A LiFePO4/C composite was synthesized by a simple solid-state reaction method using glucose as reductive agent and carbon source and FePO4 as precursor, which was prepared by introduction of Na3PO4 as phosphorus sourc...A LiFePO4/C composite was synthesized by a simple solid-state reaction method using glucose as reductive agent and carbon source and FePO4 as precursor, which was prepared by introduction of Na3PO4 as phosphorus source and pH regulator in order to pursue lower cost and environmental protection. The structure and morphology of FePO4 and LiFePO4/C were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Furthermore, electrochemical performance of LiFePO4/C was investigated by galvanostatic charge–discharge tests and cyclicvoltammogram(CV). The results indicate that FePO4 obtained has a small particle size and uniform particle distribution, which is demonstrated to be applicable as the iron source to synthesize LiFePO4/C. Prepared LiFePO4/C shows an excellent rate capability and cycle performance. At rates of 0.1 C, 0.2 C, 1 C and 2 C, the initial discharge capacities of 161, 158, 145 and 120 mAh/g were achieved, respectively and the discharge capacity is 154, 153, 140 and 116 mAh/g after 400 cycles. The employed method of preparing FePO4 by introduction of Na3PO4 has advantages such as low cost, safe raw material, environmental benign and recyclable products, which is suitable for industrial production.展开更多
Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ra...Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.展开更多
基金Funded by Natural Science Foundation of Hebei Province(No E2017409004)Department of Education of Hebei Province(No QN2016224)
文摘A LiFePO4/C composite was synthesized by a simple solid-state reaction method using glucose as reductive agent and carbon source and FePO4 as precursor, which was prepared by introduction of Na3PO4 as phosphorus source and pH regulator in order to pursue lower cost and environmental protection. The structure and morphology of FePO4 and LiFePO4/C were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Furthermore, electrochemical performance of LiFePO4/C was investigated by galvanostatic charge–discharge tests and cyclicvoltammogram(CV). The results indicate that FePO4 obtained has a small particle size and uniform particle distribution, which is demonstrated to be applicable as the iron source to synthesize LiFePO4/C. Prepared LiFePO4/C shows an excellent rate capability and cycle performance. At rates of 0.1 C, 0.2 C, 1 C and 2 C, the initial discharge capacities of 161, 158, 145 and 120 mAh/g were achieved, respectively and the discharge capacity is 154, 153, 140 and 116 mAh/g after 400 cycles. The employed method of preparing FePO4 by introduction of Na3PO4 has advantages such as low cost, safe raw material, environmental benign and recyclable products, which is suitable for industrial production.
文摘Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.
