Researchers from University of North Carolina, North Carolina State University and Chinese Academy of Sciences have fabricated a mini perovskite solar module using a novel encapsulation technique based on the use of a self-healable, lead-adsorbing ionogel that prevents lead leakage and improves stability. The solar module has an area of 31.5cm2 and has a reported efficiency of 22.9%.
Ionogel microstructure and lead adsorption mechanism. Image from article
The scientists explained that ionogel sealants were applied on the panel's front glass and between electrode and encapsulation glass, with the 100μm-thick inonogel being able to hold the shattered glass together even if the glass breaks. This is claimed to effectively suppress lead leakage from broken modules after hail test or compression by car wheels, and soaking in water for 45 days.
The module showed a power conversion efficiency of 18.5%, an open-circuit voltage of 10.09 V, a short-circuit current of 74.6 mA, and a fill factor of 0.773. The scientists tested the stability of the panel via damp heat (DH) and thermal cycling tests according to the IEC 61215 accelerated test standard.
The capability and kinetics of the PAA ionogel to prevent lead leakage were also tested by soaking PAA ionogel film into methylammonium lead iodide (MAPbI3) aqueous solution. '[The] incorporation of ionogel in the encapsulation markedly suppressed lead leakage from broken perovskite modules,' the scientists stated. 'Undetectable lead could escape from the damaged perovskite module after a simulated hail test, followed by water [soaking] for 24 hours.'
