Comparative Study of the Supercapacitive Performance of Three Ferrocene‐Based Structures: Targeted Design of a Conductive Ferrocene‐Functionalized Coordination Polymer as a Supercapacitor Electrode

Abstract

As redox-active based supercapacitors are known as highly desirable next-generation supercapacitor electrodes, the targeted design of two ferrocene-functionalized (Fc(COOH)₂ ) clusters based on coinage metals, [(PPh₃ )₂ AgO₂ CFcCO₂ Ag(PPh₃ )₂ ]₂ ⋅7 CH₃ OH (SC₁ : super capacitor) and [(PPh₃ )₃ CuO₂ CFcCO₂ Cu(PPh₃ )₃ ]⋅3 CH₃ OH (SC₂ ), is reported. Both structures are fully characterized by various techniques. The structures are utilized as energy storage electrode materials, giving 130 F g^-1 and 210 F g^-1 specific capacitance at 1.5 A g^-1 in Na₂ SO₄ electrolyte, respectively. The obtained results show that the presence of Cu^I instead of Ag^I improves the supercapacitive performance of the cluster. Further, to improve the conductivity, the PSC₂ ([(PPh₃ )₂ CuO₂ CFcCO₂ ]_∞ ), a polymeric structure of SC₂ , was synthesized and used as an energy storage electrode. PSC₂ displays high conductivity and gives 455 F g^-1 capacitance at 3 A g^-1 . The PSC₂ as a supercapacitor electrode presents a high power density (2416 W kg^-1 ), high energy density (161 Wh kg^-1 ), and long cycle life over 4000 cycles (93 %). These results could lead to the amplification of high-performance supercapacitors in new areas to develop real applications and stimulate the use of the targeted design of coordination polymers without hybridization or compositions with additive materials.