Sandwich-like NiFe-LDH/MnCO3/MXene ternary nanocomposites serve as battery-type electrode for high-performance asymmetric supercapacitor

Ti3C2Tx MXene is a promising supercapacitor electrode material, characterized by excellent conductivity and outstanding cycle stability. However, its limited gravimetric capacitance constrains the further applications of MXene materials in supercapacitors. Herein, a ternary composite NiFe-LDH/MnCO3/MXene (NFMM) composite with a three-dimensional layered structure was successfully synthesized using a straightforward hydrothermal method. MnCO3 nanoparticles were deposited onto the surface of Layered Double Hydroxide (LDH), providing significant capacitance. The collapse of LDH is largely mitigated, which may be due to the heterostructure effect. Additionally, the synergistic effect of NiFe-LDH/MnCO3 and MXene effectively enhances the conductivity of the NiFe-LDH/MnCO3 material. The results indicate that the NFMM composite exhibits a superior gravimetric capacity of 2079.6F/g at 1 A/g and retains 85 % of its capacitance at 10 A/g after 5000 cycles. An asymmetric supercapacitor was constructed using NFMM and activated carbon as the positive and negative electrodes, achieving an energy density of 67.3 W h kg- 1 and at 750.9 W kg- 1, with outstanding cyclic stability of 89 % after 5000 cycles. These findings underscore the promising potential of ternary materials for energy storage applications.