Electrical Charge Storage Research Articles

Save the giants: demand beyond production capacity of tantalum raw materials

Tantalum’s high melting point and ability to store and release electrical charges have attracted high-tech companies since its usage in capacitors began in the 1930s. During the COVID-19 pandemic lockdown, daily life relied on electronic equipment, resulting in a surge in demand for electronic and communication gadgets, which could necessitate many tantalum raw materials and an assured supply chain. Despite tantalum’s high demand from electronic manufacturers, 5G network systems and electric vehicles are currently added to the tantalum consumer list. The authors have examined three interconnected issues linked to tantalum supply interruption, which has resulted in a growing tantalum scarcity: (1) rising demand for tantalum ores and high-tech equipment while mining activities are in decline owing to the COVID-19 pandemic; (2) tantalum ore price volatility constrains the ore supply chain; (3) the challenge of pandemics that shrink mining activities and handicap supply chain. To address the issue of supply shortage in the long-term, the authors suggest that the concerned parties may adopt new norms of reliable, stable, and transparent supply channels instead of relying on an old uncertain and volatile supply system. The authors also suggest the transformation of central African artisanal and small-scale mining (mainly in Rwanda and the Democratic Republic of the Congo) into a modern mining system with a new supply channel that can resist existing and future disruptions.

Arduino Implementation for Development Digital Capacitance Meters as Laboratory Measurement Devices

Electronics Practicum in the Laboratory is a routine activity carried out to support student skills. Capacitors are one of the components that are often used in practice. Capacitors are one of the passive electronic components that have a magnitude value in the form of capacitance in Farad units. The capacitance value indicates the capacitor's ability to store electric charge. However, the value contained on the capacitor label is not necessarily the actual value because the capacitor has a tolerance range. Of course, this is very influential in the measurement and performance of electronic circuits that use capacitors. In addition, another factor that supports this research is that the available measuring instruments, such as the multimeter, are not yet equipped with capacitance measurements. Capacitance meters available in the market are still analog. The purpose of this study is to design a device that can measure the capacitance value of capacitors as a measurement device in a digital laboratory, namely the Digital Capacitance Meter. This device is made using Arduino Uno as a microprocessor for data processing. The method used is to apply the process of charging and discharging the capacitor. In this case, Arduino Uno activates a timer to measure the time required to charge and discharge the capacitor so that the Time Constant value is obtained. By using the formula T = 0.693RC, the capacitance value can be obtained. In testing using 3 different capacitors and 10 times testing on each capacitor, the accuracy of the device is 97.76% and a relative error of 2.24%.

Klasifikasi Citra Jenis Kapasitor Menggunakan Kombinasi Algoritma K-Nearest Neighbor dan Principal Component Analysis

To learn about electronic devices, one must know about the types of electronic components. Capacitors are one of several important electronic components. Capacitors are part of passive components that are able to store energy or electric charge at a temporary time. Capacitors or commonly called capacitors have many types. However, some people do not know about these types of capacitors. Especially for someone or a student who will learn about electronic components. The purpose of this study is to develop a digital image processing system for the classification of transistor types by applying the K-Nearest Neighbor (KNN) and Principal Component Analysis (PCA) methods. PCA serves to reduce and retain most of the relevant information from the original features according to the optimal criteria. Based on the results of feature extraction and data reduction performed by PCA, it is easier for the KNN algorithm to classify. KNN performs a classification based on the data closest to the object being processed. Based on the test results, the developed model is able to produce an average accuracy value of 82.50%. This means that PCA and KNN algorithms can be used in the process of classifying capacitor type images properly

Electric Energy Storage Effect in Hydrated ZrO2-Nanostructured System.

The dimensional effect of electric charge storage with a density of up to 270 μF/g by the hydrated ZrO2-nanoparticles system was determined. It was found that the place of localization of different charge carriers is the generalized heterophase boundary-nanoparticles surface. The supposed mechanism of the effect was investigated using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors, which consists of the formation of localized electronic states in the nanoparticle material due to donor–acceptor interaction with the adsorption ionic atmosphere. The effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics because it allows overcoming the basic physical restrictions on the size, temperature, and operation frequency of the device, caused by leakage currents.

