Peng Jiawu, Hong Xiaoting, Zhou Qiongxiang, Hui Kwan San, Chen Bin
Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Engineering, Faculty of Science, University of East Anglia, Norwich NR4 7TJ, U.K.
ACS Omega. 2023 Mar 29;8(14):12707-12715. doi: 10.1021/acsomega.2c07838. eCollection 2023 Apr 11.
This study presents an economic and environmentally friendly method for the synthesis of microspherical FePO·2HO precursors with secondary nanostructures by the electroflocculation of low-cost iron fillers in a hot solution. The morphology and crystalline shape of the precursors were adjusted by gradient co-precipitation of pH conditions. The effect of precursor structure and morphology on the electrochemical performance of the synthesized LiFePO/C was investigated. Electrochemical analysis showed that the assembly of FePO·2HO submicron spherical particles from primary nanoparticles and nanorods resulted in LiFePO/C exhibiting excellent multiplicity and cycling performance with first discharge capacities at 0.2C, 1C, 5C, and 10C of 162.8, 134.7, 85.5, and 47.7 mAh·g, respectively, and the capacity of LiFePO/C was maintained at 85.5% after 300 cycles at 1C. The significant improvement in the electrochemical performance of LiFePO/C was attributed to the enhanced Li diffusion rate and the crystallinity of LiFePO/C. Thus, this work shows a new three-dimensional mesoporous FePO synthesized from the iron flake electroflocculation as a precursor for high-performance LiFePO/C cathodes for lithium-ion batteries.
本研究提出了一种经济且环保的方法，通过在热溶液中对低成本铁填料进行电絮凝来合成具有二级纳米结构的微球形磷酸铁（FePO₄·2H₂O）前驱体。通过pH条件的梯度共沉淀来调节前驱体的形态和晶体形状。研究了前驱体结构和形态对合成的LiFePO₄/C电化学性能的影响。电化学分析表明，由初级纳米颗粒和纳米棒组装而成的FePO₄·2H₂O亚微米球形颗粒，使得LiFePO₄/C在0.2C、1C、5C和10C下首次放电容量分别为162.8、134.7、85.5和47.7 mAh·g时，表现出优异的倍率性能和循环性能，并且在1C下循环300次后，LiFePO₄/C的容量保持在85.5%。LiFePO₄/C电化学性能的显著改善归因于Li扩散速率的提高和LiFePO₄/C的结晶度。因此，这项工作展示了一种由铁屑电絮凝合成的新型三维介孔磷酸铁，作为锂离子电池高性能LiFePO₄/C正极的前驱体。
