Magnesium-sulfur batteries, which combine a magnesium anode with a sulfur cathode, is a promising electrochemical couple for next-generation, high energy density batteries because of the advantages of good safety, low cost, and a high theoretical energy density—higher than that achievable with lithium.

However, magnesium sulfur batteries are still in a very early stage of research and development, with the discovery of suitable electrolytes one of the key challenges for further improvement.

The new electrolyte is characterized by a number of promising properties, including an unprecedented electrochemical stability window and a very high efficiency. In addition, the electrolyte can be used in various solvents and at high concentrations. Moreover, the electrolyte is chemically compatible with a sulfur cathode, which can be discharged at a voltage close to the theoretical value.

Another advantage is the very simple production of the electrolyte using two commercially available standard chemicals, a magnesium amide and aluminium chloride.

The first use of modified electrolytes in glymes and binary solvents of glyme and ionic liquid shows beneficial effects on the performance of magnesium sulfur batteries.

—Zhao-Karger et al.

Resources

• Zhirong Zhao-Karger, Xiangyu Zhao, Di Wang, Thomas Diemant, R. Jürgen Behm, and Maximilian Fichtner (2014) “Performance Improvement of Magnesium Sulfur Batteries with Modified Non-Nucleophilic Electrolytes” Advanced Energy Materials, doi: 10.1002/aenm.201401155