Self-templated flower-like NiCoZn-carbonate hydroxide hollow nanospheres for asymmetric supercapacitors with high performance

• Published in: Nanoscale 2023-10, Vol.15 (41), p.16795-1682
• Main Authors: Liu, Rongrong, Gao, Xin, Xie, Yanqiu, Liu, Qinhan, Zhang, Kai, Sun, Yijia, Bai, He, Yao, Fei, Yue, Hongyan
• Format: Article
• Language: English
• Subjects: Asymmetry; Capacitance; Electrode materials; Electrodes; Energy sources; Hydroxides; Kirkendall effect; Nanospheres; Supercapacitors
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d3nr03839d

With the increasing demand for energy resources, it is crucial to explore electrode materials with high specific capacitance and cycling stability for supercapacitors. Herein, flower-like NiCoZn-carbonate hydroxide (NiCoZn-CH) hollow nanospheres are prepared using self-templated NiCoZn-glycerate solid nanospheres through the Kirkendall effect in a solvothermal reaction. Benefiting from a flower-like morphology, NiCoZn-CH not only provides large contact areas on the electrolyte-electrode and an abundant number of active sites but also shortens the ion transportation pathway. Meanwhile, the hollow structure also improves cycling stability by relieving stresses. Furthermore, Zn 2+ can accelerate the ion transfer and improve the electrochemical activity. Therefore, the Ni 1 Co 1 Zn 0.25 -CH electrode shows an attractive specific capacitance of 1585.2 F g −1 at 1 A g −1 and excellent cycling stability. Additionally, the asymmetric supercapacitor Ni 1 Co 1 Zn 0.25 -CH//AC delivers a superior cycling stability of 99.9% after 15 000 cycles at 10 A g −1 and an energy density of 33.7 W h kg −1 at a power density of 400 W kg −1 . This work provides a simple and efficient route for the fabrication of various carbonate hydroxides. Flower-like NiCoZn-carbonate hydroxide hollow nanospheres were prepared and used as the positive electrode in a supercapacitor having superior cycling stability of 99.9% after 15 000 cycles at 10 A g −l .