Improved Piezoelectric Performance of Electrospun PVDF Nanofibers with Conductive Paint Coated Electrode

2019 ◽  
Vol 19 (02) ◽  
pp. 1950008 ◽  
Author(s):  
R. Tamil Selvan ◽  
W. A. D. M. Jayathilaka ◽  
A. Hilaal ◽  
S. Ramakrishna

Fabrication of Nanogenerators (NGs) using Electrospun polyvinylidene fluoride (PVDF) nanofibers for sensing and energy harvesting applications is a trending research due to its flexibility, biocompatibility, low-cost, etc. Different electrode materials, polymer composites had been proposed to increase the energy output. However, the contact area between the electrode material and nanofiber mat which helps to conduct more piezoelectric charges to the electrode surface are still unexplored especially at nanoscale level. In this paper, authors have proposed the use of low-cost carbon conductive paint to increase the contact area between the electrode and nanofiber mat. The electrode material is coated with conductive paint and the NG was fabricated with that electrode to compare the performances with conventional NG. Piezoelectric performance of the proposed NG has increased substantially as it generates an open circuit voltage [Formula: see text]) of 4.5[Formula: see text]V and short circuit current [Formula: see text]) of 25[Formula: see text]nA, whereas the conventional NG can only produce 1.6 [Formula: see text]) and 1.5[Formula: see text]nA [Formula: see text]). A drop test experiment was conducted, and the device consistency was verified experimentally.

Author(s):  
Yi Zhang ◽  
Ka Chung Chan ◽  
Sau Chung Fu ◽  
Christopher Yu Hang Chao

Abstract Flutter-driven triboelectric nanogenerator (FTENG) is one of the most promising methods to harvest small-scale wind energy. Wind causes self-fluttering motion of a flag in the FTENG to generate electricity by contact electrification. A lot of studies have been conducted to enhance the energy output by increasing the surface charge density of the flag, but only a few researches tried to increase the converting efficiency by enlarging the flapping motion. In this study, we show that by simply replacing the rigid flagpole in the FTENG with a flexible flagpole, the energy conversion efficiency is augmented and the energy output is enhanced. It is found that when the flag flutters, the flagpole also undergoes aerodynamic force. The lift force generated from the fluttering flag applies a periodic rotational moment on the flagpole, and causes the flagpole to vibrate. The vibration of the flagpole, in turn amplifies the flutter of the flag. Both the fluttering dynamics of the flags with rigid and flexible flagpoles have been recorded by a high-speed camera. When the flag was held by a flexible flagpole, the fluttering amplitude and the contact area between the flag and electrode plates were increased. The energy enhancement increased as the flow velocity increased and the enhancement can be 113 times when the wind velocity is 10 m/s. The thickness of the flagpole was investigated. An optimal output of open-circuit voltage reaching 1128 V (peak-to-peak value) or 312.40 V (RMS value), and short-circuit current reaching 127.67 μA (peak-to-peak value) or 31.99 μA (RMS value) at 12.21 m/s flow velocity was achieved. This research presents a simple design to enhance the output performance of an FTENG by amplifying the fluttering amplitude. Based on the performance obtained in this study, the improved FTENG has the potential to apply in a smart city for driving electronic devices as a power source for IoT applications.


Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 45 ◽  
Author(s):  
Waleed I. Hameed ◽  
Baha A. Sawadi ◽  
Safa J. Al-Kamil ◽  
Mohammed S. Al-Radhi ◽  
Yasir I. A. Al-Yasir ◽  
...  

Prediction of solar irradiance plays an essential role in many energy systems. The objective of this paper is to present a low-cost solar irradiance meter based on artificial neural networks (ANN). A photovoltaic (PV) mathematical model of 50 watts and 36 cells was used to extract the short-circuit current and the open-circuit voltage of the PV module. The obtained data was used to train the ANN to predict solar irradiance for horizontal surfaces. The strategy was to measure the open-circuit voltage and the short-circuit current of the PV module and then feed it to the ANN as inputs to get the irradiance. The experimental and simulation results showed that the proposed method could be utilized to achieve the value of solar irradiance with acceptable approximation. As a result, this method presents a low-cost instrument that can be used instead of an expensive pyranometer.


Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 506 ◽  
Author(s):  
Zhuangzhi Sun ◽  
Lu Yang ◽  
Sicheng Liu ◽  
Jintao Zhao ◽  
Zhiwei Hu ◽  
...  

In this paper, a kind of green triboelectric nano-generator based on natural degradable cellulose is proposed. Different kinds of regenerated cellulose composite layers are prepared by a blending doping method, and then assembled with poly(tetrafluoroethylene) (PTFE) thin films to form tribioelectric nanogenerator (TENG). The results show that the open circuit output voltage and the short circuit output current using a pure cellulose membrane is 7.925 V and 1.095 μA. After adding a certain amount of polyamide (PA6)/polyvinylidene fluoride (PVDF)/barium titanate (BaTiO3), the open circuit output voltage peak and the peak short circuit output current increases by 254.43% (to 20.155 V) and 548.04% (to 6.001 μA). The surface morphology, elemental composition and functional group of different cellulose layers are characterized by Scanning Electronic Microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and tested by the electrochemical analyze. Moreover, after multiple assembly and rectification processing, the electrical output performance shows that the peak value of open-circuit output voltage and the peak value of short circuit output current increases by 132.06% and 116.13%. Within 500 s of the charge-discharge test, the single peak charge reached 3.114 V, and the two peak charges reached 3.840 V. The results demonstrate that the nano-generator based on cellulose showed good stability and reliability, and the application and development of natural biomaterials represented by cellulose are greatly promoted in miniature electronic sensing area.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3030
Author(s):  
Yuxin Jiang ◽  
Sikpaam Issaka Alhassan ◽  
Dun Wei ◽  
Haiying Wang

The world is suffering from chronic water shortage due to the increasing population, water pollution and industrialization. Desalinating saline water offers a rational choice to produce fresh water thus resolving the crisis. Among various kinds of desalination technologies, capacitive deionization (CDI) is of significant potential owing to the facile process, low energy consumption, mild working conditions, easy regeneration, low cost and the absence of secondary pollution. The electrode material is an essential component for desalination performance. The most used electrode material is carbon-based material, which suffers from low desalination capacity (under 15 mg·g−1). However, the desalination of saline water with the CDI method is usually the charging process of a battery or supercapacitor. The electrochemical capacity of battery electrode material is relatively high because of the larger scale of charge transfer due to the redox reaction, thus leading to a larger desalination capacity in the CDI system. A variety of battery materials have been developed due to the urgent demand for energy storage, which increases the choices of CDI electrode materials largely. Sodium-ion battery materials, lithium-ion battery materials, chloride-ion battery materials, conducting polymers, radical polymers, and flow battery electrode materials have appeared in the literature of CDI research, many of which enhanced the deionization performances of CDI, revealing a bright future of integrating battery materials with CDI technology.


Author(s):  
Xianzhong Sun ◽  
Penglei Wang ◽  
Yabin An ◽  
Xiong Zhang ◽  
Shuanghao Zheng ◽  
...  

Abstract Lithium-ion capacitors (LICs) bridge the gap between lithium-ion batteries (LIBs) and electrical double-layer capacitors (EDLCs) owing to their unique energy storage mechanisms. From the viewpoints of electrode materials and cell design, the pre-lithiation process is indispensable for improving the working voltage and energy density of LICs. However, the conventional physical short-circuit (PSC) method is time-consuming, which limits the mass-production of practical large-capacity LIC cells. Three alternative pre-lithiation protocols have been proposed, combining the PSC protocol and electrochemical approaches to shorten the pre-lithiation time. The prototype LIC pre-lithiated by using the open-circuit potential cycling (OPC) protocol has the lowest internal resistance and superior high-rate capability (even at 200C-rate). The 900-F large-capacity laminated LIC cells have been assembled and pre-lithiated to validate the feasibility of this method. The pre-lithiation time has been reduced from 470 h (PSC protocol) to 19 h (OPC protocol). This combined protocol is presumed to counteract the voltage loss and enhance the Li+ ion diffusion between multiple anode electrodes during the pre-lithiation process.


