The three main components of a lithium-ion battery—anode, cathode, and electrolyte—must all be optimized to produce a safe, low-cost, and high-energy product. The cathode has traditionally been the most expensive piece; it stores energy in ordered crystal structures that are based on costly and rare metals, like cobalt. In contrast, manganese is inexpensive, earth abundant, and non-toxic, but substituting the disordered crystal structures of manganese for cobalt-based structures had long been thought to introduce an energy tradeoff. Now, researchers have delivered outstanding performance using two new manganese-based materials.