Efficient synergy of MOF-derived CoTe2 polyhedron anchoring on CNTs as anode materials for Na-ion storages

The transition metal chalcogenides (TMCs) are promising anode materials with excellent theoretical ca-pacity and controllable synthesis approaches for Sodium ion batteries. However, the obvious volume effects and sluggish kinetics in the long-term sodiation/desodiation reaction limit the stability and high-capacity. Herein, the CoTe2 @carbon nanocomposite electrodes (CoTe2 @CNTs) are designed by ZIF-67 derived to conquer the volume expansion, synchronously, and CNTs anchored strategy are adopted to promote Na+ diffusion dynamics, and ensure cyclic stability and long cycle life of anode materials. Specifically, the as prepared nanocomposite constructed by CoTe2 and CNT has displayed efficient Na+ storage mechanism by providing multiple adsorption sites, interconnected conductive network and abundant ions transport pathways, which are revealed by the density functional theory calculations. Furthermore, the in-situ CNTs anchored of CoTe2 polyhedron have significantly enhanced the charge transfer capacity for Na+/electron and metallic properties of CoTe2 @CNT composites, which exhibit outstanding electrochemical capacities (112.7 mAh g-1 at 2 A g-1 after 500 cycles) and pseudocapacitive-dominated behaviors when used as anodes. This work is expected to provide a legitimate and convenient approach with the controllable preparation of nanocomposite in energy storge devices.& COPY; 2023 Elsevier B.V. All rights reserved.