Research progress on hydroxide fluoride-based electrode materials for supercapacitors

Supercapacitors have attracted much attention due to their high-power density and long cycle life, making them a potential substitute for traditional batteries. Research on hydroxide fluorides as electrode materials for supercapacitors has been increasing. Hydroxide fluorides exhibit higher specific capacitance due to the redox reactions between transition metal elements in different oxidation states. However, their high resistance limits their rate performance and cycling stability, which hinders their large-scale application. This article summarizes the main synthesis methods of hydroxide fluorides, and by controlling the reaction conditions, hydroxide fluorides with different morphologies and structures can be obtained to meet various application requirements. In addition, considering the limitations of hydroxide fluorides, this article systematically introduces the main approaches to improving their electrode performance and summarizes the electrochemical characteristics and latest research progress of hydroxide fluorides.