Suitable Morphology Makes CoSn(OH)6 Nanostructure a Superior Electrochemical Pseudocapacitor
Suitable Morphology Makes CoSn(OH)6 Nanostructure a Superior Electrochemical Pseudocapacitor
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DOI：
10.1021/acsami.6b02568
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发表时间：
2016-07-20
影响因子：
9.5
通讯作者：
Pal, Tarasankar
中科院分区：
文献类型：
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作者：
Sahoo, Ramkrishna;Sasmal, Anup Kumar;Pal, Tarasankar
具有不同表面、边缘、扭结等的材料的形态通常会影响催化反应的速率。（1,2）在此，我们考虑到纳米材料形态改变对超级电容器器件的重要性，并采用CoSn(OH)(6)作为电极材料。在不牺牲功率密度的前提下，制备稳定的水不对称超级电容器（AAS）是有益的。在这里，我们合成了一种不常见的分层介孔纳米结构（HNS） CoSn(OH)(6)来制造假电容器。在这一努力中，NH3被发现是一种非常适合的合成水解剂。(3)在NaOH溶液中，HNS偶然转化为有利的立方纳米结构（CNS）。在溶液中，NaOH作为结构导向剂和蚀刻剂。两种样品（HNS和CNS）在KOH电解液中分别用作假电容器电极，这是首次报道。HNS具有很高的比电容值（在2.5 A/g比电流下为2545 F/g），比CNS样品具有更好的循环耐久性（在2.5 A/g比电流下为851 F/g）。为了考察其在实际电池中的应用，我们以HNS样品为正极材料，活性炭（AC）为负极材料，开发了水不对称超级电容器（AAS）。在1.5 a /g的比电流下，AAS的比电容值高达713 F/g，在10000次充放电循环后，其比电容值仍保持在92%。从制备的原子吸收光谱HNS CoSn(OH)(6)//AC中确定了最大能量密度为63.5 Wh kg(-1)，最大功率密度为5277 W kg（-1）。
Morphology of a material with different facet, edge, kink, etc., generally influences the rate of a catalytic reaction.(1,2) Herein, we account for the importance of altered morphology of a nanomaterial for a supercapacitor device and employed CoSn(OH)(6) as an electrode material. Suitable fabrication of a stable aqueous asymmetric supercapacitor (AAS) using metal hydroxide as positive electrode can be beneficial if the high energy density is derived without sacrificing the power density. Here we have synthesized an uncommon hierarchical mesoporous nanostructured (HNS) CoSn(OH)(6) to fabricate a pseudocapacitor. In this endeavor, NH3 is found to be a well-suited hydrolyzing agent for the synthesis.(3) Serendipitously, HNS was transformed into favored cubic nanostructure (CNS) in NaOH solution. In solution, NaOH acts as a structure directing as well as an etching agent. Both the samples (HNS & CNS) were used as pseudocapacitor electrodes in KOH electrolyte independently, which is reported for the first time. The HNS exhibits very high specific capacitance value (2545 F/g at 2.5 A/g specific current) with better cyclic durability over CNS sample (851 F/g at 2.5 A/g specific current). To examine the real cell application, we used HNS sample as the positive electrode material with the activated carbon (AC) as the negative electrode material for the development of an aqueous asymmetric supercapacitor (AAS). The as-fabricated AAS exhibited very high specific capacitance value of 713 F/g at a specific current of 1.5 A/g and retained 92% specific capacitance value even after 10 000 charge-discharge cycles. A maximum energy density of 63.5 Wh kg(-1) and a maximum power density of 5277 W kg(-1) were ascertained from the as-fabricated AAS, HNS CoSn(OH)(6)//AC.