Power Source For Devices Research Articles

Recent Trends in Self-Powered Photoelectrochemical Sensors: From the Perspective of Signal Output.

Revolutionary developments in analytical chemistry have led to the rapid development of self-powered photoelectrochemical (PEC) sensors. Different from conventional PEC sensors, self-powered PEC sensors do not require an external power source or complex devices for the sensitive detection of targets. As a result, these sensors have enormous application potential for the development of novel portable sensors. An increasing body of work is making excellent progress toward the implementation of self-powered PEC sensors for detection, but there have been no reviews to date. The present review first introduces the state of the art in the development of self-powered PEC sensors. Then, different types of self-powered PEC sensors are summarized and discussed in detail, including their current, power, and potential. Additionally, single- and dual-photoelectrode systems are classified and systematically compared. Finally, the current developments and major challenges that need to be addressed are also summarized. This review provides valuable insights into the current state of self-powered PEC sensors to promote further progress in this field.

Design and manufacture control system for water quality based on IoT technology for aquaculture in the Vietnam

In this paper, presents solutions to apply internet of things (IoT) technology in the field of high-tech agriculture and aquaculture in coastal areas of Vietnam, which is currently a new problem. The system includes an application on a smartphone; access parameters via the web, a computer and an IoT control circuit capable of automatically drawing electricity from the solar panel to the energy storage to serve as a source of power for devices (monitoring cabinets). The product has the function of monitoring: water environmental indicators in shrimp ponds (temperature, pH, dissolved oxygen (DO), salinity, redox index at the bottom of oxygen reduction potential (ORP)), on the website 24/24h, and controllable. Automatic control of pump system and DO generator with Inverter technology. The research results in this paper have brought high economic benefits with an automatic water quality control system to improve the productivity and quality of shrimp farming in practice for people in the aquaculture area in Bach Long commune, Giao Thuy district, Nam Dinh province, Vietnam.

Design and manufacture control system for water quality based on IoT technology for aquaculture in the Vietnam

In this paper, presents solutions to apply internet of things (IoT) technology in the field of high-tech agriculture and aquaculture in coastal areas of Vietnam, which is currently a new problem. The system includes an application on a smartphone; access parameters via the web, a computer and an IoT control circuit capable of automatically drawing electricity from the solar panel to the energy storage to serve as a source of power for devices (monitoring cabinets). The product has the function of monitoring: water environmental indicators in shrimp ponds (temperature, pH, dissolved oxygen (DO), salinity, redox index at the bottom of oxygen reduction potential (ORP)), on the website 24/24h, and controllable. Automatic control of pump system and DO generator with Inverter technology. The research results in this paper have brought high economic benefits with an automatic water quality control system to improve the productivity and quality of shrimp farming in practice for people in the aquaculture area in Bach Long commune, Giao Thuy district, Nam Dinh province, Vietnam.

Wearable and Flexible All‐Solid‐State Supercapacitor Based on MXene and Chitin

Biopolymer‐based materials have recently received great interest as potential components for wearable energy‐storage devices. They can offer attractive and valuable properties such as renewability, biocompatibility, thermal and chemical stability, flexibility, durability, and biodegradability. Herein, a wearable and flexible all‐solid‐state supercapacitor that uses chitin as a biocompatible scaffold for integrating all device components, such as electrodes and an electrolyte, is developed. Chitin provides mechanical stability to electrode materials and supports the ionic liquid‐based gel electrolyte, and it also acts as a bonding agent to integrate all those components. Additionally, titanium carbide MXene is used as an active material for the proposed power source device. The MXene/chitin‐based all‐solid‐state supercapacitor exhibits impressive electrochemical performance, showing outstanding electrode conductivity, high capacitance, low internal resistance, high power density, and long‐term cycling stability. Moreover, it provides highly desired features concerning wearable devices, that is, excellent flexibility and mechanical strength under bending deformations, as well as sustainability and biodegradability. As a proof of concept, the MXene/chitin‐base device is applied for powering an electronic gadget. Herein, an important step is represented toward power‐efficient, wearable, and sustainable energy‐storage devices.

