In January, a Finnish-Estonian startup proclaimed it had developed a truly solid state battery, a holy grail for the technology industry. Donut Labs’ cell wasn’t just solid state, however. It claimed it was made from cheap and easily available materials, would charge to full in a few minutes and last for hundreds of years. If real, such a device would change the face of the world, which is why plenty of people don’t think it is. And, as the company makes more effort to demonstrate it is telling the truth, the more holes people are finding to poke their fingers into. So, what the hell is going on with Donut Labs’ battery? After many weeks of research, I’m throwing my hands in the air, tired of the endless dog and pony show the company is putting on. Solid state batteries Conventional batteries have improved a lot in the last few decades but remain imperfect in many ways. Cells found in electronics and EVs commonly use liquid or gel polymer as an electrolyte.…