Synergistically enhanced performance of supercapacitor by polypyrrole microspheres filled with poly(4-aminobiphenyl)

As one of the electrode materials for supercapacitor, polypyrrole (PPy) still face the urgent challenges such as the lower actual capacitance/energy density and poor long-term cycling stability. For the common microsphere from conducting polymers, the unfavorable void theoretically reaches at most 47.7 % of the total volume. Herein, we developed a strategy about the filling of poly(4-aminobiphenyl) (PABP) into PPy microsphere by in situ polymerization as a composite electrode material (PABP@PPy) to synergistically enhance performance for supercapacitor. The experimental results indicate that filling of PABP with the smaller size to PPy microsphere greatly compresses the transport distance of electrons/ions, reduces the internal resistance and promotes charge storage of PABP@PPy. As expected, the optimized PABP@PPy10% provided the best specific capacitance of 317 F g- 1 at 0.5 A g- 1, which is nearly 10 times for alone PABP (33 F g- 1) and PPy (58 F g- 1), indicating synergistically enhanced performance. Furthermore, PABP@PPy10% in ZHSC showed a stable reversible capacity of 156 mAh g- 1 at a current density of 0.5 A g- 1, and the capacity retention rate was measured as 95 % after 10,000 cycles at 0.5 A g- 1. Most strikingly, ZHSC with PABP@PPy10% as the cathode achieved a higher energy density of 139.5 Wh kg- 1 at 449.5 W kg- 1, which is superior to the most reported the materials. In conclusion, PABP@PPy10% with reasonable integration among microsphere with different sizes shows a synergistically enhanced electrochemical performance, and is expected to use as a promising electrode material for the supercapacitor.