LiMn2O4 nanoparticles were successfully prepared using suitable dosage carbon nanotubles (CNTs) as a fuel through multiphase combustion synthesis. The effects of CNTs on the structure and electrochemical performance of LiMn2O4 were investigated. Rate performance test demonstrates that CNTs dosage greatly affect the electrochemical behaviour of LiMn2O4 and LiMn2O4 prepared by choosing suitable CNTs dosage (7%) as a fuel (C7%-LMO) shows high rate charge–discharge capability. X-ray diffraction results indicate that C7%-LMO has the smallest distortion degree in the crystal, compared to LiMn2O4 prepared without CNTs (C0%-LMO) and LiMn2O4 prepared with 10% CNTs (C10%-LMO). SEM results reveal that the average particle size of C7%-LMO is about 100 nm, which is the smallest among the three samples (C0%-LMO, C7%-LMO and C10%-LMO). This unique microscopic features guarantee C7%-LMO possesses the highest discharge capacity, the best cycling performance and the lowest charge transfer resistance among the three samples.