Potassium citrate-derived carbon nanosheets/carbon nanotubes/polyaniline ternary composite for supercapacitor electrodes

To improve the electrochemical performance of potassium citrate-derived carbon nanosheets (PC-Cs), herein, bamboo-like carbon nanotubes (CNTs) are generated on PC-Cs to prepare PC-Cs/CNTs composite. Based on interconnected porous PC-Cs/CNTs, polyaniline (PANI) is in-situ polymerized to fabricate PC -Cs/CNTs/PANI ternary composite. Through adjusting the aniline concentration, the optimized PC-Cs/CNTs/PANI composite is obtained at the aniline concentration of 0.4 M. The result confirms that much more N-containing groups are introduced after growing PANI on PC-CS/CNTs, and the diameter of PANI-wrapped CNT is about three-time thicker than that of CNT. Served as working electrode in three electrode system, the optimized PC-Cs/CNTs/PANI composite delivers the maximum capacitance of 767 F g(-1) at 1 A g(-1), with a high capacitance retention of 87.5% for 50 0 0 cycles at 5 A g(-1). When assembled in asymmetric supercapacitor by using PC-Cs/CNTs/PANI as positive electrode and PC-Cs/CNTs as negative electrode, the device exhibits a specific capacitance of 102.5 F g(-1) at 0.5 A g(-1), and energy density is 56.9 Wh kg (-1) at the power density of 537 W kg(-1). Compared to existing carbon/PANI composites, PC -Cs/CNTs/PANI composite shows an outstanding electrochemical performance, due to the tailored pore structure of PC -Cs/CNTs and the high pseduocapacitance contributed by PANI wrapping layer.(c) 2021 Elsevier Ltd. All rights reserved.