Coal fly ash—Municipal solid waste gasification char hybrid electrodes: Pore structure and charge-transport characteristics
by Satria Pinandita, Rustam Asnawi, Mochamad Syamsiro
Energy Storage and Conversion, Vol.4, No.2, 2026;
The development of sustainable and cost-effective electrode materials is crucial for advancing metal–air battery technology and reducing dependence on conventional carbon resources. This study explores coal fly ash and Municipal Solid Waste Gasification (MSWG) char as waste-derived electrode precursors, utilizing their mineral-rich and carbonaceous characteristics to improve electrochemical performance. The objectives were to characterize the raw materials’ elemental composition and surface functional groups and to comparatively evaluate three hybrid-electrode formulations based on their pore characteristics, electrochemical response, and charge-transfer behaviour. SEM–EDX showed coal fly ash with spherical, microsphere-like particles rich in O, Si, and Al, indicating its role as a mineral-rich silicate and aluminosilicate precursor. MSWG char, however, exhibited irregular, rough, agglomerated morphology with higher carbon content, serving as the main carbon source. FTIR confirmed silicate, oxide, hydroxyl, carbonate, and carbon–mineral bonding. Among the three formulations tested, the formulation containing 20 wt.% coal fly ash (F20) showed the best overall performance, with the highest micropore surface area (1.601 m2 g⁻1) and volume (0.0006110 cm3 g⁻1). It delivered the largest CV response, energy density of ~208 Wh kg⁻1, power density of 17.8 W kg⁻1, and the lowest ΔZ′ of 0.137 Ω. The descriptive results indicate that the measured performance may depend on active-pore accessibility and ion–electron transport characteristics rather than on total BET surface area alone. Further replicated experiments are required to establish the statistical reliability of the observed differences. This study advances waste-ash-derived electrodes for sustainable metal–air battery applications. The novelty of this work is the integrated composition–pore–transport evaluation of directly blended coal fly ash and MSWG char hybrid electrodes.
show more