Recent　theoretical　studies　revealed　that　two-dimensional　(2D)　antimonene　has　attractive　characteristics,　such　as　superior　photothermal　conductivity,　absorption　over　a　wide　range,　high　mobility,　and　good　spintronic　properties.　Herein,　we　report　a　reliable　liquid　phase　exfoliation　(LPE)　route　for　the　preparation　of　high-quality　high-stability　atomically　thin　(AT)　antimonene　via　high　ultrasonic　power.　The　AT　antimonene　delivers　a　high　specific　capacity　of　up　to　860　mA·h·g–1,　with　high　rate　capability　and　good　cycling　stability　as　an　anode　of　a　sodium　ion　battery　(SIB).　The　good　conductivity　and　2D　structure　endow　AT　antimonene　with　more　active　sites　for　sodium　storage,　a　facilitated　pathway　for　electron　transfer　and　mass　transport,　and　the　capability　to　reduce　the　volume　expansion　during　the　discharge–charge　process.　[Figure　not　available:　see　fulltext.].　©　2018,　Tsinghua　University　Press　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.