Revisiting the capacitance of polyaniline by using graphene hydrogel films as a substrate: the importance of nano-architecturing

Polyaniline has long been explored as a potential candidate for supercapacitors. However, its limited rate capability and cyclability, along with large variation of reported capacitance, cast doubt on its potential for real-world applications. We use a recently developed graphene hydrogel film as a substrate to revisit the capacitance of polyaniline, and reveal that if its nanostructure is properly engineered, polyaniline can provide a combination of high capacitance, excellent rate performance and long cycling life and is promising for real applications.