Light-weight flexible solid-state supercapacitor based on highly crystalline 2D BiOCl nanoplates/ MWCNT nanocomposites

Two dimensional (2D) nanomaterials with high specific surface area and large electro-active sites have been promising candidate for flexible electrochemical energy storage applications. Here, we have adopted a simple, cost-effective hydrothermal approach for the synthesis of scalable amount of 2D bismuth oxychloride (BiOCl) nanoplates. Thin flexible films of BiOCl/MWCNT composites have been prepared with varying the weight percentage. A remarkable electrochemical performance has been obtained for BiOCl/MWCNT flexible solid state symmetric supercapacitor (FSSSC) with PVA/H2SO4 gel as solid electrolyte. Among various compositions, 60% BiOCl loaded electrodes (FSSC60) delivers a highest specific capacitance of 421 F/g at 5 mV/s. Furthermore, FSSSC60 exhibits a high energy density of 14.62 Wh/kg at power density 947.5 W/kg compared to previously reported bismuth materials. The FSSSC 60 shows excellent durability with 94% of initial specific capacitance after 2000 cycles. In addition, as fabricated device exhibits good flexibility and retains almost constant performance after bending through different angles. (C) 2019 Elsevier B.V. All rights reserved.