Self-supporting in situ growth Ni3S2/FL-Ti3C2 (MXene)/Ni composite as positive electrode for asymmetrical supercapacitor

Abstract

In this work, using foamed nickel as a nickel source, a self-supporting in situ growth binder-free Ni 3 S 2 /FL-Ti 3 C 2 /Ni electrode with a 2D heterojunction structure was synthesized via a one-step hydrothermal method after etching a few-layer Ti 3 C 2 (FL-Ti 3 C 2 ) MXene. This electrode provides a high specific capacitance of 1752 mF/cm 2 in a 3\xa0M KOH electrolyte at 1\xa0mA/cm 2 and has excellent rate performance (75.5% at 10\xa0mA/cm 2 ) and electrochemical stability (74.79% after 5000 cycles). An asymmetric supercapacitor is prepared with Ni 3 S 2 /Ti 3 C 2 /Ni as the positive electrode and AC as the negative electrode. The maximum energy density and the power density are 32.7 μWh/cm 2 and 8.0211 mW/cm 2 , respectively.