NiCo2S4 decorated multilayer titanium carbide MXene electrode for asymmetric supercapacitor

MXene, an emerging 2D material, has aroused great concern in the field of supercapacitors owing to its charming properties. However, the relatively low specific capacitance of pristine MXene is unsatisfactory, which is caused by the restacking issue of MXene nanosheets. In this paper, a facile and cost-effective electrostatic self-assembly followed by hydrothermal method was adopted to prepare NiCo2S4 decorated multilayer MXene nanosheets (MXene/NiCo2S4). The introduced NiCo2S4 effectively alleviates the self-restacking of MXene nanosheet and facilitates ion accessibility. Hence, the as-prepared MXene/NiCo2S4 electrode displays a maximum specific capacitance of 1211.1 F g−1 at 1 A g−1, surpassing the NiCo2S4 electrode (938.4 F g−1 at 1 A g−1) and pure MXene electrode (84.2 F g−1 at 1 A g−1). The assembled asymmetrical supercapacitor utilizing hybrid MXene/NiCo2S4 and RGO delivers a high energy density of 38.7 Wh kg−1 and high power density of 6137 W kg−1. This work can provide a reliable reference for the synthesis of hybrid MXene/sulfide electrodes with ideal electrochemical performance.