Fe2O3-石墨烯-碳纳米管复合材料制备条件对载硫性能的影响

锂硫电池是传统锂离子电池最有前途的替代品之一，多硫化物的溶解和导电性差是制约锂硫电池应用的两个重要因素。通过水热法合成了Fe₂O₃-还原氧化石墨烯(RGO)-碳纳米管(CNT)复合载硫材料，并通过调节氨水浓度，实现了复合材料中Fe₂O₃的颗粒尺寸的有效调控，发现小尺寸的Fe₂O₃颗粒具有更好的吸附和催化作用。合成的Fe₂O₃-RGO-CNT-S正极材料在1 C倍率下首次放电容量为1 286 mA·h/g，循环500圈后剩余718 mA·h/g，每圈的容量衰减率为0.08%。在0.2、0.5、1、2和4 C倍率下的平均比容量为983、825、769、673和604 mA·h/g，具有良好的倍率性能。在5 C倍率下循环500次仍剩余527 mA·h/g，具有良好的大电流循环性能。Fe₂O₃-RGO-CNT-S正极材料特别适用于高性能锂硫电池，具有优异的电化学性能主要是由于R...

Effect of preparation conditions of Fe2O3-graphene-carbon nanotube composites on sulfur loading properties

Lithium sulfur battery is one of the most promising alternatives to traditional lithium-ion battery. The dissolution and poor conductivity of polysulfides are two important factors restricting the application of lithium sulfur battery. In this paper, Fe₂O₃-reduced graphene oxide (RGO)-carbon nanotube (CNT) composite sulfur carrying materials are synthesized by hydrothermal method. By adjusting the ammonia concentration, the particle size of Fe₂O₃ in the composites is successfully adjusted. It is found that Fe₂O₃ with small particles had better adsorption and catalysis. Cathode material synthesized from it at 1 C, the first discharge capacity is 1286 mA·h/g, 718 mA·h/g remains after 500 cycles, and the capacity attenuation rate of each cycle is 0.08%. The average specific capacities at 0.2, 0.5, 1, 2 and 4 C are 983, 825, 769, 673 and 604 mA·h/g, which has good rate performance and good cycle performance at high current. 527 mA·h/g remains after 500 cycles at 5 C. Fe₂O₃-RGO-CNT-S cathode material is especially suitable for high-performance lithium sulfur batteries. It has excellent electrochemical performance, mainly because the three-dimensional conductive network of RGO and CNT provides strong electron transmission path, rich pore structure, and sulfur is in full contact with the three-dimensional conductive network composed of RGO and CNT.