Effect of MXene Nanosheet Sticking on Supercapacitor Device Performance

Supercapacitors have garnered significant interest in recent years due to their high power density, rapid charge/discharge rates, and long cycle life. MXenes, a family of two-dimensional (2D) transition metal carbides/nitrides, have emerged as promising electrode materials for supercapacitors. However, one major challenge associated with incorporating MXenes in supercapacitor structures is the occurrence of sticking, wherein individual MXene flakes agglomerate, leading to reduced electrode performance. This review paper discusses various causes of sticking and approaches to preventing it, offering insights into the design and development of high-performance MXene-based supercapacitors. The morphology and size of MXene flakes, flake surface chemistry, thickness, surface area/volume ratio, electrode processing techniques (including solvent selection, additives incorporation, and deposition technology), and environmental factors were shown to be the basic factors resulting in sticking of MXene sheets. Among the strategies to mitigate this challenge, surface functionalization and passivation, integration with polymer matrices or carbon nanomaterials, and electrode processing optimization were considered. Possible paths for optimization and future directions of study, such as novel MXene compositions, understanding of interfaces and electrode–electrolyte interactions, development of advanced electrode architectures, and integration of energy storage systems, were assumed.