Lithium-ion batteries are used in everything from your smartphone to your electric car, but researchers in Japan are looking to replace lithium with a much more abundant resource — sodium. Because sodium is more readily available, it could eventually lead to cheaper batteries, but in order to get it to work the team at the Tokyo University of Science had to develop a new kind of electrode. To make sodium batteries that can release as much energy as their lithium counterparts required an electrode made of an entirely new material — which was created by cramming three kinds of oxide into a pellet and heating it at high temperatures for half a day. The result put out the same amount of power as two AA batteries, though its ability to hold a charge dropped after 30 cycles. But even though your next iPhone may not feature a sodium ion battery, this breakthrough should help further the development of inexpensive rechargeable batteries.