Fabrication and floating test of an asymmetric supercapacitor based on polyaniline and MXene

Abstract

Polyaniline (PANI) exhibits considerable capacitance at positive potentials in acidic aqueous electrolytes, making it a highly promising pseudocapacitive material. Nevertheless, the absence of appropriate anode materials capable of effectively functioning at negative potentials in its asymmetric supercapacitors hinders the ability to increase the cell voltage, thereby impacting the specific energy. To address this issue, MXene (Ti3C2Tx) was utilized due to its proven efficacy in mitigating hydrogen evolution at highly negative potentials in acidic aqueous electrolytes. In this study, we fabricated an asymmetric supercapacitor consisting of a PANI nanorod array deposited on bacterial cellulose (BC) membrane and a MXene/carbon nanotube (MXene/CNT) film. The device can operate at a cell voltage of 1.3 V and exhibits exceptional specific energy and specific power (12.1 Wh kg−1/0.4 kW kg1 and 7.9 Wh kg−1/1.7 kW kg−1). It demonstrates excellent cycling performance, with a capacitance retention rate of 96% after 2000 galvanostatic charge/discharge (GCD) cycles. In addition, one practical and reliable approach, the floating test, was applied to assess the stability of this asymmetric supercapacitor. It also maintains 82% of its initial capacitance after 60 h of floating time. Our findings indicate that the combination of PANI and MXene in an asymmetric configuration represents a promising approach for the development of next-generation PANI-based supercapacitors.