Wang D Y, Dong Z Q, Zhang S, Hu T Y, Zhang X T, Li X, Li F
The 54th Research Institute of the China Electronics Technology Group Corporation, Shijiazhuang 050011, China.
School of Electronic Science and Technology, Southeast University, Nanjing 210096, China.
J Nanosci Nanotechnol. 2021 Mar 1;21(3):1687-1693. doi: 10.1166/jnn.2021.18990.
This work presents a facile strategy to develop a flexible polyaniline (PANI)-based supercapacitor (SC) with both high energy density and good capacitance retention. An electrode with a symmetrical sandwich-structured configuration (PANI/flexible porous support/PANI) is used as both working and counter electrodes for this supercapacitor. For a conventional electrode with PANI depositing on single side of the support (PANI/flexible support), the flexible support bends severely during the PANI electrodeposition process, which results in poor PANI deposition. On the contrary, for the symmetrical sandwich-structured electrode, due to the stress-compensation effect induced by this configuration, the support bending is significantly suppressed and thus PANI films with a good uniformity are realized. Moreover, the stress-compensation effect involved in the symmetrical sandwichstructured electrode can also effectively balance the stress caused by PANI expansion/shrinkage during its electrochemical charge/discharge operation, thus improving the mechanical stability. The symmetrical sandwich-structured electrode has larger PANI mass loading, better PANI morphologies and stronger mechanical stability than those of the conventional electrode. Consequently, the SC constructed by the symmetrical sandwich-structured electrode displays better electrochemical performance in terms of its larger specific areal capacitance (369.2 mF·cm at a current density of 0.25 mA·cm), higher energy density (0.031 mWh·cm at a power density of 1.21 mW·cm) and better cycling retention (93.2% of the retained capacity over 6000 cycles) than the SC constructed by the conventional electrode.
这项工作提出了一种简便的策略，来开发一种兼具高能量密度和良好电容保持率的柔性聚苯胺基超级电容器（SC）。一种具有对称三明治结构配置（聚苯胺/柔性多孔支撑体/聚苯胺）的电极被用作该超级电容器的工作电极和对电极。对于聚苯胺沉积在支撑体单侧的传统电极（聚苯胺/柔性支撑体），在聚苯胺电沉积过程中柔性支撑体会严重弯曲，这导致聚苯胺沉积效果不佳。相反，对于对称三明治结构电极，由于这种结构引起的应力补偿效应，支撑体的弯曲得到显著抑制，从而实现了具有良好均匀性的聚苯胺薄膜。此外，对称三明治结构电极中涉及的应力补偿效应还可以有效平衡聚苯胺在其电化学充放电操作过程中因膨胀/收缩引起的应力，从而提高机械稳定性。与传统电极相比，对称三明治结构电极具有更大的聚苯胺质量负载、更好的聚苯胺形态和更强的机械稳定性。因此，由对称三明治结构电极构建的超级电容器在比面积电容（在电流密度为0.25 mA·cm时为369.2 mF·cm）、能量密度（在功率密度为1.21 mW·cm时为0.031 mWh·cm）和循环保持率（在6000次循环中容量保持率为93.2%）方面表现出比由传统电极构建的超级电容器更好的电化学性能。
