在具有高性能电容性能的氧化锡纳米线上进行氧化锰的简便涂层。

Facile coating of manganese oxide on tin oxide nanowires with high-performance capacitive behavior.

机构信息

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue Blk N4.1, Singapore 639798.

出版信息

ACS Nano. 2010 Jul 27;4(7):4247-55. doi: 10.1021/nn100592d.

DOI:10.1021/nn100592d

PMID:20593844

Abstract

In this paper, a very simple solution-based method is employed to coat amorphous MnO2 onto crystalline SnO2 nanowires grown on stainless steel substrate, which utilizes the better electronic conductivity of SnO2 nanowires as the supporting backbone to deposit MnO2 for supercapacitor electrodes. Cyclic voltammetry (CV) and galvanostatic charge/discharge methods have been carried out to study the capacitive properties of the SnO2/MnO2 composites. A specific capacitance (based on MnO2) as high as 637 F g(-1) is obtained at a scan rate of 2 mV s(-1) (800 F g(-1) at a current density of 1 A g(-1)) in 1 M Na2SO4 aqueous solution. The energy density and power density measured at 50 A g(-1) are 35.4 W h kg(-1) and 25 kW kg(-1), respectively, demonstrating the good rate capability. In addition, the SnO2/MnO2 composite electrode shows excellent long-term cyclic stability (less than 1.2% decrease of the specific capacitance is observed after 2000 CV cycles). The temperature-dependent capacitive behavior is also discussed. Such high-performance capacitive behavior indicates that the SnO2/MnO2 composite is a very promising electrode material for fabricating supercapacitors.

摘要

本文采用一种非常简单的基于溶液的方法，将无定形 MnO2 涂覆在不锈钢基底上生长的结晶 SnO2 纳米线上，该方法利用 SnO2 纳米线更好的电子导电性作为支撑骨架来沉积 MnO2 作为超级电容器的电极。采用循环伏安法（CV）和恒电流充放电法研究了 SnO2/MnO2 复合材料的电容性能。在 1 M Na2SO4 水溶液中，以 2 mV s-1 的扫描速率（在 1 A g-1 的电流密度下为 800 F g-1）可获得高达 637 F g-1（基于 MnO2）的比电容。在 50 A g-1 时测量的能量密度和功率密度分别为 35.4 W h kg-1 和 25 kW kg-1，表现出良好的倍率性能。此外，SnO2/MnO2 复合电极还表现出优异的长期循环稳定性（在 2000 次 CV 循环后，比电容的衰减小于 1.2%）。还讨论了温度相关的电容行为。这种高性能的电容行为表明，SnO2/MnO2 复合材料是制造超级电容器的一种很有前途的电极材料。