The combination of a highly exfoliated, graphene-like MoS2 cathode and ultrasmall Mg nanoparticle anode is proposed, for the first time, for rechargeable Mg batteries. Such a configuration exhibits an operating voltage of 1.8 V and a well reversible discharge capacity of ca. 170 mA h g(-1), emphasizing the necessity of rational morphological control of electrode materials and opening up new opportunities for rechargeable Mg batteries.