Anchoring Metal-Organic Framework-Derived ZnTe@C onto Elastic Ti_3C_2T_x MXene with 0D/2D Dual Confinement for Ultrastable Potassium-Ion Storage

摘要

The prosperous deployments of renewable energy have stimulated thelooming exploration of K-ion batteries (KIBs) for grid-scale energy storagebecause of their high energy density and low cost. However, lacking advancedanode materials with high theoretical capacity, fast K+ storage kinetics, andeco-friendliness discourages KIB development. Here, for the first time, ZnTeas an advanced KIB anode material with a conversion reaction mechanism(yZnTe + xK~+ + xe? → yZn + K_xTe_y) is demonstrated. The ZnTe nanoparticlesare uniformly dispersed in a carbon matrix using metal–organic frameworksas starting materials, which are subsequently anchored on Ti_3C_2T_x Mxenenanosheets, forming elaborate ZnTe@C/Ti_3C_2T_x (ZCT) nanohybrids. Varioustheoretical modeling and postmortem examinations reveal the synergisticintegrations between carbon and Ti3C2Tx. Compositionally, they regulatethe electronic structure of ZnTe, providing fast K+ adsorption kinetics.Morphologically, they construct a 0D/2D dual confinement, addressing thevolume change of ZnTe upon cycling. Therefore, the ZCT exhibits a highcapacity (408.0 mA h g~（?1） at 0.1 A g~（?1）) and excellent long-term cyclability(230.2 mA h g~（?1） at 1.0 A g~（?1） after 3500 cycles), outperforming other reportedtransition-metal-chalcogenides. Significantly, the ZCT-based full cells achievea high energy density of 110.3 Wh Kg~（?1）, making ZCT promising for practicalapplications.