Magnesium-rare earth intermetallic compounds for high performance high power aqueous Magnesium-Air batteries

•Magnesium-rare earth intermetallic compounds as anodes for Mg-air battery are first investigated.•Mg3RE anodes provide higher power density and more stable discharge process.•The homogeneous RE doping in Mg3RE can suppress the H2 evolution and promote the uniform dissolution of substrate at high current.•The activation mechanism of Mg3RE anodes during discharge has been explored detailly.