Stellantis has put one of the auto industry's most closely watched battery concepts into a vehicle prototype, taking it beyond lab work. The automaker says a Dodge Charger Daytona prototype now uses battery cells from Factorial, an early sign that new EV battery designs may be moving closer to everyday use. What happened? Stellantis says it fitted the test vehicle with Factorial Electrolyte System Technology solid-state cells and started on-road…