Electrochemical study on LiCo1/6Mn11/6O4 as cathode material for lithium ion batteries at elevated temperature

A novel process via sintering of a precursor from the solution of metal acetates by spray-drying technology was used to synthesize Co-substituted LiCo_1/6Mn_11/6O₄ material for lithium ion batteries. The as-prepared particles were identified as single-phase spinel structure without any impurities in the XRD pattern. The SEM image showed that the particles had good cubic shapes and uniform size distribution with sizes of about 100–200 nm. An ex situ XRD technique was used to characterize the first charge process of the LiCo_1/6Mn_11/6O₄ electrode. The result suggested that the material configuration maintained invariability. The electrochemical properties of the synthesized cathode material were investigated using Li-ion model cells at room and elevated temperature, respectively. In the charge/discharge potential of 3.5–4.4 V at 1/10 C rate, the LiCo_1/6Mn_11/6O₄ electrode delivered high initial capacities of 123 and 127 mAh g⁻¹ at 25 and 55 °C, respectively. Electrochemical cycling tests revealed that the capacity fading occurred mainly in the high-voltage region of 4.08–4.40 V, and the fading rate was 0.107% and 0.302% per cycle at 25 and 55 °C, respectively. The excellent cycling stability and low material cost make it an attractive cathode for high-temperature lithium ion batteries.