Boosting the Power Output of a Cement-Based Triboelectric Nanogenerator by Enhancing Dielectric Polarization with Highly Dispersed Carbon Black Nanoparticles toward Large-Scale Energy Harvesting from Human Footsteps

A strategy to enhance the energy conversion performance of a cement-based triboelectric nanogenerator (TENG) has been proposed for large-scale energy harvesting from human footsteps. A cement-carbon black (CB) composite is fabricated by incorporating CB nanoparticles with a hydroxyethyl cellulose (HEC) admixture and used as a triboelectric material for TENG. The fabricated cement-CB@HEC TENG exhibits a 13-fold enhancement of the electrical output with the highest power density of 2.38 W/m2. The tremendous improvement is ascribed to a good dispersion of conductive CB nanoparticles in the cement matrix, which is key for achieving a high dielectric constant that is required to intensify the triboelectric charge density of TENG. Moreover, it was found that the addition of the HEC admixture plays a crucial role in not only providing a good dispersion of CB for generating dielectric polarization but also facilitating the development of a microstructure and crystallization of cement hydration products to reduce the formation of air voids and micropores. These factors synergistically contribute to the improved dielectric constant and compressive strength of the cement-CB@HEC composite. This remarkable strategy presents great prospects for the development of smart cement materials for realizing applications in large-scale energy harvesting toward sustainable, clean, and renewable energy sources.