The battery world is a fascinating place to be right now. There is so much innovation going on as the world sets course towards a battery-powered future. The difficulty for observers is knowing what is a legitimate breakthrough and what is just hype that will never be commercialized. Still, some undeniable trends have emerged, and chief among them is that lithium ion battery improvements are nearing their limit. This is a natural development. It was bound to happen, especially given the pace of improvement in this dominant type of battery over the last decade or so. The main problems with Li-ion batteries remain: relatively high cost, insufficient energy density in a context of ever-higher energy density demand, and safety issues because of the liquid electrolyte these batteries use. The batteries of tomorrow seek to solve these problems, and some battery researchers report success (although these alternatives have yet to […]