Electrical Disconnection Research Articles

Porous silicon/carbon composites as anodes for high-performance lithium-ion batteries

Silicon anodes are promising for use in lithium-ion batteries. However, their practical application is severely limited by their large volume expansion leading to irreversible material fracture and electrical disconnects. This study proposes a new top-down strategy for preparing microsize porous silicon and introduces polyacrylonitrile (PAN) for a nitrogen-doped carbon coating, which is designed to maintain the internal pore volume and lower the expansion of the anode during lithiation and delithiation. We then explore the effect of temperature on the evolution of the structure of PAN and the electrochemical behavior of the composite electrode. After treatment at 400 -, the PAN coating retains a high nitrogen content of 11.35%, confirming the presence of C―N and C―O bonds that improve the ionic-electronic transport properties. This treatment not only results in a more intact carbon layer structure, but also introduces carbon defects, and produces a material that has remarkable stable cycling even at high rates. When cycled at 4 A g−1, the anode had a specific capacity of 857.6 mAh g−1 even after 200 cycles, demonstrating great potential for high-capacity energy storage applications.

Deciphering the Benefits of Coordinated Binders in Si‐Based Anodes by Combined Operando/In Situ and Ex Situ X‐Ray Micro‐ and Nano‐Tomographies

AbstractThe simple addition of a Zn(II) precursor to a preoptimized poly(carboxylic acid) binder solution enhances the electrochemical performance and cycle life of silicon‐based electrodes. The binder/cation couple forms a cross‐linked coordinated binder that plays a key role in enhancing the mechanical and chemical stability of the electrode microstructure. The impact of the addition of the Zn precursor on the microstructural evolution of the electrode during cycling is investigated at different scales (from cell/electrode to silicon particle scale) using complementary operando, in situ, and ex situ X‐ray tomography techniques. Comparative analyses conducted on the reference and with Zn electrode formulations using operando and in situ X‐ray micro‐tomography allow for monitoring of the electrode morphological deformations along with the crack pattern formation and evolution during cycling. The benefits of the precursor addition include enhancing the mechanical stability of the electrode through a strengthened microstructure more apt to maintaining its integrity, as well as a better anchoring to the current collector leading to decreased electrical disconnections and capacity fade. Moreover, complementary ex situ X‐ray nano‐tomography measurements highlight the benefits of the precursor addition in terms of chemical stability with mitigated solid electrolyte interface (SEI) formation over the electrode cycling.

Development of Si-Based Anodes for All-Solid-State Li-Ion Batteries

All-solid-state Li-ion batteries (ASSBs) promise higher safety and energy density than conventional liquid electrolyte-based Li-ion batteries (LIBs). Silicon (Si) is considered one of the most promising anode materials due to its high specific capacity (3590 mAh g−1) but suffers from poor cycling performance because of large volumetric effects leading to particle pulverization, unstable solid electrolyte interphase (SEI), and electric disconnection. In ASSBs, additional issues such as poor solid–solid contacts and interfacial side reactions between Si and solid-state electrolytes (SSEs) are also hindering their practical application. This review first outlines the prospects and recent research achievements of Si-based anodes with special focuses on various Si structures and composite materials, then analyzes the issues of electrochemical–mechanical effects, and finally summarizes key factors and promising strategies for further improving Si-based anodes for high-performance ASSBs.

