Search Results (24)

With the growing interest in reducing CO₂ emissions to combat climate change, humanity is turning to green or renewable sources of electricity. There are numerous issues associated with the development of these sources. One of the key aspects of renewable energy sources is their problematic controllability, namely the control of energy production over time. Renewable sources are also associated with issues of recycling, utilization in different geographical zones, environmental impact within the required area, and so on. One of the most discussed issues today, however, is the question of efficient use of the energy produced from these sources. There are several different approaches to storing renewable energy, e.g., supercapacitors, flywheels, batteries, PCMs, pumped-storage hydroelectricity, and flow batteries. In the commercial sector, however, mainly due to acquisition costs, these options are narrowed down to only one concept: storing energy using an electrochemical storage device—batteries. Nowadays, lithium-ion batteries (LIBs) are the most widespread battery type. Despite many advantages of LIB technology, the availability of materials needed for the production of these batteries and the associated costs must also be considered. Thus, this battery type is not very ideal for large-scale stationary energy storage applications. Sodium-ion batteries (SIBs) are considered one of the most promising alternatives to LIBs in the field of stationary battery storage, as sodium (Na) is the most abundant alkali metal in the Earth’s crust, and the cell manufacturing process of SIBs is similar to that of LIBs. Unfortunately, considering the physical and electrochemical properties of Na, different electrode materials, electrolytes, and so on, are required. SIBs have come a long way since they were discovered. This review discusses the latest developments regarding the materials used in SIB technology. Full article

This paper focuses on the critical role of long-duration energy storage (LDES) technologies in facilitating renewable energy integration and achieving carbon neutrality. It presents a systematic review of four primary categories: mechanical energy storage, chemical energy storage, electrochemical energy storage, and thermal energy storage. The study begins by analyzing the technical advantages and geographical constraints of pumped hydro energy storage (PHES) and compressed air energy storage (CAES) in high-capacity applications. It then explores the potential of hydrogen and synthetic fuels for long-duration clean energy storage. The section on electrochemical energy storage highlights the high energy density and flexible scalability of lithium-ion batteries and redox flow batteries. Finally, the paper evaluates innovative advancements in large-scale thermal energy storage technologies, including sensible heat storage, latent heat storage, and thermochemical heat storage. By comparing the performance metrics, application scenarios, and development prospects of various energy storage technologies, this work provides theoretical support and practical insights for maximizing renewable energy utilization and driving the sustainable transformation of global energy systems. Full article

With the rapid development of new energy vehicles and the digital electronics industry, the demand for lithium has surged, necessitating advanced lithium extraction technologies. Electrochemical methods, noted for their high selectivity and efficiency in extracting target ions from liquid sources in an environmentally friendly manner, have become increasingly vital. These methods are versatile, applicable in scenarios such as lithium extraction from saline lakes, mother liquor separation, and lithium enrichment. They include electrochemical deintercalation, electrochemical ion pumps, and electrodialysis, each offering unique benefits and challenges depending on the application context. This review provides a detailed exploration of the research progress in lithium extraction using electrochemical methods and discusses future prospects for these technologies, emphasizing their potential to meet the growing demand for lithium. Full article

The increasing global demand for lithium, driven by its critical role in battery technology and nuclear applications, necessitates efficient and sustainable extraction methods. Lithium, primarily sourced from brine pools, igneous rocks, and low-grade ores, is extracted through various techniques including ion exchange, precipitation, electrolysis, and adsorption. This paper reviews the current state of lithium extraction, focusing on the diverse methodologies employed to meet the burgeoning demand. Extraction methods exploit the solubilities of salts in brine water, employing techniques like liquid–liquid extraction. Despite the effectiveness, challenges arise from the similar characteristics of lithium and other constituents. Adsorption methods utilize lithium-selective adsorbents, requiring stability and adaptability under varying conditions. Membrane processes, such as electrodialysis and nanofiltration, offer the potential for energy-efficient, continuous lithium recovery. Electrochemical processes facilitate lithium intercalation and deintercalation, emphasizing the need for electrode optimization. The review further delves into emerging technologies, like electrosorption and ionic pumps, highlighting their roles in lithium recovery. Challenges such as temperature dependency, impurity influence, and initial concentration are discussed, underscoring their impact on lithium recovery efficiency. Finally, this paper identifies research gaps and future directions, emphasizing the need for cost-effective, high-performance electrode materials and systems. It concludes that enhancing lithium recovery and separation techniques, particularly in electrochemical Li extraction, is crucial for sustainable lithium production in response to global demand. Full article

