Laser-Induced Graphene-Based Flexible Electrodes for Advanced Electrochemical Performance

Laser-induced graphene (LIG) has attracted considerable attention as a platform for flexible electrochemical sensors. However, conventional LIG electrodes often suffer from limited electrical conductivity and chemical stability, restricting their practical integration into fully wearable sensing systems. Herein, we report a one-step laser digital patterning (LDP) process for fabricating flexible Ni–LIG electrodes on colorless polyimide (cPI) under ambient conditions. Precise focusing of the laser at the interface between a NiOx thin film and a cPI substrate simultaneously enables the reductive sintering of NiOx into metallic Ni and the formation of LIG, resulting in hierarchically integrated electrodes. The fabricated Ni–LIG electrodes exhibit significantly enhanced electrochemical performance, delivering a high areal capacitance of 186 mF·cm–2, outperforming electrodes comprising only Ni or LIG. Furthermore, the incorporation of Ni ensures high thermal stability (up to 320 °C) and excellent corrosion resistance of the fabricated electrodes, highlighting their potential for next-generation sensor platforms, particularly in wearable or harsh-environment applications.