Hierarchical mesoporous NiO nanoarrays with ultrahigh capacitance for aqueous hybrid supercapacitor
Hierarchical mesoporous NiO nanoarrays with ultrahigh capacitance for aqueous hybrid supercapacitor
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DOI：
10.1016/j.nanoen.2016.09.012
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发表时间：
2016-12-01
期刊：
影响因子：
17.6
通讯作者：
Liu, Junfeng
中科院分区：
文献类型：
--
作者：
Meng, Ge;Yang, Qiu;Liu, Junfeng
混合超级电容器（Hybrid Supercapacitors，HSC）是一种由法拉第电容或赝电容正极材料和双电层电容负极材料组成的新型超级电容器，具有比传统双电层电容器更高的能量密度。为了赋予材料更高的能量密度和功率密度，具有分级介孔结构的电极的合理设计和合成是非常重要的。在这项工作中，我们报道了多级介孔NiO纳米阵列（NiO-HMNAs）的制备作为混合超级电容器的电池型电极，其比电容（在5 mA cm（-2）的电流密度下为3114 F g（-1）），这超出了NiO的理论法拉第电容值。采用自生成牺牲模板法制备了NiO-HMNAs，该方法包括通过Zn 2+和Ni 2+共沉积制备ZnO/NiO分级复合材料，并通过碱腐蚀过程去除ZnO以构建介孔结构。NiO-HMNAs的电化学电容归因于NiO在独特的分级介孔结构中几乎完全的氧化还原反应，以及在纳米阵列的扩大表面处提高的双电层电容。此外，通过使用NiO-HMNAs作为正极和大孔石墨烯整料（MGM）作为负极制造的优化的HSC已经证明了在320 W kg（-1）的功率密度下67.0W h kg（-1）的高能量密度，最大电压为1.6V和出色的循环能力（6000次循环后的电容保持率为89.6%）。(C)2016爱思唯尔有限公司版权所有
Hybrid supercapacitors (HSCs), which usually involve faradaic or pseudocapacitive positive materials and electric double-layer capacitive negative materials, have demonstrated great potentials with enhanced energy density outdistancing traditional electrical double-layer capacitors. To endow materials with higher energy density and power density, the rational design and synthesis of electrodes with hierarchical and mesoporous structure are highly desired. In this work, we report the fabrication of hierarchical mesoporous NiO nanoarrays (NiO-HMNAs) as a battery-type electrode for hybrid supercapacitor with an ultrahigh specific capacitance (3114 F g(-1) at the current density of 5 mA cm(-2)), which is beyond the theoretical faradaic capacitance value of NiO. NiO-HMNAs were prepared by a self-generated sacrificial template approach, which involves the preparation of hierarchical ZnO/NiO composites by co-deposition of Zn2+ and Ni2+ and the removal of ZnO by an alkali etching process to construct mesoporous structure. The ultrahigh capacitance of NiO-HMNAs is ascribed to the nearly full redox reaction of NiO in the unique hierarchical mesoporous architecture, and the raised electrical double-layer capacitance at the enlarged surface of nanoarrays. Moreover, the optimized HSC fabricated by using NiO-HMNAs as the positive electrode and macroporous graphene monoliths (MGMs) as the negative electrode has demonstrated a high energy density of 67.0 W h kg(-1) at a power density of 320 W kg(-1) with a maximum voltage of 1.6 V and outstanding cycleability (capacitance retention of 89.6% after 6000 cycles). (C) 2016 Elsevier Ltd. All rights reserved.