Dai Xiaoli, Zhang Ming, Li Jitao, Yang Dingyu
College of Optoelectronic Technology, Chengdu University of Information Technology Chengdu 610225 China
School of Precision Instruments and Optoelectronics Engineering, Tianjin University Tianjin 300072 China
RSC Adv. 2020 Apr 21;10(27):15860-15869. doi: 10.1039/d0ra01681k.
As is well known that the specific capacitance of supercapacitors cannot be improved by increasing the mass of the deposited MnO films, which means an appropriate deposition duration is important. In this study, nanobelt-structured MnO films were prepared by the electrochemical deposition method under different deposition time to explore the effects of electrodeposition time change on the microstructure and electrochemical properties of this material. Benefiting from the microstructure of the MnO films, the transfer properties of the charged electrons and ions were promoted. Meanwhile, a 3D porous nickel foam was chosen as the deposition substrate, which rendered an enhancement of the MnO conductivity and the mass of the active material. The enhanced specific capacitance and specific surface area attributed to synergistic reactions. Subsequently, the electrochemical performances of the as-prepared materials were analyzed cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) tests. Results show that the optimum sample deposited for 50 s has a specific capacitance of 291.9 F g at the current density of 1 A g and lowest . However, its electrochemical stability cannot come up to the level of the 300 s sample due to the microstructure change.
众所周知，通过增加沉积MnO薄膜的质量并不能提高超级电容器的比电容，这意味着合适的沉积持续时间很重要。在本研究中，采用电化学沉积法在不同沉积时间下制备了纳米带结构的MnO薄膜，以探究电沉积时间变化对该材料微观结构和电化学性能的影响。得益于MnO薄膜的微观结构，带电电子和离子的传输性能得到了提升。同时，选择三维多孔泡沫镍作为沉积基底，这提高了MnO的导电性以及活性材料的质量。比电容和比表面积的提高归因于协同反应。随后，通过循环伏安法（CV）、恒电流充放电（GCD）和电化学阻抗谱（EIS）测试分析了所制备材料的电化学性能。结果表明，在1 A g的电流密度下，沉积50 s的最佳样品具有291.9 F g的比电容，且内阻最低。然而，由于微观结构的变化，其电化学稳定性达不到沉积300 s样品的水平。
