Two-dimensional (2D) MXene as the Building Block of Three-dimensional (3D) Ordered Electrode Architectures and Their Application in Energy Storage Systems

Abstract

Transition metal carbides and nitrides (MXenes) are an emerging class of two-dimensional (2D) materials with interesting properties that have gained enormous attention since their discovery in 2011. Extensive theoretical and experimental research effort has been devoted to this family of materials in various research fields, including energy storage, hydrogen evolution reaction, sensors, water purification, and catalysis due to their unique morphologies properties and diverse chemistries. To date, while Ti3C2Tz is the most studied member of the MXene family, other members, including Ti2CTz, Nb2CTz, Nb4C3Tz, Mo1.33CTz, Mo2TiC2Tz, etc. due to their unique electrochemical performance, have been widely and extensively studied for energy storage applications. Similar to other 2D materials, MXenes suffer from restacking, which limits their electrochemical performance. Restacking blocks the ionic transport channels, resulting in inadequate electrolyte access to the active redox sites, hence reducing the electrochemical performance of the electrode material. Thus, designing electrode architectures with a predominant aim to inhibit restacking while being cost-effective and straightforward is of great importance. Employment of new fabrication methods such as additive manufacturing could offer a simple yet effective route to address the current problems and advance the engineering of the electrode structure. I shed light on the importance of structure on electrochemical performance, fabrication of advanced electrode materials, and introduce enlightening progress for effective structural design, and provide perspective and possible opportunities for MXene to get closer to be considered for practical applications and broaden its application in fields beyond energy storage.