Controllable Intercalated Polyaniline Nanofibers Highly Enhancing the Utilization of Delaminated RuO2 Nanosheets for High-Performance Hybrid Supercapacitors

Ruthenium oxide (RuO2) and polyaniline (PANI) are attracting extensive attention as electrode materials due to their remarkable pseudocapacitance. However, RuO2 suffers from low utilization and PANI sustains poor stability. Herein, both defects were optimized by designing intercalated-structure PANI/RuO2 composites, which were fabricated for the first time by controllable chemical polymerization of aniline on the delaminated RuO2 nanosheets. Intercalated PANI nanofibers not only highly prevent the RuO2 nanosheets from their reassembling as well as increase the interlayer spacing among RuO2 nanosheets but also alleviate the swelling/shrinking of PANI during charge-discharge progress. In comparison to the pristine RuO2 nanosheets, the obtained intercalated structure is beneficial for creating channels for better ion transfer and electron transport, which leads to a high-efficiency utilization of RuO2 nanosheets. The optimized PANI/RuO2-38 electrode with a RuO2 content of 61.7 wt% shows the highest utilization of 72.1 % of RuO2, resulting in the highest specific capacity of 816 F g(-1). The asymmetric supercapacitor PANI/RuO2//AC offers a high energy density of 25.7 Wh kg(-1) at 375 kW kg(-1), further indicating a good potential as energy-storage device.