The design of an efficient thermal management system for a lithium-ion battery pack hinges on a deep understanding of the cells’ thermal behavior. This understanding can be gained through theoretical or experimental methods. While the theoretical study of the cells using electrochemical and numerical methods requires expensive computing facilities and time, the Equivalent Circuit Model (ECM) offers a more direct approach. However, upfront experimental cell characterization is needed to determine the ECM parameters. In this study, the behavior of a cell is characterized experimentally, and the results are used to build a second-order equivalent electrical circuit model of the cell. This model is then integrated with the cooling system of the battery pack for effective thermal management. The Equivalent Circuit Model estimates the internal heat generation inside the cell using instantaneous load current, terminal voltage, and temperature data. By extrapolating the heat generation data of a single cell, we can determine the heat generation of the cells in the pack. With the implementation of the ECM in the cooling system, the coolant flow rate can be adjusted to ensure the attainment of a safe operating cell temperature. Our study confirms that 14% of pumping power can be reduced when compared to the conventional constant flow rate cooling system, while still maintaining the temperature of the cells within safe limits. Full article

The sodium pump, or Na⁺/K⁺-ATPase (NKA), is an essential enzyme found in the plasma membrane of all animal cells. Its primary role is to transport sodium (Na⁺) and potassium (K⁺) ions across the cell membrane, using energy from ATP hydrolysis. This transport creates and maintains an electrochemical gradient, which is crucial for various cellular processes, including cell volume regulation, electrical excitability, and secondary active transport. Although the role of NKA as a pump was discovered and demonstrated several decades ago, it remains the subject of intense research. Current studies aim to delve deeper into several aspects of this molecular entity, such as describing its structure and mode of operation in atomic detail, understanding its molecular and functional diversity, and examining the consequences of its malfunction due to structural alterations. Additionally, researchers are investigating the effects of various substances that amplify or decrease its pumping activity. Beyond its role as a pump, growing evidence indicates that in various cell types, NKA also functions as a receptor for cardiac glycosides like ouabain. This receptor activity triggers the activation of various signaling pathways, producing significant morphological and physiological effects. In this report, we present the results of a comprehensive review of the most outstanding studies of the past five years. We highlight the progress made regarding this new concept of NKA and the various cardiac glycosides that influence it. Furthermore, we emphasize NKA’s role in epithelial physiology, particularly its function as a receptor for cardiac glycosides that trigger intracellular signals regulating cell–cell contacts, proliferation, differentiation, and adhesion. We also analyze the role of NKA β-subunits as cell adhesion molecules in glia and epithelial cells. Full article

Modern concepts in irreversible thermodynamics are applied to system transformation and degradation analyses. Phenomenological entropy generation (PEG) theorem is combined with the Degradation-Entropy Generation (DEG) theorem for instantaneous multi-disciplinary, multi-scale, multi-component system characterization. A transformation-PEG theorem and space materialize with system and process defining elements and dimensions. The near-100% accurate, consistent results and features in recent publications demonstrating and applying the new TPEG methods to frictional wear, grease aging, electrochemical power system cycling—including lithium-ion battery thermal runaway—metal fatigue loading and pump flow are collated herein, demonstrating the practicality of the new and universal PEG theorem and the predictive power of models that combine and utilize both theorems. The methodology is useful for design, analysis, prognostics, diagnostics, maintenance and optimization. Full article

