Although　considerable　effort　has　been　devoted　to　purifying　nitrogen　oxides　(NOx),　it　is　still　challenging　to　effectively　reduce　NO,　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.　(C)　2019　Science　China　Press.　Published　by　Elsevier　B.V.　and　Science　China　Press.　All　rights　reserved.