Amorphous cellulose nanofiber supercapacitors with voltage-charging performance

The electric charge storage properties of amorphous cellulose nanofiber (ACF) supercapacitors with different metal carboxylate radicals (COOM; M: Na(I), Ca(II), Al(III)) was investigated in terms of charging/discharging behaviours, alternating current impedance analysis, and plane-wave-based first-principles density functional calculations. Na-ACF exhibited a higher storage effect than Ca- and Al-ACFs. The charge storage mechanism for an Na-ACF supercapacitor was proposed using an electric double layer model in a C12H17O11Na electrolyte with an electrical resistivity of 6.8 × 103 Ω cm, based on the migration of protonic soliton. The supercapacitor, which demonstrated fast charging upon voltage application, could illuminate a white LED for 7 s after charging with 10 mA at 18.5 V.

Piezoelectric mathematical modeling; technological feasibility in the generation and storage of electric charge

Emerging technologies are efficient alternatives for satisfying the growing demand for sustainable and cheap energy sources. Piezoelectrics are one of the most promising energy sources derived from emerging technologies. These materials are capable of converting mechanical energy into electricity or vice versa. Piezoelectrics have been used for almost a hundred years to generate electrical and sound pulses. However, the use of piezoelectrics for power generation is constrained by the cost associated with equipment and infrastructure. This problem has been addressed through mathematical models that relate the physical and electrical properties of the piezoelectric material with the voltage generated. Although these models have high performance, they do not incorporate voltage rectification and electrical charge storage stages. This work presents a mathematical model that describes the relationship of the physical and electromechanical properties of a system employing a piezoelectric for energy generation. The voltage of the system and the charge stored in a capacitor are calculated through this model. Also, contour diagrams are presented as a tool for facilitating the efficiency of energy generation.

A mini-review of artificial intelligence techniques for predicting the performance of supercapacitors

Supercapacitors are used to store and release electrical charges like batteries and conventional capacitors. Unlike conventional capacitors, they have higher capacitance and power density, and they charge faster than batteries can. Supercapacitors are mainly classified as hybrid supercapacitors, pseudocapacitors, and electrochemical double-layer capacitors. To predict the application behaviour and optimization of supercapacitors, artificial intelligence, specifically machine language is utilized more recently. Models based on artificial intelligence are less complicated and maybe accurate enough. This paper identifies machine language models that have been employed to predict the supercapacitors’ performance.

Effects of nanostructuration on the electrochemical performance of metallic bioelectrodes.

The use of metallic nanostructures in the fabrication of bioelectrodes (e.g., neural implants) is gaining attention nowadays. Nanostructures provide increased surface area that might benefit the performance of bioelectrodes. However, there is a need for comprehensive studies that assess electrochemical performance of nanostructured surfaces in physiological and relevant working conditions. Here, we introduce a versatile scalable fabrication method based on magnetron sputtering to develop analogous metallic nanocolumnar structures (NCs) and thin films (TFs) from Ti, Au, and Pt. We show that NCs contribute significantly to reduce the impedance of metallic surfaces. Charge storage capacity of Pt NCs is remarkably higher than that of Pt TFs and that of the other metals in both morphologies. Circuit simulations of the electrode/electrolyte interface show that the signal delivered in voltage-controlled systems is less filtered when nanocolumns are used. In a current-controlled system, simulation shows that NCs provide safer stimulation conditions compared to TFs. We have assessed the durability of NCs and TFs for potential use in vivo by reactive accelerated aging test, mimicking one-year in vivo implantation. Although each metal/morphology reveals a unique response to aging, NCs show overall more stable electrochemical properties compared to TFs in spite of their porous structure.

Effect of surface area on electrical properties of NiCo2O4-reduced graphene oxide nanocomposites for supercapacitor electrodes applications

Based on the method of electrical charge storage, supercapacitors are divided into two categories, double-layer electrical capacitor (EDLC) and pseudocapacitors. Utilizing three processes—reversible adsorption, redox reactions on metal oxides, and reversible electrochemical—pseudocapacitors are utilized for high power applications involving metal oxide electrodes and the transfer of electric charge based on a reversible faradaic. In the fabrication of supercapacitors, a high specific surface area with a relatively narrow pore size distribution is essential. Therefore, it is required to increase the capacitance of the material. In this work, nickel cobaltite (NiCo2O4) synthesized from nanocomposite NiS·5H2O and Co2SO4·7H2O precursors were mixed with reduced graphene oxide (rGO). Coprecipitation and calcination were used to create the nanocomposites. The produced NiCo2O4/rGO nanocomposite was used as a pseudocapacitive supercapacitor electrode. The results showed that sample code S2 with mass variations of NiO, Co3O4, and rGO at a ratio of 2:3:2 had the best performance. The sample had a hexahedron-shaped surface morphology, an average particle size of about 0.005 m2, a specific surface area of 12.75 m2/g, an average pore radius of 9.534 nΩ.m, and a pore volume of 0.06404 cm3/g. It also performed exceptionally well in terms of electrical conductivity of 6.078 S/m,electrical resistivity of 0.16 nΩ.m, and capacitance of 289.93 F/g.

