The lithium-ion battery cathode materials spinel LiMn2O4, LiAl0.1Mn1.9O4 and Li0.94Na0.06Al0.1Mn1.9O4 materials are synthesised by sol–gel method. The structure, morphology and electrochemical performances of the aluminium and sodium co-doped materials are studied by X-ray diffraction measurement, scanning electron microscopy, and Electron diffraction spectroscopy, respectively. The results reveal that appropriate amount doping of aluminium and sodium does not change the spinel structure of LiMn2O4. Those materials have a good crystallinity and the sizes are approximately 150 nm. The initial discharge capacity of Li0.94Na0.06Al0.1Mn1.9O4 is 113.8 mAh/g at 0.5 C. Compared with the rate capability of LiMn2O4, the discharge capacity of 107.5 mAh/g at 5 C for Li0.94Na0.06Al0.1Mn1.9O4 has 46.8% improvement. Obviously, aluminium and sodium co-doping is a very effective way to improve LiMn2O4 rate capability.