Combination Of Electrodes Research Articles

Effect of High-Rate Aeration in the Electrocoagulation Treatment of Pharmaceutical and Synthetic Textile Industrial Wastewater Effluents

Despite the extensive literature on the effects of implementing aeration in the electrocoagulation (EC) treatment of industrial wastewater, few studies evaluate the performance of this technique at high aeration rates. In this work, we present the outcomes derived from EC treatment of pharmaceutical and synthetic textile wastewater effluents in two lab-scale reactors with and without aeration, each equipped with different electrode combinations of aluminium and iron (Al/Al, Al/Fe, and Fe/Fe). In the non-aerated EC reactor, maximum chemical oxygen demand (COD) reductions of 56% and 80% were achieved for the pharmaceutical and textile effluents, respectively, with up to 100% removal of turbidity and colour with the Al/Al combination. The installation of high-rate aeration to prevent sludge accumulation on the electrode surface markedly reduced residence times and enhanced the COD removal in the pharmaceutical effluent. However, this implementation potentially reduced the process efficiency for thesynthetic textile effluent as prolonged operation led to flocculation breakdown and subsequent re-dissolution of the contaminants in the water.

High-Energy LiNiO2 Li Metal Batteries Enabled by Hybrid Electrolyte Consisting of Ionic Liquid and Weakly Solvating Fluorinated Ether.

In pursuit of the highest possible energy density, researchers shift their focus to the ultimate anode material, lithium metal (Li0), and high-capacity cathode materials with high nickel content (Ni > 80%). The combination of these aggressive electrodes presents unprecedented challenges to the electrolyte. Here, wereport a hybrid electrolyte consisting of a highly fluorinated ionic liquid and a weakly solvating fluorinated ether, whose hybridization structure enables the reversible operation of a battery chemistry based on Li0 and LiNiO2 (Ni = 100%), delivering nearly theoretical capacity of the latter (up to 249mAhg-1) for >300cycles with retention of 78.6% and in absence of unwanted morphological changes in both electrodes. Extensive characterization assisted by molecular dynamic simulation and density functional theory calculations reveals the function of the fluorinated ether to be far more profound than simple dilution and viscosity reduction. Instead, it induces drastic changes in Li+-solvation environment, the consequence of which engenders simultaneous stabilization of electrode/electrolyte and interfacing via formation of respective interfacial chemistries. This study further unlocks fundamental knowledge underneath the prevailing "diluent strategy" that is extensively applied by the electrolyte researchers and opens more design space for the next-generation electrolytes and interphases for these coveted battery chemistries.

A simplified coaxial ion trap mass analyzer: Characterization of the simplified toroidal ion trap with a rectilinear ion guide

A new miniature coaxial ion trap mass analyzer with a rectilinear ion guide has been constructed using a combination of planar and cylindrical electrodes. The results reported here focus on characterizing the performance of the rectilinear ion guide and simplified toroidal ion trap components. The simplified toroidal ion trap was found to have an ion capacity in excess of 105 ions and mass spectral resolution of 0.5–0.6 when used as a mass analyzer. The ion storage efficiency within the toroidal trapping region was evaluated and found the stored ion population decreased exponentially with storage time. Ion losses depended slightly on the stored βz condition. Ion losses within the toroidal region are attributed primarily to field instabilities at the intersection point of the two components while charge exchange reactions were observed but considered a minor loss mechanism. The ability to mass selectively ejection ions of a specific mass from the toroidal trapping region was characterized and found to approach 100 % efficiency under appropriate ejection conditions.

Improved Electrode Performance Using Fine‐Tuned Poly(arylene piperidinium) Ionomers In Anion Exchange Membrane Fuel Cells

AbstractIonomers based on poly(arylene piperidinium)s with varying ion exchange capacities are evaluated in different combinations of anode and cathode electrodes in anion exchange membrane fuel cells. The operational conditions are chosen with an asymmetrical regime including a dry anode with 50% relative humidity at the inlet, and full humidification at the cathode. Polarization and impedance measurements are carried out in potentiostatic steps within 0.3–0.9 V and distribution of relaxation times analysis is utilized to deconvolute resistance contributions. The results show that the best cell performance is achieved with both electrodes utilizing an ionomer with the highest ion exchange capacity (IEC) of 2.79 meq g−1. Cells built exclusively from this ionomer achieved a peak power density of 1.01 W cm−2. Deconvolution of the resistance contributions revealed the impact of water content on the effective charge transfer resistance in both electrodes and a diffusion resistance associated with the movement of water from anode to cathode side. The higher conductivity and water uptake of the high IEC ionomer resulted in a reduction of both resistance contributions, leading to the highest performance under the conditions evaluated. These findings provide important insights into how to tailor the electrode layers for optimum fuel cell output.

