Cobalt-nickel coordinated polyaniline as electrodes for high performance flexible asymmetric supercapacitor

Abstract

Polyaniline (PANI) is commonly employed as a material for supercapacitor electrodes. However, its molecular structure is susceptible to disruption due to high volume expansion, leading to a significant decline in cycling performance. Enhancing the cyclic stability of PANI is of utmost importance. In here, a one-step electrodeposition method is utilized to produce cobalt-nickel coordinated PANI (PCN) on a carbon cloth (CC) substrate. By coordinating the intra- and inter-chain interactions of PANI molecules with Co2+ and Ni2+, the expansion of PANI volume during charging and discharging can be significantly reduced, resulting in enhanced cycle performance. The CC/PCN electrode exhibits a high capacitance of 592.5 F g−1 at 1 A g−1. The assembled asymmetric device, comprising PCN as the positive electrode and MXene as the negative electrode (PCN//MXene), demonstrates a capacitance of 131.8 F g−1 at 1 A g−1. Moreover, the asymmetric device exhibits a remarkable capacitance retention of 85.9 % at 5 A g−1 even after 5000 cycles, and exhibits an energy density of 799.89 W kg−1 at a power density of 46.86 W h kg−1. Additionally, the supercapacitor demonstrates exceptional flexibility by maintaining its excellent capacitance even after undergoing 1000 bending cycles. The research presented herein showcases that PCN//MXene asymmetric supercapacitor exhibits great potential for applications in the field of next-generation flexible energy storage devices.