Sodium-ion　batteries　(SIBs)　have　been　regarded　as　a　promising　substitute　for　lithium-ion　batteries　but　there　are　still　formidable　challenges　in　developing　an　anode　material　with　adequate　lifespan　and　outstanding　rate　performance.　Transition　metal　dichalcogenides　(TMDs)　are　promising　anode　materials　for　SIBs　due　to　their　high　theoretical　capacities.　However,　their　severe　volume　expansions　and　low　electronic　conductivity　impede　their　practical　developments.　In　addition,　the　synthesis　of　energy　storage　materials　from　waste　biomass　has　aroused　extensive　attention.　Herein,　we　synthesize　WS2　nanocrystals　embedded　in　N　and　P　co-doped　biochar　via　a　facile　bio-sorption　followed　by　sulphurization,　employing　waste　chlorella　as　the　adsorbent　and　bio-reactor.　The　WS2　nanocrystals　are　beneficial　for　storing　more　sodium　ions　and　expediting　the　transportation　of　sodium　ions,　thus　improving　the　capacity　and　reaction　kinetics.　Chlorella　acts　as　a　reactor　and　not　only　inhibits　the　stacking　of　WS2　nanocrystals　during　the　synthesis　process　but　also　alleviates　the　mechanical　pressure　of　composite　during　the　charge/discharge　process.　As　a　result,　the　WS2/NPC-2　electrode　delivers　a　high　specific　capacity　(436　mA　h　g-1　at　0.1　A　g-1)　and　superior　rate　performance　of　311　mA　h　g-1　at　3　A　g-1　for　SIBs.　It　also　exhibits　excellent　stability　even　up　to　6000　cycles　at　5　A　g-1,　which　is　one　of　the　optimal　long-cycle　properties　reported　for　WS2-based　materials　to　date.　This　journal　is　©　The　Royal　Society　of　Chemistry.