Electrochemical oxidation of Mn/MnO films: formation of an electrochemical capacitor
Electrochemical oxidation of Mn/MnO films: formation of an electrochemical capacitor
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DOI：
10.1016/j.actamat.2004.10.041
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发表时间：
2005-02
期刊：
影响因子：
9.4
通讯作者：
B. Djurfors;J. Broughton;M. Brett;D. Ivey
中科院分区：
文献类型：
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作者：
B. Djurfors;J. Broughton;M. Brett;D. Ivey
对多孔锰氧化物材料制备电化学电容器所需的氧化步骤进行了深入研究。氧化过程发生在1 M Na 2SO 4溶液中施加小阳极电流的情况下，导致形成三层结构。在氧化过程中，未受干扰的锯齿形材料的基层从Mn/MnO氧化成Mn 3 O 4。同时，第二层直接形成在锯齿形材料的表面上。该层是部分结晶Mn 3 O 4和部分非晶。最后也是最重要的一层是无定形的水合MnO 2表面膜。据信，该层单独负责这些膜的电容行为。在氧化之前的电极的孔隙率被证明是无关紧要的，因为完全致密的膜的氧化导致归因于多孔表面层的形成的类似的高电容值。
An in-depth study of the oxidation step required to produce electrochemical capacitors from porous manganese-oxide materials was carried out. The oxidation process takes place under the application of a small anodic current in a solution of 1 M Na2SO4, resulting in the formation of a three-layered structure. During the oxidation process, a base layer of undisturbed zigzag material oxidizes from Mn/MnO to Mn3O4. At the same time, a second layer forms directly on the surface of the zigzag material. The layer is partly crystalline Mn3O4and partly amorphous. The final and most important layer is the amorphous, hydrated MnO2surface film. It is believed that this layer is solely responsible for the capacitive behavior of these films. The porosity of the electrode prior to oxidation is shown to be immaterial as oxidation of a fully dense film results in similarly high capacitive values attributed to the formation of a porous surface layer.