The scope of this article is to study and propose optimized electricity production plants powered by renewable energy sources, in the frame of energy transition in non-interconnected, rural monasteries. Energy transition, namely, the transition from fossil fuels to renewables and rational use of energy, constitutes a major component of sustainability. In particular, monasteries constitute a special and unique category of rural communities, given their size and the scale of the electricity demand. As a case study, this work focuses on the Xenofontos Monastery, in Mount Athos. Mount Athos, practically a mountainous peninsula at the North Aegean Sea (central-south Macedonia, Greece), is an independent and self-governed community of 20 different monasteries, with no electrical interconnection between them. The electrification of these monasteries started in the 1980s, with the installation of autonomous small diesel generators. Since 2010, an attempt has been initiated to replace these generators with power production and storage technologies based on renewable energy sources, aiming to approach a more energy-independent and sustainable pattern in the peninsula. The article examines two alternative systems, with small wind turbines and photovoltaic panels as the power production units and small pumped hydro storage or electrochemical batteries as storage technologies. New operation algorithms were developed and the sizing of the systems was accomplished through the computational simulation of the examined plants’ annual operations, aiming at full coverage of the power demand. The article proves that 100% power demand coverage from hydro power plants is possible with the support of pumped storage, achieving a Levelized Cost Of Electricity in the range of 0.22 EUR/kWh. This feature can be reduced at 0.11 EUR/kWh with the support of lithium-ion batteries, yet with annual power demand coverage at 90%. Full article

The electrochemical ion pumping device is a promising alternative for the development of the industry of recovering metals from natural sources—such as seawater, geothermal water, well brine, or reverse osmosis brine—using electrochemical systems, which is considered a non-evaporative process. This technology is potentially used for metals like Li, Cu, Ca, Mg, Na, K, Sr, and others that are mostly obtained from natural brine sources through a combination of pumping, solar evaporation, and solvent extraction steps. As the future demand for metals for the electronic industry increases, new forms of marine mining processing alternatives are being implemented. Unfortunately, both land and marine mining, such as off-shore and deep sea types, have great potential for severe environmental disruption. In this context, a green alternative is the mixing entropy battery, which is a promising technique whereby the ions are captured from a saline natural source and released into a recovery solution with low ionic force using intercalation materials such as Prussian Blue Analogue (PBA) to store cations inside its crystal structure. This new technique, called “electrochemical ion pumping”, has been proposed for water desalination, lithium concentration, and blue energy recovery using the difference in salt concentration. The raw material for this technology is a saline solution containing ions of interest, such as seawater, natural brines, or industrial waste. In particular, six main ions of interest—Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, and SO₄²⁻—are found in seawater, and they constitute 99.5% of the world’s total dissolved salts. This manuscript provides relevant information about this new non-evaporative process for recovering metals from aqueous salty solutions using hexacianometals such as CuHCF, NiHCF, and CoHCF as electrodes, among others, for selective ion removal. Full article

In this study, α-LiAlO₂ was investigated for the first time as a Li-capturing positive electrode material to recover Li from aqueous Li resources. The material was synthesized using hydrothermal synthesis and air annealing, which is a low-cost and low-energy fabrication process. The physical characterization showed that the material formed an α-LiAlO₂ phase, and electrochemical activation revealed the presence of AlO₂* as a Li deficient form that can intercalate Li⁺. The AlO₂*/activated carbon electrode pair showed selective capture of Li⁺ ions when the concentrations were between 100 mM and 25 mM. In mono salt solution comprising 25 mM LiCl, the adsorption capacity was 8.25 mg g⁻¹, and the energy consumption was 27.98 Wh mol Li⁻¹. The system can also handle complex solutions such as first-pass seawater reverse osmosis brine, which has a slightly higher concentration of Li than seawater at 0.34 ppm. Full article

In this paper, we propose a sophisticated battery model for vanadium redox flow batteries (VRFBs), which are a promising energy storage technology due to their design flexibility, low manufacturing costs on a large scale, indefinite lifetime, and recyclable electrolytes. Primarily, fluid distribution is analysed using computational fluid dynamics (CFD) considering only half-cells. Based on the analysis results, a novel model is developed in the MATLAB Simulink environment which is capable of identifying both the steady-state and dynamic characteristics of VRFBs. Unlike the majority of published studies, the inherent characteristics of the flow battery, such as shunt current, ion diffusion, and pumping energy consumption, are considered. Furthermore, simplified charge transfer resistance (CTR) is taken into account based on electrochemical impedance spectroscopy (EIS) measurement results. The accuracy of the model was determined by comparing the simulation results generated by the equivalent circuit battery model developed in this study with real datasets. The obtained results indicate that the developed model has an accuracy of 3% under the sample operating conditions selected. This study can also be used to fill the gap left by the absence of the VRFB battery model in commonly used programs for renewable energy systems, such as TRNSYS. Full article

