Carbon-coated tungsten and molybdenum carbides for electrode of electrochemical capacitor
Carbon-coated tungsten and molybdenum carbides for electrode of electrochemical capacitor
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DOI：
10.1016/j.electacta.2006.08.056
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发表时间：
2007-02
影响因子：
6.6
通讯作者：
T. Morishita;Y. Soneda;H. Hatori;M. Inagaki
中科院分区：
文献类型：
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作者：
T. Morishita;Y. Soneda;H. Hatori;M. Inagaki
将K2 WO 4和K2 MoO 4分别与羟丙基纤维素混合，通过简单的热处理制备了多孔碳包覆碳化钨WC和碳化钼Mo 2C的电化学电容器电极材料。在H2SO 4水溶液中，第1次充放电循环时，碳化物转变为氢氧化物，在后续充放电循环中，碳化物发生氧化还原反应，并在其表面形成碳的双电层。在1 molL − 1H 2SO 4电解液中，碳包覆的碳化钨的电容约为350 Fcm − 3，碳包覆的钼碳的电容约为550- 750 Fcm − 3。碳的涂层抑制碳化物颗粒在其形成过程中的生长，其中小的颗粒尺寸使得在第一次充放电循环期间可以完全转化为氢氧化物，并且还干扰钨和钼氢氧化物在充放电循环期间的团聚，以及多孔碳涂层作为电解质离子的双电层的电极材料。
New electrode materials for electrochemical capacitor, tungsten carbide WC and molybdenum carbide Mo2C coated by porous carbon, were prepared through a simple heat treatment of the mixture of K2WO4and K2MoO4, respectively, with hydroxy propyl cellulose. Carbide changed to hydroxide during the 1st charge–discharge cycle in H2SO4aqueous electrolyte, which showed redox reaction in further charge–discharge cycles, in addition to electric double layers of the carbon formed on its surface. The carbon-coated carbide gave a high capacitance in 1molL−1H2SO4electrolyte, as about 350Fcm−3for carbon-coated WC and 550–750Fcm−3for carbon-coated Mo2C. Coating of carbon inhibits the growth of carbide particles during their formation, of which the small particle size make possible to complete transformation to hydroxides during the 1st charge–discharge cycle, and also disturbs the agglomeration of tungsten and molybdenum hydroxides during charge–discharge cycles, as well as porous carbon coated act as electrode material for electric double layers of electrolyte ions.