Mixing a form of rust and water might help to make inexpensive battery electrodes with long cycle lives a real possibility. If they have much higher energy densities than more expensive “conventional” electrodes used in lithium batteries, so much the better. Zhaolin Liu of the A*STAR (Agency for Science, Technology and Research) Institute of Materials Research and Engineering, Singapore; Aishui Yu of Fudan University, China, and co-workers have created an electrode material that’s not only inexpensive, but scalable to large-scale manufacturing. Normally, lithium batteries “shuttle” lithium ions between two electrodes connected in a circuit. According to A*STAR, “During charging, lithium ions escape from the cathode, which is made from materials such as lithium cobalt oxide. The ions migrate through a liquid electrolyte and into the anode, which is usually made of graphite riddled with tiny pores. When the battery discharges, the process runs in reverse, generating an electrical current between the electrodes.” That norm for lithium batteries tends to reduce …