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

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. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

NiCo-LDH hollow spheres were prepared using Co-glycerate as the sacrificial template and cobalt source, showing high specific capacitance and good capacitance retention rate. Asymmetric supercapacitors fabricated with these hollow spheres as positive electrode exhibited a large energy density, providing a new approach for supercapacitor research.