Core-Shell Structure of Polypyrrole Grown on V2O5 Nanoribbon as High Performance Anode Material for Supercapacitors
Core-Shell Structure of Polypyrrole Grown on V2O5 Nanoribbon as High Performance Anode Material for Supercapacitors
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V2O5纳米带上生长的聚吡咯核壳结构作为高性能超级电容器负极材料
DOI：
10.1002/aenm.201200088
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发表时间：
2012-08-01
影响因子：
27.8
通讯作者：
Wu, Yuping
中科院分区：
文献类型：
--
作者：
Qu, Qunting;Zhu, Yusong;Wu, Yuping
V2O5和PPy@V2O5电极的恒流充放电曲线(图3c)由于聚吡咯[39]和V2O5的法拉第伪电容性质而偏离理想的线性形状。在100mA g−1的电流密度下，V2O5和Ppy@V2O5的比容分别为162和308Fg−1，这表明V2O5材料的利用效率提高归因于纳米复合材料的电荷转移的改善，如图2d所示。PPy的存在不会降低PPy@V2O5复合材料的比电容，因为PPy本身在阳极电位范围内提供了有用的假电容(支持信息中的图S3)。PPy@V2O5纳米复合材料的比容量高于许多金属氧化物负极材料[23-26，45-48]，与MnO2，Co3O4，MoO3等正极材料相当，甚至更高。[15，19，49-51]它的平均工作三元混合物是V2O5或PPy@V2O5，乙炔黑，聚四氟乙烯在镍网上。图3a和b显示了V2O5和PPy@V2O5电极在-0.9至0.1V(vs.SCE)的阳极电位[40]范围内的循环伏安曲线。在扫描速度为5 mV的S−1电极上，原始V2O5电极出现四对可逆电流峰，表明V2O5的氧化还原反应与其可变的V价态有关。在PPy@V2O5电极的情况下，除了V2O5电极的氧化还原电流特性外，另一对氧化还原峰出现在-0.70和-0.50V，这可以被指定为PPy[41-44]的去掺杂/掺杂过程，因为纯PPy薄膜在-0.60和-0.40V表现出相似的一对电流峰(支持信息中的图S3)。当扫描速度增加到50 mV S−1时，PPy@V2O5纳米复合材料表现出比原始V2O5更好的倍率性能，这归因于由PPy涂层得到的纳米复合材料的电子导电性得到了改善。
The galvanostatic charge–discharge curves of the V2o 5 and PPy@ V2o 5 electrodes (Figure 3 c) deviate from an ideal linear shape due to the faradic pseudocapacitive property of PPy [39] and V2o 5. The specific capacitances of V2o 5 and PPy@ V2o 5 at a current density of 100 mA g− 1 are 162 and 308 F g− 1, respectively, suggesting an enhanced utilization efficiency of V2o 5 material attributable to the improved charge transfer of the nanocomposites, as shown in Figure 2 d. Meanwhile, the presence of PPy does not reduce the specific capacitance of the PPy@ V2o 5 composite as PPy itself provides useful pseudocapacitance in the anodic potential range (Figure S3 in the Supporting Information). The capacitance of the PPy@ V2o 5 nanocomposite is higher than those of many metal oxide anode materials [23–26, 45–48] and comparable to or even higher than those of the cathode materials such as MnO 2, Co 3O 4, and MoO 3.[15, 19, 49–51] Its average working ternary mixture of V2o 5 or PPy@ V2o 5, acetylene black, and PTFE onto Ni-mesh. Figure 3a and b present the CV curves of the V2o 5 and PPy@ V2o 5 electrodes in the anodic potential range [40] of–0.9 to 0.1 V (vs. SCE). At a scan rate of 5 mV s− 1, the virgin V2o 5 electrode exhibits four pairs of reversible current peaks, signifying the redox reaction of V2o 5 related to its variable V valence states. In the case of the PPy@ V2o 5 electrode, besides the redox current characteristic of the V2o 5 electrode, another pair of redox peaks appear at–0.70 and–0.50 V, which can be designated to the undoping/doping process of PPy [41–44] since pure PPy film exhibits a similar pair of current peaks at–0.60 and–0.40 V (Figure S3 in the Supporting Information). When the scan rate increases to 50 mV s− 1, the PPy@ V2o 5 nanocomposite exhibits a much better rate capability than the virgin V2o 5 attributable to the improved electronic conductivity of the nanocomposite derived from PPy coating.