MXene-driven in situ construction of hollow core-shelled Co3V2O8@Ti3C2Tx nanospheres for high-performance all-solid-state asymmetric supercapacitors

Abstract

Ti₃C₂T_x MXene-wrapped hollow Co₃V₂O₈ nanospheres were simply prepared by using the pre-prepared Ti₃C₂T_x nanoflakes as the nucleation site and precursor to promote the uniform growth of hollow Co₃V₂O₈ nanospheres as well as to achieve in situ encapsulation. Profiting from the specific interface coupling and hollow architecture, the unique core-shelled Co₃V₂O₈@Ti₃C₂T_x presented outstanding capacitive performances in terms of large specific capacitance, fine rate capability, and long-term cycle life. In particular, its capacitance as high as 94.5% could be maintained upon 10 000 cycles even at a high current density of 80 mA cm⁻² (∼10 A g⁻¹). The as-fabricated solid-state asymmetric supercapacitor assembled by Co₃V₂O₈@Ti₃C₂T_x and active carbon could output an energy density of 70.2 μW h cm⁻² at a power density of 3.3 mW cm⁻² with 87.1% of the initial capacity retained after 10 000 cycles, outperforming many similar electrode materials in previous reports. In view of the remarkable performances and facile preparation, Co₃V₂O₈@Ti₃C₂T_x holds good prospective application potential as a promising cathode candidate for supercapacitors.