Exploring charge accumulation mechanisms in graphite and aluminum-based hygrogenerators: experimental and theoretical perspectives

Since their introduction in 2010, hygroelectric generators have emerged as innovative devices capable of harnessing energy from atmospheric humidity, presenting potential solutions for low-power applications. While various hygrogenerators have been developed since then, most of them still feature complex and costly manufacturing processes that hinder their scalability. Furthermore, understanding the underlying charge accumulation mechanisms within the hygroelectric effect remains limited. In response, we propose a scalable and flexible hygroelectric generator made from Kraft paper, graphite, and aluminum. This compact device, measuring 2.5 x 2.5 cm2$$ ^{2} $$, produces an impressive 1 V and 0.12 μ$$ \mu $$A, successfully illuminating high-brightness LEDs when connected in series. Remarkably, after enduring thousands of charge-discharge cycles, the generator retains over 50% of its initial output, showcasing exceptional durability. Additionally, we performed quantum and classical simulations to provide physical and chemical insights into the charge accumulation mechanisms and how they affect the material’s capacity to generate power. This work offers an in-depth exploration of charging processes present in hygrogenerator devices, revealing opportunities for enhancing their overall efficiency.Graphical abstract