Novel carbon coating source for better LiMn0.6Fe0.4PO4/C materials

Compared with LiFePO4 materials, manganese-based olivine is a promising cathode candidate with high energy and low cost for Li-ion batteries (LIBs). Its rate capability and cyclability challenges still remain even with nano-size and carbon coating. Herein, a high-rate performance is achieved by introducing a novel carbon coating source, poly propylene glycol (PPG 2000). Compared with traditional glucose carbon coating source, it is found that PPG facilitates a highly uniform conductive carbon coating during the carbonized process. Moreover, laser particle size analyzer also suggest that PPG 2000 can act as a highly effective dispersant, which can result in finer primary particles during grinding. Therefore, electronic and ionic conductivity are greatly improved so that the highly Li+ conductive nature of olivine materials can be fully unleashed. The final LiMn0.6Fe0.4PO4/C materials can deliver a capacity of 120 mAh·g−1 even at 10 C rate. This work demonstrates the importance of novel carbon coating source to the active cathode particles and opens upon a new venue for the large-scale fabrication of manganese-based olivine cathode materials.