Electrode properties of layered tungsten-based oxides for electrochemical capacitors
Electrode properties of layered tungsten-based oxides for electrochemical capacitors
复制标题
电化学电容器用层状钨基氧化物的电极性能
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Miyayama
中科院分区：
文献类型：
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作者：
E. Kim;Shinya Suzuki;M. Miyayama
首次研究了层状结构H2 W2 O 7在水溶液中的电化学性能。以Bi 2 W2 O 9为原料，经酸处理后进行质子交换，合成了H2 W2 O 7。H2 W2 O 7在H2SO 4电解液中的氧化还原电位较低，约为<$0.3V。在电流密度为300 mAg <$1时，H2 W2 O 7电极的氧化容量为56 mAhg <$1，这与假设0.5个电子与一个钨离子反应的理论容量相等。H2 W2 O 7在高电流密度（2Ag <$1）下的氧化能力比低电流密度（300 mAg <$1）下的氧化能力提高了88%。假设氧化还原反应速率主要取决于质子在H2 W2 O 7中的扩散.此外，该材料在1000次循环中显示出优异的循环稳定性而没有容量损失。艾德指出，H2 W2 O 7电极具有高倍率性能和良好的循环寿命，是一种很有前途的电化学电容器电极。
Electrochemical properties of layer-structured H 2 W 2 O 7 for electrochemical capacitors were investigated in an aqueous electrolyte for the fi rst time. H 2 W 2 O 7 was synthesized from Bi 2 W 2 O 9 by proton-exchanges with acid treatment. H 2 W 2 O 7 exhibited a low redox potential of about ¹ 0.3V in a H 2 SO 4 electrolyte solution. The H 2 W 2 O 7 electrode showed an oxidation capacity of 56 mAhg ¹ 1 at a current density of 300mAg ¹ 1 , which is equal to the theoretical capacity assuming that 0.5 electrons react with one tungsten ion. H 2 W 2 O 7 also retained 88 % oxidation capacity at a high current density of 2Ag ¹ 1 against that at a low current density of 300mAg ¹ 1 . It is assumed that redox reaction rate mainly depends on proton diffusion in H 2 W 2 O 7 . Moreover, this material showed excellent cycle stability over 1000 cycles without capacity loss. It is clari fi ed that a H 2 W 2 O 7 electrode is a promising electrode for electrochemical capacitors featuring a high rate capability and good cycle life.