LDH-derived flower-like Co-Ni fluorides as electrode material for asymmetric supercapacitors

Transition metal fluorides have great potential in energy-related applications, but are relatively scarce investigated. Herein, bimetallic Co-Ni fluorides (CNF) were prepared with Co-Ni-layered double hydroxide (LDH) as a template, which were characterized by using XRD, SEM, TEM, XPS, and EDS mapping. Benefiting from the synergistic effect of flower-like structure and two components, CNF exhibited commendable electrochemical performance. Typically, the CNF-6 sample exhibits a high specific capacitance of 1892 F<middle dot>g-1 at a current density of 1 A<middle dot>g-1 and excellent rate capability (66.1% capacity retention from 1 to 10 A<middle dot>g-1). To explore the great potential of CNF materials, the CNF-6//AC asymmetric supercapacitor was assembled, which presents a high energy density of 37 Wh kg-1 at a power density of 900 W kg-1, confirming that CNF material can be a potential electrode material for supercapacitors.