Polyaniline and Polypyrrole Pseudocapacitor Electrodes with Excellent Cycling Stability
Polyaniline and Polypyrrole Pseudocapacitor Electrodes with Excellent Cycling Stability
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DOI：
10.1021/nl500255v
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发表时间：
2014-05-01
期刊：
影响因子：
10.8
通讯作者：
Li, Yat
中科院分区：
文献类型：
--
作者：
Liu, Tianyu;Finn, Lauren;Li, Yat
聚苯胺、聚吡咯等导电聚合物已被广泛用作超级电容器的伪电容电极材料。然而，由于充放电过程中反复的体积膨胀和收缩导致的结构不稳定性一直是其实际应用的主要障碍。这项工作展示了一种简单而通用的策略，通过在导电聚合物电极表面沉积一层薄的碳质外壳来显著提高其循环稳定性。值得注意的是，碳壳包裹的聚苯胺和聚吡咯电极在10000次循环后的容量保持率分别达到了95和85%。电子显微镜研究表明，厚度接近5 nm的碳素壳的存在可以有效地防止聚合物电极在充放电过程中的结构击穿。重要的是，具有类似于5 nm厚的碳质外壳的聚合物电极表现出与裸聚合物电极相当的比电容和伪电容行为。我们预计，同样的策略也可以应用于稳定其他聚合物电极材料。制备稳定的聚合物电极的能力可能会为伪电容器件打开新的机会。
Conducting polymers such as polyaniline and polypyrrole have been widely used as pseudocapacitive electrode materials for supercapacitors. However, their structural instability resulting from repeated volumetric swelling and shrinking during charge/discharge process has been a major hurdle for their practical applications. This work demonstrates a simple and general strategy to substantially enhance the cycling stability of conductive polymer electrodes by deposition of a thin carbonaceous shell onto their surface. Significantly, carbonaceous shell-coated polyaniline and polypyrrole electrodes achieved remarkable capacitance retentions of similar to 95 and similar to 85% after 10 000 cycles. Electron microscopy studies revealed that the presence of similar to 5 nm thick carbonaceous shell can effective prevent the structural breakdown of polymer electrodes during charge/discharge process. Importantly, the polymer electrodes with a similar to 5 nm thick carbonaceous shell exhibited comparable specific capacitance and pseudocapacitive behavior as the bare polymer electrodes. We anticipate that the same strategy can be applied for stabilizing other polymer electrode materials. The capability of fabricating stable polymer electrodes could open up new opportunities for pseudocapacitive devices.