Synthesis and Comparative Electrochemical Evaluation of Polymer Cobalt Phthalocyanine and SWCNT-Modified Composite as High-Performance Anode Materials for Lithium-Ion Batteries

The development of high-performance anode materials remains a key challenge for advancing lithium-ion battery (LIB) technology. In this work, an oxy-bridged polymer cobalt phthalocyanine (Poly-CoPc) and its single-walled carbon nanotube-modified composite (Poly-CoPc/SWCNT) were successfully synthesized and systematically investigated as potential anode materials. The structural, chemical, and morphological properties of the materials were thoroughly characterized using Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscopy (TEM) techniques. Morphological studies demonstrated a uniform dispersion of Poly-CoPc over the SWCNT network, leading to an interconnected conductive structure with enhanced surface area. Electrochemical performance was evaluated and compared with pristine Poly-CoPc. Compared to pristine Poly-CoPc, the Poly-CoPc/SWCNT composite exhibited significantly improved electrochemical behavior, including higher specific capacity, enhanced rate performance, and superior cycling stability. The composite delivered a high initial discharge capacity of 2016 mA g−1 and maintained an excellent reversible capacity of 1047 mA g−1 after 100 cycles at 0.1 A g−1. Furthermore, it demonstrated outstanding rate capability, retaining a capacity of 855 mA g−1 at 0.5 A g−1. This enhanced performance is attributed to the synergistic effect between the redox-active Poly-CoPc and the highly conductive SWCNT network, which facilitates efficient electron transport, improves ion diffusion, and stabilizes the electrode structure during cycling. These results highlight that SWCNT-modified Poly-CoPc is a promising candidate for next-generation high-performance LIB anodes.