Flexible all-solid-state asymmetric supercapacitors with three-dimensional CoSe2/carbon cloth electrodes
Flexible all-solid-state asymmetric supercapacitors with three-dimensional CoSe2/carbon cloth electrodes
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DOI：
10.1039/c5ta00725a
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发表时间：
2015-03
影响因子：
--
通讯作者：
N. Yu;Mingqiang Zhu;Di Chen
中科院分区：
文献类型：
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作者：
N. Yu;Mingqiang Zhu;Di Chen
金属硫族化合物作为储能器件的电极材料，由于其独特的结构和电化学性能，近年来引起了人们的极大关注。在本文中，分级CoSe 2纳米结构成功地生长在导电碳纤维织物与强大的粘附通过一个简单的两步法。在三电极和双电极体系中研究了所制备的分级CoSe 2结构的电化学性质。在三电极系统中，分层CoSe 2架构在1 mA cm-2的电流密度下表现出332 mF cm-2的大比电容。充放电5000次后，电极仍表现出良好的上级稳定性，容量保持率约为95.4%。当组装成基于分级CoSe 2负电极和MnO 2纳米线正电极的非对称超级电容器（ASC）时，电位窗口增加到1.6 V，大于基于CoSe 2//CoSe 2电极的对称超级电容器（SC）的电位窗口。在0.282 W cm-3的功率密度下，所制造的ASC也达到了0.588 mW h cm-3的高能量密度。令人兴奋的是，组装后的ASC的电化学性能即使在严重的弯曲条件下也几乎没有降解，表现出优异的柔韧性和机械稳定性。具有3D分级结构的生长态CoSe 2电极可以是高性能ASC的潜在候选者，因为其改善的电化学活性位点、电子导电性和减少的离子扩散路径。
As electrode materials for energy storage devices, metal chalcogenides have recently attracted great attention due to their unique structure related electrochemical properties. In this paper, hierarchical CoSe2 nanostructures are successfully grown on conductive carbon fabrics with robust adhesion by a facile two-step method. The electrochemical properties of the as-prepared hierarchical CoSe2 architectures were investigated in three- and two-electrode systems. In the three-electrode system, the hierarchical CoSe2 architectures exhibit a large specific capacitance of 332 mF cm−2 at a current density of 1 mA cm−2. After charging/discharging for 5000 cycles, the electrode still showed superior stability with the capacity retention of about 95.4%. When assembled into asymmetric supercapacitors (ASCs) based on the hierarchical CoSe2 negative electrode and MnO2 nanowire positive electrode, the potential window increased to 1.6 V, larger than that of symmetric supercapacitors (SCs) based on CoSe2//CoSe2 electrodes. And a high energy density of 0.588 mW h cm−3 at a power density of 0.282 W cm−3 was also reached for the fabricated ASCs. Excitingly, the electrochemical performance of the as-assembled ASCs showed little degradation even under severe bending conditions, demonstrating excellent flexibility and mechanical stability. The as-grown CoSe2 electrode with a 3D hierarchical structure can be a potential candidate for high-performance ASCs because of its improved electrochemically active sites, electronic conductivity and the reduced ion diffusion path.