Performance enhanced triboelectric nanogenerator by taking advantage of water in humid environments

Improving the performance of triboelectric nanogenerator (TENG) in environment with high humidity is critical for their applications in blue energy, humidity sensing, implantable nanodevice etc. Here, we report a kind of humidity-resisting TENG (HR-TENG) by using polyvinyl alcohol/lithium chloride (PVA/LiCl) as the triboelectric layer, the output of which is much enhanced (similar to 5 times) with the increase of relative humidity (RH, from 20% to 99%). Abundant hydroxyl groups in PVA can fix water molecules to form more tribo-positive surface polarity, and LiCl can regulate the water absorption ability of PVA/LiCl film. The combined effect brings in numbers of wrinkle microstructure on its surface and synchronously decreases its modulus, enabling more efficient contact. Charge density of the HR-TENGs are higher than 115 mu C/m(2) in a wide range of RH (from 60% to 99%), especially, reaches a maximum value of 244 mu C/m(2) in 90% RH, which is much larger than the highest value 110 mu C/m(2) among reported HR-TENGs (RH>50%). Moreover, the PVA/LiCl based TENGs can be acted as power source in high RH (93%) condition and respiratory monitoring sensor for human physiological monitoring. These results provide an efficient way for TENG with high output in high humidity environments.

Automated summary

In this study, a humidity-resisting TENG (HR-TENG) using PVA/LiCl as the triboelectric layer was developed, showing significantly enhanced output in high humidity conditions. The combination of PVA and LiCl resulted in higher charge density and output, making HR-TENG a potential power source and physiological monitoring sensor in high humidity environments.