Unraveling the role of copper intercalation and doping on NiTe2 to enhance electrochemical performances

• A reliable synthesis method was developed for Cu-intercalated and Cu-doped NiTe 2 , enabling detailed investigation of their structural and functional properties. • Cu intercalation retains the parent NiTe 2 structure, confirming its high structural stability under intercalation. • In contrast, Cu doping disrupts the layered structure of NiTe 2 , indicating a fundamental change in crystallography and bonding. • Cu-doped NiTe 2 exhibits significantly enhanced electrochemical performance compared to Cu-intercalated NiTe 2 , revealing the critical role of substitutional doping in tuning functional properties. • The findings demonstrate a strategic approach to tailoring the electronic and magnetic behavior of transition metal dichalcogenides for energy-related applications. Layered Transition Metal Dichalcogenides (LTMDs) are now frequently employed as useful materials for catalysis, energy storage, and environmental applications. It is still extremely difficult to create synergistic bimetallic tellurides with great electrochemical performance, particularly in high-performance supercapacitors. Here, the standard solid state technique is used to make high-capacity Cu intercalated and doped NiTe 2 . Both compounds feature a P 3 m 1 space group and a CdI2-type trigonal structure, following the pattern of X-ray powder diffraction (XRPD). The transition electron microscope (TEM) also reveals the periodic arrangement of the crystalline structure. Additionally, the multilayer structures of this chemical are seen by the field emission scanning electron microscope (FESEM). We confirm the elemental composition and oxidation state analysis by using EDX and X-ray photoemission spectroscopy (XPS) respectively. Cu 0.05 NiTe 2 and Ni 0.95 Cu 0.05 Te 2 shows specific capacitance of about 212F/g and 478F/g at 1 A/g. Ni 0.95 Cu 0.05 Te 2 shows excellent cyclic stability (99.18 %) and coulombic efficiency (81.58 %) for 5000 cycles, which confirms the doping of nickel enhances the electrochemical properties.