9 Natural Fiber Welding
223
Fig. 9.9 Scanning electron microscopy of composite supercapacitor yarns. Cotton fibers (a) are
controllably fused with high surface-area carbon (b) that becomes entrapped. A stainless-steel
current collector (c) is plied with the welded fiber construct to create the composite yarn (d and
e) that is capable of storing charge. Figure is data from Jost et al. [38]
high-surface area capacitive carbon materials are shown entrapped within cottonbased composite yarns. These composite yarns were plied with stainless-steel current
collectors and subsequently coated with a flexible polymer electrolyte. The result
was a flexible yarn-based supercapacitor that was able to be knit into fabrics, as
shown in Fig. 9.10. In this seminal 2015 study, the capacitance of the yarns produced
topped out at 37 mF cm
−1 and was one of the highest values for carbon-based
yarns ever reported. NFW has recently substantially improved on these results and
with processes capable of mass production of energy storage yarns. As the e-textile
and other textile submarkets develop, NFW is demonstrating value with generalpurpose processes that deliver both “practical” and “exotic” performance that can be
custom-tuned.
9.5 Conclusions
The development of commercially available ILs is a key factor that is enabling new
tunable processes that produce robust, functional composites using natural materials.
When necessary, IL-based solvents can be tuned to enable processes that are tolerant
of, and even work synergistically with, synthetic materials. Of course, complete
223
Fig. 9.9 Scanning electron microscopy of composite supercapacitor yarns. Cotton fibers (a) are
controllably fused with high surface-area carbon (b) that becomes entrapped. A stainless-steel
current collector (c) is plied with the welded fiber construct to create the composite yarn (d and
e) that is capable of storing charge. Figure is data from Jost et al. [38]
high-surface area capacitive carbon materials are shown entrapped within cottonbased composite yarns. These composite yarns were plied with stainless-steel current
collectors and subsequently coated with a flexible polymer electrolyte. The result
was a flexible yarn-based supercapacitor that was able to be knit into fabrics, as
shown in Fig. 9.10. In this seminal 2015 study, the capacitance of the yarns produced
topped out at 37 mF cm
−1 and was one of the highest values for carbon-based
yarns ever reported. NFW has recently substantially improved on these results and
with processes capable of mass production of energy storage yarns. As the e-textile
and other textile submarkets develop, NFW is demonstrating value with generalpurpose processes that deliver both “practical” and “exotic” performance that can be
custom-tuned.
9.5 Conclusions
The development of commercially available ILs is a key factor that is enabling new
tunable processes that produce robust, functional composites using natural materials.
When necessary, IL-based solvents can be tuned to enable processes that are tolerant
of, and even work synergistically with, synthetic materials. Of course, complete