Hierarchical unidirectional graphene aerogel/polyaniline composite for high performance supercapacitors

A free-standing unidirectional graphene aerogel/polyaniline (UGA/PANI) composite possessing the oriented PANI nanowire arrays on highly aligned and interconnected graphene network is obtained, through a facile in-situ polymerization of PANI on a unidirectional graphene aerogel scaffold. The resulted novel hierarchical structure can reduce the internal resistance and facilitate ion diffusion, which allows this electrode material to exhibit better electrochemistry performances. The UGA/PANI composite subsequently displays an enhanced specific capacitance of 538 F g-1 at 1.0 A g−1 with appreciable rate capability (keeps 73% even at 10 A g−1) as well as fine cycle stability (remains 74% of its initial specific capacitance after 1000 cycles at 3 A g−1). Besides, the electrochemical performances of UAG/PANI composite reported far excel that of conventional graphene aerogel/polyaniline (GA/PANI) composite with random graphene network and tortuous pores (345 F g-1 at 1.0 A g−1, 39% retention at 10 A g−1), demonstrating that proper construction of oriented structure is beneficial for achieving potential of PANI.