Effect of carbon sources on the microstructure and performance of LiFePO4 microspheres from hydrous FePO4

Due to its low cost, exceptional long-term cycling stability and robust thermal resilience, lithium iron phosphate (LiFePO₄, LFP) has gained widespread application across various societal sectors. However, traditional preparation methods of LFP obtained from anhydrous iron phosphate (FePO₄, FP) are hindered by high cost and long process. Therefore, there is a pressing need to develop cost-effective and short-process route for producing LFP. In this study, we employ hydrous FP as the iron and phosphorus sources to investigate the effect of carbon sources with different decomposition temperatures on the composition, morphology, and electrochemical behaviors of the products. The results confirm that when glucose is used as the carbon source, the resultant LFP microspheres display higher capacity, superior cycling stability and faster Li⁺ ion diffusion capability at room temperature. Furthermore, this sample delivers a capacity of 149.6 mAh g^-1 at 0.1 C and 147.0 mAh g^-1 at 0.2 C, and retains a capacity of 128.0 mAh g^-1 at 1 C over 100 cycles, with a remarkable capacity retention of 97.4%. This study highlights the significance of carbon source in the synthesis of LFP materials and its crucial role in shaping their morphology and electrochemical performance.