A high-performance asymmetric supercapacitor consists of binder free electrode materials of bimetallic hydrogen phosphate (MnCo(HPO4)) hexagonal tubes and graphene ink

Novel bimetallic manganese-cobalt hydrogen phosphate (MnxCox(HPO4)) hexagonal tubes were efficiently prepared by a direct and simple chemical bath deposition (CBD) procedure. The prepared MnxCox(HPO4) materials have been analysed through Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) methods. The surface morphology and the particle size of the materials were studied using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The textural characteristics and elemental composition of the MnxCox(HPO4) were measured using nitrogen sorption isotherms and X-ray photoelectron spectroscopy (XPS) analysis. Owing to its unique hexagonal structures and porous nature, the Mn0.5Co0.5(HPO4) electrode is measured via a three-electrode system and achieved the highest specific capacitance of 1,727 F g−1 at the current density of 1.0 A g−1. An aqueous asymmetric supercapacitor (AAS), Mn0.5Co0.5(HPO4)//G-ink device based on Mn0.5Co0.5(HPO4) as the cathode and graphene ink (G-ink) as an anode material. The fabricated device might function well in a large operating potential window of +1.6 V. The Mn0.5Co0.5(HPO4)//G-ink AAS exhibited the maximum power and specific energy of 9,000 W kg−1 and 56.16 Wh kg−1, correspondingly at 1.0 A g−1. Furthermore, the fabricated device could withstand 95.5% of its primary capacitance after 5,000 galvanostatic charge/discharge (GCD) turns, which illustrates that the materials could be a prominent contender for supercapacitor applications. © 2022 Elsevier Ltd