Hybrid nanostructured PAN@NiCu(CO3)(OH)2 composite for flexible high-performance supercapacitors

Abstract A binder-free porous NiCu(CO3)(OH)2 composite was grown on a polyacrylonitrile (PAN) nanofiber substrate using a hydrothermal method. PAN nanofibers were fabricated by the electrospinning method, thus producing a substrate with a nano-sized diameter and high specific surface area. The composite NiCu(CO3)(OH)2 nanowires on PAN nanofibers provided the large specific surface area required for the redox reaction. Transition metal-based nanowires and nano-sized PAN substrates indicate a synergistic effect in electrochemical performance. The NiCu(CO3)(OH)2 on PAN composite showed a remarkable maximum specific capacity of 870 mAh g−1 at a current density of 3 A g−1, which indicates that it can be a suitable electrode material. In addition, an asymmetric supercapacitor with NiCu(CO3)(OH)2 on PAN composite as the cathode and graphene as the anode showed an ultra-high energy density of 89.2 W h kg−1 at a power density of 835 W kg−1 and a capacitance retention of 90.1% after 5000 cycles. Graphic abstract