Motivated by a challenge from the Department of Energy to drastically reduce the cost of storing renewable energy on the grid while capturing more of it, a group of Massachusetts Institute of Technology scientists has developed a battery powered by sulfur, air, water, and salt—all readily available materials—that is nearly 100 times less expensive to produce than batteries currently on the market and can store twice as much energy as a lead-acid battery. The inventors present their prototype October 11 in the journal Joule.