Xiaohe Ren1,Ziwei Gan1,Mengxuan Sun1,Chunyang Jia1,Zhijie Li1
University of Electronic Science and Technology of China1
Xiaohe Ren1,Ziwei Gan1,Mengxuan Sun1,Chunyang Jia1,Zhijie Li1
University of Electronic Science and Technology of China1
It is a great challenge to achieve both high specific capacity and high energy density of supercapacitors by designing and constructing hybrid electrode materials through a simple but effective process. In this paper, we proposed a hierarchically nanostructured hybrid material combining Zn<sub>0.76</sub>Co<sub>0.24</sub>S (ZCS) nanoparticles and Co(OH)<sub>2</sub> (CH) nanosheets using a two-step hydrothermal synthesis strategy. Synergistic effects between ZCS nanoparticles and CH nanosheets result in efficient ion transports during the charge-discharge process, thus achieving a good electrochemical performance of the supercapacitor. The synthesized ZCS@CH hybrid exhibits a high specific capacity of 1152.0 C g<sup>-1</sup> at a current density of 0.5 A g<sup>-1</sup> in 2 M KOH electrolyte. Its capacity retention rate is maintained at ~70.0% when the current density is changed from 1 A g<sup>-1</sup> to 10 A g<sup>-1</sup>. A hybrid supercapacitor (HSC) assembled from ZCS@CH as the cathode and active carbon (AC) as the anode displays a capacitance of 155.7 F g<sup>-1</sup> at 0.5 A g<sup>-1</sup>, with a remarkable cycling stability of 91.3% after 12,000 cycles. Meanwhile, this HSC shows a high energy density of 62.5 Wh kg<sup>-1</sup> at a power density of 425.0 W kg<sup>-1</sup>, proving that the developed ZCS@CH is a promising electrode material for energy storage applications.