Sodium/potassium-ion　batteries　(SIBs/PIBs)　arouse　intensive　interest　on　account　of　the　natural　abundance　of　sodium/potassium　resources,　the　competitive　cost　and　appropriate　redox　potential.　Nevertheless,　the　huge　challenge　for　SIBs/PIBs　lies　in　the　scarcity　of　an　anode　material　with　high　capacity　and　stable　structure,　which　are　capable　of　accommodating　large-size　ions　during　cycling.　Furthermore,　using　sustainable　natural　biomass　to　fabricate　electrodes　for　energy　storage　applications　is　a　hot　topic.　Herein,　an　ultra-small　few-layer　nanostructured　MoSe2　embedded　on　N,　P　co-doped　bio-carbon　is　reported,　which　is　synthesized　by　using　chlorella　as　the　adsorbent　and　precursor.　As　a　consequence,　the　MoSe2/NP-C-2　composite　represents　exceedingly　impressive　electrochemical　performance　for　both　sodium-ion　batteries　(SIBs)　and　potassium-ion　batteries　(PIBs).　It　displays　a　promising　reversible　capacity　(523　mAh　g−1　at　100　mA　g−1　after　100　cycles)　and　impressive　long-term　cycling　performance　(192　mAh　g−1　at　5　A　g−1　even　after　1000　cycles)　in　SIBs,　which　are　some　of　the　best　properties　of　MoSe2-based　anode　materials　for　SIBs　to　date.　To　further　probe　the　great　potential　applications,　full　SIBs　pairing　the　MoSe2/NP-C-2　composite　anode　with　a　Na3V2(PO4)3　cathode　also　exhibits　a　satisfactory　capacity　of　215　mAh　g−1　at　500　mA　g−1　after　100　cycles.　Moreover,　it　also　delivers　a　decent　reversible　capacity　of　131　mAh　g−1　at　1　A　g−1　even　after　250　cycles　for　PIBs.　©　2019　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim