Vanadium Oxide Pillared by Interlayer Mg2+ Ions and Water as Ultralong-Life Cathodes for Magnesium-Ion Batteries

？ Bilayer structured Mg 0.3V 2O 5·1.1H 2O was developed via chemical modification of α-V 2O 5 ？ High voltage, high rates, and ultralong life for a MIB cathode ？ The pre-inserted Mg 2+ and water endow good structural stability and fast Mg 2+ diffusio