Tailoring Cobalt Phthalocyanine‐Based Anodes: Unveiling the Superiority of Cross‐Linked Polymer Architectures over Monomers for Lithium‐Ion Storage

ABSTRACT The development of high‐capacity and stable anode materials beyond graphite remains a critical challenge for advancing lithium‐ion battery (LIB) technology. Organometallic materials such as metallophthalocyanines (MPcs) offer reversible redox activity, tunability, and high theoretical capacity, yet their practical use is constrained by low conductivity, electrolyte solubility, and limited cycling stability. In this study, we address these limitations through a molecular engineering strategy by synthesizing and directly comparing monomeric cobalt phthalocyanine (CoPc) with a novel cross‐linked polymeric cobalt phthalocyanine (pCoPc) as anode materials for LIBs. The pCoPc is prepared via a one‐pot cyclotetramerization of pyromellitic dianhydride with a cobalt source, forming an extended conjugated network. FTIR, Raman, XRD, and electron microscopy confirm the successful construction of the polymeric framework, which exhibits reduced particle size and a porous, interconnected morphology relative to monomeric CoPc. As a LIB anode, pCoPc delivers a high specific capacity of 1087 mAh g ⁻¹ at 100 mA g ⁻¹ over 100 cycles, along with excellent rate capability and long‐term stability. These improvements arise from enhanced structural integrity, increased accessible redox sites, improved conductivity, and suppressed dissolution. This work highlights polymeric MPcs as promising anode materials and presents a rational design strategy for high‐energy organometallic electrodes.