A number of startups have developed promising prototypes, but working out how to manufacture these kinds of batteries at scale is a major challenge.Even newer solid-state battery companies are proposing to use the same production process, but Sakuú is taking a completely different approach.On its website, Sakuú claims this is because its manufacturing process allows for thinner structural layers and a novel stacked structure.Chinese battery maker Contemporary Amperex Technology and electric vehicle Leapmotor are working on ways to build batteries into the chassis of cars, while Tesla says it has devised a new glue that will make its batteries load-bearing, allowing them to be used as structural parts.While it told The Verge that each of its printers will eventually be able to churn out about 40 megawatt hours of energy storage—the equivalent of 500 electric car batteries—so far it only has a prototype of its machine, and it has not yet been used to make any batteries."