Advances in TENGs for Marine Energy Harvesting and In Situ Electrochemistry

From Wave Energy to Electricity: Functional Design and Performance Analysis of Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) offer a self-sustaining power solution for marine regions abundant in resources but constrained by energy availability. Since their pioneering use in wave energy harvesting in 2014, nearly a decade of advancements has yielded nearly thousands of research articles in this domain. Researchers have developed various TENG device structures with diverse functionalities to facilitate their commercial deployment. Nonetheless, there is a gap in comprehensive summaries and performance evaluations of TENG structural designs. This paper delineates six innovative structural designs, focusing on enhancing internal device output and adapting to external environments: high space utilization, hybrid generator, mechanical gain, broadband response, multi-directional operation, and hybrid energy-harvesting systems. We summarize the prevailing trends in device structure design identified by the research community. Furthermore, we conduct a meticulous comparison of the electrical performance of these devices under motorized, simulated wave, and real marine conditions, while also assessing their sustainability in terms of device durability and mechanical robustness. In conclusion, the paper outlines future research avenues and discusses the obstacles encountered in the TENG field. This review aims to offer valuable perspectives for ongoing research and to advance the progress and application of TENG technology.

Skeleton Enhanced Dispersed Lubricant Particle Based Triboelectric Nanogenerator for Droplet Energy Harvesting

Liquid-solid triboelectric nanogenerators (LS-TENGs) can be widely utilized for droplet energy harvesting, in which slippery modification of triboelectric layer is crucial for output enhancement. However, classical slippery lubricant-infused surfaces suffer from the blocked triboelectric effect and the poor durability. Herein, a controllable phase separation method is reported to disperse skeleton-enhanced lubricant particles on triboelectric layer, leading to the development of a stretchable slippery triboelectric nanogenerator (SS-TENG) based on a modified slippery triboelectric layer and a liquid metal electrode. The dispersed lubricant particles (DLPs) ensure triboelectric effect between droplet and triboelectric layer, in addition to improving energy harvesting and charge transfer efficiencies. As a result, the open circuit voltage significantly increases from 0.9 to 14.4 V, with a transfer charge density of 6.95 × 10-3 C m-2 L-1. The embedded skeleton within lubricant particle significantly improves the durability of triboelectric layer, ensuring nearly no decline in output performance of SS-TENG during long-term operation. Furthermore, the SS-TENG exhibits stable output even under 300% stretching, as the DLPs remain firmly anchored to triboelectric layer during deformation. Owing to its excellent triboelectric performance, durability, and flexibility, the SS-TENG can be integrated into various objects to harvest raindrop energy and power electronic devices.

Green and efficient fabrication of high-damping porous films for energy harvesting and self-powered sensing

Finding a sustainable and scalable strategy for the fabrication of triboelectric materials with unique damped capabilities to enhance the stability and durability of triboelectric nanogenerators (TENGs) is a challenging task. Here, the styrene-ethylene-butylene-styrene (SEBS) foam with a high-damping property was prepared via the supercritical nitrogen dioxide (scN2) foaming process, resulting in an 87.5 % reduction in rebound height, 700 % increase in buffering effect, and nearly zero rebound times. A complementary-shaped TENG (CS-TENG) was fabricated using a convex polydimethylsiloxane and concave porous-surface foamed SEBS films, which can be obtained by slicing SEBS foam. The optimized CS-TENG increased the output voltage by 270 % to 310 V and current by 287.5 % to 1.15 μA, enabling it to charge capacitors and power small devices. Moreover, the flexible and robust friction layers of the CS-TENG ensured durability across 40,000 cycles, allowing it to serve as a self-powered sensor for the detection of forces and deformations. For feasibility testing, a self-powered remote-control system with four CS-TENGs was developed for the intellectual development of children and rehabilitation support of the elderly. This work offers new insights into the green fabrication of high-damping triboelectric materials and the development of surface-engineered TENGs with high output and durability.