Li Mai, Zhu Kailan, Zhao Hanxue, Meng Zheyi, Wang Chunrui, Chu Paul K
College of Science, Donghua University, Shanghai 201620, China.
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science, Donghua University, Shanghai 201620, China.
Nanomaterials (Basel). 2022 Jun 11;12(12):2020. doi: 10.3390/nano12122020.
In this study, α-MnO and FeO nanomaterials are prepared on a carbon fiber modified with carbon nanotubes to produce the nonbinder core-shell positive (α-MnO@CNTs/CC) and negative (FeO@CNTs/CC) electrodes that can be operated in a wide voltage window in ultrafast asymmetrical flexible supercapacitors. MnO and FeO have attracted wide research interests as electrode materials in energy storage applications because of the abundant natural resources, high theoretical specific capacities, environmental friendliness, and low cost. The electrochemical performance of each electrode is assessed in 1 M NaSO and the energy storage properties of the supercapacitors consisting of the two composite electrodes are determined in NaSO and EMImBF4 electrolytes in the 2 V and 4 V windows. The 2 V supercapacitor can withstand a large scanning rate of 5000 mV S without obvious changes in the cyclic voltammetry (CV) curves, besides showing a maximum energy density of 57.29 Wh kg at a power density of 833.35 W kg. Furthermore, the supercapacitor retains 87.06% of the capacity after 20,000 galvanostatic charging and discharging (GCD) cycles. The 4 V flexible supercapacitor shows a discharging time of 1260 s and specific capacitance of 124.8 F g at a current of 0.5 mA and retains 87.77% of the initial specific capacitance after 5000 GCD cycles. The mechanical robustness and practicality are demonstrated by physical bending and the powering of LED arrays. In addition, the contributions of the active materials to the capacitive properties and the underlying mechanisms are explored and discussed.
在本研究中，α - MnO和FeO纳米材料在碳纳米管修饰的碳纤维上制备，以生产可在超快非对称柔性超级电容器的宽电压窗口中运行的无粘结剂核壳正极（α - MnO@CNTs/CC）和负极（FeO@CNTs/CC）电极。MnO和FeO作为储能应用中的电极材料，因其自然资源丰富、理论比容量高、环境友好且成本低而引起了广泛的研究兴趣。在1 M NaSO中评估每个电极的电化学性能，并在2 V和4 V窗口的NaSO和EMImBF4电解质中测定由这两种复合电极组成的超级电容器的储能性能。2 V超级电容器在循环伏安（CV）曲线无明显变化的情况下，能够承受5000 mV s的大扫描速率，此外，在功率密度为833.35 W kg时，其最大能量密度为57.29 Wh kg。此外，在20000次恒流充放电（GCD）循环后，超级电容器保留了87.06%的容量。4 V柔性超级电容器在0.5 mA电流下的放电时间为1260 s，比电容为124.8 F g，在5000次GCD循环后保留了87.77%的初始比电容。通过物理弯曲和为LED阵列供电证明了其机械稳健性和实用性。此外，还探索和讨论了活性材料对电容性能的贡献及其潜在机制。
