Hollow CeO2 spheres conformally coated with graphitic carbon for highperformance supercapacitor electrodes
Hollow CeO2 spheres conformally coated with graphitic carbon for highperformance supercapacitor electrodes
复制标题
空心 CeO2 球保形涂覆石墨碳，用于高性能超级电容器电极
DOI：
10.1016/j.apsusc.2018.08.224
复制
发表时间：
2019
影响因子：
6.7
通讯作者：
Wang Guoxiu
中科院分区：
文献类型：
--
作者：
Wu Wenjian;Qi Wentao;Zhao Yufei;Tang Xiao;Qiu Yongfu;Su Dawei;Fan Hongbo;Wang Guoxiu
超级电容器是一种重要的高功率储能装置，电极材料是其关键。本文采用水热法成功制备了一种新型的纳米CeO2-石墨碳共形包覆纳米空心球（H-CeO2@GC），作为超级电容器电极材料。所制备的H-CeO2@GC空心球呈现出高比表面积（153 m2·g-1）、良好限定的空心结构（单分散尺寸为260 nm，内径为200 nm，壳厚为30 nm）和共形封装在超薄石墨碳层中的CeO2纳米晶体（10 nm）。当应用于超级电容器时，H-CeO2@GC空心球在1 A·g-1的电流密度下提供了501 F·g-1的高比电容，由于其独特的结构，具有高能量/功率密度，优异的倍率性能和长循环寿命。特别是，实现了17.2 Wh·kg-1的能量密度和2600 W·kg-1的功率密度。超级电容器即使在15 A·g-1的高电流密度下也保持85%的比电容（参考1 A·g-1），并且在10 A·g-1下5000次循环后具有93%的容量保持率，显示出优异的循环稳定性。这项工作提供了一种新的方法来开发高性能的超级电容器使用的策略相结合的空心纳米球架构和导电石墨碳纳米涂层。
Electrode material is essential for supercapacitors which are an important energy storage device that can deliver high power. Herein, we report the successful synthesis of hollow CeO2nanospheres conformally coated with graphitic carbon (H-CeO2@GC) via a facile hydrothermal method as a kind of electrode materials of supercapacitors. The as-prepared H-CeO2@GC hollow spheres presented a high specific surface area (153 m2∙g−1), a well-defined hollow structure (a monodisperse size of ∼260 nm with inner diameter of ∼200 nm and shell thickness of ∼30 nm), and nanocrystals of CeO2(∼10 nm) conformally encapsulated in ultra-thin graphitic carbon layers. When applied in supercapacitors, the H-CeO2@GC hollow spheres delivered a high specific capacitance of 501 F∙g−1at a current density of 1 A∙g−1, a high energy/power density, excellent rate capability and long cycle life owing to its unique architecture. In particular, an energy density of 17.2 Wh∙kg−1with a power density of 2600 W∙kg−1was achieved. The supercapacitors retained 85% of the specific capacitance (refer to 1 A∙g−1) even at a high current density of 15 A∙g−1and exhibited excellent cycling stability with 93% of the capacity retention after 5000 cycles at 10 A∙g−1. This work offers a new approach to developing high-performance supercapacitors using the strategy of combining hollow nanosphere architecture and conductive graphitic carbon nanocoating.