Contribution of carbon fiber paper (CFP) to the capacitance of a CFP-supported manganese oxide supercapacitor
Contribution of carbon fiber paper (CFP) to the capacitance of a CFP-supported manganese oxide supercapacitor
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DOI：
10.1016/j.jpowsour.2013.09.068
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发表时间：
2014-02
影响因子：
9.2
通讯作者：
Dongchang Chen;Min-Kyu Song;Shuang Cheng;Liang Huang;Meilin Liu
中科院分区：
文献类型：
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作者：
Dongchang Chen;Min-Kyu Song;Shuang Cheng;Liang Huang;Meilin Liu
虽然碳纤维纸（CFP）已广泛应用于电池、燃料电池和超级电容器，但它对设备性能的影响可能相当复杂。在本研究中，我们研究了不同批次的 CFP 对 CFP 支持的 MnOx 混合超级电容器 (CFP/MnOx) 性能的影响。研究发现，如果 CFP 上的 MnOx 涂层致密且保形，则 MnOx 对电容的贡献占主导地位，但如果 CFP 上的 MnOx 涂层是多孔或非保形的，那么 MnOx 对电容的贡献就变得不那么重要。这是因为需要在空气中 400°C 下对 CFP/MnOx 进行退火，以获得高电容所需的适当 MnOx 相；如果 CFP 没有被 MnOx 完全覆盖，则退火过程可能会增加 CFP 的比表面积。此外，碳表面的蚀刻削弱了MnOx与CFP的附着，并恶化了MnOx与CFP的电连接，进一步降低了MnOx对电容的贡献。最后，令我们惊讶的是，我们发现 CFP 的性能因批次而异，这严重影响了 MnOx 涂层的形态/密度。这些因素反过来极大地影响了每个组件对 CFP/MnOx 混合超级电容器电容的贡献。
While carbon fiber paper (CFP) has been widely used in batteries, fuel cells, and supercapacitors, its effect on device performance can be rather complicated. In this study, we examined the effect of CFP from different batches on the performance of a CFP-supported MnOx hybrid supercapacitor (CFP/MnOx). It is found that the contribution of the MnOx to the capacitance is dominating if the MnOx coating on CFP is dense and conformal, but becomes much less significant if the MnOx coating on CFP is porous or non-conformal. This is because annealing CFP/MnOx at 400 °C in air is necessary to obtain proper MnOx phases for high capacitance; the annealing process may increase the specific surface area of CFP if it is not fully covered by MnOx. Also, the etching of carbon surface weakens the attachment of MnOx to CFP and worsens the electrical connection of MnOx to CFP, further reducing the contribution of MnOx to capacitance. Finally, much to our surprise, it is found that the properties of the CFP varied from batches to batches, which critically influence the MnOx coating morphology/density. These factors in turn greatly affect the contribution of each component to the capacitance of the CFP/MnOx hybrid supercapacitors.