Solid-state batteries remain several years from auto showrooms. The auto industry is pursuing the batteries, which replace liquid electrolytes with a solid ceramic or glass material, because of their potential to carry decisively more energy, charge faster and improve vehicle safety by reducing flammability over other types of lithium-ion batteries.Now, Mercedes-Benz and solid-state battery manufacturer Factorial Energy have reached a hopeful halfway point, strapping semi-solid-state cells to th...