One-step designing of spinel CuCr2O4/Cr2O3 nanostructures as efficient positive electrode for a high-performance supercapacitor

초록

Although transition metal oxides (TMOs) have theoretical benefits for supercapacitors (SCs), their low conductivity and stability restrict their wide practical utilization. In this context, TMOs-based composite materials with a spinel structure have emerged as efficient positive electrodes for high-performance SCs. It could improve energy storage properties such as capacitance, stability, and energy density. In light of this, in this work, we proposed a nanostructured spinel CuCr2O4/Cr2O3 composite via a facile one-step coprecipitation method. Owing to the advantages of abundant reactive sites, effective electron transport, desirable electrical conductivity, better surface area, mesoporous channels, and synergistic effects of the two, the energy storage properties of the composite on nickel foam (CuCr2O4/Cr2O3@NF) were significantly improved. The resultant CuCr2O4/Cr2O3@NF electrode material shows a high capacitance (capacity) of 1027.5 F g -1 (411 C g-1) at a current density of 1 A g-1. Besides, the composite electrode exhibits rapid faradaic reactions and retains structure integrity over 5000 cycles, affording a good cyclic stability of 86.01 % of its initial capacitance at 15 A g-1. Moreover, the asymmetric device (CuCr2O4/Cr2O3@NF//AC@NF) composed of CuCr2O4/Cr2O3@NF (positive electrode) and AC@NF (negative electrode) delivers an ideal energy density of 38.89 Wh Kg-1 at 800.02 W kg-1, which surpasses the recent spinel metal chromate-based devices and maintains 88.67 % of its capacitance after 5000 charge- discharge cycles. This work may open the path for combining two effective materials to form a multifaceted structure with enhanced energy storage properties.

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