Sahoo Ramkrishna, Acharyya Paribesh, Singh Navin Kumar, Pal Anjali, Negishi Yuichi, Pal Tarasankar
Department of Chemistry and Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
Department of Applied Chemistry, Tokyo University of Science, Tokyo 1628601, Japan.
ACS Omega. 2017 Oct 9;2(10):6576-6585. doi: 10.1021/acsomega.7b01091. eCollection 2017 Oct 31.
NiCoO nanostructure is a widely studied pseudocapacitor material because of its high specific capacitance value. Most of the time, the thickness of the nanostructure inhibits the electrode material from whole-body participation and causes sluggish charge transportation. These phenomena directly interfere with the electrochemical performance of the electrode, such as specific capacitance value, stability, energy density, and so forth. Here, two different thin two-dimensional morphologies (nanosheet and nanoplate) of the NiCoO nanocomposite with a large lateral size are reported using ammonia as a hydrolyzing agent. The large size and flat surface of the as-synthesized materials offer enormous active sites during the electrochemical reaction, and the thin wall makes the ion penetration and transportation very effective and facile. Therefore, the NiCoO nanosheet and nanoplate structures exhibited high specific capacitance values of 1540 and 1333 F/g, respectively, with excellent rate and good cycling stability. Here also, two different advance aqueous asymmetric supercapacitors have been reported utilizing two NiCoO nanostructure materials as positive electrodes and the rGO@FeO composite as a negative electrode, which exhibited excellent rate and high specific energy without sacrificing the specific power. We also studied the electrochemical activity of the rGO@FeO composite at different compositions.
由于其高比电容值，NiCoO纳米结构是一种被广泛研究的赝电容材料。大多数情况下，纳米结构的厚度会阻碍电极材料的整体参与，并导致电荷传输缓慢。这些现象直接影响电极的电化学性能，如比电容值、稳定性、能量密度等。在此，报道了以氨作为水解剂制备的具有大横向尺寸的两种不同二维薄形态（纳米片和纳米板）的NiCoO纳米复合材料。所合成材料的大尺寸和平坦表面在电化学反应过程中提供了大量活性位点，而薄壁使离子渗透和传输非常有效且容易。因此，NiCoO纳米片和纳米板结构分别表现出1540和1333 F/g的高比电容值，具有优异的倍率性能和良好的循环稳定性。在此还报道了两种不同的先进水系不对称超级电容器，它们以两种NiCoO纳米结构材料作为正极，rGO@FeO复合材料作为负极，在不牺牲比功率的情况下表现出优异的倍率性能和高比能量。我们还研究了rGO@FeO复合材料在不同组成下的电化学活性。
