LAUSR

Abstract Aimed at improving the electric efficacy of supercapacitor, we designed a novel binder and conductive agent‐free electrode material by integrating varying amounts of aluminum into ultrathin nanosheets of NiCo layer double hydroxide on nickel foam via a one step hydrothermal treatment. We investigated the remarkable impact of Al on the morphology and electrical performance of NiCo2Alx-OH. A transfiguration occurred from β-phase of NiCo2–OH to α-phase of NiCo2Alx-OH with the introduction of Al in NiCo–OH. The NiCo2Al0.5-OH electrode has 1570 F g−1 specific capacitance at a current density of 2 A g−1. A high performance aqueous asymmetric supercapacitor (NiCo2Al0.5-OH//AC) was designed with NiCo2Al0.5-OH as the positive electrode. This device demonstrated an excellent energy density of 56.8 W h kg−1 at 618 W kg−1 power density and 98% capacitance retention over 6000 cycles at a current density of 20 A g−1.