Unlocking potential: temperature-driven morphology and electrolyte influence on chemical-free pineapple peel-derived amorphous carbon for enhanced electrochemical performance.

In this study, we present a novel approach to synthesizing amorphous carbon from agricultural waste, specifically pineapple peel, for electrochemical energy storage applications. The research emphasizes the critical role of calcination temperature and the subsequent interplay with different electrolytes (basic, neutral, and acidic) to tailor the material's properties for improved performance. A controlled calcination of the bio-waste was carried out at varying temperature of 400, 500, and 600 °C which yielded three separate samples. The sample calcinated at 500 °C is considered the best sample among the three, demonstrating the most favourable electrochemical properties. The calcination temperature was found to be pivotal in determining the material's structural and functional characteristics particularly for the said best sample, which exhibited an optimal balance of morphological structure and functional groups that facilitated enhanced charge storage and energy density, especially when interfaced with acidic electrolytes. Comprehensive characterization through XRD and FTIR affirmed the amorphous nature of the carbon and the presence of electrochemically active functional groups. Electrolyte selection proved to be a determining factor in the material's capacitive behaviour, with each electrolyte types bringing forth distinct capacitance and energy density profiles. The sample calcined at 500 °C consistently showed good performance in all the electrolyte system, and outperformed in acidic media due to the optimal interaction between the electrolyte ions and the tailored surface chemistry of the carbon. The insight from this research highlights the influence of calcination temperature in modifying the physical and chemical characteristics of carbon materials derived from biomass, without the need for additional porosity-enhancing treatments. The results contribute to a greener pathway for producing advanced materials for energy storage, reinforcing the potential of agricultural by-products in crafting next generation energy solution. [ABSTRACT FROM AUTHOR]