SnSe— a material that shows great promise for allowing commercial solid-state batteries. The tube-like filaments show the liquid-like distribution of silver ions flowing through the crystalline scaffold of tin and selenium atoms . Credit: Olivier Delaire, Duke University
These limitations stem primarily from the chemically reactive liquid electrolytes inside Li-ion batteries that allow lithium ions to move relatively unencumbered between electrodes. While great for moving electric charges, the liquid component makes them sensitive to high temperatures that can cause degradation and, eventually, a runaway thermal catastrophe.
“Every electric vehicle manufacturer is trying to move to new solid-state battery designs, but none of them are disclosing which compositions they’re betting on,” Delaire said. “Winning that race would be a game changer because cars could charge faster, last longer, and be safer all at once.” “It’s sort of like the silver atoms are marbles rattling around about the bottom of a very shallow well, moving about like the crystalline scaffold isn’t solid,” Delaire said. “That duality of a material living between both a liquid and solid state is what I found most surprising.”