The Digital–Analog Hybrid Cable Voltage-Drop Compensation Control Strategy Based on a Novel Impedance Detection Method

A voltage drop normally occurs when a power source runs for a load system through long-distance cables. To compensate for such voltage drops, it is necessary to provide remote detecting and controlling of the load-side voltage and boost to the required voltage. In this article, a novel impedance detection method providing more reliable and accurate resistance and inductance measured results for remote cables is presented. Meanwhile, a digital–analog hybrid control strategy based on the impedance detection method is presented to compensate for the voltage drop and delayed response caused by cable intrinsic impedance. Compared with traditional methods, the proposed strategy performs detection and compensation at the source of the cable, and can be integrated into power source devices without imposing extra burden to the load system, which is more attractive and promising in engineering application. Finally, a prototype is built for experimental verification, and a systematic and intuitive comparison is conducted with existing voltage-drop compensation methods. The experimental and comparative results indicate that the problems of voltage drop and delayed response caused by long-distance cables are solved, and the accurate and rapid regulation of the remote voltage is achieved.

Carbon-Based Modification Materials for Lithium-ion Battery Cathodes: Advances and Perspectives.

Lithium-ion batteries (LIBs) have attracted great attention as an advanced power source and energy-storage device for years due to their high energy densities. With rapid growing demands for large reversible capacity, high safety, and long-period stability of LIBs, more explorations have been focused on the development of high-performance cathode materials in recent decades. Carbon-based materials are one of the most promising cathode modification materials for LIBs due to their high electrical conductivity, large surface area, and structural mechanical stability. This feature review systematically outlines the significant advances of carbon-based materials for LIBs. The commonly used synthetic methods and recent research advances of cathode materials with carbon coatings are first represented. Then, the recent achievements and challenges of carbon-based materials in LiCoO2, LiNixCoyAl1-x-yO2, and LiFePO4 cathode materials are summarized. In addition, the influence of different carbon-based nanostructures, including CNT-based networks and graphene-based architectures, on the performance of cathode materials is also discussed. Finally, we summarize the challenges and perspectives of carbon-based materials on the cathode material design for LIBs.

Investigation and fabrication triboelectric nanogenerator using commercial Polytetrafluoroethylene and Aluminum

Triboelectric nanogenerator (TENG) is an energy technology that can convert mechanical energy into electricity based on the conjunction of triboelectric friction and electrostatic induction. TENG possesses a high potential as an alternative artificial energy source to develop the integrated power source device, active sensor, or massive scale power source. In this research, the vertical contact triboelectric nanogenerators using commercial grade Polytetrafluoroethylene (PTFE) and Aluminum were successfully fabricated. It performs the output voltage and current of 145 V and 8.5 μA, respectively. Moreover, the maximum power of 510 μW was observed at the external contact force of 11 N.

Highly flexible all-solid-state microsupercapacitors for on chip applications using a transfer-free fabrication process

Recent research efforts in flexible electronics focus on developing lightweight, thin, and flexible micro scale supercapacitor devices integratable on a chip as power source devices. The key requirements for such devices are high performance, 2D form factor, and compatibility with thin-chip technology. We report the fabrication of an ultra-thin flexible microsupercapacitor (fMSC) based on a highly aligned horizontal array of carbon nanotube (HACNT) sheet with in-plane interdigitated configuration using a facile, single-step and scalable fabrication process. The devices exhibited, excellent flexibility under various bending states, and outstanding bending durability up to 10,000 cycles under bending angle of 180°. A representative fMSC with resolution of 40 μm showed a high peak energy density of 54 mWh cm−3. It was observed that the electrolyte deposition technique (drop-cast vs. spin-coating) affects the performance of fMSC devices. Drop-cast devices showed a higher specific capacitance (almost double) compared to spin-coated devices, but at the expense of flexibility. To demonstrate on-board integration, an array of these fMSCs was used as an energy storage unit in a vibrational energy-harvesting device, powered by a piezoelectric disk. This work demonstrates the potential of HACNT sheet based fMSCs with spin-coat electrolytes as ultra-thin microsupercapacitor devices for portable and wearable electronics.