10.29007/34bz ◽  
2019 ◽  
Author(s):  
Masoud Alajmi ◽  
Sultan Aljahdali ◽  
Sultan Alsaheel ◽  
Mohammed Fattah ◽  
Mohammed Alshehri

Solar energy, one of many types of renewable energy, is considered to be an excellent alternative to non-renewable energy sources. Its popularity is increasing rapidly, especially because fuel energy consumes and depletes finite natural resources, polluting the environment, whereas solar energy is low- cost and clean. To produce a reliable supply of energy, however, solar energy must also be consistent. The energy we derive from a photovoltaic (PV) array is dependent on changeable factors such as sunlight, positioning of the array, covered area, and status of the solar cell. Every change adds potential for the creation of error in the array. Therefore, thorough research and a protocol for fast, efficient location and correction of all kinds of errors must be an urgent priority for researchers.For this project we used machine learning (ML) with voltage and current sensors to detect, localize and classify common faults including open circuit, short circuit, and hot-spot. Using the proposed algorithm, we have improved the accuracy of fault detection, classification and localization to 100%. Further, the proposed method can execute all three tasks (detection, classification, and localization) simultaneously.


2021 ◽  
Vol 9 ◽  
Author(s):  
Ismael Domingos ◽  
Ana I. S. Neves ◽  
Monica F. Craciun ◽  
Helena Alves

A rapid development in personal electronics has raised challenging requirements for portable and sustainable power sources. For example, in wearable technologies, the concept of wearable body area network brings body motion and vital signs monitoring together in synergy. For this, a key aspect is sustainable portable energy, available anywhere, at any time, as generated by triboelectric nanogenerators (TENG). This technology usually demands high-cost processes and materials and still suffer from low power output, as well as unstable output values due to charge generating stimulus with variable intensities. In this work, we present TENGs using shear exfoliated graphene as electrodes as well as active triboelectric layer deposited by a simple solution process. Graphene in combination with polymers such as polydimethylsiloxane (PDMS) were used to produce TENG devices using low-cost solution processing methods. Device electrical power generation was tested with a cyclic physical stimulus for better control and understanding of device output. The triboelectric response of these materials showed open circuit voltages (Voc) and short-circuit currents (Isc)of approximately 233 V and 731 nA respectively when stimulated at 1.5 Hz. A power density of 13.14 μW/cm2 under a load of 200 MΩ was achieved, which can be 40 times higher when compared to devices made with aluminum and PDMS. These results demonstrate the potential of solution process for low-cost triboelectric devices for self-sustainable wearable portable nanogenerators on health and security applications using contact and positional sensors.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shibu Joseph ◽  
Albin John P. Paul Winston ◽  
S. Muthupandi ◽  
P. Shobha ◽  
S. Mary Margaret ◽  
...  

This paper is aimed at how to select, extract, and characterize natural dyes and to use them as sensitizers in dye-sensitized solar cells (DSSCs). Dyes obtained from fresh sources of annatto fruits, black plums, cactus fruits, turmeric roots, and red spinach leaves were used as sensitizers. The dye pigments were analyzed using UV-Vis spectrophotometer and FT-IR for the characterization of their spectral properties. The combination from Titanium dioxide paste with the powdered nanotubes was used as photoanodes for DSSCs. The photovoltaic properties of the DSSCs such as efficiency, fill factor, open-circuit voltage, and short circuit current were studied using a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm2. The highest power conversion efficiencies (η) of 0.7% was achieved for the DSSCs fabricated using dye extracted from annatto fruits and 0.4% each for dyes extracted from black plum fruits and cactus fruits, respectively. The widespread accessibility of these fruits, roots, and leaves and ease of extraction of dyes from these ordinarily available natural resources render them unique and low-cost candidates for solar cell fabrication.


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