In this work, a novel aqueous battery consisting of manganese in (Mn Sn) redox chemistries is proposed, where Mn redox reactions occur in the positive electrode and Sn deposition/stripping reactions occur in the negative electrode. The battery exhibits an open circuit voltage of 1.7 V, while a coulombic efficiency of higher than 98.8% is obtained at an operating current density of 30 mA cm−2. Cyclic tests show that the energy efficiency can be kept above 91.5% with no observable decay at a current density of 10 mA cm−2. In addition, due to the high hydrogen overpotential of Sn metal, the parasitic hydrogen evolution reaction can be largely avoided. With decent battery performance, the Mn Sn system offers a promising solution for future energy storage applications.