Abstract:Cobalt telluride (CoTe₂) has been extensively investigated as an anode material for sodium-ion batteries (SIBs) stemming from its large ionic radius, high density (7.92 g cm_-3^{) and unique crystal structure.} However, the inherent low conductivity of CoTe₂ and the large volume change during Na₊ ^de-embedding greatly limits the application of CoTe₂ in SIBs. Metal-organic skeletons possess special topologies, adjustable compositions and large specific surface areas, which are ideal templates for the synthesis of electrode materials. In this paper, a N-doped carbon limited CoTe₂ polyhedral anode materials were successfully in-situ constructed by high-temperature tellurization using Co-based metal-organic skeleton (ZIF-67) as a precursor, and the effects of different tellurization temperatures on the morphology, the physical phase composition, and the charge/discharge behaviors of the final products were also discussed. The results show that the prepared CoTe₂ exhibits a uniform particle distribution at 550°C, and the crystal shape is more compatible with that of standard CoTe₂ crystals. The material is tested at a constant current density of 0.1 A g_-1^. After 100 cycles, the specific capacity is 137.7 mAh g_-1^, while the specific capacity of CoTe₂ synthesized at 450 and 650°C are only 91.5 and 66.3 mAh g_-1^{, respectively.}

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