NiCo-MOF nanosheets wrapping polypyrrole nanotubes for high-performance supercapacitors

Metal-organic frameworks (MOFs) are widely used as supercapacitor electrode materials because of their large specific surface area and tunable pore structure. However, the limited electronic conductivity of MOFs deteriorates the capacitive performance. Herein, bimetal-organic framework nanosheets wrapping polypyrrole nanotubes (NiCo-MOF@PNTs) were successfully prepared by an easy ultrasonic method. In the NiCo-MOF@PNTs nanocomposites, PNTs can boost the electronic conductivity of NiCo-MOF and effectively impede the aggregation of NiCo-MOF nanosheets. The unique structure of NiCo-MOF@PNTs allows for exhibiting the superior electrochemical performance. The specific capacitance of NiCo-MOF@PNTs is 1109 F g(-1) at 0.5 A g(-1). Furthermore, the assembled NiCo-MOF@PNTs//AC asymmetric supercapacitor demonstrates a high energy density of 41.2 Wh kg(-1) at a power density of 375 W kg(-1), and the excellent cycling stability with a capacitance retention of 79.1% after 10,000 cycles, demonstrating that NiCo-MOF@PNTs nanocomposites are a promising candidate for supercapacitor electrode materials.