<p>Na_2+2xFe_2-x(SO₄)₃ (NFS), as a novel cathode material for sodium-ion batteries, offers advantages such as low cost and environmental friendliness. This stems from its non-stoichiometric ratio generating fewer impurities during synthesis, effectively enhancing charge/discharge capacity, the ready availability of Na-Fe–O elements, and the absence of environmentally harmful byproducts during preparation. However, its inherent low conductivity limits its high-rate capability. To address this issue, a high-capacity Na_2+2xFe_2-x(SO₄)₃/CNT/AB cathode material was synthesized using the conventional spray drying method employed in lithium batteries. A mixed carbon source of carbon nanotubes (CNTs) and acetylene black (AB) was used with ethanol as the solvent. The composite carbon source facilitates electron conduction at the electrode/electrolyte interface by enabling AB to bridge the active material particles and CNTs, allowing rapid electron transfer to the external circuit. The synergistic effect of AB and CNTs within the composite sample constructs an efficient electron transport network, thereby improving the high-rate performance. At room temperature, the NFS/CNT/AB sample delivers a reversible capacity of 102 mAh g⁻¹, and a capacity retention of &gt; 94% is retained after 200 cycles at 2C. This work addresses the shortcomings of NFS within the CNT system and provides valuable insights for the development of Na_2+2xFe_2-x(SO₄)₃.</p>