ЛОГІСТИЧНЕ УПРАВЛІННЯ ДІЯЛЬНІСТЮ АГРОПРОМИСЛОВОГО ПІДПРИЄМСТВА В УМОВАХ ВОЄННОГО СТАНУ

Today, logistical problems are definitely relevant, because the military operations on the territory of Ukraine are significant influenced the logistics processes not only of our country, but also the logistics system of the world as a whole. Destroyed or partially damaged by the effects of war, supply chains face many challenges that, if not addressed, will hinder economic recovery and long-term growth. The article is devoted to the definition and systematization of the actual problems of logistics management of the activities of domestic agro-industrial enterprises in the conditions of martial law. It is well-founded that the high level of logistical threats and the high probability of their further escalation require research in order to find mechanism for the formation of an effective system for the restoration of logistics processes and management of their development. The value of the logistics efficiency index, which is an interactive tool of comparative analysis and created to help countries identify problems in the field of logistics, was analyzed. In view of the new geopolitical challenges caused by the military aggression of the russian federation, the need to assess the real state and prospects for the restoration of the Ukrainian logistics system has been proven. The key problems of logistics management in the agricultural sector have been identified, which include: insufficient qualified workers; weak protection of property rights and raiding; problems in settlements with trade networks; risks associated with the possibility of disconnection of electricity; unpredictable actions of the state and constant changes in legislation. A model of the organization of the agribusiness system is proposed, which ensures the regulation of flow processes, their transformation and integration, and is a form of management that surpasses traditional processes, both in terms of creative potential and in terms of the effectiveness of final results, thanks to the ability to recover significantly more reserves for improving activity indicators and ensuring better conditions for the implementation of the total quality management strategy. Reorganization of storage systems, anticipation of risks and development of new routes will be the starting point for the post-war recovery of logistics.

Temperature and Humidity Control System for Pole-Mounted Metering Circuit Breaker with Artificial Neural Network Methods

Pole-mounted Metering Circuit Breaker (PMCB) is a medium voltage protection device. Problems in the PMCB because operating at medium voltage causes insulation problems. The isolation problem that arises is due to partial discharge. Partial discharge can trigger the risk of flashover. In addition, corona discharge causes corrosion of the conductor, the effect is a failure and disconnection of electricity. This control system aims to maintain the temperature and humidity of the PMCB at the nominal values according to the standard. Based on SPLN D3.021-1:2020, it is known that under normal service conditions, the ambient air temperature does not exceed 40°C and the average temperature for 24 hours does not exceed 35°C and the highest relative humidity is 100% RH. The control system uses an AC voltage controller which is used to control the input voltage of the heater and exhaust fan so that the temperature and humidity can reach nominal operating conditions. The control method used is an artificial neural network (ANN) to find the ignition angle of the AC voltage controller as a TRIAC control. The test results using the ANN control method, system simulation produces a temperature error of 1.029% and humidity error of 2.48% and the hardware system produces a temperature error of 2.364% and humidity error of 8.673% compared to the set point temperature of 35°C and humidity of 50% RH. It can be concluded that the ANN control method can maintain the PMCB temperature and humidity according to standards

Selective Inhibition of Pulmonary Vein Excitability by Constitutively Active GIRK Channels Blockade in Rats.

Pulmonary veins (PV) are the main source of ectopy, triggering atrial fibrillation. This study investigated the roles of G protein-coupled inwardly rectifying potassium (GIRK) channels in the PV and the left atrium (LA) of the rat. Simultaneous intracellular microelectrode recording from the LA and the PV of the rat found that in the presence or absence of acetylcholine, the GIRK channel blocker tertiapin-Q induced AP duration elongation in the LA and the loss of over-shooting AP in the PV, suggesting the presence of constitutively active GIRK channels in these tissues. Patch-clamp recordings from isolated myocytes showed that tertiapin-Q inhibited a basal inwardly rectified background current in PV cells with little effect in LA cells. Experiments with ROMK1 and KCa1.1 channel blockers ruled out the possibility of an off-target effect. Western blot showed that GIRK4 subunit expression was greater in PV cardiomyocytes, which may explain the differences observed between PV and LA in response to tertiapin-Q. In conclusion, GIRK channels blockade abolishes AP only in the PV, providing a molecular target to induce electrical disconnection of the PV from the LA.

Design of Automatic Disconnection Device for Non-power Outage Operation of High-voltage Line

A set of remote electric control disconnection device for high-voltage line with strong adaptability, easy operation, and high safety has been designed to address the problems of multiple spans, wide coverage, and difficulty in coordinating power failure with construction crossing operation. The design process aimed to reduce the weight and improve the reliability of the mechanical structure, and conducted computation and simulation of the traction force and safety load of the electrified tight cable. Based on the designed live disconnection device, experiments were conducted for different spans and cable diameters, while meeting the scope of infrastructure crossing sections. The experiments proved that the designed disconnection device has good effects in practical applications, and can select any point in the straight span to break the cable, in order to achieve safe and convenient uninterrupted operations in power recovery service.

