Mn-doped Li 3 V 2− x Mn x (PO 4 ) 3 nanocrystals with enhanced electrochemical properties for lithium-ion batteries were synthesized by aerosol process successfully. The nanocrystals synthesized from aerosol-assisted spray process have an average particle size smaller than 500 nm, with some initial particle size of about 100 nm. The Mn-doped Li 3 V 2 (PO 4 ) 3 cathode materials show higher capacity and coulombic efficiency than pure Li 3 V 2 (PO 4 ) 3 materials. Especially, the Mn-doped Li 3 V 1.94 Mn 0.06 (PO 4 ) 3 shows a capacity of 130 mAh/g in the voltage range of 3.0–4.4 V and a coulombic efficiency of 99.5 % at 1C. The results from XRD, SEM, HRTEM, and EIS suggested that lattice changes of Li 3 V 2 (PO 4 ) 3 due to Mn doping and the fine particles enabled by aerosol-assisted spray process can significantly reduce the charge-transfer resistance and improve the apparent Li + diffusion coefficient of insertion/desertion in the electrodes, which were the critical reason of better electrochemical performance of Mn-doped Li 3 V 2 (PO 4 ) 3 cathode materials.