Nanosheet-assembled NiCo-LDH hollow spheres as high-performance electrodes for supercapacitors

• Published in: Journal of colloid and interface science 2022-01, Vol.606, p.1120-1127
• Main Authors: Zhang, Xu, Lu, Wang, Tian, Yuhan, Yang, Shixuan, Zhang, Qiang, Lei, Da, Zhao, Yingyuan
• Format: Article
• Language: English
• Subjects: Co-glycerate; Hollow spheres; Layered double hydroxides; Supercapacitors
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2021.08.094

[Display omitted] •NiCo-LDH hollow spheres were prepared by using Co-glycerate as the sacrificial template and cobalt source.•The frizzy NiCo-LDH nanosheets as the hollow sphere shells can expose the active sites more sufficiently.•The hollow structure can protect serious agglomeration of the LDH nanosheets and reduce the transport path of electrolyte.•An outstanding performance of 1962F g−1 was obtained for NiCo-LDH at 1 A g−1. Layered double hydroxides (LDHs) have been considered as favorable pseudocapacitive electrode materials for supercapacitors due to their tunable layered structure/compositions and low cost. Here, we report the NiCo-LDH hollow spheres prepared with Co-glycerate as the sacrificial template and cobalt source. The hollow spheres are assembled with frizzy NiCo-LDH nanosheets, where the hollow structure can inhibit agglomeration of the LDH nanosheets to expose more active sites and shorten the diffusion path of electrolyte ions. The prepared NiCo-LDH hollow spheres show a high specific capacitance of 1962 F g−1 at 1 A g−1 and good capacitance retention rate of 66.4 % at 30 A g−1. The asymmetric supercapacitors fabricated using NiCo-LDH hollow spheres as positive electrode yields a large energy density 62.9 Wh kg−1 at the power density of 0.8 kW kg−1. This research may develop a facile synthesis way to prepare LDH hollow spheres for supercapacitors.