Spenel lithium manganese oxides with a nominal composition of LiMn2O4 are prepared by using a conventional ceramic synthesis method and are coated by a chemical deposition of silver particles. The silver-coated nano-particle LiMn2O4 shows excellent cycleability at 2C galvanostatic conditions. The high surface electronic conductivity caused by the metal coating reduces cell polarization. The results indicate that such surface treatment of cathode powders should be an effective way to improve cycle-life with high current retention.