Sulphur and salt could power tomorrow's EVs

Two future battery cathode chemistries — sodium ion and lithium sulphur — 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 US 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”.

Here are 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 SULPHUR

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