Development of micro flower petal-structured NiCo₂S₄/Ti₃C₂T_x MXene nanosheets on nickel foam for superior supercapacitor applications

Transition metal sulfides have recently emerged as promising materials for supercapacitors owing to their high energy density, abundant resources, electrical conductivity, and environmental benignity. However, the challenges associated with increased internal resistance and volume fluctuations during prolonged charge and discharge cycles have raised concerns regarding their long-term stability in energy storage devices. In this study, micro flower petal-architectures NiCo₂S₄ and Ti₃C₂T_x MXene nanosheets were prepared by direct growth onto a binder-free nickel foam (NF) electrode. The resulting NiCo₂S₄/Ti₃C₂T_x MXene@NF (NCSMX@NF) electrode revealed an unparalleled capacitance of 2169.9 F g⁻¹ at 0.5 A g⁻¹, including lower charge transfer resistance of 0.13 Ω. Furthermore, the asymmetric supercapacitor device (ASC) was configured with NCSMX@NF and activated carbon (AC) as positive and negative electrodes, respectively. The as-fabricated NCSMX@NF//AC@NF ASC device achieved an extensive energy and power densities of 19.2 Wh kg⁻¹ and 7500 W kg⁻¹, with an impressive capacitance retention of 80.8 % and a coulombic efficiency of 98.6 % at 2 A g⁻¹. Therefore, the NiCo₂S₄/Ti₃C₂T_x MXene binder-free electrode demonstrated exceptional electrochemical performance. This study holds significant potential for the development of advanced energy storage devices, offering insights into the design and fabrication of high-performance electrodes.