In the last few days stealth US battery start-up Form Energy leaked its technology to the Wall Street Journal in an exclusive interview in the hope of controlling the narrative arounds its value and the suitability of its technology to replace lithium ion in static grid energy storage. Most news outlets fell for it hook line and sinker – we’re not so sure. First the technology – it is iron oxide or rust-based – using a water based electrolyte, internal strips of iron and air – the re-charge process separates the oxygen and iron once again. In other words it is just like zinc and aluminum oxide batteries – and we are fairly sure there will be issues with it…