Preparation of CuMn2O4/Ti3C2 MXene composite electrodes for supercapacitors with high energy density and study on their charge transfer kinetics

Abstract

In this study, we present a novel electrode material that combines Ti3C2 MXene and high-capacity CuMn2O4 to increase the energy density of supercapacitors, which are a popular choice for energy storage due to their high-performance potential. The electrode material was synthesized using the hydrothermal method with varying deposition times (3 h, 6 h and 9 h), and the resulting composite materials were characterized using advanced analytical techniques. The CuMn2O4/MXene composite electrode synthesized at 3h exhibited exceptional performance, with a specific capacitance of 628 mF/cm2 at 4 mA/cm2, due to the enhanced electrical conductivity and charge storage properties of CuMn2O4 and MXene sheets. We also uncovered an intricate charge transfer mechanism and storage kinetics of CuMn2O4/MXene composite on a nickel foam electrode, revealing a diffusion-controlled energy storage mechanism with fast mass transportation. To demonstrate practicality, we constructed an asymmetric coin cell supercapacitor device using CuMn2O4/MXene composite synthesized at 3h and activated carbon as the positive and negative electrodes, respectively. The device showed a specific capacitance of 496 mF/cm2 at 6 mA/cm2 with cyclic stability of 80% for up to 10,000 cycles, and a power density of 1.5 mW/cm2 at a higher energy density of 0.073 mWh/cm2. Our results demonstrate the potential to significantly advance the development of high-performance supercapacitors by combining Ti3C2 MXene and high-capacity oxides, refining the synthesis process, and exploring innovative electrode architectures.