Earlier this year, a relatively unknown startup from Finland made a startling announcement: It had finally solved solid-state batteries.Not only that, but Donut Lab, a spinoff of Verge Motorcycles, said that its solid-state battery - long considered the "Holy Grail of batteries" for their high-density, durable, fast-charging abilities - would go into production later this year.Battery experts were understandably skeptical. After all, solid-state batteries are one of those technologies, along with artificial general intelligence and the hyperloop, that seem perpetually two years away. And while most legitimate efforts in this field - whet …Read the full story at The Verge.