MXene-integrated Ni–Co telluride composites as restacking-free electrodes for boosted pseudocapacitive performance

Abstract

Transition metal chalcogenides are promising electrode materials for electrochemical supercapacitors; however, their performance is often hindered by restacking issues during energy storage processes. Alternatively, integrating MXene nanosheets with chalcogens such as tellurides can effectively mitigate these issues. Thus, this study explores the potential of NiCoTe₂ (bimetallic tellurides) for energy storage applications, highlighting that the synergistic interaction existing between MXene (Ti₃C₂T_x) and NiCoTe₂ significantly enhances their electrochemical performance. Initially, NiCoTe₂ nanorod arrays were synthesized via a hydrothermal method, and the NiCoTe₂/MXene composite was subsequently developed using a sonochemical approach. Subsequently, electrochemical characterization of the composite, employing a graphite sheet (GS) as the working electrode, demonstrated a high specific capacity of 582 mAh g⁻¹ at a current density of 1 A g⁻¹ within the negative potential range. Moreover, the asymmetric supercapacitor device, NiCoTe₂/MXene||AC, delivered a specific capacity of 298 mAh g⁻¹ at 1 A g⁻¹, along with exceptional cyclic stability (94% capacity retention after 10 000 cycles), an energy density of 83.38 Wh kg⁻¹, and a power density of 577.24 W kg⁻¹. Thus, the results underscore the potential of this composite for application in practical energy storage systems.