ScholarWorks@중앙대학교

초록

Understanding dynamic storage mechanisms and tuning electrode interfaces is vital for designing high-performance potassium-ion battery (KIB) anodes. Despite their high capacities, transition metal telluride (TMTe) anodes often suffer from sluggish K+ diffusion and severe volume expansion during cycling, highlighting the need for structurally optimized and interface-engineered architectures. While such strategies have been proven to be effective in lithium- and sodium-ion batteries, their use in TMTe-based KIB anodes remains largely unexplored. In this study, we firstly introduce a heterointerface-engineered three-dimensional microsphere composed of ZnTe nanoparticles and uniformly encapsulated by MXene (denoted MX/ZnTe@NC). Importantly, a built-in electric field (BIEF) is induced at the MXene-ZnTe interface due to their work function. This interfacial field modulates the local electronic structure and significantly accelerates K+ adsorption and diffusion kinetics, especially under high current densities. First-principles simulations and spectroscopic analyses confirm that the BIEF significantly increases the K+ adsorption strength and lowers the energy barriers for ion transport. Electrochemical analyses reveal that the MX/ZnTe@NC anode delivers a high reversible capacity of 283 mAh g−1 after 1000 cycles at 0.5 A g−1, with nearly 100 % Coulombic efficiency. Even at 10 A g−1, the anode retains a capacity of 83 mAh g−1, indicating excellent rate performance. Additionally, in-situ and ex-situ characterizations reveal a highly reversible ZnTe conversion mechanism involving dynamic intermediate phases. This study provides mechanistic insight into the structural and chemical evolution during cycling and highlights the synergistic role of interfacial field engineering and three-dimensional heterostructure design in advancing MXene-based KIB anodes.

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