Tannic Acid Modified Epoxidized Natural Rubber Based High Performing Triboelectric Nanogenerator

Considering today's environmental concerns, the development of triboelectric nanogenerator (TENG) is gaining immense interest as a green energy harvesting technology. However, most materials leveraged in TENG construction are based on non-renewable resources. Therefore, developing a bio-based composite with high performance for the TENG application is extremely desirable. This study uses Tannic acid (TA), a naturally occurring polyphenolic compound, as a reactive bio-filler in the bio-based elastomer Epoxidized natural rubber (ENR-50). This bio-composite is utilized as a tribo-positive pair for TENG construction, which resulted in a very high output voltage of 751 V (at 9 Hz) and 568 V (at 5 Hz). The maximum obtained power density recorded at 9 Hz is 37 W m^-2 at 1 MΩ external load resistance and an average power density is 20 W m^-2 at a load resistance of 10-100 MΩ. This excellent output performance results from the high electron-donating ability of TA. It is many-fold higher in terms of power density than recently reported all the bio-composites. Density Functional Theory is leveraged to probe contact electrification process. The result correlates with surface energy, dielectric, dynamic mechanical properties, and surface morphologies (roughness). Notably that such a bio-composite can be a promising material for next-generation power harvesting technology.