The field of smart textiles has been advancing rapidly over the last decade and has found applications in a variety of industries, including sports, medicine, and military. Of many functions, these smart garments are capable of providing and tracking physiological data, retraining use of impaired limbs, and giving feedback to athletes on their performance. Many smart garments require energy storage devices for operation. However, most smart garments still utilize conventional battery architectures such as coin or pouch cells, which can be uncomfortable and unsafe and also can impose design limitations to the final device. Designing an energy storage device for integration into textiles requires the development of fiber-based electrodes that exhibit high conductivity and promote diffusion of ions.
Carbons, including activated carbon and carbon onions, and 2D metal carbides, such as Ti3C2Tx MXene, are promising candidates for achieving the next generation of smart textile energy storage devices thanks to their high specific surface area, high electrochemical activity, and chemical stability. Ti3C2Tx MXene, the most widely studied MXene to date, has demonstrated outstanding performance as a freestanding paper electrode, exhibiting excellent cyclability, with no significant change in capacitance reported after 10,000 cycles1. These properties are attractive for wearable energy storage devices, which require long lifetime and fast charge-discharge rates. As such, researchers are beginning to explore the incorporation of Ti3C2Tx MXene into fibers.
Carbons and 2D carbides enable different design approaches to be implemented such as (1) coated textile energy storage, (2) fiber or yarn energy storage, (3) custom textile structures that incorporate energy storage. Each approach has its advantages, for instance, coating pre-existing textiles with energy storing materials helps pre-made garments to be outfitted with new technology at ease. As MXenes are hydrophilic, they can be incorporated into conventional yarns using a simple dipping and drying procedure. This procedure can easily be scaled-up and used in industrial-scale textile manufacturing processes. On the other hand, fibers and yarns that can act as energy storage devices can be woven or knitted into full fabrics enabling integration into many different kinds of garments. Lastly, custom designing knitted structures that incorporate all the components of energy storage devices give engineers the advantage to design fabrics with specified power and energy densities. In this talk, recent advancements in the field will be presented regarding integration of carbon and 2D carbides into smart textiles structures, as well as potential challenges facing the field of wearable energy storage.
1. Ghidiu, M., Lukatskaya, M. R., Zhao, M.-Q., Gogotsi, Y. & Barsoum, M. W. Conductive two-dimensional titanium carbide ‘clay’ with high volumetric capacitance. Nature 516, 78–81 (2014).