Prussian blue analogues derived from NiFe-hydroxide nanoplates with synergistic effect and as high performance supercapacitors

The electrochemical performance of nickel hydroxide is limited by its poor electron transfer ability and limited ion transport channels, while Prussian blue analogues (PBAs) have the advantages of high specific surface area and high porosity, which can provide more transport channels for electron transfer. Therefore, Fe-Ni(OH)2/PBAs heterogeneous structures electrode materials with good electrochemical properties were obtained by etching nickel foam with trivalent iron ions and then partially converting to PBAs in situ. Due to the synergistic interaction between Fe-Ni(OH)2 and PBAs, the heterogeneous structures is 3324.1 F g−1 at 1 A g−1, which is much higher than that of Fe-Ni(OH)2 (only 1494.9 F g−1). In addition, the hybrid asymmetric button-type supercapacitor with Fe-Ni(OH)2/PBAs heterogeneous structures as positive electrode and activated carbon as negative electrode has a specific capacitance of 851.1 F g−1 at 1 A g−1, an energy density power density of 231.7 W h kg−1 at 699.9 W kg−1, the cycling stability performance can reach 100.2% at 10 A g−1 after 6000 cycles. This research evidence a solution for the study of supercapacitor electrodes by constructing heterogeneous structures of high-performance electrode materials from the idea of synergistic effects.