Ultrafast charging, the Holy Grail of batteries, has been elusive for years. It is one big reason—perhaps the biggest—why electric cars have not taken off the way they should have and the way many have hoped. But now, an international team of researchers has uncovered the secret to superbatteries: ones not just a lot more energy dense than what we currently have, but also capable of delivering an electric charge much faster than existing batteries. The secret has to do with how electricity is stored in a group of fascinating materials called transition-metal oxides. These compounds, made up of oxygen bound with iron, nickel, zinc, or another transition metal, can store electricity physically, inside themselves, and they can store a lot of it. That is compared to the dominant lithium-ion technology where lithium ions move from anode to cathode (made from the same materials) or change their crystal structure […]