Conversion-type　transition　metal　phosphides　(TMPs)　are　competitive　anode　materials　to　overcome　the　volumetric　energy　density　limits　of　hard　carbon for　sodium-ion　batteries　(SIBs).　However,　the application　of　TMPs　is　generally　constrained　by　their　low　initial　coulombic　efficiency　(ICE),　unsatisfied　cycling　stability　and　poor low-temperature (LT)　performance.　Herein,　a　green　synthesis　method　is　reported　to　prepare　carbon　quantum　dots　modified　Cu3P　nanoparticles　anchored　on　carbon　fibers　(CF@Cu3P-CQDs)　as　anode　for　high-energy　and　LT　SIBs.　It　is　disclosed　that　such　a　structure　enables　good　interface　contact　between　electrodes/electrolytes,　thus　prompting　the　formation　of　a　uniformly　fine　solid　electrolyte　interphase　and　hence　a　record-high　ICE　of　93%　with　a　volumetric　capacity　of　1343　mAh·cm−3.　Distribution　of　relaxation　time　analysis　unveils　that　the　rapid Na+ transfer　between　electrode/electrolyte　interfaces　and　Na+ diffusion　ability　in　CF@Cu3P-CQDs　underlies　the　main　reason　for　its　high-rate　capability　(369–101　mAh·g−1 @0.1-50　C)　and　LT　performance　(368/350　mAh·g−1　@　0.1C　under　−20/−40 °C).　Promisingly,　the　CF@Cu3P-CQDs　are　directly　used　toward　three　cathode　materials　(namely　P2-type　Na0.78Ni0.31Mn0.67Nb0.02O2, carbon　coated　Na3V2(PO4)3, and　low-cost　Na4Fe3(PO4)2P2O7) without　pre-sodiation　process　to　assemble　full-cells.　This　work　sheds　light　on　the　fundamental　understanding　of　electron/ion　transfer　kinetics of　TMPs during　de/sodiation　and　lays　a　foundation　for　the　practical　application　of　TMPs.　©　2025　Wiley-VCH　GmbH.