Studies On Synthesis And Electro-Chemical Characteristics Of Layered Li_x[Mn_1-yCo_y]O₂ Cathode Materials

Layered LiMnO₂ as cathode materials for rechargeable lithium-ion batteries have many merits, such as the safety, low cost, high theoretical capacity, and low toxicity of manganese-based materials. However, the fundamental problem of layered LiMnO₂ is the instability of the layered structure and poor cycling performance. Researches focus on doping LiMnO₂ by substituting part of the Mn with other metal ions such as Cr³⁺, Al³⁺, Ga³⁺, Co³⁺, Ni²⁺, Li⁺ and so on, have been shown to stabilize the layered structure and improve cycling stability during charge-discharge process. But the content of Li in the layered compound is low, correspond to Li⁺ deintercalation-intercalation is low and the reversible capacity is low. Furthermore, part doping compound convert to spinel structure during charge-discharge process, which lead to the degradation of capacity and bad cycling stability. So, we improve the reversible capacity and cycling stability by increasing the content of lithium and the stability of structure.