Electrical charge storage effect in carbon based polymer composite for long-term performance enhancement of the triboelectric nanogenerator

The triboelectric nanogenerator (TENG) is considered as a promising small-scale energy harvester with its advantages such as material selection diversity, design flexibility, and versatile application. Although there are numerous reports about mechanism to instantaneously enhance the output performance of the TENG, there have been few reports about the long-term output enhancement of the TENG with dynamic movement of charges in the TENG. In this study, PDMS based carbon black composite (PCC), which has excellent charge storage ability, is utilized as a contact layer of the TENG and the effect of the charge storage ability on the long-term transient output performance of the TENG is investigated. As the carbon content in composite varies, the long-term output performances of the TENGs exhibit significantly different behavior with the different charge storage ability of the contact layer. Use of PCC with derived optimal carbon black content exhibit more than 2 times increase of long-term output performance of the TENG. To effectively operate the TENG adopting PCC with high number of contact/separation cycles, a rationally designed power transmission unit based on scotch yoke mechanism is applied and as a result, a ubiquitous rotational motion around us could be easily harvested. The system generates the output current of 320 μA and it easily turns on hundreds of light emitting diodes as well as the commercial electronic devices. The present strategy would provide the outstanding approach to enhance the long-term output performance of the TENG.