Ultra-stability and high output performance of a sliding mode triboelectric nanogenerator achieved by an asymmetric electrode structure design†

The sliding mode triboelectric nanogenerator (S-TENG) is a highly efficient technology for harvesting environmental mechanical energy due to its advantages of sustainable energy output and simple structure design. However, boosting the output performance of the S-TENG remains a challenge because of the bottleneck of air breakdown. Herein, a new type of an asymmetric electrode structure S-TENG (AE-S-TENG) is proposed by designing asymmetric top and bottom electrodes, which is quite different from the previous symmetric electrode structure. The electrostatic shielding mechanism and quantified charge transfer analysis are presented. The ultra-stability and high output performance of the AE-S-TENG are achieved by balancing the electrostatic shielding to inhabit the air breakdown and the charge supplement to enhance the charge density through the asymmetric electrodes and non-electrode shielding areas. The output charge of the AE-S-TENG with equal size is 1.89-fold higher than that of the normal S-TENG. The output charge, current and average power of rotation AE-S-TENG at 60 rpm maintain 3.01 μC, 120 μA and 48.64 mW after more than 72 000 cycles, respectively. This work provides insights into the electrostatic shielding and charge transfer mechanism of the asymmetric electrode structure, which provides a new idea for designing high-output and superdurability TENGs.