A facile sol–gel approach combined with a carbon-coating technique via high-temperature thermally decomposing C₂H₂ has been developed for the synthesis of a Li₃V₂(PO₄)₃/C (LVP/C) cathode material employing the biomass of phytic acid as an eco-friendly phosphorus source. The effects of the carbon-coating on the structural, morphological and electrochemical properties of LVP have been investigated. Compared with pristine LVP, the LVP/C composite presents a higher discharge capacity of 127 mA h g⁻¹ at 0.1 C, better rate capability and long-term cyclability in the voltage range of 3.0–4.3 V. Even at a high charge–discharge rate of 5 C, it can still deliver a reversible capacity of 107 mA h g⁻¹ over 400 cycles without obvious fading, demonstrating great potential as a superior cathode material for lithium-ion batteries.