Engineering highly active surfaces in molybdenum-integrated cobalt telluride electrodes for enhanced battery-type charge-storage in supercapacitors

The rapid depletion of conventional energy resources has accelerated the global transition towards sustainable alternatives for future generations. Two-dimensional (2D) materials have consequently emerged as promising candidates for a variety of applications, including energy storage. Among these, dual metal chalcogenides have attracted significant attention for their favourable electrochemical properties. In this study, we report the synthesis of Mo-interconnected CoTe₂ (MCT) solid-solution materials engineered specifically for supercapacitor applications. By modulating the Mo content incorporated into the CoTe₂ matrix, we achieved controlled morphological evolution from nanoclusters (MCT-1) to polygonal structures (MCT-2) and ultimately to nano-dots (MCT-3). The nano-dot-based MCT-3 electrode exhibited an outstanding capacitance of 691 C g⁻¹ at a current density of 1 A g⁻¹ and retained 98% of its capacity after 10 000 cycles. Furthermore, an MCT-3//AC asymmetric device delivered a maximum energy density of 122 Wh kg⁻¹ at a power density of 2 kW kg⁻¹, while maintaining 90% capacitance retention over extended cycling at high applied current. The remarkable electrochemical performance of MCT-3 is primarily attributed to the strategic incorporation of molybdenum, which enhances the hierarchical nano-dot architecture. This structure not only preserves the integrity of the layered TeMo–CoTe framework but also promotes synergistic charge-storage interactions between the CoTe and MoTe components. These findings highlight the potential of Mo-modified dual metal chalcogenides as advanced functional materials for next-generation energy storage systems.