Surface-vacancy filling engineered MnO cobalt with cobalt phthalocyanine for admirable suppression of volume expansion and kinetics enhancement

MnO has the advantages of high theoretical capacity, abundant resources and environmental friendliness, which is a potential material for lithium-ion storage. However, severe volume expansion and sluggish kinetics make MnO difficult to maintain long-term stability. In this study, MnO/C@CoPPc micro-rods composed of coral-like MnO/C nanobundles coated with CoPPc was synthesized via facile method. CoPPc impregnated into the empty space and simultaneously coated on the surface of the needles of MnO/C functions as an elastic layer to accommodate the mechanical stress caused by volume expansion of MnO/C, and simultaneously function as a buffering layer to keep electric disconnection on cycling. The volume of MnO/C is dramatically suppressed from 370% to 120%, and the reversible capacity is improved. Therefore, the configured MnO/C@CoPPc exhibits a high stability and delivers a high reversible capacity of 679.6 mAh/g after 200 cycles.

A strategy of boosting the effect of carbon nanotubes in graphite-blended Si electrodes for high-energy lithium-ion batteries

High capacity silicon (Si) has been added in graphite electrodes to overcome the theoretical capacity limit of the carbonaceous anode. However, different active materials that store Li+ ions via intercalation and alloying mechanisms are prone to suffer electrical disconnection due to the large gap derived from their different volume shrinkage ratios during delithiation. Herein, to address this poor compatibility on graphite-blended Si composite electrode (Gr-SC), a strategic usage of carbon nanotubes (CNTs) as electric bridge between graphite and Si is investigated through the comparison of three different types of Si blended graphite anodes (Gr-SC, Gr-SC with CNTs as additive, and Gr-MSC having implanted multi-walled CNTs on Si). Among the comparison group, the selectively located MW-CNT around Si in Gr-MSC exhibits outperformed capacity retention (98.4 %) and faster charge transfer kinetics after 50 cycles in a half cell, demonstrating a great compatibility between graphite and Si. This study presents a comprehensive understanding on the role of CNTs as an electric bridge on the electrode exploiting multiple Li storage mechanisms which undergo dissimilar volume change.

Highly Robust and Strain-Resilient Thin Film Conductors Featuring Brittle Materials.

Stretchable conductors with stable electrical conductivity under various deformations are essential for wearable electronics, soft robots, and biointegrated devices. However, brittle film-based conductors on elastomeric substrates often suffer from unexpected electrical disconnection due to the obvious mechanical incompatibility between stiff films and soft substrates. We proposed a novel out-of-plane crack control strategy to achieve the strain-insensitive electrical performance of thin-film-based conductors, featuring conductive brittle materials, including nanocrystalline metals (Cu, Ag, Mo) and transparent oxides (ITO). Our metal film-based conductors exhibit an ultrahigh initial conductivity (1.3 × 105 S cm-1) and negligible resistance change (R/R0 = 1.5) over wide strain range from 0 to 130%, enabled by film-induced substrate cracking and liquid metal-induced electrical self-repairing. They could function well under multimodal deformations (stretching, bending, and twisting) and severe mechanical damage (cutting and puncturing). We demonstrated the strain-resilient electrical functionality of metal film-based conductors in a flexible light-emitting diode display that shows high mechanical compliance.

A Conductive and Adhesive Hydrogel Composed of MXene Nanoflakes as a Paintable Cardiac Patch for Infarcted Heart Repair.

