Nowadays, the development of direct current triboelectric nanogenerators (DC‐TENGs) is oriented toward practical applications such as real‐time efficient harvesting and supplying energy. This demands DC‐TENGs with a low loss factor, high energy utilization efficiency, device portability, and output stability. Herein, a constant‐voltage DC‐TENG (C‐DC‐TENG) with robust output performance, using the ternary dielectric triboelectrification effect is demonstrated, which gives a crest factor of 1.0082. The key to improving the output charge density is the number of subdivision units, a result of theoretical simulations and experiments of C‐DC‐TENG. The optimized C‐DC‐TENG achieves not only an output charge density of 3.902 mC m−2 per round but also an average power density of 8.77 W m−2 (3.508 W m−2 Hz−1), which both set a new record for the rotary DC‐TENG. Moreover, introducing soft polyester fur enables C‐DC‐TENG to maintain 100% output without wear after 800 000 cycles. This C‐DC‐TENG is faultlessly competent for powering 2784 LEDs in series and 25 parallel‐connected hygrothermographs continuously. This work provides a promising technique for large‐scale clean energy harvesting, accelerating the progress toward practical applications of DC‐TENG.

The triboelectric nanogenerator (TENG) as an ideal low-frequency mechanical energy harvester has received extensive attention, while low output charge density limits its application. A charge excitation strategy is one of the techniques to effectively improve the surface charge density of the TENG. However, there is little in-depth research on the matching factors between the TENG and excitation circuit. Herein, a soft-contact charge excitation rotary TENG (SCER-TENG) is developed to explore the matching mechanism of different charge excitation strategies. The total output power transferred by the voltage-multiplying circuit (VMC) is 2.13 times that of the full-wave bridge rectifier, which effectively improves the output performance of the SCER-TENG. Moreover, through the established capacitor model and the theoretically calculated maximum output charge of the SCER-TENG with VMC and Zener diodes (VMC-Z), it is found that the output of the Main TENG is mainly affected by capacitors and Zener diodes. The theories have been verified by experiments. After optimization, the output charge of the Main TENG with VMC-Z (1.54 μC) is 3850% higher than that without excitation (0.04 μC). The SCER-TENG successfully harvests low-speed (2.5 m s–1) wind energy to form a self-powered system. This work has crucial instructive implications for using charge excitation strategies to improve the performance of the rotary TENG.

No abstract

Efficient harvesting and storage of dispersed irregular energy from the environment are crucial to the demand for the distributed devices of the Internet of Things (IoTs). Here, a carbon felt (CF)-based energy conversion-storage-supply integrated system (CECIS) that contains a CF-based solid-state supercapacitor (CSSC) and a CF-based triboelectric nanogenerator (C-TENG) is presented, which is capable of simultaneously energy storage and conversion. The simple treated CF not only delivers a maximal specific capacitance of 402.4 F g −1 but also prominent supercapacitor characteristics with fast charge and slow discharge, enabling 38 LEDs successfully lightened for more than 900 s after a wireless charging time of only 2 s. With the original CF as the sensing layer, buffer layer, and current collector of C-TENG, the maximal power of 91.5 mW is attained. The CECIS shows a competitive output performance. The time ratio of the duration of supply energy to the harvesting and storage reaches 9.6:1, meaning that it is competent for the continuous energy application when the effective working time of C-TENG is longer than one-tenth of the whole day. This study not only highlights the great potential of CECIS in sustainable energy harvesting and storage but also lays the foundation for the ultimate realization of IoTs.