FACTBOX-Sulfur and salt could power tomorrow's electric vehicles

Two future battery cathode chemistries — sodium ion and lithium sulfur — could unlock the door to more affordable electric vehicles while reducing reliance on scarce, expensive and unsustainably mined raw materials. But neither is likely to make it into volume production before 2025. Experts like Shirley Meng, chief scientist at the U.S. Argonne National Laboratory's Collaborative Center for Energy Storage Science, say diversifying battery materials is critical "to keep the cost low and the supply secure."

Some key elements of each chemistry: SODIUM ION Replaces: Lithium Supply: Abundant Cost: Extremely low Environmental Impact: Benign Recyclability: High Reliance on China: No Typical Anode Material: Hard carbon Upside: High stability, less flammable than lithium ion, easy to refine, uses same manufacturing equipment as lithium ion Downside: Low energy density, low cycle life, heavier than lithium ion LITHIUM SULFUR Replaces: Nickel, cobalt Supply: Abundant Cost: Extremely low Environmental Impact: Lower than cells that use nickel and cobalt, but lithium still not sustainably mined and refined Recyclability: High Reliance on China: No Typical Anode Material: Lithium metal Upside: High energy density, long range, lighter weight than lithium ion, potential for use in electric aircraft Downside: Limited cycle life, potential energy loss, electrode corrosion