Polyaniline nanoarrays grown on holey graphene constructed by frozen interfacial polymerization as binder−free and flexible gel electrode for high−performance supercapacitor

Compared with disordered structures, electrode materials with nanoarray structures can effectively improve the energy storage capacity of supercapacitors. Therefore, the construction of nanoarrays structures is an important research direction. Here, one kind of frozen interfacial polymerization was used to create a polyaniline (PANI) nanoarrays grown on holey graphene (HG). Long polyaniline nanoarrays were constructed with the promotion of ice crystal growth and the abundant pores of the HG. It is demonstrated that the formation of PANI array and hierarchical nanofiber structures is not only conducive to shorten charge transport, but also can effectively alleviate interfacial side reactions. Moreover, benefiting from the abundant active sites and hierarchical porous structure of the HG, highly oriented growth of PANI arrays, efficient charge diffusion and electrolyte infiltration can be achieved. As a result, specific capacitance, reversibility and cycling stability could be significantly improved. Especially, the PANI/HG−10 exhibited the maximum specific capacitance of 793.7 F g−1 at a current density of 1 A g−1. The all−solid−state flexible symmetric supercapacitor assembled by gel electrode possesses the energy density of 32.5 Wh kg–1 at a power density of 326.5 W kg–1, and maintained an excellent cycle retention approaching 90.5 % after 5000 cycles. This work expands the ideas for array structure construction and electrode fabrication.