Breaking the 2 V Barrier in Aqueous Zinc Chemistry: Creating 2.45 and 2.8 V MnO 2 –Zn Aqueous Batteries

We report for the first time the creation of 2.45 and 2.8 V aqueous manganese dioxide (MnO 2 )|zinc (Zn) batteries without the use of expensive ion-selective membranes separating the anodes and cathodes. This new high-voltage aqueous battery (HiVAB) is able to charge and discharge 20–100% of MnO 2 ’s theoretical capacity (308 mAh/g) repeatedly for many cycles, thereby establishing this new MnO 2 |Zn battery as the forerunner for the possible replacement of lithium-ion batteries for applications where cost, safety, and energy density characteristics are considered paramount.