Bifunctional CoO/CoS2 hierarchical nanospheres electrocatalyst for rechargeable Zn-Air battery

Limited by sluggish kinetics of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), exploring low-cost nonprecious materials to replace precious catalysts is urgently desired for the commercialization of efficient rechargeable Zn-air batteries. Herein, a rationally designed oxide/sulfide heterostructures, which named as CoO/CoS2, are successfully realized. Benefited from the electrons interaction between multiple components at the heterojunction interface and the defect structure, the CoO/CoS2 displays highly effective bifunctional catalytic performance and robust durability. CoO/CoS2 expresses a truncated overpotential of 320 mV at 10 mA cm−1 for OER, a half-wave potential of 0.78 V for ORR, and a potential difference of approximately 0.78 V. For practical application, the assembled aqueous Zn-air battery with CoO/CoS2 as the air cathode displays a large open-circuit voltage of 1.40 V, a high power density (84 mW cm−2) and superb charge–discharge stability. This work illustrates the great application prospects of CoO/CoS2 as a next-generation power source device.

Mechanical Conversion and Transmission Systems for Controlling Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) are a promising renewable energy technology. Many applications have been successfully demonstrated, such as self-powered Internet-of-Things sensors and many wearables, and those portable power source devices are useful in daily life due to their light weight, cost effectiveness, and high power conversion. To boost TENG performance, many researchers are working to modulate the surface morphology of the triboelectric layer through surface-engineering, surface modification, material selection, etc. Although triboelectric material can obtain a high charge density, achieving high output performance that is predictable and uniform requires mechanical energy conversion systems (MECSs), and their development remains a huge challenge. Many previous works did not provide an MECS or introduced only a simple mechanical system to support the TENG integration system device. However, these kinds of designs cannot boost the output performance or control the output frequency waveform. Currently, some MECS designs use transmission conversion components such as gear-trains, cam-noses, spiral springs, flywheels, or governors that can provide the step-up, controllable, predictable, and uniform output performance required for TENGs to be suitable for daily applications. In this review, we briefly introduce various MECS designs for regulating the output performance of TENGs. First, we provide an overview of simple machines that can be used when designing MECSs and introduce the basic working principles of TENGs. The following sections review MECSs with gear-based, cam-based, flywheel-based, and multiple-stage designs and show how the MECS structure can be used to regulate the input flow for the energy harvester. Last, we present a perspective and outline for a full system design protocol to correlate MECS designs with future TENG applications.

Investigation of Textile Heating Element in Simulated Wearing Conditions

Abstract The research was focused on the heating capacity of developed, isolated from water penetration, knitted textile heating element with incorporated conductive silver (Ag)- plated yarns, which can be used in manufacturing heating textile products intended for recreation, sports, or health care for elderly. The aim of the investigation was to obtain an appropriate temperature on a human skin, generated by the textile heating element surface at a lower voltage depending on a variety of wearing conditions indoor. Depending on the supplied voltage to the heating element, an incoming electric energy can be converted into different heat. Therefore, the electrical and achieved temperature parameters of heating elements are very important by selecting and adapting required power source devices and by setting the logical parameters of programmable controllers. The heating–cooling dynamic process of developed textile heating element was investigated at different simulated wearing conditions on a standard sweating hot plate and on a human skin at applied voltages of 3V and 5V. It was discovered that a voltage of 5 V is too big for textile heating elements, because the reached steady state temperature increases to approximately 39–40°C, which is too hot for contact with the human skin. The voltage of 3 V is the most suitable to work properly and continuously, i.e., to switch on when the adjusted temperature is too low and to turn off when the necessary temperature is reached. Based on the values of reached steady-state heating temperature, the influence of the applied voltage, ambient air flow velocity, and heating efficiency, depending on various layering of clothes, was determined. Recorded temperatures on the external surface of the heating element provided the possibility to assess its heat loss outgoing into the environment. It was suggested that heat loss can be reduced by increasing thermal insulation properties of the outer layer of the heating element or using layered clothing. On the basis of the resulted heating characteristics, recommended parameters of power source necessary for wearable textile heating element were defined.

