A compact triboelectric nanogenerator with ultrahigh output energy density of 177.8 J m−3 via retarding air breakdown

Improving the output energy is critical for the wide application of triboelectric nanogenerators (TENGs), of which increasing the surface charge density is an effective approach. However, when the surface charge density increases to a certain value, air breakdown will occur and become the main obstacle to the further improvement of the output . Herein, we report a strategy to retard air breakdown and enhance the output energy for contact-separation mode TENG in this work. By utilizing a tailored external capacitor and multilayer structure with a small air gap in each layer, we establish a compact TENG (2 cm × 2 cm × 2 mm, at separation) with an ultrahigh output energy density of 177.8 J m−3 cycle−1 (13 times elevation than a conventional one), which is a new record. Combining with a passive power management circuit, the stored energy of 118.5 J m−3 cycle−1 and average power density of 107.9 W m−3 at 1 Hz are achieved (350 times elevation than a conventional one). The compact TENG can continuously drive various portable electronics at 1 Hz excitation. Our research greatly promotes TENG toward practical applications.