Перспективные материалы для гидридных суперконденсаторов на основе гидроксида никеля и восстановленного оксида графена

Abstract

Using microwave-irradiation-reduced graphene oxide (RGO) and nickel hydroxide as precursors, the composites (Ni–RGO) of variable composition are fabricated in two ways: by precipitation of Ni(OH)₂ on RGO in situ or by mixing the suspensions RGO and Ni(OH)₂ . As revealed, the Ni–RGO composites have a high specific capacity when tested as a supercapacitor electrode in 1 M KOH (150 to 330 F/g). As shown, the RGO has high stability during the charge–discharge cycling mode, but a low capacity (≅25 F/g). Pure Ni(OH)₂ , on the contrary, has a high specific capacity in the range of 450–500 F/g, but lack the stability during cycling. Capacitive factor and stability of the Ni– RGO composites under galvanostatic tests take intermediate values as compared with their components, depending on the percentage of Ni(OH)₂ . The introduction of RGO enhances the resistance of electrode mass during cycling after the first 100 charge–discharge cycles. Thus, RGO can serve as a stabilizing additive, which increases both the cycle life and the range of the operating current of supercapacitors based on the Ni(OH)₂ .