Fabric to energy storage via oxygen-tuned graphene engineered by laser crafting

Abstract

Fabric-based energy storage devices are essential for next-generation wearable electronics, requiring materials that combine lightweight structure, high conductivity, and mechanical durability. Laser-induced graphene (LIG) is a promising candidate due to its tunable surface chemistry, excellent electrical properties, and compatibility with textile substrates. However, improving its electrochemical performance often involves chemical modifications with metal oxides or polymers, complicating processing and limiting scalability. Traditional synthesis methods for oxygen-rich graphene rely on hazardous chemicals and labor-intensive procedures. In this work, we present an eco-friendly, one-step laser-scribing technique to fabricate oxygen-functionalized LIG directly on Kevlar textiles, enabling the creation of flexible, fabric-based energy storage devices without the need for chemical treatments. By carefully controlling the laser power (P) and scan speed (S), we achieve a precise balance between graphitization and oxygen functionalization. Density functional theory analysis reveals that specific oxygen groups—carboxyl, hydroxyl, epoxy, and carbonyl—play a key role in enhancing potassium-ion adsorption. The optimized LIG-P3S1 sample (laser power level 3, scan speed level 1) exhibits a high carbon content of 89.12 At%, with 67.51% of oxygen groups from C–O and C–OH bonds. This surface chemistry results in an areal capacitance of 88.92 mF cm⁻² at 0.3 mA cm⁻², along with good cycling stability, retaining 66.67% capacitance after 10 000 cycles. The device also demonstrates stable performance under bending angles of up to 120°, making it suitable for wearable applications. This work offers a scalable, sustainable approach to flexible energy storage, with potential applications in wearable and biomedical electronics.