Integrated ammonia sensing and energy storage in confined spaces via polyaniline-modified LIG composites

Detecting NH 3 in confined spaces is essential for operational safety. To address this demand, a dual-functional micro-supercapacitor (MSC) is developed by electrodepositing polyaniline (PANI) onto a laser-induced graphene (LIG) framework, followed by encapsulation with a poly(vinyl alcohol) (PVA)/H 2 SO 4 gel electrolyte prepared via an acid-assisted non-solvent induced phase separation (acid-NIPS) process. The acid-NIPS-tailored architecture provides sufficient ionic conductivity while facilitating gas transport kinetics. Finite element simulations were used to evaluate NH 3 diffusion at 40 ppm, a concentration relevant to confined-space safety monitoring. The specific deprotonation of PANI chains by NH 3 increases the electrical resistance of the composite electrode, yielding a reliable quantitative concentration-dependent response. Under extreme mechanical disturbances, the device maintains a highly stable electrical baseline without significant fluctuation in initial resistance after 12 h of ultrasonic vibration and 120° bending, confirming its robust structural integrity. Additionally, it functions as a reliable energy storage unit, delivering an areal capacitance of 246.8 mF cm −2 and retaining 95.3% of its initial capacitance after 3000 cycles under a restricted 0–0.8 V window. This work provides an integrated device architecture for simultaneous steady-state environmental monitoring and energy storage in confined operational conditions.