Iqbal Muhammad Zahir, Khan Junaid, Awan Hafiz Taimoor Ahmed, Alzaid Meshal, Afzal Amir Muhammad, Aftab Sikandar
Nanotechnology Research Laboratory, Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhwa, Pakistan.
Dalton Trans. 2020 Dec 8;49(46):16715-16727. doi: 10.1039/d0dt03313h.
State of the art supercapatteries have received considerable attention for their significant electrochemical performance; however, electrode materials with enhanced charge storage capabilities are desired. Here, we report the synthesis of mixed metal phosphate nanomaterials with different concentrations via a sonochemical approach. Initially, binary metal phosphates based on zinc, cobalt, and manganese were synthesized. Then, the composition of zinc and cobalt was optimized in ternary metal phosphates. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques were utilized to examine the surface morphology, elemental analysis and crystal structure of as-synthesized nanomaterials. The electrochemical characterizations were performed in a three cell configuration. Zn0.50Co00.50Mn(PO4)2 delivers the optimum performance with a specific capacity of 1022.52 C g-1 (specific capacitance of 1704.21 F g-1) at 1.2 A g-1. This optimized material was further engaged in an asymmetric device (supercapattery) as a positive electrode material to explore the real device performance. The supercapattery device was found to have an impressive specific energy of 45.45 W h kg-1 at 0.5 A g-1 and provide a remarkable specific power of 4250 W kg-1 at 5 A g-1 current density. The device exhibits excellent capacity preservation of 93% examined after 1500 charge discharge cycles. In addition, to scrutinize the supercapattery performance in terms of capacitive and diffusion controlled processes, a simulation approach was adopted. The real device comprises a capacitive contribution of 8.42% at 3 mV s-1 and 66.56% at 100 mV s-1. This novel progress in ternary metal phosphates results in a fine electrode material for high performance supercapattery applications.
先进的超级电容器因其显著的电化学性能而备受关注；然而，人们期望获得具有增强电荷存储能力的电极材料。在此，我们报告了通过声化学方法合成不同浓度的混合金属磷酸盐纳米材料。首先，合成了基于锌、钴和锰的二元金属磷酸盐。然后，在三元金属磷酸盐中优化了锌和钴的组成。利用扫描电子显微镜、能量色散X射线光谱和X射线衍射技术来检查合成纳米材料的表面形态、元素分析和晶体结构。电化学表征在三电极配置中进行。Zn0.50Co00.50Mn(PO4)2在1.2 A g-1下具有1022.52 C g-1的比容量（1704.21 F g-1的比电容），展现出最佳性能。这种优化后的材料进一步作为正极材料用于非对称器件（超级电容器）中，以探索实际器件性能。发现该超级电容器器件在0.5 A g-1下具有45.45 W h kg-1的可观比能量，在5 A g-1电流密度下提供4250 W kg-1的卓越比功率。该器件在1500次充放电循环后检查显示具有93%的出色容量保持率。此外，为了从电容控制和扩散控制过程方面详细研究超级电容器的性能，采用了一种模拟方法。实际器件在扫描速率为3 mV s-1时电容贡献为8. ,42%，在100 mV s-1时为66.56%。三元金属磷酸盐的这一新颖进展产生了一种用于高性能超级电容器应用的优良电极材料。
