Carbon nanotube fibers (CNTFs) are a macroscale material with high conductivity and porosity, and they hold promise as an electrode material for lithium-ion batteries (LIBs), without the need for conducting agents, binders, or current collectors. In this study, to develop an eco-friendly and scalable approach for manufacturing LIB anodes, we investigated the morphological characteristics and anode performance of SnO₂@CNTF nanocomposites synthesized under various conditions. Synthesis experiments were conducted with different temperatures, different precursor concentrations, and different synthesis times. Under high temperatures and high precursor concentrations, SnO₂ nanoparticles grew uniformly and formed a porous structure through which the electrolyte could penetrate deep into the fiber. Furthermore, the effect of the heat treatment temperature of the SnO₂@CNTF was examined, and it was found that higher temperatures led to coarsening and reduction, resulting in performance degradation. Increasing the synthesis time increased the proportion of tin oxide, which in turn increased the overall capacity at low charge-discharge rates. However, for synthesis times exceeding 24 h, the specific capacity at high charge-discharge rates decreased significantly. The results of this study provide insights into the synthesis conditions of tin oxide and the effect of the conditions on the morphology, structure, and anode performance of the compound.

Keywords: CNT Fiber, Tin Oxide, Lithium-ion Battery, Anode, CNT Yarn