Spinel LiMn 2− y M y O 4 (M = Cr and Co, where y = 0.0, 0.1, and 0.2) powders with narrow and uniformly sized particles were successfully synthesized by microwave-induced combustion, using lithium nitrate, manganese nitrate, chromium nitrate, cobalt nitrate, and urea as the starting materials. The LiMn 2− y M y O 4 powders synthesized by microwave-induced combustion were investigated by thermogravimeter analyzer (TGA), X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The Cr and Co-substituted spinel samples were used as cathode materials for lithium-ion battery, whose discharge capacity and electrochemical characteristic properties in terms of cycle performance were also investigated. The results revealed that the Li/LiMn 2− y M y O 4 (M = Cr, Co) cells can be ranked in terms of initial capacity as follows: LiMn 2O 4 > LiMn 1.9Cr 0.1O 4 > LiMn 1.9Co 0.1O 4 > LiMn 1.8Cr 0.2O 4 > LiMn 1.8Co 0.2O 4. The Li/LiMn 2− y M y O 4 (M = Cr, Co) cells showed lower fading rate than Li/LiMn 2O 4 cell during 30 cycles, while Cr-substituted spinel exhibited the lower fading rate than Co-substituted spinel. On the other hand, the fading rate of Li/LiMn 2− y M y O 4 cells can be ranked as follows: LiMn 2O 4 > LiMn 1.9Co 0.1O 4 > LiMn 1.8Co 0.2O 4 > LiMn 1.9Cr 0.1O 4 > LiMn 1.8Cr 0.2O 4.