Spinel LiMn1.5Ni0.5O4 (LMNO) sub-micrometer-sized spheres were prepared in one step using porous MnCO3 microspheres as a self-supporting template. The LMNO spheres were characterized by XRD, SEM and TEM. The obtained LMNO was in a well-crystallized cubic phase with little impurity. It showed high rate capability and excellent cycling stability as a cathode material for lithium ion batteries. Initial discharge capacities of 122.0, 120.3, 119.5 and 112.1 mAh g(-1) were found at 2, 3,5 and 10C respectively with 1C being 146.7 mA g(-1). Their capacity retentions are 92, 91, 82 and 79% respectively after 500 cycles. The as-prepared LMNO is a promising cathode material for high power and long-life lithium ion batteries. (C) 2012 Elsevier B.V. All rights reserved.