With the gradual miniaturization of electronic devices and the increasing interest in wearable devices, flexible microelectronics is being actively studied. Owing to the limitations of existing battery systems corresponding to miniaturization, there is a need for flexible alternative power sources. Accordingly, energy harvesting from surrounding environmental systems using fluorinated polymers with piezoelectric properties has received significant attention. Among them, polyvinylidene fluoride (PVDF) and PVDF co-polymers have been researched as representative organo-piezoelectric materials because of their excellent piezoelectric properties, mechanical flexibility, thermal stability, and light weight. Electrospinning is an effective method for fabricating nanofibrous meshes with superior surface-to-volume ratios from polymer solutions. During electrospinning, the polymer solution is subjected to mechanical stretching and in situ poling, corresponding to an external strong electric field. Consequently, the fraction of the piezoelectric β-phase in PVDF can be improved by the electrospinning process, and enhanced harvesting output can be realized. An overview of electrospun piezoelectric fibrous meshes composed of PVDF or PVDF co-polymers to be utilized is presented, and the recent progress in enhancement methods for harvesting output, such as fiber alignment, doping with various nanofillers, and coaxial fibers, is discussed. Additionally, other applications of these meshes as sensors are reviewed.

Electrospinning enables the rapid and facile production of nanofibers with desired structures and morphologies at room temperature and ambient pressure. These nanofibers are suitable cathode, anode, and separator materials for Li‐ion batteries (LIBs) because of their one‐dimensional(1‐D) structures and mechanical strength as well as their ability to enable rapid Li‐ion transport through short diffusion pathways. The use of electrospun nanofibers in LIBs can lead to better battery rechargeability, lifespan, and performance than those of existing LIBs. In this review article, we first discuss the problems associated with the cathode, anode, and separator materials currently used in LIBs. Next, we describe the improvements achieved by incorporating electrospun nanofibers as cathode, anode, and separator materials in LIBs. We believe that electrospun nanofibers can promote the advancement of LIB technology to realize very‐high‐energy‐density energy storage systems.

Nanogenerators have garnered significant interest as environmentally friendly and potential energy-harvesting systems. Nanogenerators can be broadly classified into piezo-, tribo-, and hybrid nanogenerators. The hybrid nanogenerator used in this experiment is a nanogenerator that uses both piezo and tribo effects. These hybrid nanogenerators have the potential to be used in wearable electronics, health monitoring, IoT devices, and more. In addition, the versatility of the material application in electrospinning makes it an ideal complement to hybrid nanogenerators. However, despite their potential, several experimental variables, biocompatibility, and harvesting efficiency require improvement in the research field. In particular, maximizing the output voltage of the fibers is a significant challenge. Based on this premise, this study aims to characterize hybrid nanogenerators (HNGs) with varied structures and material combinations, with a focus on identifying HNGs that exhibit superior piezoelectric- and triboelectric-induced voltage. In this study, several HNGs based on coaxial structures were fabricated via electrospinning. PVDF-HFP and PAN, known for their remarkable electrospinning properties, were used as the primary materials. Six combinations of these two materials were fabricated and categorized into homo and hetero groups based on their composition. The output voltage of the hetero group surpassed that of the homo group, primarily because of the triboelectric-induced voltage. Specifically, the overall output voltage of the hetero group was higher. In addition, the combination group with the most favorable voltage characteristics combined PVDF-HFP@PAN(BTO) and PAN hollow, boasting an output voltage of approximately 3.5 V.

In this study, we analyze metal–insulator–metal (MIM) capacitors with different thicknesses of SixNy film (650 Å, 500 Å, and 400 Å) and varying levels of film quality to improve their capacitance density. SixNy thicknesses of 650 Å, 500 Å, and 400 Å are used with four different conditions, designated as MIM (N content 1.49), NEWMIM (N content 28.1), DAMANIT (N content 1.43), and NIT (N content 0.30). We divide the C–V characteristics into two categories: voltage coefficient of capacitance (VCC) and temperature coefficient of capacitance (TCC). There was an overall increase in the VCC as the thickness of the SixNy film decreased, with some variation depending on the condition. However, the TCC did not vary significantly with thickness, only with condition. At the same thickness, the NIT condition yielded the highest capacitance density, while the MIM condition showed the lowest capacitance density. This difference was due to the actual thickness of the film and the variation in its k-value depending on the condition. The most influential factor for capacitance uniformity was the thickness uniformity of the SixNy film.

The cathode of a lithium‐ion battery (LIB) is made from a slurry of cathode active materials, conductive additives, and binder mixtures, which is blade‐coated to fabricate the cathode electrode. The blade coating is a wet coating technology, which requires a heat treatment process after casting to volatilize the solvent. In addition, due to the dense surface, the reaction occurs mainly on the surface during the charge and discharge cycle, which accelerates degradation. To address these problems, this study introduces electrospun coatings during slurry casting. Electrospinning (ES) is a fast, easy, and low‐cost process that is not limited by external conditions and is typically used to produce nanofibers. However, if the polymer solution concentration is extremely low, a porous film can be formed by electrospraying. Porous films tend to degrade more slowly because the reaction occurs across the entire electrode. In addition, ES does not require a drying process as the solvent is volatilized during the process. While the blade coating shows 47.13% retention after 100 cycles at 1C, ES shows an improved retention of 75.98%. The application of ES to LIB results in a significant improvement in cycle performance, which can be developed into a breakthrough technology in electrode fabrication.