Magnesium-ion batteries (MIBs) show great potential for large-scale energy storage because of the advantages of low cost and safety, but their application is severely hindered by the difficulty in finding desirable electrode materials. Herein, we develop a bilayer-structured vanadium oxide (Mg 0.3 V 2 O 5 $1.1H 2 O) with synergistic effect of Mg 2+ ions and lattice water as the cathode material for MIBs. The pre-intercalated Mg 2+ ions provide high electronic conductivity and excellent structural stability. The lattice water enables fast Mg 2+ ions mobility because of its charge shielding effect. As a result, the Mg 0.3 V 2 O 5 $1.1H 2 O exhibits excellent rate performance and an unprecedented cycling life with capacity retention of 80.0% after 10,000 cycles. In addition, the Mg 0.3 V 2 O 5 $1.1H 2 O exhibits good electrochemical performance in full MIBs. This scalable Mg 2+ host material is a promising candidate as a cathode for MIBs, and its high performance is expected to meet the requirements for large-scale storage applications.

The development of rechargeable magnesium ion batteries (MIBs) has received increasing attention due to its low cost, high theoretical volumetric capacities, environmental friendliness and good safety.

No abstract