Nano- and micro-sized LiNi0.5Mn1.5O4 particles are prepared via the thermal decomposition of a ternary eutectic Li-Ni-Mn acetate. Lithium acetate, nickel acetate and manganese acetate can form a ternary eutectic Li-Ni-Mn acetate below 80 degrees C. After further calcination, nano-sized LiNi0.5Mn1.5O4 particles can be obtained at an extremely low temperature (500 degrees C). When the sintering temperature goes above 700 degrees C, the particle size increases. and at 900 degrees C micro-sized LiNi0.5Mn1.5O4 particles (with a diameter of about 4 mu m) are obtained. Electrochemical tests show that the micro-sized LiNi0.5Mn1.5O4 powders (sintered at 900 degrees C) exhibit the best capacity retention at 25 degrees C, and after 100 cycles, 97% of initial discharge capacity can still be reached. Nano-sized LiNi0.5Mn1.5O4 powders (sintered at 700 degrees C) perform the best at low temperatures; when cycled at -10 degrees C and charged and discharged at a rate of 1 C, nano-sized LiNi0.5Mn1.5O4 powders can deliver a capacity as high as 110 mAhg(-1). (C) 2009 Elsevier Ltd. All rights reserved.