Nanoenergy Adv., Volume 2, Issue 2 (June 2022) – 3 articles

A triboelectric nanogenerator (TENG) is a noteworthy mechanical energy harvester that can convert mechanical energy into electricity by combining triboelectrification and electrostatic induction. However, owing to the nature of its working mechanism, TENGs have critical limitations in mechanical and electrical aspects, which prevent them from being utilized as primary power sources. To overcome these limitations, several studies are turning their attention to utilizing lubricants, which is a traditional method recently applied to TENGs. In this review, we introduce recent advances in lubricant-based TENGs that can effectively enhance their electrical output and mechanical lifespan. In addition, this review provides an overview of lubricant-based TENGs. We hope that, through this review, researchers who are trying to overcome mechanical and electrical limitations to expand the applications of TENGs in industries will be introduced to the use of lubricant materials. Full article

Zinc oxide (ZnO) nanogenerators have attracted increasing interest in the scientific community for use in energy harvesting and mechanical sensing applications. Understanding the interplay between piezoelectricity and semiconductor physics is fundamental to enhancing these devices’ performances, although direct characterization at the nanoscale is challenging. With this work, we present a new strategy to improve piezoresponse force microscopy (PFM) measurements and analysis. This strategy was applied to study the piezoelectric performances of ZnO nanowires grown on seed layers deposited by gravure printing onto flexible substrates. We demonstrate the influence of nanowire diameter and atomic force microscope (AFM) tip position on the piezoresponse amplitude. We also explain our results with simulations showing the importance of considering semiconducting properties in the analysis. Full article

Silicon is considered as one of the most promising candidates for the next generation negative electrode (negatrode) materials in lithium-ion batteries (LIBs) due to its high theoretical specific capacity, appropriate lithiation potential range, and fairly abundant resources. However, the practical application of silicon negatrodes is hampered by the poor cycling and rate performances resulting mainly from the huge volume change during Li⁺ insertion/extraction. Various composite structures have been investigated to maintain the structural integrity and improve the stability and electric conductivity of silicon-based negatrodes. Of these, 2D transition-metal carbides, also known as MXenes (e.g., Ti₃C₂T_x), have become increasingly attractive for energy storage applications because of their excellent electric, electrochemical and mechanical properties and potential uses as the matrix for construction of 3D networks with larger buffering spaces and more effective charge carrier conduction in silicon-based negatrodes. This article reviews specifically composite negatrodes of silicon with titanium-carbide-based MXenes for LIBs from the materials perspective. The structures design, preparation method, interface control, and their effects on electrochemical performances are comprehensively elaborated on. It is shown that the recent development of Si/MXene-based negatrodes presents great potential for future applications. Full article