Room-temperature reduction of NO2 in a Li-NO2 battery: a proof of concept.

Although considerable effort has been devoted to purifying nitrogen oxides (NOx), it is still challenging to effectively reduce NOx at room temperature and ambient pressure without catalysts. In this study, as a proof-of-concept, we have for the first time demonstrated the room-temperature reduction of nitrogen dioxide (NO2) using a rechargeable lithium-nitrogen dioxide (Li-NO2) battery. The battery shows a capacity of 884 mAh g-1 at 50 mA g-1 (an actual energy density of 666 Wh kg-1) and a promising electrochemical Faraday efficiency (FE) of 67%. The unique properties of Li-NO2 rechargeable batteries not only provide a way to reduce and recycle NO2 but also highlight the potential of oxidative air pollutants as energy sources for next-generation electrochemical energy storage (EES) systems.