Music Familiarization Elicits Functional Connectivity Between Right Frontal/Temporal and Parietal Areas in the Theta and Alpha Bands

Frequent listening to unfamiliar music excerpts forms functional connectivity in the brain as music becomes familiar and memorable. However, where these connections spectrally arise in the cerebral cortex during music familiarization has yet to be determined. This study investigates electrophysiological changes in phase-based functional connectivity recorded with electroencephalography (EEG) from twenty participants’ brains during thrice passive listening to initially unknown classical music excerpts. Functional connectivity is evaluated based on measuring phase synchronization between all pairwise combinations of EEG electrodes across all repetitions via repeated measures ANOVA and between every two repetitions of listening to unknown music with the weighted phase lag index (WPLI) method in different frequency bands. The results indicate an increased phase synchronization during gradual short-term familiarization between the right frontal and the right parietal areas in the theta and alpha bands. In addition, the increased phase synchronization is discovered between the right temporal areas and the right parietal areas at the theta band during gradual music familiarization. Overall, this study explores the short-term music familiarization effects on neural responses by revealing that repetitions form phasic coupling in the theta and alpha bands in the right hemisphere during passive listening.

Benchmarking the Performance of Lithium and Sodium‐Ion Batteries With Different Electrode and Electrolyte Materials

ABSTRACTSodium‐ion (Na‐ion) batteries are considered a promising alternative to lithium‐ion (Li‐ion) batteries due to the abundant availability of sodium, which helps mitigate supply chain risks associated with Li‐ion batteries. Many studies have focused on the design of Li‐ion batteries, exploring their energy, power, and cost aspects. However, there is still a lack of similar research conducted on Na‐ion batteries. A comparison of the cell voltage characteristics and rate capability of sodium and lithium‐ion batteries using different types of electrodes and electrolytes. For sodium‐ion batteries electrolytes used are NaPF6 and NaClO4 and electrodes used are NaCoO2, NaNiO2, NaFePO4, (Na3V2(PO4)3), graphite, hard carbon, sodium metal, and sodium titanate. For lithium‐ion batteries with LiPF6 and KOH electrolytes and electrodes as LiCoO2, NMC, LVP, Li2MnSiO4, graphite, silicon, lithium titanate (LTO), lithium metal. A thorough analysis of six important performance metrics is part of the investigation: Ragone plots, Electrolyte salt concentration versus spatial coordinate, electrolyte potential versus spatial coordinate, Cell voltage versus battery cell state of charge, Cell voltage versus time, and state variable versus time. Comparing operating voltage and rated capacity NMC and graphite is selected for lithium‐ion batteries as this combination provides operating voltage up to 4.2 V and a rated capacity of 275 Wh/kg, for sodium‐ion for NaCoO2 and hard carbon which has an operating voltage of 2.5–3.8 V and rated capacity around 200 Wh/kg and another combination of electrode as NaFePO4 and sodium metal with NaClO4 electrolyte has a maximum operating voltage of 2.8–3.8 V and rated capacity around 200 Wh/kg. This paper shows significant influence of electrolyte selection on battery performance. The Ragone plots demonstrate that LiPF6 electrolytes in lithium‐ion batteries and NaPF6 electrolytes in sodium‐ion batteries both exhibit superior specific energy densities compared to their KOH and NaClO4 counterparts, respectively. The work presented in this paper encourages researchers to select alternate electrolytes and electrodes for lithium‐ion and sodium‐ion batteries in order to obtain optimal device performance.

Effect of different set of electrodes for degradation of distillery spent wash promoted by electrocoagulation

ABSTRACT One of the most polluting industries in the world is the distillery industry, which produces strong distillery wastewater that has an adverse impact on the environment since it contains high organic matter. Using various combinations of electrodes in the electrocoagulation process, to examined the operational variables, viz., total dissolved solids (TDS), electrical conductivity (EC) and turbidity from the distillery spent wash. With a constant pH of 7, an agitation speed of 500 RPM, and optimizing the operating parameters, viz., varying the electrode distance (2, 3, 4, 5, and 6 cm), voltage (5–25 volts) current density of 1.5 A/cm2, and electrolysis time (30–150 min). Aluminium (Al) electrodes were observed to perform slightly better than iron (Fe) and zinc (Zn) electrodes, with punched Al electrodes outperforming plane Al electrodes. The highest removal efficiencies were achieved with punched Al electrodes in an optimized condition of voltage 25 volts, electrode distance (2 cm), and electrolysis time 150 minutes, with removal efficiencies of 91% for TDS, 92% for EC and 92% for turbidity. This study highlights the potential of electrocoagulation with optimized parameters for improving the purification of distillery spent wash and enhancing the removal of TDS, EC, and turbidity.

