Macroporous spinel-structured LiMn2O4 microparticles have been successfully prepared by a facile template-free synthesis process. Morphological characterization shows that the porous particles with size of about 4μm are composed of small primary particles of about 200nm with many tiny channels inside the microparticles. Electrochemical measurements reveal that the porous LiMn2O4 cathode has a high specific capacity and superior high rate performance. It exhibits a reversible discharge capacity of about 132.9mAhg−1 at a low charge/discharge rate of 0.1C. When tested at high rates of 20C and 50C, the discharge capacities still remain at 106 and 67mAhg−1, respectively. Furthermore, the porous LiMn2O4 possesses excellent cyclability. All the results suggest this porous LiMn2O4 to be highly promising for wide application in high power lithium ion batteries.