Two-Dimensional Titanium Carbide with Interlayer Spacing as Electrode Material for Supercapacitors

It is essential to investigate novel electrode materials to advance the development of supercapacitors and their implementations in electronic applications. A group of two-dimensional (2D) transition metal carbides and nitrides known as MXenes (Ti₃C₂T_z) have earned more attention as electrode materials for industrial supercapacitors. It has the distinctive features that bulk materials lack, such as a large specific surface area, thermal resistive properties, a low energy barrier for electron transport, and a short ion diffusion path, which make desirable electrodes for energy storage devices.<br/>Titanium Carbide (Ti₃C₂T_z) is synthesized in this study using a relatively simple chemical method to develop low defects and high-quality MXene while keeping the stacking and interlayer spacers intact. The crystalline structure and surface morphology are investigated by XRD, SEM, TEM and BET analyses. An electrode is fabricated using a synthesized Ti₃C₂T_z as an active electrode material and Ni-foil as a current collector. The layered morphology is confirmed using a field emission scanning electron microscope, and the presence of the elements of the synthesized MXene is verified using energy-dispersive spectroscopy analysis. The specific surface area of MXene is estimated to be 38 m²g^-1 using the BET measurement by nitrogen adsorption and desorption isotherm, with a pore volume of 0.4029 cm³g^-1 and average pore size of 4 nm. The electrochemical performance of a Ti₃C₂T_x electrode is tested using cyclic voltammetry with a 6M KOH electrolyte.<br/>When used as an electrode for supercapacitors, Ti₃C₂T_x MXene demonstrated an exceptional specific capacitance of 831 Fg-1 at a 2 mVs^-1 scan rate in the voltage window of 0.0-0.6 V. The layered structures of MXene improve electrolyte ion transport while also providing transition metal active redox sites on the surface. The electrode has remarkable cyclic stability of 97% over 10000 continuous cycles at 50 mV s^-1. The findings suggest an appealing strategy for producing two-dimensional nanomaterials-based electrodes and composites for improved implementation and innovative supercapacitor designs.<br/><br/><b>Keywords: </b>MXene, Energy Storage, 2D materials<br/><br/>References:<br/>R. Li, L.Zhang, L. Shi, and P. Wang, MXene Ti₃C₂: an effective 2D light-to-heat conversion material, <i>ACS nano</i><i>.</i>, 2017, <b>11</b>, 3752-3759.<br/>S. Nam, J.N. Kim, S. Oh, J. Kim, C.W. Ahn, and I.K. Oh, Ti₃C₂T_x MXene for wearable energy devices: Supercapacitors and triboelectric nanogenerators, <i>APL Material</i><i>.</i>, 2020<i>, </i><b>8</b>, 110701.<br/>B. Anasori, M.R. Lukatskaya, and Y. Gogotsi, 2D metal carbides and nitrides (MXenes) for energy storage, <i>Nature Reviews Materials</i><i>.</i>, 2017, <b>2</b>,1-17.<br/>X.Wang, Y. Li, S. Wang, F. Zhou, P. Das, C. Sun, S. Zheng and Z.S. Wu, MXene for energy storage: present status and future perspectives, <i>Journal of Physics: Energy</i><i>.</i>, 2020, <b>2</b>, 032004.