【摘要】 以水热法制备的羟基氧化铁纳米棒作为反应原料，首先采用室温聚合法，在其表面包覆一层均匀的聚多巴胺，获得聚多巴胺包覆的羟基氧化铁，然后通过后续热处理，获得氮掺杂碳包覆的Fe₃O₄和Fe₇S₈复合材料（Fe₃O₄@NC和Fe₇S₈@NC）。采用XRD、拉曼光谱仪、XPS、SEM以及TEM等技术对上述两种复合材料的结构和形貌进行表征。将上述制备的两种复合材料分别作为负极材料，组装纽扣半电池，测试并研究其储锂、储钠性能。实验结果表明：Fe₃O₄@NC相比Fe₇S₈@NC展现出了更高的可逆比容量和更优异的高倍率储锂循环性能，在2 A·g^-1的电流密度下，循环300圈，其可逆比容量可分别维持在1 083和859 mAh·g^-1;作为钠离子电池负极材料，Fe₃O₄@NC相比Fe₇S₈@NC展现出了更平稳的循环稳定性，而Fe₇S₈@NC出现容量明显上升的趋势。在1 A·g^-1的电流密度下，循环350圈后，二者的电池容量分别为100和259 mAh·g^-1;其优异的储锂、储钠性能主要取决于Fe₃O₄和Fe₇S₈纳米棒与氮掺杂碳层的协同作用。更多还原

【Abstract】 N-doped carbon coated Fe₃O₄ and Fe₇S₈ composite materials（Fe₃O₄@NC and Fe₇S₈@NC） were prepared by three-steps synthesis strategy. First, the FeOOH nanorod was prepared by a facile hydrothermal method. Second, the FeOOH@PDA composite was obtained via the room temperature polymerization reaction. Third, the Fe₃O₄@NC and Fe₇S₈@NC were finally prepared by the subsequent heat treatment. A series of characterization techniques containing XRD, Raman spectra, XPS, SEM, and TEM were employed to analyze the structures and morphologies of Fe₃O₄@NC and Fe₇S₈@NC. The Fe₃O₄@NC and Fe₇S₈@NC were used as the anode materials to assemble the button cells, and their electrochemical performances for lithium ion batteries and sodium ion batteries were tested and discussed. Experimental results indicate that Fe₃O₄@NC exhibits higher reversible capacities and more excellent lithium storage performances than Fe₇S₈@NC. At 2 A·g^-1 for 300 cycles, the reversible capacity can maintain at 1 083 and 859 mAh·g^-1. As anode materials for sodium ion batteries, Fe₃O₄@NC shows more stable cycling performance than Fe₇S₈@NC. At a high current density of 1 A·g^-1, the reversible capacitiesare 100 and 259 mAh·g^-1 up to 350 cycles. The good lithium or sodium storage performances can be attributed to the synergistic effect of N-doped carbon and Fe₃O₄ or Fe₇S₈ nanorods.更多还原