Myocardial infarction (MI) is a major cause of death worldwide. After the occurrence of MI, the heart frequently undergoes serious pathological remodeling, leading to excessive dilation, electrical disconnection between cardiac cells, and fatal functional damage. Hence, extensive efforts have been made to suppress pathological remodeling and promote the repair of the infarcted heart. In this study, we developed a hydrogel cardiac patch that can provide mechanical support, electrical conduction, and tissue adhesiveness to aid in the recovery of an infarcted heart function. Specifically, we developed a conductive and adhesive hydrogel (CAH) by combining the two-dimensional titanium carbide (Ti3C2Tx) MXene with natural biocompatible polymers [i.e., gelatin and dextran aldehyde (dex-ald)]. The CAH was formed within 250 s of mixing the precursor solution and could be painted. The hydrogel containing 3.0 mg/mL MXene, 10% gelatin, and 5% dex-ald exhibited appropriate material characteristics for cardiac patch applications, including a uniform distribution of MXene, a high electrical conductivity (18.3 mS/cm), cardiac tissue-like elasticity (30.4 kPa), strong tissue adhesion (6.8 kPa), and resistance to various mechanical deformations. The CAH was cytocompatible and induced cardiomyocyte (CM) maturation in vitro, as indicated by the upregulation of connexin 43 expression and a faster beating rate. Furthermore, CAH could be painted onto the heart tissue and remained stably adhered to the beating epicardium. In vivo animal studies revealed that CAH cardiac patch treatment significantly improved cardiac function and alleviated the pathological remodeling of an infarcted heart. Thus, we believe that our MXene-based CAH can potentially serve as a promising platform for the effective repair of various electroactive tissues including the heart, muscle, and nerve tissues.

Covalent Coating of Micro‐Sized Silicon With Dynamically Bonded Graphene Layers Toward Stably Cycled Lithium Storage

AbstractState‐of‐the‐art carbon coatings are sought to protect high‐capacity silicon anodes, which suffer from low conductivity, large volume change and fast degradation. However, this approach falls short when handling physical–electrical disconnections between carbon shells and silicon microparticulate (SiMP) with drastic size variations. Here, a strategy of covalent coating is developed to establish a robust encapsulation structure. The obtained covalent SiC bonds enable an effectively dynamic connection between the electrochemically deforming SiMP and the sliding graphene layers, preventing the evolution of gaps between SiMP and the carbon shell and maintaining persistent electrical connections as well as mechanical toughness. As a result of high structure reversibility, the cycling stability of thick SiMP anodes is greatly improved, up to a high areal capacity of 5.6 mAh cm−2 and volumetric capacity of 2564 mAh cm−3. This interface bonding effect demonstrates the great potential for suppressing deformation involved degradation of high‐capacity materials through coating strategies.

Bifunctional role of carbon nanofibrils within Li powder composite anode: More Li nucleation but less Li isolation

Enlarging the surface area in the Li metal electrode is practically attractive for increasing long-term cycle life. In this regard, Li metal powders (LMPs) have a larger surface area, which is very beneficial for controlling dendrites and fast charging compared to planar Li metal foil. However, there is the need to increase nucleation sites in LMP electrodes for faster charging and suppress unavoidable dead Li formation caused by an electrical disconnection between individual LMPs and current collector for their commercial application. Herein, we present a 40 μm-thick, carbon nanotube-embedded LMP (CNT-LMP) electrode. The CNTs improve the LMP inter-particle contact and the contact with the Cu current collector and provide additional Li nucleation sites. As a result, the Li/Li symmetric cell with the CNT-LMP electrode exhibited a stable cycling and a longer cycle life (over 1000 h) than the bare LMP electrode (680 h). Furthermore, a full cell of LiNi0.6Mn0.2Co0.2O2/CNT-LMP could achieve a longer and more stable cycle performance of up to 600 cycles under practical current conditions (0.5 C/2 C, Charge/Discharge). In comparison, the bare cell without CNT decayed suddenly after 300 cycles.

Kadirli Uygulamalı Bilimler Fakültesi Öğrencilerinin Uzaktan Eğitime Bakış Açılarına İlişkin Bir Anket Çalışması

