Enhancing output performance of surface-modified wood sponge-carbon black ink hygroelectric generator via moisture-triggered galvanic cell

A promising strategy to use alkali and alkaline earth metals chloride as an ideal high-efficiency atmospheric moisture catcher has been introduced in hygroelectric generator (HEG) engineering. However, the achievement of high output power density for commercial electronics by most HEGs is challenging. To address this issue, a novel approach is proposed to generate highly efficient HEGs. The approach relies on the use of carbon black (CB) ink to modify the surface of wood sponge with an LiCl solution, and copper electrodes to generate a highly efficient device with the power output of 216 μW. Specifically, the primary battery system composed of Cu electrodes and CB ink in water interface can compensate for decrease in streaming potential to further improve the output performance of the system, and successfully solve the problem of low output power of HEGs as an independent power source. Furthermore, the influences of different electrodes on electricity generation are comprehensively and systematically investigated for the first time. Moreover, the open-circuit voltage (VOC) of a HEG can be boosted to 33 V by simple integration in series, and it can drive commercial electronic devices in various weather conditions. It is anticipated that this new approach will facilitate the growth of green electronics in the future.