Membrane-Free Zn/MnO2 Flow Battery for Large-Scale Energy Storage

Stanford researchers have developed a low cost, safe, environmentally friendly, rechargeable Zn/MnO₂ flow battery with the potential for grid scale energy storage. Due to capacity decay, primary (non-rechargeable) Zn/MnO₂ batteries have dominated until now. The Yi Cui Group addresses capacity decay/poor cathode reaction reversibility in their membrane-free aqueous flow Zn/MnO₂ battery, where the anode is zinc-based chemistry with the reversible Zn2+/Zn deposition/stripping reaction, and the cathode is based on the dissolution-precipitation reaction (Mn2+/MnO2).

The cell consists of MnSO₄ solution as catholyte and ZnSO₄ solution as anolyte, that mix without a membrane between the two electrodes with carbon felt as cathode collector and Zn metal foil as current collector (figure 1). This redox flow battery exhibits excellent energy density and cycling stability (figure 2), and has great potential to achieve large-scale energy storage.

Stage of Development - Proof of Concept