Sustainable Supercapacitors: Exploring the Electrochemical Performance of Acacia Leucophloea Wood Sawdust-Based Activated Carbon and ZnCo₂O₄@PPy Composite

Abstract

This project aims to convert renewable waste Acacia leucophloea wood sawdust into low-cost, environmentally friendly porous activated carbon (AC) through a hydrothermal process that produces zinc cobaltite and ALWSD (whereas polypyrrole is produced chemically and used in renewable energy storage devices). The statistical analysis of the diffusive and capacitive contributions to the supercapacitor performance is conducted by the application of numerical techniques. Asymmetric Supercapacitor (ASC) is a technology that uses sawdust from Acacia Leucophloea wood to create innovative activated carbon and zinc cobaltite composited polypyrrole. The instruments used are FESEM, XRD, and EDX to analyse elements, crystallinity, structural, and morphological features. The ZAHC has excellent electrochemical stability, maintaining 98.6% after 10,000 cycles, and outstanding capacitive performance of 331 Fg⁻¹ at 2 Ag⁻¹ in a three-electrode arrangement. The ZAHC electrode exhibits a small series resistance of 0.17 Ω and a charge transfer resistance of 1.2 Ω respectively. Based on the Trasatti method, the ZCOP electrode exhibits 13.2% capacitive behaviour at 5 mVs⁻¹ and 86.8% capacitive behaviour at 100 mVs⁻¹. The ZnCo₂O₄@PPy exhibits excellent electrochemical stability, maintaining 96.9% after 10,000 cycles, and outstanding capacitive performance of 853 Fg⁻¹ at 2 Ag⁻¹. The ZCOP electrode exhibits a small series resistance of 0.12 Ω and a charge transfer resistance of 3.2 Ω respectively The ZAHC/ZCOP ASC in a two-electrode configuration shows long durability of 99.09% after 10,000 cycles in addition to a large specific capacity of 320 Cg⁻¹at 2 Ag⁻¹, the manufactured ZAHC/ZCOP ASC displays a high power and energy density of 108 Whkg⁻¹ and 6821 Wkg⁻¹. Capacitive and diffusive behaviours of the prepared electrode and ASC device were discussed by using the Trsasatti model.