Boosting supercapacitor performance via flower-like Cu₂XSnS₄ (X = Mn, Co, Ni, Ba, Zn) chalcogenides: solvothermal synthesis and charge storage behavior

Abstract

In the present work, a series of Cu₂XSnS₄ (X = Mn, Co, Ni, Zn, Ba) quaternary chalcogenide phases were synthesized by a simple solvothermal method and evaluated as electrode materials in symmetric two-electrode supercapacitor cells. Structural and morphological analyses demonstrated the formation of flower-like crystalline structures, with significant variations in texture and surface area depending on the substituted metal. Among the synthesized samples, the Mn-substituted CMnTS electrode exhibited the highest specific capacitance of 386.0 F/g at a current density of 1.0 A/g and maintained 92 % of its initial capacity after 10,000 charge-discharge cycles. Electrochemical tests revealed that CMnTS stored charge predominantly through capacitive mechanisms, while the Zn-substituted sample exhibited diffusion-limited behavior. EPR analysis indicated the presence of paramagnetic species in CMnTS, which may contribute to its electrochemical performance. These findings highlight the critical role of metal substitution in tailoring the charge storage characteristics of quaternary chalcogenides and provide a promising approach for optimizing electrode materials