Synchronous construction of oxygen vacancies with suitable concentrations and carbon coating on the surface of Li-rich layered oxide cathode materials by spray drying for Li-ion batteries

Lithium-rich layered oxide materials with high reversible capacities (over 250 mAh g−1) are considered as one of the most promising cathode materials for the next generation of lithium-ion batteries. However, some challenges including low initial Coulombic efficiency, voltage decay and poor cycling restrict their commercial application. Herrin, Li-rich layered oxide materials Li1.2Ni0.2Co0.08Mn0.52O2 co-modified by constructing oxygen vacancies with suitable concentration and C coating layer have been synthesized via a facile spray drying process. The oxygen vacancies with suitable concentration can not only suppress the release of O2 and improve the stability of the layered structure, but also facilitate Li diffusion. Moreover, C coating layer acts as a physical barrier to protect the materials from electrolyte, and reduce the interface impedance. The co-modified material shows excellent electrochemical properties: a high initial Coulombic efficiency of 83.1%, a small voltage decay rate of 0.306 mV, and a capacity retention of 78.3% after 1000 cycles at 5 C. And it provides a simple and feasible way to improve the properties of lithium-rich layered oxide materials.