Optimization of Li1.17[Mn0.6Ni0.2Co0.2]0.83O2 Cathode Materials for Li-ion batteries

Abstract

In the face of growing green energy needs and pressure on the environment, lithium ion batteries have been paid lots of attention. Recently, with growing needs of energy have been significantly increased due to electric vehicles and energy storage system, bigger scale batteries are getting more important than before. Lithium rich materials with higher reversible capacity than 240 mAh/g is regarded the most encouraging cathode material to solve low energy density which is one of the biggest limits of commercialized LIBs cathode materials. However, there have been several problems needed to overcome for commercialization of lithium rich cathode materials. First of all, to achieve high tap density, preparation of powder is important. Co-precipitation method has been known as the best way to produce uniform distribution of powders with spherical shape which are key factors to have a high tap density, but this method is really hard to optimize because there are too many factors to optimize co-precipitation condition such as pH, the amount of chelating agent and stirring speed. Also, lithium rich cathode materials have several drawbacks on electrochemical properties. For example, this cathode material has low initial coulombic efficiency, which is the main problem of full-cell operation, compared to other cathode materials due to the activation process of Li2MnO3 component. Herein, to solve these problems of lithium rich cathode materials, we suggest the optimized co-precipitation condition under oxygen inert atmosphere for high tap density, and blending lithium rich with nickel rich cathode materials to overcome the drawbacks of electrochemical properties.