The development of the Internet of Things (IoT) and artificial intelligence has accompanied the evolution of energy demand and structure in the new era, and the power sources for billions of distributed electronics and sensors have aroused worldwide interest. As an alternative energy harvesting technology, triboelectric nanogenerators (TENGs) have received remarkable attention and have shown attractive potential applications for use in micro/nano power sources, self-powered sensors, high-voltage power sources and blue energy due to their advantages of small size, light weight, flexibility, low cost, and high efficiency at low frequency. In this review, we discuss high-performance TENGs from the perspectives of triboelectric charge density, output voltage, energy density and corresponding quantification methods. Among these topics, the limitations, optimization methods and techniques, and potential directions to challenge these limits are comprehensively discussed and reviewed. Finally, we discuss the emerging challenges, strategies and opportunities for research and development of high-performance TENGs.

Based on the conjunction of contact electrification and electrostatic induction, triboelectric nanogenerators (TENGs) can harvest mechanical energy dispersed in our environment. With the characteristics of simple structure, light weight, broad material availability, low cost, and high efficiency even at low operation frequency, TENG can serve as a promising alternative strategy for meeting the needs of distributed energy for the internet of things and network. The major potential applications of TENG can be summarized as four fields containing micro/nano power sources, self-powered sensors, large-scale blue energy, and direct high-voltage power sources. In this paper, the fundamental physics, output performance enhancement, and applications of TENGs are reviewed to timely summarize the development of TENGs and provide a guideline for future research.