Influence of plant biomass activation conditions on the structure and electrochemical properties of nanoporous carbon material

In this paper, the main methods of obtaining nanoporous carbonaceous material have been analyzed. The expediency and advantages of thermochemical activation for obtaining a carbon material with predicted parameters of the porous structure and electrochemical properties have been shown. The electrochemical behavior of the obtained materials as an electrode material in electric charge storage systems based on an aqueous electrolyte has been studied. The mechanisms of charge accumulation in the nanoporous carbon / electrolyte system have been analyzed.

Perangkat Penyimpanan Muatan Listrik Ramah Lingkungan Berbasis Karbon Aktif Dari Limbah Hasil Pengolahan Muntok White Pipper

The national need for advanced materials is spread across several fields, such as industry, transportation, information systems and military defense systems. In the field of transportation, the government continues to innovate by shifting fuel-based vehicles (BBM) towards environmentally friendly cars in the form of electric cars. However, the main challenges in developing this electric car are the electric energy charge storage system which is durable, has high storage capacity, and short charging time. In this study, carbon was activated gradually using a 7% H3PO4 solution followed by heating at a temperature of 700oC for 3 hours under nitrogen gas (N2). The results of the FTIR analysis showed that the activated carbon N2 gas had a strong and sharp C=C group along the absorption band 1500 cm-1 – 1400 cm-1 which indicated that the activated carbon had high quality and purity. This result was strengthened based on the EDS spectra which showed a carbon content of 90.56%. In addition, based on SEM micrographs, it can be observed that the morphology of the carbon produced has pores scattered on the surface. The presence of these pores will provide space for the transfer of charge or ions to the electrode. The best electrode was obtained on activated carbon with N2 gas activation treatment with a conductivity of 3.92 x 10-2 S/m and a capacitance of 1.44 x 10-3 F, so it was concluded that activated carbon muntok white paper can be used as an electric charge storage material.

Insights into MWCNTs/polyimide nanocomposites: from synthesis to application as free-standing flexible electrodes in low-cost micro-supercapacitors

In the pursuit to enlarge the library of polyimide materials for energy applications, new polyimide/MWCNTs composite films have been developed by MWCNTs-assisted polycondensation reaction of a hydroxyl and triphenylmethane-containing diamine with benzophenone tetracarboxylic dianhydride targeting to highlight their electrical storage capability as flexible electrodes in micro-supercapacitors (mSCs). The Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, UV–vis, fluorescence, and Raman spectroscopies were used to demonstrate the evolution of interfacial interactions between MWCNTs and the precursors (diamine monomer and intermediate polyamidic acid) and polyimide matrix that proved to be the origin of MWCNTs homogeneous dispersion. Thus, composite films incorporating 1, 3, 5, and 10 w.t.% MWCNTs were obtained and thoroughly investigated with regard to their morphology, mechanical behavior, thermal stability, and electrical conductivity. The electrochemical performance of these composites was first analyzed in a classical three-electrode cell by cyclic voltammetry and galvanostatic charge-discharge in both aqueous and organic electrolyte systems. By far, the best electrical storage capacity was obtained with the composite polyimide film containing 10% MWCNTs that was further used as both active material and current collector in a flexible symmetric mSC realized by a straightforward and low-cost procedure. In the attempt to better exploit the advantages of this composite film, it was layered with a graphite-containing paint and tested as an electrode in a flexible mSC, which provided satisfactory results. To our knowledge, this is the first report on the electrical charge storage capability of a polyimide/MWCNTs free-standing film as a flexible electrode in mSCs, which do not require time- and resource-consuming processing steps.

Rancang Bangun Alternator Mobil Menggunakan Magnet Permanen

The electric power system is one of the sources of electricity found in the vehicle which functions as a starter and electric component of the vehicle. The battery (battery) is a source of electricity to meet the electrical system in the car, but the battery is only a place to store electric charge. Therefore, there is an alternator as a power generator to charge the battery. The alternator on a car uses artificial magnets in its rotor which still require excitation. Therefore, it encourages the author to analyze the comparison of alternators using permanent magnets and artificial magnets. The problem that arises is how to compare rotation, voltage, and output power on the alternator using permanent magnets and artificial magnets. The purpose of this study was to determine the ratio of the output power generated by the alternator using permanent magnets and artificial magnets. Research and Development Methods are research methods used to produce certain products, and test the effectiveness of these products. Based on the results of the tests carried out, it was found that at the same rotation an alternator with a permanent magnet generates a greater output power than the artificial magnet. However, at the same rotation the motor requires more input power to rotate the alternator when using permanent magnets. When the alternator output voltage is the same, the rotation of the alternator using the permanent magnet is lower.

