Boosting K+ storage capacity in carbon nanofibers: A synergistic strategy involving amorphous SnO2, ZnO integration, and graphene decoration
摘要
Potassium-ion batteries (KIBs) are rising as a noteworthy contender to lithium-ion batteries (LIBs), particularly for large-scale applications, driven by the natural abundance and cost-effectiveness of potassium resource. Yet, lacking anodes which can reversibly accommodate the larger K+ currently poses a critical development hurdle, highlighting an urgent need for innovative solutions. Herein, porous ZnO-SnO2-graphene-carbon (ZTO-G-C) nanofibers are presented, featuring amorphous SnO2 and ZnO nanoparticles homogeneously dispersed within a carbon matrix, with the strategic graphene incorporation for enhanced performance. Employing an adjustable and straightforward electrospinning method, the nanofibers were crafted to achieve a stable fibrous architecture. When evaluated as KIB anodes, the ZTO-G-C nanofibers demonstrated remarkable cycling stability (retaining 230.82 mA·h/g over 100 cycles at 100 mA/g), and rate capability (184.78 mA·h/g at 1 A/g). This outstanding performance is due to the synergistic interaction among all active components, collectively enhancing the structural stability against volume expansion during K+ intercalation, facilitating efficient charge transport, and delivering exceptional cyclability, capacity, and rate performance. Moreover, the intrinsic pseudocapacitive behavior stemming from the porous carbon substrate of ZTO-G-C further boosts its overall K-storage capacity. It is anticipated that the insights gained from this study offer fresh perspectives for developing next-generation high-performance KIB anodes.