LiMn1.5Ni0.5O4 powders were prepared by solution combustion synthesis using cetyltrimethylammonium bromide (CTAB) as fuel. The spinel LiMn1.5Ni0.5O4 powders were directly formed due to the low decomposition rate as characterized by thermal analysis and X-ray powder diffraction techniques. The microstructure observed by electron microscopy showed the particle size increased from 10 to 90 nm with the increase of fuel amount. However, the specific surface area decreased from 211 to 105 m(2) g(-1). The highest discharge capacity at 1C obtained for the LiMn1.5Ni0.5O4 powders synthesized at low fuel contents, which retain a capacity of 90 mAh g(-1) after 30 cycles due to the lower electrode resistance as confirmed by electrochemical impedance analysis. The high electrode kinetics was attributed to the small particle size and high specific surface area. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.