A LiCoMnO4 (5V spinel) material has been synthesized by annealing a sol–gel precursor utilizing lithium acetate, cobalt acetate, manganese acetate, and citric acid. The as-prepared sample has been determined to be LiCo1.09Mn0.91O4 via inductive coupled plasma-atomic emission spectroscopy. The deviation of the molar ratio of Co/Mn from 1:1 is designed to minimize the amount of LiMn2O4 impurity in our sample. The produced spinel material possesses an initial discharge capacity of 87.1mAhg−1 with two voltage plateaus at 5.1 and 4.9V. The LiCo1.09Mn0.91O4 cathode has been assembled with a Li4Ti5O12 anode to form a full-cell which delivered a discharge capacity of 131.2mAhg−1, centered at 3.2V. It is of great interest that despite the low coulombic efficiency of the full-cell, it shows good cyclic performance. In addition, The LiCo1.09Mn0.91O4/Li4Ti5O12 cell shows an excellent rate capability, delivering a capacity of 84.2mAhg−1, corresponding to a high power density of 4.70kWkg−1 at the current density of 1700mAg−1.