【摘要】 利用物理浸渍和冷冻干燥等方法制备了具有三维网状结构的Ru/石墨烯/碳纳米管复合材料,对该材料的结构、形貌及电化学性能进行了表征和研究.结果表明,当Ru含量为30%,热处理温度为500℃时,材料的催化性能最优.将其用作锂氧电池的正极催化剂,以50 m A/g电流密度进行首次充放电时,放电比容量约为5800 m A·h/g,且在放电比容量为4000 m A·h/g以内时,其极化电压仅为0. 9 V;当以50 m A/g电流密度进行恒容（500 mA·h/g）充放电循环时,在极化电压低于1. 1 V时,仍能稳定循环12周.复合材料电催化机理的研究结果表明,三维网状结构不仅提供了O₂和Li⁺的传输通道,更增加了放电产物Li₂O₂的储存场所.金属钌纳米粒子的负载既增加了复合材料的反应活性位点,又促进了放电产物Li₂O₂的分解.更多还原

【Abstract】 Ru/graphene/carbon nanotube composites with three-dimensional network structure were prepared by physical impregnation and freeze drying. When the Ru content was 30%（ mass fraction） and the heat treatment temperature was 500 ℃,the catalytic performance of the composite was optimal. When the composite was used as a cathode catalyst for lithium oxygen batteries,it exhibited excellent battery performance.When the first charge and discharge were performed at a current density of 50 m A/g,the discharge capacity density was about 5800 m A·h/g,and when the discharge capacity density was within 4000 m A·h/g,the polarization voltage was only was 0. 9 V; when a constant-capacitance（ 500 m A·h/g） charge-discharge cycle was performed at a current density of 50 m A/g,the battery was stable for 12 cycles even when the polarization voltage was lower than 1. 1 V. The three-dimensional network structure not only provided a transmission channel for O₂ and Li+,but also increased the storage location of the discharge product Li₂O₂. The loading of the metal ruthenium nanoparticles not only increased the reactive site of the composite,but also promoted the decomposition of the discharge product Li₂O₂.更多还原