The　large　ionic　size　of　Na+　and　K+　leads　to　severe　volume　variation　and　sluggish　reaction　kinetics,　hindering　the　cycle　stability　and　specific　capacity　of　sodium/potassium-ion　batteries　(SIBs/PIBs).　It　is　of　great　importance　to　develop　high-performance　anodes　for　SIBs/PIBs　with　superior　stability,　high　capacity,　and　low　cost.　Herein,　we　elaborately　designed　MoSe2　encapsulated　in　biomass-derived　nitrogen　(N)-doped　carbon　(MoSe2/N–C)　composite,　where　chitosan　acts　as　an　adsorbent　and　carbon　precursor.　In　the　composite,　the　ultra-thin　MoSe2　nanosheets　compose　of　(size　of　ca.　10　nm)　nanocrystals　embed　on　the　chitosan　derived　N-doped　carbon.　The　resultant　MoSe2/N–C　electrode　exhibits　admirable　electrochemical　performance　for　SIBs　and　PIBs.　It　displays　a　Na　storage　capacity　of　505　mAh　g−1　at　0.1　A　g−1　for　100　cycles.　More　importantly,　the　composite　anode　also　exhibits　impressive　long-term　cycling　performance,　which　retains　266　mAh　g−1　at　1　A　g−1　over　1200　cycles.　When　employed　as　an　anode　of　PIBs,　it　also　displays　an　impressive　storage　capacity　of　240　mAh　g−1　at　0.1　A　g−1　after　100　cycles.　This　finding　is　expected　to　be　of　immediate　benefit　to　researchers　in　using　biomass　to　fabricate　energy　storage　applications.　©　2022　Elsevier　Ltd