Engineered flower-like hierarchical Cu2S architectures mediated by carbon nanotubes and Ti3C2 for enhanced ionic diffusion and charge carriers in hybrid supercapacitors

Abstract

Growing global energy demands have stimulated extensive efforts toward sustainable energy solutions. In this work, Cu₂S (CS) and its composites (CS-CNTs and CS-MXene) were studied for advanced supercapacitor devices. Surface analysis revealed a flower-like hierarchical architecture with high porosity, as evident by Brunauer–Emmett–Teller analysis, providing abundant active sites and promoting fast ion transport. Dunn's model analysis revealed a hybrid charge-storage behavior of all the prepared electrode materials. Among all prepared electrodes, the CS/MXene demonstrated the most superior electrochemical features in half-cell analysis, exhibiting a specific capacity (C_sc) of 1692C g⁻¹ with an impressive energy density (E_d) of 112 Wh kg⁻¹ at a current density (I_d) of 11.7 A g⁻¹. Upon full-cell analysis, the CS/MXene composite delivered a remarkable C_sc of 371.63C g⁻¹ at I_d of 3.13 A g⁻¹, with E_d of 61.93 Wh kg⁻¹ at P_d of 1882.35. Furthermore, the CS/MXene retained 97.5% of its initial capacity after 5000 consecutive charge/discharge cycles. Furthermore, the electrode exhibited the shortest relaxation time, moderate diffusion coefficient and the highest ionic conductivity (0.092 S cm⁻¹), confirming its superior charge transport efficiency compared to other electrodes. Collectively, these results highlight the potential of these materials for high-performance hybrid supercapacitors.