Aqueous Zn||NO2 electrochemical cell

Abstract

The present invention relates to an electrochemical cell based on an aqueous Zn∥NO2 system with a nano-NiO catalyst deposited as gas diffusion cathode, a metallic Zn foil as anode and a ZnCl2 aqueous solution as electrolyte. Importantly, the electrolyte can efficiently capture NO2, then convert it to NO2 and eventually to the value-added NH3, while simultaneously producing electric power. The obtained electrochemical cell exhibits bifunctional activity and stability (>100 h) towards reversible NO2 reduction and evolution reactions. A high cell-level energy density of 553.2 Wh·kg−1cell/1589.6 Wh·L−1cell from pouch cells (2.4 Ah) has been achieved. As an additional green feature, the produced NO2− by the Zn∥NO2 cell is subsequently converted to NH3 by a self-power mechanism, thereby servicing multiple key conversion steps in the nitrogen cycle all within a single device, paving the way to scalable, highly integrated solutions.

Dependencies are inferred from the claim text.