Stoldt said. “This new, low-cost chemistry has a capacity that’s nearly 10 times greater than state-of-the-art cathodes.”
Specific attributes of the solid state battery technology includes:
* A specific energy (Wh/kg) that is nearly 3-times greater than current Li-ion batteries
* Low-cost ceramic ceramic precursor materials
* Materials that are inherently non-volatile and non-flammable