Modeling the performance of contact-separation triboelectric nanogenerators

Abstract

Triboelectric nanogenerators (TENGs) are a promising and attractive energy harvesting technology because they are environmentally friendly and low cost. Here, the performance of dielectric-dielectric TENGs operating in the contact-separation mode was studied using time-dependent finite-element numerical simulations. To evaluate the TENG performance, the open-circuit voltage, short-circuit current and optimum resistance were obtained. The results are in agreement with the available physical models for the short-circuit current, with the current increasing (decreasing) with the TENG's area (material's thickness). Contrarily to established models, the open-circuit voltage varied with the area and material's thickness and reasons for such disagreement are given. A better understanding on the effect of high load resistance values is also provided due to their impact on charge flow in the TENG cycle (transient state) and performance. This work shows that finite-element simulations are a viable tool to provide a deeper understanding and new paths to optimize contact-separation TENGs.