Hierarchical architecture of MXene/PANI hybrid electrode for advanced asymmetric supercapacitors

MXene layers surface-anchored with chain-like polyaniline (PANI) was wrapped by PANI nanofibers via hydrothermal reaction. Layered MXene as active materials with large surface area and a framework, could provide significant paths for ion insertion/extraction. The chain-like PANI used as structure coupling bridges and conductive chains for linking adjacent layers of MXene together, could accelerate the charge transfer among different MXene layers. Besides, the introduction of PANI could also enhance the electrochemical properties due to their excellent pseudocapacitance behavior and increased surface area of active materials. The MXene/PANI 1:3 electrode exhibits high specific capacity of 563 F g−1 at 0.5 A g−1 and a high capacitance retention of 84.72% with the current densities increasing from 0.5 to 20 A g−1. The MXene/PANI 1:3 electrode also exhibits a high cycle lifespan with a capacitance retention of 95.15% after 10000 cycles. An asymmetric supercapacitance based on MXene/PANI hybrids as positive electrode and activated carbon as negative electrode is also synthesized. More promising, fully packaged devices based on asymmetrical capacitor has achieved an energy and power densities of 22.67 Wh/kg and 0.217 kW/kg. This research propels a novel way of using MXene/PANI as electrode materials for next-generation electrochemical electrode.