Hard carbon, a commonly used anode material for sodium-ion batteries, often suffers from deteriorated sodium storage performance owing to excessive graphitization that leads to highly ordered crystallite growth.  Herein, a strategy for constructing soft–hard carbon composites (PPRCs) via pre-oxidized coal tar pitch and phenolic resin as raw materials is developed.  Through incorporating the three-dimensionally cross-linked network from phenolic resin during carbonization, the resulting PPRCs a high content of pseudo-graphitic domains (44.1%), an optimized interlayer distance (0.372 nm), and a greater number of closed pores interconnected by short-range ordered microcrystals. Tuning the phenolic resin content enables efficient modulation of the PPRCs microstructure. Employed as anode for sodium-ion batteries, the PPRCs deliver an enhanced sodium storage capacity, initial Coulombic efficiency and long-term cycling stability. The optimized PPRCs anode exhibits a reversible sodium storage capacity of 312 mAh g^-1 and an ICE of 74.98%, with a retention rate of 95.6% after 1000 cycles. When paired with a NaNi₁/₃Fe₁/₃Mn₁/₃O₂ cathode, the full cell delivers a higher reversible capacity of 342.8 mAh g^-1 with an ICE of 96.4% and maintains 141 mAh g^-1 at 200 mA g^-1, achieving a maximum energy density of 335.4 Wh kg^-1 at a power density of 16.9 W kg^-1. A synergistic sodium storage mechanism involving adsorption, intercalation, and pore filling is proposed. This work provides an effective strategy for designing advanced carbon anodes toward practical high-energy-density SIBs.
 

Soft–hard carbon composites; Pseudo-graphitic domains; Anode Material; Sodium-ion Battery; Electrochemical Performance