Porous nanoscaled LiMn2O4 sample has been successfully prepared by a polymer-assisted sol–gel method. The porous structure is composed of nanoparticles ranging from 50 to 100nm. The as-obtained LiMn2O4 exhibits specific capacity of 131mAhg−1 at 0.5C and 105mAhg−1 even at 20C. At 2C, the capacity retention reaches 73.3% after 1000 cycles at room temperature and 77.3% after 100 cycles at 60°C. Such outstanding rate capability and cyclic performance can be ascribed to the unique porous nanoscaled structure. Short Li-ion diffusion path and high diffusion coefficient lead to the superior rate capability. The improved cyclic performance originates from low Mn dissolution and accommodation to the structural distortion provided by the porous structure during cycling.