High-Performance Polyimide-Based Water-Solid Triboelectric Nanogenerator for Hydropower Harvesting

Area of Science:

• Energy Harvesting
• Materials Science
• Nanotechnology

Background:

• Water-solid triboelectric nanogenerators (TENGs) offer potential for stable water-energy harvesting and self-powered sensors due to humidity insensitivity.
• However, widespread application is hindered by the low triboelectrification performance of existing water-solid TENGs.

Purpose of the Study:

• To enhance the output performance of water-solid TENGs.
• To investigate the effect of a polyimide (PI) intermediate layer on TENG triboelectrification and electrical output.

Main Methods:

• A novel water-solid TENG was designed by incorporating a polyimide (PI) layer as a charge storage intermediate between the friction and conducting layers.
• The output performance of the PI-TENG was compared to a TENG without the PI layer.
• The influence of PI layer thickness, droplet contact angle, and falling height on electrical performance was analyzed.

Main Results:

• The PI-TENG demonstrated a significant improvement in output performance, reaching 1.260 mW, a five-fold increase compared to the 0.234 mW of the TENG without the PI layer.
• The enhanced performance is attributed to the PI layer's high density of electron capture sites, which retain more triboelectric charge.
• Electrical performance showed a non-linear correlation with PI layer thickness, and was also affected by droplet contact angle and falling height.

Conclusions:

• The addition of a PI intermediate layer effectively boosts the triboelectric charge retention and overall electrical performance of water-solid TENGs.
• The developed water-solid PI-TENG shows promise for practical applications in hydropower harvesting and powering safety devices, such as warning signals in adverse weather conditions.