A nitrogen-doped NiCo2S4/CoO hollow multi-layered heterostructure microsphere for efficient oxygen evolution in Zn-air batteries.

Exploring highly effective and low-cost non-noble metal-based electrocatalysts for oxygen evolution reaction (OER) is critical for renewable energy conversion and metal-air batteries. Herein, a novel and high-efficient OER catalyst was reported with nitrogen-doped oxide/sulfide heterostructures (named N-NiCo2S4/CoO microsphere). The N-NiCo2S4/CoO microsphere was synthesized by annealing NiCo-BTC MOF to a multi-layered hollow structure of NiCo2O4 microspheres, followed by the direct vulcanization in the presence of NH4HCO3, resulting in an oxide/sulfide heterojunction. Benefiting from the nitrogen doping, the abundant multi-layered hollow heterostructure and the interfaces between multiple components, the N-NiCo2S4/CoO microsphere exhibited excellent OER activity with a low overpotential of 227 mV at 10 mA cm-2. The Zn-air battery based on the N-NiCo2S4/CoO + Pt/C catalyst displayed excellent cycling stability after 900 cycles at a large current density of 5 mA cm-2, where the commercial RuO2 + Pt/C-based battery exhibited a big drop after only 30 cycles, suggesting its great application prospects as power source devices.

An Efficient Testing Scheme for Power-Balanceability of Power System Including Controllable and Fluctuating Power Devices

Renewable power sources are environmentally friendly power generation systems, such as wind turbines or photovoltaics; however, the output power fluctuations due to the intermittence and variability of these power systems can greatly affect the quality and stability of the power system network. Furthermore, the power fluctuations that are triggered by power load devices also have similar results on the power system. Therefore, it is essential to introduce power level control for controllable power devices and connection in order to lessen the effects of dynamic power fluctuations that are caused by fluctuating power source devices and load devices. The issue of power balancing as a part of power level control presented in this paper assigns power levels to controllable power devices and connections between power source devices and load devices to absorb dynamic power fluctuations. In this paper, we focus on power conservation law instead of detailed voltage or current-based network characterization and present a new power balanceability test for a power flow system that comprises of both fluctuating and controllable power devices. Our proposed power balanceability test can assure the existence of a power flow assignment of power devices and connections for any value of power generation and/or the consumption of fluctuating power devices. Our proposed power balanceability test method can be expressed as a linear programming problem, and it can be resolved in polynomial time complexity.

Discharge Behaviors of Disulfide with Core-Shell Structure for Thermal Batteries

Thermal batteries are adopted as the power sources for devices, due to the high power density and long life for storage. So far, disulfides, such as FeS2, CoS2, Fe1-xCoxS2 (0<x<1) are selected as the best cathodes. But limitations are existed, for example, FeS2 is low conductive, and CoS2 exhibits poor environmental stability. Therefore, structure modifications are used to improve the properties. We have done lots of work on constructing the materials with core-shell structure, such as CoS2@FeS2, C@CoS2, FeS2@CoS2, for conductivity, stability and wetting improvement. The results show that performance enhancements of thermal batteries are achieved, with proper adjustment of the composition and thickness of the shell layer. Fig. 1 illustrates the discharge curves of CoS2, with surface covered by the molten salt adsorbent, which is used to enhance the wettability of molten salt on CoS2. The discharge capacity of CoS2 is increased from ~310 mAh/g to ~380 mAh/g, with a current of 200 mA cm-2 at 525 °C, by surface reconstruction. Figure 1

Interfacial Engineering of NiO/NiCo2O4 Porous Nanofibers as Efficient Bifunctional Catalysts for Rechargeable Zinc–Air Batteries

