Constructing pseudocapacitance synergistic effect of cobalt phthalocyanine based anode with electronic delocalization for lithium-ion batteries

Metal phthalocyanines and naphthocyanines have wide application prospects as energy-storage material candidates. In this article, cobalt phthalocyanine (CoPc) and cobalt naphthalocyanine (CoNc) are assembled onto graphene oxide (GO) via π-π interactions and subsequently subjected to high-temperature calcination to synthesize Co₃O₄/N-doped graphene composites (Co₃O₄/N) for lithium ion batteries (LIBs) anodes. The results demonstrate that the cobalt naphthalocyanine/graphene oxide (CoNc/GO) composite exhibits significantly enhanced electrochemical performance as an anode material for LIBs. This enhancement is mainly attributed to the extended π-conjugated structure, which facilitates electronic delocalization and markedly improves electrical conductivity. Additionally, the composite constructs a pseudocapacitive synergistic effect, which further enhancing its overall electrochemical performance. The as-prepared CoNc/GO composite exhibits a high initial discharge capacity of 1502.4 mAh g⁻¹ and maintains 574 mAh g⁻¹ after 250 cycles at 100 mA g⁻¹, significantly exceeding that of the cobalt phthalocyanine/graphene oxide (CoPc/GO) composite. The improved lithium ion insertion/extraction efficiency is primarily attributed to enhanced electron delocalization and conductivity, suggesting that CoNc/GO composite exhibit greater potential for LIBs anodes.