A step towards realising a rechargeable magnesium/sulphur battery is demonstrated in Nature Communications this week. This potentially low-cost, high energy density rechargeable battery could be suitable for use in electric vehicles.

Owing to its natural abundance and high capacity for storing energy, magnesium is an ideal rechargeable battery anode material. The surface chemistry of magnesium limits the choice of compatible cathodes and electrolytes. Sulphur cathodes are low-cost and have a high theoretical capacity, but coupling requires a specific type of electrolyte. John Muldoon and colleagues prepare a non-nucleophilic electrolyte from hexamethyldisilazide magnesium chloride and aluminium trichloride, and show its compatibility with a sulphur cathode.

These proof-of-concept results may represent a step towards practical rechargeable magnesium/sulphur rechargeable batteries; however, the authors note that new solvents are needed to reduce the polysulphide sulphur dissolution, which reduces the availability of active sulphur material.