Synthesis of redox-active dendronized poly(ferrocenylsilane) and application as high-performance supercapacitors

Abstract

A novel dendronized poly(ferrocenylsilane) (PFS-D) is prepared by ionic self-assembly of cationic poly(ferrocenylsilane) of [Fe(η-C5H4)2SiMe- (OCH2CH2NMe3I)]n (PFS) with anionic dendrons of 3,4,5-tris(n-octane-1-yloxy)- benzoic acid [(3,4,5)8G1-COOK]. XRD profiles and POM indicated the presence of the liquid crystalline phase in the PFS-D at room temperature that is resulted from the dendritic amphiphiles, which formed the end-to-end bilayer lamellar structure with the long period d = 3.27 nm. PFS-D coated on Ni foam (PFS-D/Ni) was applied as electrode materials for supercapacitors. CV measurements indicated that PFS-D/Ni exhibited a good reversible redox process and this observation was deemed to originate from its ferrocenyl moieties in liquid crystalline phase. The as-prepared PFS-D/Ni possessed a specific capacitance as high as 197 F g−1 calculated from discharge curve with current density 5 A g−1. The long-term cycle life stability for PFS-D/Ni was examined and the results showed that the capacitance decay was ∼14% over 3000 cycles, indicating its long cycle life. Furthermore, they could also be used to assemble a simple solid-state supercapacitor. In a word, the PFS-D/Ni was reported as a promising electrode material for efficient pseudo-capacitors for the first time.