This study was carried out to examine the thoughts and perspectives of Kadirli Faculty of Applied Sciences students about distance education and to reveal the thoughts and suggestions of these students in this direction. For this purpose, a survey was conducted with a total of 153 students by communicating with the students in the faculty via the digital platform.
 This study was approved by Osmaniye Korkut Ata University Science Scientific Research and Publication Ethics Committee (2021/2/3).
 62.1% of the students participating in the study are female and 37.9% are male. In the age range evaluation, it was observed that 94.8% of them consisted of young students between the ages of 18-30. In the study, it is seen that 45.8% of the students who participated in the survey were in the 1st grade, 21.6% were in the 2nd grade, 19% were in the 4th grade and 11.1% were in the 3rd grade. The students were asked about the departments they studied, and 42.5% of them stated that they were in gastronomy and culinary arts, 24.2% of them were in food technology, 22.9% of them were in organic agriculture management, 10.5% of them were recreation management and 2% were postgraduate students. When students were asked about their technology ownership, it was seen that 56.2% of the participants had sufficient technological equipment to participate in online courses; To the question of what would be your education preference if the conditions were suitable for the students, 72.5% of the answers were formal education, 15.7% distance education, 11.8% coeducation. 
 It has been seen that the biggest reason for the preference of distance education is due to the necessity due to the pandemic; it has been concluded that the health factor is more important than the education factor. The rate of those who think this way is 69.9%. The students were asked whether the online processing of the courses was sufficient for learning, and 54.9% of them stated that it was partially sufficient; 35.3% of them gave a negative opinion saying that it is not enough. When asked how the duration of the lessons should be, 43.8% of the participants stated that it is more appropriate that the duration of the lecture should vary according to the subject of the lesson. When the students were asked what is the biggest problem they encounter in the online course, it was emphasized that the biggest problem with 48.4% was the inaccessibility of the course due to the disconnection of electricity or the internet.

Identification of the electrical connection in the catalyst layer of the polymer electrolyte membrane water electrolyzer

Mechanical deterioration of the catalyst layer (CL) in contact with the porous transport layer (PTL) can disconnect it from the electrical network and deactivate it during proton exchange membrane water electrolysis (PEMWE). This study presents a method for visual identification of the electrically connected region in the CL using in situ electrochemical reduction of iridium oxide to iridium, coupled with energy dispersive X-ray spectroscopy (EDS) mapping and environmental scanning electron microscopy (E-SEM) analyses. Because the iridium oxides in the catalyst layer can be electrochemically reduced to iridium only when they are in both ionic and electronic connection, the reduced portion corresponds to electrically connected region. Our results revealed that the region under the rib not in contact with porous transport layer (PTL) (non-PTL-contact region) is the most prone to electric disconnection because of the cracks formed by PTL compression. Finer CL fragmentation at lower catalyst loadings aggravates such disconnection. Cell polarization of a low catalyst-loaded CL is greatly reduced when the electrical connection at the non-PTL-contact region under the rib is improved with the addition of carbon nano-fibers to the CL. These results emphasize the importance of the electrical connection in the non-PTL-contact region for achieving high-performance low-catalyst-loaded PEMWE.

Liquid Metal Remedies Silicon Microparticulates Toward Highly Stable and Superior Volumetric Lithium Storage

AbstractA silicon microparticulate material (SiMP) used as the anode for lithium‐ion batteries promises higher volumetric capacity and less interfacial reactions than its costly nanoparticulate counterpart. However, what mostly hinders its practical use is its expansion and pulverization during cycling that induces electrical disconnection and electrode polarization. A liquid metal (LM) is proposed as a remedy for these problems that acts as an adaptive conducting continuum to cure both short‐ and long‐range electrical disconnection. LM encapsulated in a carbon layer constructs a local electrical “ocean” adaptively connecting pulverized Si “islands” upon cycling. Furthermore, carbon nanofibers grown on the LM provide long‐range conducting bridges between the microparticulates, which allow the production of thick electrodes that can be used with SiMPs. With the increased tap densities (4.15 and 1.75 g cm−3 respectively for the composite and the electrode), these thick electrodes give highly stable and superior volumetric lithium storage. These results pave the way for practical compact lithium batteries with SiMPs that have a high‐volumetric energy density.

Highly thermostable ultrathin planar Ag transparent heaters

We report highly thermostable heaters composed of ultrathin (UT) planar Ag layers sandwiched between ZnO layers. Owing to the planar structure of the heating element, the transparent heaters exhibited excellent thermal stability and reproducibility at temperatures up to 400 °C, which is higher by a factor of three than the maximum operating temperatures of the emerging network-type transparent heaters composed of metallic nanowires. With increasing direct current voltages, the current–voltage relation exhibited three distinct zones. In Zone I, Ohmic behavior was observed with preserved structural integrity, and the heating capability was highly reproducible. In Zone II, the current plateaued with increasing voltage resulting from reduced current paths due to the solid-state thermal dewetting activated across the entire heater area. In Zone III, the current–voltage plot shows a negative slope, resulting from severe dewetting, and eventual heater failure was observed when the detwetted area coalesced to form a macroscopic electrical disconnection at sufficiently high temperatures (~700 °C). The UT–Ag heater structure, which is visibly transparent, can serve as an efficient heat-transfer blocker, confirmed by two tests using an artificial heat source and natural sunlight, rendering the transparent heaters highly suitable for energy-saving smart windows.