To meet the crucial demand of regenerative Zn-air (ZA) batteries, low cost, highly efficient, and durable electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are needed to replace the noble metal. Herein, porous NiO/NiCo2O4 nanofibers with superior electrocatalytic performance are synthesized by a facile electrospinning strategy with precursor transition metal salts in nonstoichiometric ratio, which confers the heterostructured NiO/NiCo2O4 with abundant interface-related active sites and electronic transmission channels. Density functional calculation results reveal the chemical bonds easily form between NiO and NiCo2O4 to facilitate the charge transfer, while X-ray absorption fine spectroscopy and X-ray photoelectron spectroscopy results demonstrate there are abundant Ni3+ and Co3+ species in NiO/NiCo2O4 due to the interfacial engineering. As a result, the NiO/NiCo2O4 porous nanofibers exhibit highly efficient and durable performances of OER and ORR in KOH solution, including a lower overpotential of 357 mV at 10 mA cm-2 (OER) and half-wave potential of 0.73 V (ORR) than that of the individual. What's more, the NiO/NiCo2O4-based ZA battery displays excellent specific capacities of 814.4 mA h g-1, and good cycling stability of 175 h. Additionally, the flexible ZA battery displays a long cycling life of 14 h and decent flexibility. This work shows that construction of the heterostructure could provide a feasible method to optimize their electrocatalytic performance and make them widely used in power source devices.

Implementation of Magnetic Pulse Shape Stimulation Device Suitable for Cerebral Cortical Modification of Alzheimer"s Disease

In general, when a brain neural stimulation device is used in brain disease or dementia, it does not reflect the pathophysiology, because regardless of the brain disease state, it stimulates only the motor cortex. In particular, it is necessary to be more cautious about the reactivity, plasticity, and connectivity of brain diseases and the dementia-related cortex. The brain neural stimulation device affects the distance and intensity of the stimulus coil from the initial brain axis of Alzheimer’s Disease (AD). The volume of cerebrospinal fluid increased by cortical hyperactivity and cerebral atrophy changes the characteristics of the brain tissue, and the current induced in the magnetic stimulation device has a negative effect. The stimulation site is biochemically and metabolically invaded by areas other than the motor cortex. Changes in the motor cortex cause problems later on. The present research confirms the cerebral state in real time by the EEG sensor that grasps the cerebral state, and the EMG sensor that can grasp the nerve conduction state, for the treatment suitable for the modified cortical form of the brain disease patient. The optimal stimulation therapy pulse and optimal pulse-forming device suitable for lesion-modified cerebral morphology were used. EEG and EMG are monitored in real time by cell phones, computers, and the web to implement the neural stimulation device of therapy pulse suitable for the modified cerebral cortex. In addition, stimulation coils can be replaced or added depending on the performance and capacity of the power source device, and control of the pulse shaping device, in order to implement a therapy pulse corresponding to the modified cortical morphology of the brain disease patient.

Enhancement of piezoelectric energy-harvesting capacity of electrospun β-PVDF nanogenerators by adding GO and rGO

In this paper, the electrical output voltage of highly piezoelectric properties of polyvinylidene fluoride (PVDF) was enhanced by using graphene oxide (GO) and reduced graphene oxide (RGO) additives. GO and RGO materials were synthesized by Hummer's method and their morphology, crystallinity and the effect of electrical outputs of β-PVDF were investigated. Different amounts of GO and RGO additives (0.4 and 0.8 wt%) embedded in PVDF polymeric material and electrospun nanofibres that show piezoelectric features were prepared by electrospinning process. All of the produced nanofibres were characterized in terms of structural and morphological properties by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The piezoelectric nanogenerators prepared using electrospun β-PVDF mats with different amounts of GO and RGO were fabricated by sandwiching between two conductive aluminium plates. The same dimension (4 cm × 5 cm) of nanogenerators with a mat thickness of 50 µm was used to evaluate the electrical output data. All of the produced nanogenerators were examined for a finger-tapping action with a frequency of ~ 5 Hz. It was observed that the presence of 0.8 wt% of RGO increased the open-circuit voltage of β-PVDF for approximately nine times. This enhancement is associated with a certain and powerful interfacial interaction that occurs within the adsorption of molecular chain conformation of β-PVDF onto the GO and RGO surfaces. This new type of RGO-based nanogenerator could be of great advantage for a wide range of applications such as a self-charging power source, flexible and stretchable electronic devices, energy-harvesting devices, sensors and other electronic-based systems

