From the ACS Press Room
Stretching the Capacity of Flexible Energy Storage “Crumpled MXene Electrodes for Ul- surface area for energy storage when they’re trastretchable and High-Area-Capacitance used in electrodes. However, previous reSupercapacitors” searchers have had to incorporate polymers and other nanomaterials to keep these types Nano Letters of electrodes from breaking when bent, Some electronics can bend, twist and stretch which decreases their electrical storage cain wearable displays, biomedical applications pacity. So, Desheng Kong and colleagues and soft robots. While these devices’ circuits wanted to see if deforming a pristine titanium have become increasingly pliable, the batter- carbide MXene film into accordion-like ies and supercapacitors that power them are ridges would maintain the electrode’s electristill rigid. Now, researchers in ACS’ Nano cal properties while adding flexibility and Letters report a flexible supercapacitor with stretchability to a supercapacitor. electrodes made of wrinkled titanium carbide The researchers disintegrated titanium alumi— a type of MXene nanomaterial — that num carbide powder into flakes with hydromaintained its ability to store and release fluoric acid and captured the layers of pure electronic charges after repetitive stretching. titanium carbide nanosheets as a roughly texYoutube ID: Y1asjrBcx0M& tured film on a filter. Then they placed the film on a piece of pre-stretched acrylic elasOne major chaltomer that was 800% its relaxed size. When lenge stretchathe researchers released the polymer, it ble electronics shrank to its original state, and the adhered must overcome nanosheets crumpled into accordion-like is the stiff and wrinkles. inflexible nature of their enIn initial experiments, the team found the ergy storage best electrode was made from a 3 µm-thick components, film that could be repetitively stretched and batteries and relaxed without being damaged and without supercapacitors. modifying its ability to store an electrical Supercapacitors charge. The team used this material to fabrithat use eleccate a supercapacitor by sandwiching a polytrodes made vinyl(alcohol)-sulfuric acid gel electrolyte from transitional metal carbides, carboni- between a pair of the stretchable titanium trides or nitrides, called MXenes, have desir- carbide electrodes. The device had a high enable electrical properties for portable flexible ergy capacity comparable to MXene-based devices, such as rapid charging and discharg- supercapacitors developed by other researching. And the way that 2D MXenes can form continued on next page multi-layered nanosheets provides a large Septemeber 2021
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