Fabrication of In Situ N,P‐Codoped Carbon‐Coated LiFePO ₄ Nanocomposites With Herbal Polysaccharides for High‐Performance Lithium‐Ion Batteries

Due to the excellent structural stability and low cost, olivine‐type lithium iron phosphate LiFePO 4 (LFP) is widely used as the cathode for lithium‐ion batteries. Herein, LFP/C composites are preparedusing the extract of Eucommia polysaccharides as carbon source, which is environmentally friendly and economical and provides a uniform in situ N,P‐codoped carbon layer. On the one hand, polysaccharides and monosaccharides in extracts have strong steric hindrance, which inhibits the growth of particles during sintering. On the other hand, the uniform N and P codoping adjusts the electron cloud distribution of the carbon layer and improves the electron conductivity. As a result, the prepared LFP/C composites exhibit enhanced rate properties and structural stability. Detailedly, the material delivers the initial specific discharge capacity of 130.3 mAh·g −1 with capacity retention of 93.4% after 1000 cycles at a high rate of 1 C. Even at a higher rate of 5 C, it has a specific discharge capacity of 116.3 mAh·g −1 . Therefore, this work has demonstrated the advantages of using the polysaccharide extract from Eucommia ulmoides as the carbon source for the LFP cathode material. This is also feasible for other carbon‐coated cathode or anode materials and is conducive to improving the power density of lithium‐ion batteries.