o-Fe双金属复配比例调控氮掺杂碳纳米管的构建及其高稳定储锂性能研究

o address the issues of low specific capacity and significant Coulombic efficiency decay in carbon nanotube-based anode materials, this study proposes an innovative strategy for constructing self-supported flexible nitrogen-doped carbon nanotubes (NCNTs) via chemical vapor deposition (CVD). By optimizing the cobalt-iron (Co-Fe) bimetallic ratio, we enhanced the structure and lithium storage performance of the carbon nanotube composite (CoFe@NCNTs/CC). Comprehensive characterization through SEM, XRD, Raman spectroscopy, and electrochemical testing revealed that the Co:Fe=2:1 ratio delivers optimal performance. SEM demonstrates uniformly distributed carbon nanotubes with small diameters and evenly embedded metal particles, effectively alleviating volume expansion. XRD confirms the complete crystallization of CoFe alloy without impurity phases. Raman analysis indicates a balanced defect density and graphitization degree, ensuring both sufficient active sites and structural stability. Electrochemical tests show that the Co:Fe=2:1 composite achieves a discharge specific capacity of 2.63 mAh/cm2 at 1 mA/cm2 current density, along with the lowest charge transfer resistance (Rct). After 250 cycles at 1 A/g, the capacity retention remains stable at 93.6% with Coulombic efficiency consistently exceeding 99.5%. These superior properties are attributed to the Co-Fe synergistic effects that optimize interfacial kinetics and reinforce structural stability.