The solid-state battery has been heralded as the next quantum leap for electromobility. Compared to the current lithium-ion batteries which power our smartphones, they should in future be able to store more energy in less time and also cost less, all without increasing in size. The name and the properties are down to their construction: Instead of moving through a fluid, as has previously been the case, the charges between the anode and cathode instead pass through a solid substance, such as ceramics or glass. This makes them less combustible and therefore easy to maintain. And yet, we will not see the back of burning batteries for some years to come. Researchers from Toyota, Samsung and MIT are still working on getting the technology ready for mass production.