Hard carbon is the sole anode material employed in commercial sodium-ion batteries. However, its intrinsic defects and impurities will lead to battery failure, diminishing further development of sodium batteries in energy storage. Here, an acrylonitrile copolymer and poly(ethylene oxide) (LA/PEO) composite binder is developed to address these challenges in biomass-derived hard carbon. Typical commercial biomass-derived hard carbon with this binder (HC-LA/PEO) achieved an initial coulombic efficiency (ICE) of 91.1% and a reversible capacity of 341.12 mAh g