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