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Abstract The utilization of redox‐active gas as cathode materials has been proposed as a promising approach to meet the demand for next‐generation battery technologies. Toward this end, nitrogen oxides (NO_x)—inexpensive, abundant gases readily produced from ammonia on an industrial scale—is a promising energy storage media; however, its utilization as cathode material has not been achieved. In this work, the cage effect of NO and NO₂radicals are utilized to stabilize the charge product of Li‐NO_xcell as N₂O₃. This cell operates via reversible redox of LiNO₃to N₂O₃, achieving a specific capacity of 1,570 mA h g_carbon⁻¹or 25 mA h cm_electrode⁻² at a full cell voltage of 3.85 V with an average energy efficiency of 89% at a current density up to 2 mA cm_electrode⁻². These metrics represent one of the highest areal capacity, current density, cell voltage, and energy efficiency reported for a metal‐gas cells. 

Abstract There is a strong interest in finding highly soluble redox compounds to improve the energy density of redox flow batteries (RFBs). However, the performance of electrolytes is often negatively influenced by high solute concentration. Herein, we designed a high‐potential (0.5 V vs. Ag/Ag⁺) catholyte for RFBs, where the charged and discharged species are both gaseous nitrogen oxides (NO_x). These species can be liberated from the liquid electrolyte and stored in a separate gas container, allowing scale‐up of storage capacity without increasing the concentration and volume of the electrolyte. The oxidation of NO in the presence of NO₃⁻affords N₂O₃, and the reduction of N₂O₃regenerates NO and NO₃⁻, together affording the electrochemical reaction: NO₃⁻+3 NO⇌2 N₂O₃+e⁻with a low mass/charge ratio of 152 grams per mole of stored electron. A proof‐of‐concept NO_xsymmetric H‐cell shows 200 stable cycles over 400 hours with >97 % Coulombic efficiency and negligible capacity decay. 

Aqueous zinc-ion batteries (AZIBs) are promising candidates for large-scale electrical energy storage due to the inexpensive, safe, and non-toxic nature of zinc. One key area that requires further development is electrode materials that store Zn 2+ ions with high reversibility and fast kinetics. To determine the viability of low-cost organosulfur compounds as OEMs for AZIBs, we investigate how structural modification affects electrochemical performance in Zn-thiolate complexes 1 and 2. Remarkably, modification of one thiolate in 1 to sulfide in 2 reduces the voltage hysteresis from 1.04 V to 0.15 V. While 1 exhibits negligible specific capacity due to the formation of insulating DMcT polymers, 2 delivers a capacity of 107 mA h g −1 with a primary discharge plateau at 1.1 V vs. Zn 2+ /Zn. Spectroscopic studies of 2 suggest a Zn 2+ and H + co-insertion mechanism with Zn 2+ as the predominant charge carrier. Capacity fading in Zn-2 cells likely results from the formation of (i) soluble H + insertion products and (ii) non-redox-active side products. Increasing electrolyte concentration and using a Nafion membrane significantly enhances the stability of 2 by suppressing H + insertion. Our findings provide insight into the molecular design strategies to reduce the polarization potential and improve the cycling stability of the thiolate/disulfide redox couple in aqueous battery systems.