The reported specific capacitance (3612 F/g) and energy density (53.6 Wh/kg) are unusually high compared to similar materials, raising concerns about measurement accuracy and potential overestimation. The claim of a single-phase spinel structure is questionable, as XRD and Raman analyses suggest mixed sulfide/oxide phases, which could impact stability. The significant capacitance loss (52% after 20,000 cycles) indicates material degradation, contradicting the claim of long-term performance. I recommend that the authors thoroughly examine these concerns and offer additional clarification to address the identified issues.
