American and European companies are racing to develop new batteries for electric vehicles using two readily available and less costly materials: sodium and sulfur. The new batteries could help bring more electric vehicles, or EVs, to the market and reduce China’s lead in battery production. Today's EVs run on lithium-ion batteries which cost about $10,000 to $12,000 to make. They are mostly made with lithium, cobalt, manganese and nickel. And the materials have increased in price during the last two years. The new batteries under development could cost one-third to two-thirds less. But their promise depends on overcoming difficulties in working with the materials. Sodium does not hold as much energy, while sulfur can easily damage key parts of a battery. Still, companies have brought in millions of dollars and government support to develop new kinds of batteries - called sodium-ion or lithium-sulfur.