Inkjet‐Printed 2D Heterostructures for Smart Textile Micro‐Supercapacitors

Abstract Wearable electronic textiles (e‐textiles) have emerged as promising healthcare solutions, offering point‐of‐care diagnostics while maintaining breathability, comfort, durability, and environmental stability with strong mechanical performance. However, the lack of thin and flexible power supplies hinders their practical adoption. In this regard, textile‐based micro‐energy storage devices present an appealing solution. Inkjet printing offers the capability to produce high‐quality prints with sharp details and versatile substrate compatibility, making it an ideal choice for a wide array of printing applications. Here, the preparation of a range of inkjet‐printable 2D material inks is reported for the fabrication of ultra‐flexible and machine‐washable textile micro‐supercapacitors. Then 2D material heterostructures are proposed to enhance the performance of textile supercapacitors. This study reveals that a unique combination of highly conductive graphene with an insulator hexagonal boron nitride (h‐BN) can enhance the areal capacitance of graphene‐based textile supercapacitors by ≈82.48%. The heterostructure‐based supercapacitors also demonstrate higher energy (≈18.06 µWh cm −2 ) and power densities (≈4333.33 µW cm −2 ) with excellent capacitance retention (≈95% after 1000 cycles). These findings on inkjet‐printed heterostructure‐based supercapacitors may herald a new era for the future application of high‐performance micro‐supercapacitors within textile‐based wearable technology.