Controllable preparation of hydrangea-shaped CoAl-LDHs/CoF2 composite for supercapacitor electrode with superior performance

Exploring the method for rational design of hierarchical structures such as hollow, sphere, and core–shell structures is a crucial challenge for enhancing the electrochemical performance of supercapacitor electrodes. In this study, we demonstrate a facile method for controllable preparation of hydrangea-shaped CoAl-LDHs/CoF2 composite and used as a positive electrode for supercapacitor. A series of contrast tests are performed to select optimal experiment condition. CoAl-LDHs obtained at a metal ratio of 2:1, reacting 8 h with the addition of NH4F, display optimal performance associated with the hierarchical structure, where NH4F plays a vital role in regulating this uniform generation process. The fabricated working electrode shows a high specific capacitance of 827.8 Fg−1, with excellent capacitance retention of 62.8