ScholarWorks@중앙대학교

초록

Potassium-ion batteries (KIBs) have recently garnered significant attention as cost-effective alternatives to lithium-ion batteries, necessitating substantial development in terms of material aspects to meet industrial demands. MXenes, a family of two-dimensional (2D) transition-metal carbides and nitrides, have attracted attention owing to their excellent electrical conductivity, mechanical robustness, and surface functional groups that promote uniform deposition of active materials. However, traditional 2D MXenes suffer from restacking, which limits their accessible surface area and ion transport. To overcome this, we fabricate novel three-dimensional (3D) porous N-doped-carbon–coated MXene/CoSe2 microspheres via spray drying, which prevents restacking and enhances electrochemical performance. Spray drying offers several advantages, including the transformation of 2D materials into 3D structures with high reproducibility, making it suitable for mass production. The 3D structure leverages synergistic effects: MXene provides a stable substrate for uniform CoSe2 nanocrystal dispersion, whereas the N-doped-carbon matrix prevents CoSe2 overgrowth and mitigates volume expansion. As a KIBs anode, the composite delivers a stable reversible capacity of 328 mAh g−1 at 0.5 A g−1 after 400 cycles and exhibits an excellent rate performance of 171 mAh g−1 at 3.0 A g−1. This study offers a strategy for overcoming the limitations of 2D MXenes by transforming them into 3D porous structures, paving the way for advanced MXene-based anodes.

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