Research status and prospect of rechargeable magnesium ion batteries cathode materials

Rechargeable Magnesium ion batteries (RMBs) are investigated as lithium-ion batteries (LIBs) alternatives owing to their favorable merits of high energy density, abundance and low expenditure of Mg, as well as especially non-toxic safety and low risk of dendrite formation in anodes, which endows them to be more easily assembled in electric-power vehicles for the extended application of civilian-military fields. Nevertheless, the high charge density, strong polarization effect, and slow diffusion kinetics of Mg2+ remain a large obstacle and thus enormous efforts have to be paid to mend the gap with commercial demand for cathode materials. At present, RMBs cathode materials mainly contain transition metal sulfides/oxides, polyanionic compounds and Prussian blue analogs, and several methods such as nano structuring, doping regulation and coating modification have been applied to materials design for better performance. In this paper, the current research status of RMBs cathode materials at home & abroad is arranged and summarized along with challenges of development in the future focusing on synthesis of RMBs cathode materials with high energy density as well as satisfactory cycling performance. And this analysis aims to provide reference and basis for researchers working on RMBs technology advancement.