The interplay between different potassium electrolytes and MoS2@SiC@S cathodes in the performance of potassium-sulfur batteries

Abstract

Potassium-sulfur batteries (KSBs) have garnered immense attention as a high-energy, cost-effective energy storage system. Nevertheless, achieving optimal sulfur utilization and long-term cycling is the primary challenge. To address some of the different challenges of KSBs, a potassium-sulfur (K/S) battery cathode was fabricated using MoS2, SiC, and S (Mo@Si@S) in a fixed ratio. The powder was characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), and energy dispersive X-ray (EDX) mapping analysis. Coin cells were fabricated using K metal as an anode, and three different electrolytes were used to determine the effect of electrolytes on electrochemical performance. The battery using the KPF6 electrolyte displayed the best electrochemical performance with a 713 mA h g−1 capacity compared to the other two electrolytes. The structure and morphological evolution of pristine, charged, and discharged states were explored using XRD, SEM, and EDX mapping. The results showed that sulfur was successfully diffused within the cathode, and K was homogeneously distributed, suggesting the good performance of the modified electrode.