BEHOLD - THE MRB

Magnesium rechargeable batteries (MRBs), in which high-capacity Mg metal is used as the anode material, are promising candidates for next-generation batteries due to their energy density, safety, and cost. However, the lack of high-performance cathode materials impedes their development.

Like their lithium-ion counterparts, transition metal oxides are the staple cathode materials in MRBs. Yet the slow diffusion of Mg ions inside the oxides poses a serious problem. To overcome this, some researchers have explored sulfur-based materials. 

But sulfur-based cathodes for MRBs have severe limitations: low electronic conductivity, sluggish Mg diffusion in solid Mg-S compounds, and dissolubility of polysulfides into electrolytes, which results in low-rate capability and poor cyclability.

Now, researchers at Tohoku University in Japan have developed liquid-sulfur/sulfide composite cathodes enabling high-rate magnesium batteries. Their paper has been published in the Journal of Materials Chemistry A.

The liquid-sulfur/sulfide composite materials can be spontaneously fabricated by electrochemically oxidizing metal sulfides, such as iron sulfide, in an ionic liquid electrolyte at intermediate temperatures (~150 ˚C). The composite material showed high performance in capacity, potential, cyclability, and rate capability - link - link - more like this - link