The discovery of liquid crystalline (LC) phases in dispersions of two-dimensional (2D) materials has enabled the development of macroscopically aligned three-dimensional (3D) macrostructures. Here, we report the first experimental observation of self-assembled LC phases in aqueous Ti 3 C 2 T x MXene inks without using LC additives, binders, or stabilizing agents. We show that the transition concentration from the isotropic to nematic phase is influenced by the aspect ratio of MXene flakes. The formation of the nematic LC phase makes it possible to produce fibers from MXenes using a wet-spinning method. By changing the Ti 3 C 2 T x flake size in the ink formulation, coagulation bath, and spinning parameters, we control the morphology of the MXene fibers. The wet-spun Ti 3 C 2 T x fibers show a high electrical conductivity of ∼7750 S cm −1 , surpassing existing nanomaterial-based fibers. A high volumetric capacitance of ∼1265 F cm −3 makes Ti 3 C 2 T x fibers promising for fiber-shaped supercapacitor devices. We also show that Ti 3 C 2 T x fibers can be used as heaters. Notably, the nematic LC phase can be achieved in other MXenes (Mo 2 Ti 2 C 3 T x and Ti 2 CT x ) and in various organic solvents, suggesting the widespread LC behavior of MXene inks.
This paper describes a flexible and lightweight fabric supercapacitor electrode as a possible energy source in smart garments. We examined the electrochemical behavior of porous carbon materials impregnated into woven cotton and polyester fabrics using a traditional printmaking technique (screen printing). The porous structure of such fabrics makes them attractive for supercapacitor applications that need porous films for ion transfer between electrodes. We used cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy to study the capacitive behaviour of carbon materials using nontoxic aqueous electrolytes including sodium sulfate and lithium sulfate. Electrodes coated with activated carbon (YP17)
MXene/carbon composite electrodes with high loadings of MXene were prepared via electrospinning. These flexible and free-standing electrodes exhibit high areal capacitance relative to pure carbon nanofibers and MXene-coated fibers and textiles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.