Structural changes of Li3.1Mn0.91Cr1.09O4 cathode material

Changes in the microstructure of Li3.1Mn0.91Cr1.09O4 cathode materials have been studied with cycled electrodes at 21 or 55°C. During cycling, the structure of Li3.1Mn0.91Cr1.09O4 maintained its original hexagonal symmetry. However, a decreased peak intensity ratio of 003 to 104 with little lattice-constant shifts was observed. These are due to increased cation-mixing and dissolution of Mn3+ ions in the electrolyte, thus leading to structural degradation of the material. Hence, the cathode exhibited a specific discharge capacity decay of 29% from its initial capacity (220 mAh/g) after 60 cycles between 4.5 and 2 V with a 0.1 C rate at 21°C.