Researchers developed a flexible supercapacitor with MXene nanomaterials that can maintain its ability to store and release electronic charges after repetitive stretching.
Flexible electronics are gaining much attention due to their applicability in wearable devices, health monitors, and displays. These types of electronic devices can bend, twist and stretch. However, one of the major challenges stretchable electronics must overcome is the stiff and inflexible nature of their energy storage components, batteries and supercapacitors.
Supercapacitors that use electrodes made from MXenes have desirable electrical properties for portable flexible devices, such as rapid charging and discharging. MXenes are transitional metal carbides, carbonitrides or nitrides, and they can form multi-layered nanosheets, providing a large surface area for energy storage when they’re used in electrodes. However, polymers and other nanomaterials has to be added to keep MXenes from breaking while bent.
Researchers, in their paper published in ACS’ Nano Letters, report their development of a flexible supercapacitor with electrodes made of wrinkled titanium carbide that maintained its ability to store and release electronic charges after repetitive stretching. Wrinkled titanium carbide is a type of MXene nanomaterial used by the researchers.
The researchers disintegrated titanium aluminum carbide powder into flakes with hydrofluoric acid, and captured the layers of pure titanium carbide nanosheets as a roughly textured film on a filter. They then placed the film on a piece of pre-stretched acrylic elastomer that was 800% its relaxed size. Upon releasing, it shrank to its original state, and the adhered nanosheets crumpled into wrinkles.
The researchers, upon testing, found that the device had a high energy capacity comparable to MXene-based supercapacitors developed by other researchers, but it also had extreme stretchability up to 800% without the nanosheets cracking.
The researchers say their supercapacitor’s excellent energy storage and electrical stability is attractive for stretchable energy storage devices and wearable electronic systems.