Sree Raj K A, Shajahan Afsal S, Chakraborty Brahmananda, Rout Chandra Sekhar
Centre for Nano and Material Science, Jain University, Jain global campus, Jakkasandra, Ramanagaram, Banglore, 562112, India.
High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
Chemistry. 2020 May 20;26(29):6662-6669. doi: 10.1002/chem.202000243. Epub 2020 Apr 17.
In this work, the ternary hybrid structure VSe /SWCNTs/rGO is reported for supercapacitor applications. The ternary composite exhibits a high specific capacitance of 450 F g in a symmetric cell configuration, with maximum energy density of 131.4 Wh kg and power density of 27.49 kW kg . The ternary hybrid also shows a cyclic stability of 91 % after 5000 cycles. Extensive density functional theory (DFT) simulations on the structure as well as on the electronic properties of the binary hybrid structure VSe /SWCNTs and the ternary hybrid structure VSe /SWCNTs/rGO have been carried out. Due to a synergic effect, there are enhanced density of states near the Fermi level and higher quantum capacitance for the hybrid ternary structure compared to VSe /SWCNTs, leading to higher energy and power density for VSe /SWCNTs/rGO, supporting our experimental observation. Computed diffusion energy barrier of electrolyte ions (K ) predicts that ions move faster in the ternary structure, providing higher charge storage performance.
在这项工作中，报道了用于超级电容器应用的三元混合结构VSe /单壁碳纳米管/还原氧化石墨烯。在对称电池配置中，该三元复合材料表现出450 F g的高比电容，最大能量密度为131.4 Wh kg，功率密度为27.49 kW kg。该三元混合材料在5000次循环后还显示出91％的循环稳定性。已经对二元混合结构VSe /单壁碳纳米管和三元混合结构VSe /单壁碳纳米管/还原氧化石墨烯的结构以及电子性质进行了广泛的密度泛函理论（DFT）模拟。由于协同效应，与VSe /单壁碳纳米管相比，三元混合结构在费米能级附近的态密度增强，量子电容更高，从而导致VSe /单壁碳纳米管/还原氧化石墨烯具有更高的能量和功率密度，这支持了我们的实验观察结果。计算得出的电解质离子（K）的扩散能垒表明，离子在三元结构中移动更快，从而提供了更高的电荷存储性能。