Green Synthesis of [EMIm]Ac Ionic Liquid for Plasticizing MC-based Biopolymer Electrolyte Membranes

Lithium-ion batteries (LIBs) are favorable power source devices at the last two decades, owing to high energy density, rechargeable, long life cycle, portable, safe, rechargeable, good performance and friendly environment. To support their development, in this research has been successfully prepared polymer electrolyte membrane, a main component of LIBs, based on 1-ethyl-3-methylimidazolium acetate ([EMIm]Ac) ionic liquid-plasticized methyl cellulose/lithium perchlorate (MC/LiClO4). [EMIm]Ac ionic liquid was easy synthesized by metathesis reaction between 1-ethyl-3-methylimidazolium bromide ([EMIm]Br) ionic liquid and potassium acetate (CH3COOK) at ambient temperature, for 1 hour. [EMIm]Ac ionic liquid was functional groups analyzed with Fourier Transform Infra-red (FT-IR) and structural analyzed with 1H-Nuclear Magnetic Resonance (NMR) and 13C-NMR. [EMIm]Ac ionic liquid-plasticized MC/LiClO4 biopolymer electrolyte membrane was prepared by casting solution, with [EMIm]Ac ionic liquid content, 0, 5, 10, 15, 20, 25, and 30% (w/w). Effect of 15% (w/w) [EMIm]Ac ionic liquid incorporation to MC/LiClO4 showed the best condition and selected as the optimum condition with conductivity, tensile strength, elongation break, and thermal stability of 9.160×10-3 S.cm-1, 24.19 MPa, 36.43%, ~256 and ~370 ºC, respectively. These results confirm that [EMIm]Ac ionic liquid can plasticize biopolymer electrolyte membranes of MC/LiClO4 to be appealing performances to fulfill the LIB’s separator requirement. Copyright © 2019 BCREC Group. All rights reserved

New marking method involving a light-emitting diode and power source device to localize gastrointestinal cancer in laparoscopic surgery

Although the preoperative endoscopic marking method using dye is widely used, the dye can spread into the tissue or abdominal cavity, inducing the inflammation and leading to the wrong dissection. We developed a novel marking method using an endoscopic clip with a light emitting diode (LED) and a power source device to detect the accurate location of the site of interest. We performed this new marking method in three patients with gastrointestinal cancers. We placed an endoscopic clip with an LED on the gastrointestinal mucosa and used a power source device outside of the human body to detect the LED. We detected the clip with the LED using the power source device. We also confirmed the usefulness of this clip in three of three (100%) patients with colorectal and gastric cancer. We developed a novel marking device using an LED to identify an objective location successfully.

3D printed flexible triboelectric nanogenerator with viscoelastic inks for mechanical energy harvesting

With the rising development of the portable and wearable sensors and displays, the compact power source devices have become increasingly important and indispensable in our daily life. In this study, a flexible triboelectric nanogenerator (TENG), fabricated by the direct ink writing (DIW) method, has been proposed for the purpose of vibration energy harvesting to support power for these electronic devices. To strengthen the effective contact area of the opposite triboelectric polarities, the silicone elastomer, as viscoelastic inks, is extruded out directly onto the aluminum foil through the nozzle tip to construct the triboelectric patterns with rich and regular micro structures on the surface. Various film thickness, printing fibers spaces, contact frequencies, applied forces and printing paths are investigated to better understand the effects of the printing parameters in detail. The results show that the TENG can yield an output voltage of 124 V and the corresponding maximum power density of 608.5 mW/m2. Meanwhile, via vibration energy harvesting, the TENG is demonstrated to sustainably drive 51 LEDs and a 3-in. electrowetting display. Our work paves a new way for the individual design and digital manufacture of friction surface structures for the flexible, stretchable and wearable TENG.