Zhang Jijun, Chen Zexiang, Wang Yan, Yan Xinyu, Zhou Zhiyu, Lv Huifang
School of Optoelectronic Science And Engineering, University of Electronic Science and Technology of China, North Jianshe Road 4, Chengdu, 610054, China.
Nanoscale Res Lett. 2019 Mar 11;14(1):87. doi: 10.1186/s11671-019-2910-5.
High electrochemical performance of asymmetric supercapacitor (ASC) depends on exquisite nanostructure design and synthesis of electrodes, including structural controllable design and synthesis of high theoretical performance materials and nanocomposite materials. Herein, a template-free hierarchical core-shell nanostructure of CoNiO@NiAl-layered double hydroxide (NiAl-LDH) and α-FeO with a hollow spherical structure composed of nanoparticles are successfully prepared. The CoNiO@NiAl-LDH as the cathode electrode and the hollow spherical α-FeO as the anode electrode of the ASC devices exhibit superior electrochemical performance. The gel of polyvinyl alcohol (PVA) and KOH acts as the solid electrolyte and the separator to assemble into the all-solid-state flexible ASC devices. Two of the CoNiO@NiAl-LDH//α-FeO ASC devices in series are fabricated to meet the voltage requirement of mobile energy equipment, which exhibit a maximum energy density of 65.68 Wh kg at the power density of 369.45 W kg. Interestingly, in addition to many advantages that the solid electrolyte in ASC devices already have, we find that it can be an alternative way of solving the problem of iron oxide cycling performance, and of course it can also be used as a reference for other materials with poor cycling performance.
不对称超级电容器（ASC）的高电化学性能取决于电极的精细纳米结构设计与合成，包括具有高理论性能材料和纳米复合材料的结构可控设计与合成。在此，成功制备了由纳米颗粒组成的具有中空球形结构的CoNiO@NiAl层状双氢氧化物（NiAl-LDH）和α-FeO的无模板分级核壳纳米结构。作为ASC器件阴极电极的CoNiO@NiAl-LDH和作为阳极电极的中空球形α-FeO表现出优异的电化学性能。聚乙烯醇（PVA）和KOH的凝胶用作固体电解质和隔膜，组装成全固态柔性ASC器件。制造了两个串联的CoNiO@NiAl-LDH//α-FeO ASC器件以满足移动能源设备的电压要求，在功率密度为369.45 W kg时，其最大能量密度为65.68 Wh kg。有趣的是，除了ASC器件中固体电解质已有的许多优点外，我们发现它可以作为解决氧化铁循环性能问题的一种替代方法，当然它也可以作为其他循环性能较差材料的参考。
