A Novel And Efficient Water-based Composite Binder For LiFePO₄ Cathodes In Lithium-ion Batteries

Recently, olivine-type LiFePO₄ has received much attention as lithium insertion compounds for cathode material of rechargeable lithium batteries. Compared with other cathode materials,LiFePO₄ possesses many advantages such as suitable discharge plateau, a high theoretical charge capacity, excellent electrochemical stability, abundant raw materials, low cost and environmental friendliness.In his paper, the cathode material LiFePO₄ was pretreatmented in gelatin solution, then stired with conductive agent , SBR and polyethylene oxide (PEO) together. we assembled the cell with the mixture after evenly stired,and text the electrochemical performance. We conpared the performance with the tradition, it exishted good electrochemical performance .we could summatized the reasons that contributed to the well performance as follows:1. The gellatin solution has the function that perserves the colloid. After the pretreatment ,the conductive agent could form a thin film on the surface of LiFePO₄ ,which can enhance the conductivity. After the electron scanning by microscope.2. we found that the conductive agent of cathode material prepared with water soluble binder were dispersed more equably than the conductive agent in traditional cathode material, and then the electrochiemical examination was performed .The results showed that the cathode material prepared with water soluble binder has higher specific capacity and excellent circularity, the capacity is 135mAh/g.3. As a result of the good coherence of gellatin, the well flexibility of SBR and the heigher tap density improved by PEO ,the cathode material can be well clung to the collector.