A High-Performance Hierarchical Graphene@Polyaniline@Graphene Sandwich Containing Hollow Structures for Supercapacitor Electrodes

An effective design and fabrication of a more steady structure for high-performance electrodes applications still remains a challenge. Herein, we have designed and fabricated a hierarchical heterostructure of a graphene@polyaniline@ graphene sandwich consisting of hollow polyaniline spheres as the sandwich layer and graphene both as an internal skeleton shell and a cladding layer. The special sandwich configuration not only enlarged the specific surface area but also improved the electrical conductibility. Most importantly, the graphene double shells could prevent the structural breakdown (swelling or shrinkage) of polyaniline. Therefore, as a supercapacitor electrode, the hybrid exhibited excellent performance with a specific capacitance of 682.75 F g(-1) at 0.5 A g(-1) and a remarkable cycling stability with capacitance retentions of 92.8% after 1000 cycles and even 87.6% after 10,000 cycles, which were better than those of pure polyaniline. In addition, the specific capacitance could reach 217.11 F g(-1) at a high current density of 20 A g(-1) Thus, it could be considered as a perspective electrode for the next generation of high-performance supercapacitors.