Solid-state batteries have become one of the most closely watched frontiers in clean-energy technology.
Their defining innovation is the replacement of the flammable liquid electrolyte, found in today's cells, with a stable solid one.
That single change promises higher energy density, notably faster charging and a substantially reduced risk of fire.
Unsurprisingly, engineers routinely cite them as the pivotal upgrade that could transform both electric vehicles and the emerging generation of humanoid robots.
The stumbling block, at least for now, is manufacturing: producing these cells reliably and affordably at large volumes has proved stubbornly difficult.
Because the commercial prize is so vast, however, a crowded field of established carmakers and specialist start-ups is pouring resources into cracking the problem.
The company that first delivers durable, mass-producible solid-state cells could reshape the economics of transport and robotics for a generation.