Metallic 1T phase MoS2 nanosheets as supercapacitor electrode materials
Metallic 1T phase MoS2 nanosheets as supercapacitor electrode materials
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DOI：
10.1038/nnano.2015.40
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发表时间：
2015-04-01
影响因子：
38.3
通讯作者：
Chhowalla, Manish
中科院分区：
文献类型：
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作者：
Acerce, Muharrem;Voiry, Damien;Chhowalla, Manish
离子在层状材料中的高效嵌入构成了电池和电容器等电化学储能装置的基础（1 - 6）。近期的研究重点是层状材料的剥离，然后重新堆叠二维剥离的纳米片以形成具有增强电化学反应的电极（7 - 11）。在此，我们表明含有高浓度金属1T相的化学剥离二硫化钼纳米片能够以极高的效率电化学嵌入诸如氢离子、钠离子和钾离子等，并在多种水性电解质中实现从约400到约700 F/cm³的电容值。我们还证明这种材料适用于非水有机电解质中的高压（3.5 V）操作，展现出主要的体积能量和功率密度值、超过95%的库仑效率以及超过5000次循环的稳定性。正如我们通过X射线衍射分析所表明的，1T二硫化钼层的这些良好电化学性能主要是由于其亲水性和高导电性，以及剥离层动态膨胀和嵌入各种离子的能力。
Efficient intercalation of ions in layered materials forms the basis of electrochemical energy storage devices such as batteries and capacitors(1-6). Recent research has focused on the exfoliation of layered materials and then restacking the two-dimensional exfoliated nanosheets to form electrodes with enhanced electrochemical response(7-11). Here, we show that chemically exfoliated nanosheets of MoS2 containing a high concentration of the metallic 1T phase can electrochemically intercalate ions such as H+, Na+ and K+ with extraordinary efficiency and achieve capacitance values ranging from similar to 400 to similar to 700 F cm(-3) in a variety of aqueous electrolytes. We also demonstrate that this material is suitable for high-voltage (3.5 V) operation in non-aqueous organic electrolytes, showing prime volumetric energy and power density values, coulombic efficiencies in excess of 95%, and stability over 5,000 cycles. As we show by X-ray diffraction analysis, these favourable electrochemical properties of 1T MoS2 layers are mainly a result of their hydrophilicity and high electrical conductivity, as well as the ability of the exfoliated layers to dynamically expand and intercalate the various ions.