以Fe2(SO4)2、H3PO4和NH3·H2O为原料,采用控制结晶法制备了多孔的前驱体FePO4·xH2O.通过研究pH值和合成时间对前驱体的物相结构、成分、表面形貌、粒度、比表面积和振实密度的影响,发现在PH=2.1的条件下反应8h制备的前驱体性能最佳。将前驱体、Li2CO3及葡萄糖均匀混合,用碳热还原法合成了LiFePO4/C,结果表明,以PH=2.1时制备的前驱体为原料合成的LiFePO4/C在0.1C时的首次放电比容量为156mAh/g,其振实密度高达1.20g/cm^3。
The porous precursors (FePO4 · xH2O) were prepared by controlled crystallization method, with Fe2 (SO4)3, H3PO4 and NH3 · H2O as raw materials. The effects of pH and synthesis time on phase structure, component, surface morphology, particle size, specific surface area and tap density were studied. It was found that the precursor prepared under the condition of pH of 2.1 and synthesis time of 8h possessed excellent performance. The LiFePO4/C was synthesized by carbothermal reduction, with the homogeneous mixtures of asprepared precursors, Li2CO3 and glucose. The results showed that the LiFePO4/C which was synthesized with the precursor prepared under pH of 2.1 had an initial discharge specific capacity of 156mAh/g at 0.1C rate and a high tap density of 1.20g/cm^3.