Vanadium-based　composite　anodes　have　been　designed　for　applications　in　alkali　metal　ion　batteries,　including　lithium-ion　batteries　(LIBs),　sodium-ion　batteries　(SIBs)　and　potassium-ion　batteries　(PIBs).　However,　the　problems　of　inferior　long-term　cycling　stability　caused　by　the　large　volume　change　and　dissolution　of　vanadium-based　active　materials　during　cycles　and　slow　diffusion　for　large　radii　of　Na+　and　K+　still　limit　their　underlying　capability　and　need　to　be　addressed.　In　the　present　work,　we　initially　designed　and　fabricated　a　vanadium　nitride/carbon　fiber　(VN/CNF)　composite　via　a　facile　electrospinning　method　followed　by　the　ammonization　process.　The　obtained　VN/CNF　composite　anode　exhibited　excellent　half/full　sodium　and　potassium　storage　performance.　When　used　as　an　anode　material　for　SIBs,　it　delivered　a　high　capacity　of　403　mA　h　g-1　at　0.1　A　g-1　after　100　cycles　and　as　large　as　237　mA　h　g-1　at　2　A　g-1　even　after　4000　cycles　with　negligible　capacity　fading.　More　importantly,　the　VN/CNFs//Na3V2(PO4)3　full　cell　by　coupling　the　VN/CNF　composite　anode　with　the　Na3V2(PO4)3　(NVP)　cathode　also　exhibited　a　desirable　capacity　of　257　mA　h　g-1　at　500　mA　g-1　after　50　cycles.　Besides,　when　further　evaluated　as　an　anode　for　PIBs,　the　VN/CNF　composite　anode　achieved　a　large　capacity　of　266　mA　h　g-1　after　200　cycles　at　0.1　A　g-1　and　maintained　a　stable　capacity　of　152　mA　h　g-1　at　1　A　g-1　even　after　1000　cycles,　showing　significant　long-term　cycling　stability.　This　is　one　of　the　best　performances　of　vanadium-based　anode　materials　for　SIBs　and　PIBs　reported　so　far.　©　2020　The　Royal　Society　of　Chemistry.