In this study, dihydrate iron phosphates with primary and secondary morphology were first prepared with ferric sulfate and phosphoric acid as the major raw materials, which were then taken as the precursor to prepare carbon-coated lithium iron phosphate composite material. Results show that structures of synthesized lithium iron phosphate/Carbon materials are the same, however, the morphologies are significantly different, especially the one synthesized with the secondary morphology iron phosphate precursor. Thus, the particle size, specific surface area and carbon coating effect of the material are changed accordingly, which can affect the electrochemical performance of the composite. The lithium iron phosphate/Carbon synthesized with spherical aggregation morphology (secondary morphology) iron phosphate precursor showed the best electrochemical property. At 0.5C and 10C rates, the first specific discharge capacity is 155.6 and 103.8 mA h/g respectively, which is better than that prepared with cabbage shape aggregation morphology (secondary morphology) and near-spherical simplex (primary morphology), increasing 1.38%, 1.37% and 3.58%, 9.05%, respectively. This research result provided new thoughts to further improve the electrochemical property of lithium iron phosphate/Carbon composites.

在这项研究中，首先以硫酸铁和磷酸为主要原料制备具有一级和二级形态的二水合磷酸铁盐，然后将其作为前体制备碳包覆的磷酸锂铁复合材料。结果表明，合成的磷酸铁锂/碳材料的结构相同，但形貌差异很大，特别是第二形态的磷酸铁前驱体合成的。因此，材料的粒径，比表面积和碳涂层效果会相应改变，这可能会影响复合材料的电化学性能。具有球形聚集形态（二次形态）的磷酸铁锂/磷酸铁锂前驱体表现出最佳的电化学性能。在0.5C和10C的速率下，第一比放电容量分别为155.6和103.8 mA h / g，比用卷心菜形状聚集形态（二次形态）和近球形的单纯形（主要形态）制备的放电容量高1.38％。分别为1.37％和3.58％，9.05％。该研究结果为进一步改善磷酸铁锂/碳复合材料的电化学性能提供了新思路。比用卷心菜形状聚集形态（次要形态）和近球形单纯形（主要形态）制备的分别提高了1.38％，1.37％和3.58％，9.05％。该研究结果为进一步改善磷酸铁锂/碳复合材料的电化学性能提供了新思路。比用卷心菜形状聚集形态（次要形态）和近球形单纯形（主要形态）制备的分别提高了1.38％，1.37％和3.58％，9.05％。该研究结果为进一步改善磷酸铁锂/碳复合材料的电化学性能提供了新思路。