It has become increasingly important to monitor environment contamination by such chemicals as chemical warfare agents (CWAs) and industrial toxic chemicals (TICs), as well as radiation hazards around and inside collective protection facilities. This is especially important given the increased risk of terrorist or military attacks. The Military Institute of Chemistry and Radiometry (MICR) has constructed and developed the ALERT device for the effective monitoring of these threats. This device uses sensors that detect chemical and radiological contaminations in the air. The CWA detector is an ion mobility spectrometer, TICs are detected by electrochemical sensors, and radiation hazards are detected via Geiger–Muller tubes. The system was designed to protect the crew from contamination. When chemical or radioactive contamination is detected at the air inlet for the shelter, air filtration through a carbon filter is activated. At this time, the air test procedure at the filter outlet is started to test the condition of the filter on an ongoing basis. After detecting contamination at the filter outlet, the system turns off the air pumping and the service can start the procedure of replacing the damaged carbon filter. This paper presents the results of laboratory testing of the ALERT gas alarm detector, which showed high measurements for important parameters, including sensitivity, repeatability, accuracy, and speed. Full article

P-type ATPases are a large family of membrane transporters that are found in all forms of life. These enzymes couple ATP hydrolysis to the transport of various ions or phospholipids across cellular membranes, thereby generating and maintaining crucial electrochemical potential gradients. P-type ATPases have been studied by a variety of methods that have provided a wealth of information about the structure, function, and regulation of this class of enzymes. Among the many techniques used to investigate P-type ATPases, the electrical method based on solid supported membranes (SSM) was employed to investigate the transport mechanism of various ion pumps. In particular, the SSM method allows the direct measurement of charge movements generated by the ATPase following adsorption of the membrane-bound enzyme on the SSM surface and chemical activation by a substrate concentration jump. This kind of measurement was useful to identify electrogenic partial reactions and localize ion translocation in the reaction cycle of the membrane transporter. In the present review, we discuss how the SSM method has contributed to investigate some key features of the transport mechanism of P-type ATPases, with a special focus on sarcoplasmic reticulum Ca²⁺-ATPase, mammalian Cu⁺-ATPases (ATP7A and ATP7B), and phospholipid flippase ATP8A2. Full article

In the process of finding new forms of energy extraction or recovery, the use of various natural systems as potential clean and renewable energy sources has been examined. Blue energy is an interesting energy alternative based on chemical energy that is spontaneously released when mixing water solutions with different salt concentrations. This occurs naturally in the discharge of rivers into ocean basins on such a scale that it justifies efforts for detailed research. This article collects the most relevant information from the latest publications on the topic, focusing on the use of the mixing entropy battery (MEB) as an electrochemical ion pumping device and the different technological means that have been developed for the conditions of this process. In addition, it describes various practices and advances achieved by various researchers in the optimization of this device, in relation to the most important redox reactions and the cathode and anodic materials used for the recovery of blue energy or salinity gradient energy. Full article

Two important ions, K⁺ and Na⁺, are unequally distributed across the contemporary phospholipid-based cell membrane because modern cells evolved a series of sophisticated protein channels and pumps to maintain ion gradients. The earliest life-like entities or protocells did not possess either ion-tight membranes or ion pumps, which would result in the equilibration of the intra-protocellular K⁺/Na⁺ ratio with that in the external environment. Here, we show that the most primitive protocell membranes composed of fatty acids, that were initially leaky, would eventually become less ion permeable as their membranes evolved towards having increasing phospholipid contents. Furthermore, these mixed fatty acid-phospholipid membranes selectively retain K⁺ but allow the passage of Na⁺ out of the cell. The K⁺/Na⁺ selectivity of these mixed fatty acid-phospholipid semipermeable membranes suggests that protocells at intermediate stages of evolution could have acquired electrochemical K⁺/Na⁺ ion gradients in the absence of any macromolecular transport machinery or pumps, thus potentially facilitating rudimentary protometabolism. Full article