Enabling Distributed Intelligence with Ferroelectric Multifunctionalities.

Distributed intelligence involving a large number of smart sensors and edge computing are highly demanded under the backdrop of increasing cyber‐physical interactive applications including internet of things. Here, the progresses on ferroelectric materials and their enabled devices promising energy autonomous sensors and smart systems are reviewed, starting with an analysis on the basic characteristics of ferroelectrics, including high dielectric permittivity, switchable spontaneous polarization, piezoelectric, pyroelectric, and bulk photovoltaic effects. As sensors, ferroelectrics can directly convert the stimuli to signals without requiring external power supply in principle. As energy transducers, ferroelectrics can harvest multiple forms of energy with high reliability and durability. As capacitors, ferroelectrics can directly store electrical charges with high power and ability of pulse‐mode signal generation. Nonvolatile memories derived from ferroelectrics are able to realize digital processors and systems with ultralow power consumption, sustainable operation with intermittent power supply, and neuromorphic computing. An emphasis is made on the utilization of the multiple extraordinary functionalities of ferroelectrics to enable material‐critical device innovations. The ferroelectric characteristics and synergistic functionality combinations are invaluable for realizing distributed sensors and smart systems with energy autonomy.

Flexible memory uses less power

When researchers make electronics on flexible substrates, device performance typically suffers. A new, flexible version of a promising class of computer memory bucks that trend, using one-tenth to one-hundredth the power of previously reported rigid memory devices that use the same phase-change approach ( Science 2021, DOI: 10.1126/science.abj1261 ). Phase-change materials that reversibly switch between amorphous and crystalline states can be made into memory cells where the two phases, which have different electrical properties, represent the 1 and 0 of digital logic. Phase-change memory has been proposed as a more stable, faster-switching alternative to flash memory, which uses transistors to store electrical charges. But the high current needed to heat the material and change its phase consumes a lot of energy, so this approach remains expensive and niche. Flash, which is made relatively inexpensively and at large scale, still rules the day in cell phones and lightweight laptops. The benchmark

Self-activated ‘green’ carbon nanoparticles for symmetric solid-state supercapacitors

Tuning of porosity and surface properties of nanoparticles especially on carbon-based nanomaterials, adopting a ‘greener’ or self-activation synthesis technique for electrical charge storage, is progressing. Herein, we report the self-activation of Teak wood sawdust in a nitrogen atmosphere at different activation temperatures to synthesize carbon nanoparticles. The activated carbon nanoparticles synthesized at 900 °C exhibits a maximum ~ 360 m2 g−1 surface area with ~ 2 nm average pore size diameter. Five electrolytes viz. KOH, KCl, Na2SO4, NaCl, and H3PO4 are used for studying the supercapacitance nature of the activated carbon nanoparticles in a 3-electrode configuration. A maximum specific capacitance of ~ 208 F g−1 @ 0.25 A g−1 is obtained in 1 M KOH as the electrolyte. Two symmetric supercapacitors, aqueous (1 M KOH) and solid-state (PVA/KOH), are fabricated, and their performance difference is compiled. The solid-state symmetric supercapacitor performs in a wider voltage window (1.7 V) with a superior energy density of 27.1 Wh kg−1 at a power density of 178 W kg−1.

Fibrinogen, collagen, and transferrin adsorption to poly(3,4-ethylenedioxythiophene)-xylorhamno-uronic glycan composite conducting polymer biomaterials for wound healing applications.

We present the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) doped with an algal-derived glycan extract, Phycotrix™ [xylorhamno-uronic glycan (XRU84)], as an innovative electrically conductive material capable of providing beneficial biological and electrical cues for the promotion of favorable wound healing processes. Increased loading of the algal XRU84 into PEDOT resulted in a reduced surface nanoroughness and interfacial surface area and an increased static water contact angle. PEDOT-XRU84 films demonstrated good electrical stability and charge storage capacity and a reduced impedance relative to the control gold electrode. A quartz crystal microbalance with dissipation monitoring study of protein adsorption (transferrin, fibrinogen, and collagen) showed that collagen adsorption increased significantly with increased XRU84 loading, while transferrin adsorption was significantly reduced. The viscoelastic properties of adsorbed protein, characterized using the ΔD/Δf ratio, showed that for transferrin and fibrinogen, a rigid, dehydrated layer was formed at low XRU84 loadings. Cell studies using human dermal fibroblasts demonstrated excellent cell viability, with fluorescent staining of the cell cytoskeleton illustrating all polymers to present excellent cell adhesion and spreading after 24 h.

