Na/K-ion　batteries　(SIBs/PIBs)　owing　to　their　low　cost,　earth　abundance,　appropriate　redox　potential　and　comparable　electrochemical　performance,　have　gained　ever-growing　attention.　Nevertheless,　it　remains　a　major　challenge　for　high　performance　of　SIBs/PIBs　applications.　Herein,　with　the　assistance　of　waste　chlorella　as　the　reactor　and　phosphorous　source,　we　designed　few-layered　tin　sulfides　immobilized　on　nitrogen　and　phosphorus　dual-doped　carbon　nanofibres　(SnSx-N/P-CNFs).　The　characterization　and　DFT　calculation　results　demonstrate　that　N/P　co-doping　is　expected　to　favour　the　distribution　of　electron　density　and　strengthen　ion　reaction　kinetics,　which　can　enhance　the　Na+/K+　storage　performance.　As　expected,　as　an　anode　material　for　SIBs,　the　SnSx-N/P–CNF　electrode　displays　an　impressive　capacity　(522　mAh　g−1　after　50　cycles　at　0.1　A　g−1)　and　promising　long-life　cycling　performance　(214　mAh　g−1　up　to　32,000　cycles　at　10　A　g−1).　Moreover,　it　also　exhibits　exceedingly　impressive　potassium-ion　storage　performance　(468　mAh　g−1　at　0.1　A　g−1　after　100　cycles　and　170　mAh　g−1　exceed　10,000　cycles　at　5　A　g−1),　which　is　the　one　of　the　optimal　long-cycle　properties　reported　for　Sn-based　anode　for　PIBs　to　date.　Our　work　provides　a　reference　for　using　biomass　algae　as　the　nitrogen　and　phosphorous　source　in　constructing　energy　storage　materials.　©　2021　Elsevier　Ltd