Extracellular matrix remodeling is associated with the survival of cardiomyocytes in the subendocardial region of the ischemic myocardium.

A significant amount of cardiomyocytes in subendocardial region survive from ischemic insults. In order to understand the mechanism by which these cardiomyocytes survive, the present study was undertaken to examine changes in these surviving cardiomyocytes and their extracellular matrix. Male C57BL/6 mice aged 8-12 weeks old were subjected to a permanent left anterior descending coronary artery ligation to induce ischemic injury. The hearts were collected at 1, 4, 7, or 28 days after the surgery and examined by histology. At day 1 after left anterior descending ligation, there was a significant loss of cardiomyocytes through apoptosis, but a proportion of cardiomyocytes were surviving in the subendocardial region. The surviving cardiomyocytes were gradually changed from rod-shaped to round-shaped, and appeared disconnected. Connexin 43, an important gap junction protein, was significantly decreased, and collagen I and III deposition was significantly increased in the extracellular matrix. Furthermore, lysyl oxidase, a copper-dependent amine oxidase catalyzing the cross-linking of collagens, was significantly increased in the extracellular matrix, paralleled with the surviving cardiomyocytes. Inhibition of lysyl oxidase activity reduced the number of surviving cardiomyocytes. Thus, the extracellular matrix remodeling is correlated with the deformation of cardiomyocytes, and the electrical disconnection between the surviving cardiomyocytes due to connexin 43 depletion and the increase in lysyl oxidase would help these deformed cardiomyocytes survive under ischemic conditions.

Engineering Nanostructured Silicon and its Practical Applications in Lithium‐Ion Batteries: A Critical Review

Silicon is regarded as one of the most important high‐capacity materials and has been added to some commercial anodes to increase the specific energy of lithium‐ion batteries (LIBs). However, the large volume change of Si during cycling leads to cracking, continuous accumulation of solid electrolyte interphase (SEI), and electric disconnection, posing a major challenge to practical applications. In this review, the latest progress on practical Si anodes and the scalable fabrication technologies, including synthesis of nanostructured Si, Si/C, SiOx composites, and binders is proposed. At last, a perspective of future studies on nano‐Si‐based anodes is suggested and, from a practical viewpoint, the rational design of high‐capacity Si anodes for better LIBs to narrow the gap between nanostructural design and practical applications is discussed.

Monitoring Status Gangguan Listrik Pada Saluran Distribusi Berbasis Arduino

Abstract power is a source of strength that has a very critical role in normal existence, beginning from domestic affairs, workplaces, and so forth. If the electricity is cut off or dead, a lot of work using these electronic devices will be neglected. If a power cut occurs due to a disruption in the distribution line, the public can provide an information report in the form of a telephone call or visit the PLN office to report to the operator if in their area the electricity has problems. However, unlike people in areas such as rural areas, there is very little attention to this kind of information and it is difficult for operators to monitor distribution channels in the area. Therefore, it is necessary to make a monitoring tool for the status of electrical disturbances on an Arduino-based distribution channel, so that if there is a disturbance or disconnection in the distribution channel it can be quickly detected. Where the system works with the Arduino Mega2560 control and is monitored using Android via the Blynk programming. The system begins by activating the device and is continued by connecting (pairing) the ESP8266 with Android Wifi, with the name test wifi and password 88888888, if it is connected, the user can open the Blynk application on a Smartphone. The ACS712 sensor on the device is used to detect current and the ZMPT101B sensor is used to detect voltage and the results of the reading will be processed by Arduino Mega2560. Then if there is a short circuit / disconnection of electricity in the power line, the notification will enter the android via the Blynk application. The process of sending data from Arduino is carried out by ESP8266 which has been configured with Arduino. So that monitoring of disturbance status can be seen on Android