Energy storage devices use materials that have a high level of dielectric permittivity and that are capable of storing large amounts of energy. In most cases, the role of such materials is played by polymeric substances, in the voids between the threads of which fillers that can conduct electric current are placed. The authors of the study put forward a hypothesis, according to which the capacity of polymeric materials can be increased by placing into them particles of so-called MXenes – two-dimensional nanomaterials the flat layers of which consist of atoms of transition metals, carbon and nitrogen.
To test this hypothesis, the scientists created a material from the fluorine-containing polymer PVDF, which is often used in lithium-ion batteries, and MXene particles, which have an accordion-like structure that can be “stretched” by introducing molecules of dimethyl sulfoxide, a solvent popular in the chemical industry. The authors of the study conducted an experiment during which they compared the effectiveness of a polymer filler with added “pure” particles of MXenes and their “stretched” version.
The experiment showed that the addition of a solvent made it possible to more evenly distribute the layers of MXenes across the polymer material. As a result, its specific capacity tripled in comparison with existing fillers. The scientists estimate that such composites will find application in energy storage devices in the next five years.
“The increase in dielectric permittivity allows us not only to accumulate more energy, but also to enhance the responsiveness of the material to the impact of an external electric field. This is important for devices in healthcare, the aerospace industry and consumer electronics,” Nikolai Gorshkov, senior researcher at the Solid State Ionics Laboratory of the Yuri Gagarin State Technical University of Saratov, is quoted as saying by the Russian Science Foundation.
