Investigations toward a Non‐Aqueous Hybrid Redox‐Flow Battery with a Manganese‐Based Anolyte and Catholyte

A new all-Manganese flow battery (all-MFB) as a non-aqueous hybrid redox-flow is reported. The discharged active material [Cat]2[MnIICl4] (Cat = organic cation) utilized in both half-cells supports long cycle life. reversible oxidation of [MnIICl4]2− to [MnIIICl5]2− at the positive electrode and manganese metal deposition from negative give cell voltage 2.59 V. Suitable electrolytes are prepared optimized, followed by characterization static cells pumped flow-cell. Several materials, solvents, membranes tested for their feasibility all-MFB. An electrolyte consisting [EMP]2[MnCl4] some solvent γ-butyrolactone cycled 500 times, well flow-cell, over period two months, with coulombic efficiencies up 83%. With this work, energy densities 74 Wh L−1 possible, exceeding VRFB benchmark system, using solely cheap abundant element material. Although further optimizations necessary, system represents promising setup toward sustainable stationary storage.