Hydrothermal synthesis and energy storage performance of ultrafine Ce₂Sn₂O₇ nanocubes

Abstract

Ultrafine cube-shape Ce₂Sn₂O₇ nanoparticles crystallized in pure pyrochlore phase with a size of about 10 nm have been successfully synthesized by a facile hydrothermal method. Conditional experiments have been conducted to optimize the processing parameters including temperature, pH, reaction duration, precipitator types to obtain phase-pure Ce₂Sn₂O₇. The crystal structure, morphology and sizes and specific surface area have been characterized by X-ray diffractometer (XRD), Raman spectrum, transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM), and Brunauer-Emmett-Teller (BET). The as-synthesized Ce₂Sn₂O₇ ultrafine nanocubes have been evaluated as electrode materials for pseudo-capacitors and lithium ion batteries. When testing as supercapacitors, a high specific capacitance of 222 F/g at 0.1 A/g and a good cycling stability with a capacitance retention of higher than 86% after 5000 cycle have been achieved. When targeted for anode material for lithium ion batteries, the nanocubes deliver a high specific reversible capacity of more than 900 mA∙h/g at 0.05C rate. The rate capability and cycling performance is also very promising as compared with the traditional graphite anode.

摘要

采用简单水热法合成了尺寸为10 nm 左右的纯烧绿石相超细Ce₂Sn₂O₇ 立方晶体。通过优化温 度、pH、反应时间、前驱体类型等参数获得最佳实验条件。通过X 射线衍射仪、拉曼光谱、透射电 子显微镜、高分辨透射电子显微镜和BET 等表征技术对样品的晶体结构、形貌、尺寸和比表面积进 行表征。将制备的Ce₂Sn₂O₇ 超细纳米立方晶体用作电极材料,并通过超级电容器和锂离子电池对其性 能进行评估。将其应用于超级电容器,在 0.1 A/g 下具有 222 F/g 的高比电容,并且在5000 次循环后 仍具有良好的循环稳定性,电容保持率高于86%。将其用于锂离子电池负极材料时,在0.05C 倍率下 具有超过900 mA∙h/g 的高电池容量。与传统的石墨阳极相比,其倍率性能和循环性能呈现出较好的应 用前景。