The Effect of Modifications of Activated Carbon Materials on the Capacitive Performance: Surface, Microstructure, and Wettability

In this review, the efforts done by different research groups to enhance the performance of the electric double-layer capacitors (EDLCs), regarding the effect of the modification of activated carbon structures on the electrochemical properties, are summarized. Activated carbon materials with various porous textures, surface chemistry, and microstructure have been synthesized using several different techniques by different researchers. Micro-, meso-, and macroporous textures can be obtained through the activation/carbonization process using various activating agents. The surface chemistry of activated carbon materials can be modified via: (i) the carbonization of heteroatom-enriched compounds, (ii) post-treatment of carbon materials with reactive heteroatom sources, and (iii) activated carbon combined both with metal oxide materials dan conducting polymers to obtain composites. Intending to improve the EDLCs performance, the introduction of heteroatoms into an activated carbon matrix and composited activated carbon with either metal oxide materials or conducting polymers introduced a pseudo-capacitance effect, which is an additional contribution to the dominant double-layer capacitance. Such tricks offer high capacitance due to the presence of both electrical double layer charge storage mechanism and faradic charge transfer. The surface modification by attaching suitable heteroatoms such as phosphorus species increases the cell operating voltage, thereby improving the cell performance. To establish a detailed understanding of how one can modify the activated carbon structure regarding its porous textures, the surface chemistry, the wettability, and microstructure enable to enhance the performance of the EDLCs is discussed here in detail. This review discusses the basic key parameters which are considered to evaluate the performance of EDLCs such as cell capacitance, operating voltage, equivalent series resistance, power density, and energy density, and how these are affected by the modification of the activated carbon framework.

Functionalization Mechanism of Reduced Graphene Oxide Flakes with BF3·THF and Its Influence on Interaction with Li+ Ions in Lithium-Ion Batteries

Doping of graphene and a controlled induction of disturbances in the graphene lattice allows the production of numerous active sites for lithium ions on the surface and edges of graphene nanolayers and improvement of the functionality of the material in lithium-ion batteries (LIBs). This work presents the process of introducing boron and fluorine atoms into the structure of the reduced graphene during hydrothermal reaction with boron fluoride tetrahydrofuran (BF3·THF). The described process is a simple, one-step synthesis with little to no side products. The synthesized materials showed an irregular, porous structure, with an average pore size of 3.44–3.61 nm (total pore volume (BJH)) and a multi-layer structure and a developed specific surface area at the level of 586–660 m2/g (analysis of specific surface Area (BET)). On the external surfaces, the occurrence of irregular particles with a size of 0.5 to 10 µm was observed, most probably the effect of doping the graphene structure and the formation of sp3 hybridization defects. The obtained materials show the ability to store electric charge due to the development of the specific surface area. Based on cyclic voltammetry, the tested material showed a capacity of 450–550 mAh/g (charged up to 2.5 V).

Electrical charge storage effect in carbon based polymer composite for long-term performance enhancement of the triboelectric nanogenerator

The triboelectric nanogenerator (TENG) is considered as a promising small-scale energy harvester with its advantages such as material selection diversity, design flexibility, and versatile application. Although there are numerous reports about mechanism to instantaneously enhance the output performance of the TENG, there have been few reports about the long-term output enhancement of the TENG with dynamic movement of charges in the TENG. In this study, PDMS based carbon black composite (PCC), which has excellent charge storage ability, is utilized as a contact layer of the TENG and the effect of the charge storage ability on the long-term transient output performance of the TENG is investigated. As the carbon content in composite varies, the long-term output performances of the TENGs exhibit significantly different behavior with the different charge storage ability of the contact layer. Use of PCC with derived optimal carbon black content exhibit more than 2 times increase of long-term output performance of the TENG. To effectively operate the TENG adopting PCC with high number of contact/separation cycles, a rationally designed power transmission unit based on scotch yoke mechanism is applied and as a result, a ubiquitous rotational motion around us could be easily harvested. The system generates the output current of 320 μA and it easily turns on hundreds of light emitting diodes as well as the commercial electronic devices. The present strategy would provide the outstanding approach to enhance the long-term output performance of the TENG.