Synergistic effects of various membrane and cathode electrode types in dual chamber microbial fuel cells for wastewater treatment: Investigation of the start-up phase, modeling using artificial neural networks, and cost analysis

Although various membrane and cathode electrode types have been investigated in dual chamber microbial fuel cells (DCMDCs), there is no agreement on which combination of electrodes and separator materials works best. The main objective of this study is to investigate the synergistic effects of cathode electrodes and membranes on the performance of DCMFCs during the start-up phase, to model the DCMFCs through artificial neural networks (ANN), and to determine the most cost-effective choice. Principal component analysis was used to analyze the interrelationships among various factors that influence DCMFCs. Two types of ion exchange membranes (cation exchange membrane and anion exchange membrane) and two types of cathode electrodes (carbon cloth covered with 20% Pt as catalyst and plain carbon cloth) were studied. Electrodes and membranes were analyzed using AFM, TEM, SEM, XRF, and FTIR to investigate changes in morphology and the potential of fouling. The results showed that DCMFC with cation exchange membrane (CEM) and plain carbon cloth (CC) generated the maximum power among the investigated configurations. The average voltage values and COD removal efficiency reached 748 ± 13 mV and 57.8 ± 2.5%, respectively. The maximum power density achieved was obtained when the external resistance was set at 1000 Ω and was 180 mA/m2. ANN was successful in predicting the output voltage for the examined DCMFCs. The use of DCMFC with CC and CEM can be considered optimal in terms of performance and cost.

Active-matrix extended-gate field-effect transistor array for simultaneous detection of multiple metabolites

With the deepening understanding of diseases, increasing attention has been paid to personalized healthcare and precise diagnosis, which usually depend on the simultaneous monitoring of multiple metabolites, therefore requiring biological sensing systems to possess high sensitivity, specificity, throughput, and instant monitoring capabilities. In this work, we demonstrated the active-matrix extended-gate field-effect transistor (AMEGFET) array that can perform instant analysis of various metabolites in small amounts of body fluids collected during routine physiological activities. The extended gate electrodes of the AMEGFETs comprise ordered mesoporous carbon fibers loaded with both oxidoreductase enzymes for specific metabolites and platinum nanoparticles. By selecting customized electrode combinations, the AMEGFET array can monitor the concentrations of metabolites closely associated with chronic diseases and lifestyles, such as glucose, uric acid, cholesterol, ethanol, and lactate. The switch function of AMEGFET not only simplifies the readout circuitry for large-scale arrays but also avoids the mutual interferences among sensing units. The high flexibility and scalability make the AMEGFET array widely applicable in establishing high-throughput sensing platforms for biomarkers, providing highly efficient technical support for proactive health and intelligent healthcare.

Electro-sustainable Synthesis: Rapid and Efficient Production of Benzothiazole Derivatives through Electrochemical Means for Sustainable Chemistry

Abstract: Electro-organic synthesis suggested a mild, environmentally benign, and atom-efficient pathway to interesting and useful organic compounds. Organic electrochemistry offers an excellent alternative to conventional methods of organic synthesis, avoiding harsh, oxidizing and reducing agents, etc. In our reported work, electro-organic synthesis was carried out in an undivided cell at room temperature in the presence of lithium perchlorate as a supporting electrolyte. Electricity is utilized here instead of a chemical substance with a simple graphite-iron electrode combination. The generation of 2-substituted benzothiazoles was achieved through the amalgamation of bis(2- aminophenyl)disulfides with aromatic aldehydes under the influence of the electrodes. This synthetic process yielded a diverse array of 2-substituted benzothiazoles with satisfactory to excellent yields (64-91%). This is a gentle, sustainable, and metal-free condition for the synthesis of 2-substituted benzothiazoles. In this procedure, subsequent procedural steps encompassed the introduction of distilled water followed by filtration and drying processes to ensure the refinement of the final products.

SILAR synthesized α-Fe2O3 thin film anode for the development of all binder-free, high-performing Mg-ion asymmetric supercapacitors

Divalent-ion electrolyte-based supercapacitors (D-ISCs) have been gaining prominence due to their affordability and potential to deliver superior electrochemical performance as compared to single-ion electrolyte-based supercapacitors. Moreover, to satisfy the high energy demands of advanced electronic devices, a rational combination of electrodes and electrolytes in D-ISCs is required to enhance their power and energy densities further. Therefore, the present work describes the development of all binder-free magnesium-ion supercapacitor (Mg-ISC) using α-Fe2O3 as an anode and MnO2 thin films as a cathode. The binder-free thin films are fabricated using the SILAR method, allowing for direct formation of uniform and nanocrystalline thin films on the substrate, confirmed through structural and morphological analysis. Individually, both α-Fe2O3 and MnO2 thin film electrodes employed as anode and cathode exhibit excellent electrochemical properties, achieving a specific capacitance (Csp) of 381 F g−1 and 587 F g−1 at 0.2 mA cm−2, respectively, and confirms that both electrodes can be effective and reversible host materials. Furthermore, the developed Mg-ISC delivers a remarkable Csp of 234 F g−1 at a current density of 0.2 mA cm−2. Moreover, the aqueous Mg-ISC achieves a significant energy density of 105.2 Wh kg−1 at a high-power density of 619.4 W kg−1, suggesting that the device can deliver both high energy and power simultaneously. Moreover, Mg-ISC retained 86 % of its capacitance through 10,000 cycles at 5 mA cm−2. The current work lays the basis for developing D-ISC that are safe, sustainable, and provide improved electrochemical performance for a wide range of applications.

The influence of cathodic materials and optimization of the removal of the chromium (VI) from tannery wastewater by electrocoagulation

The present work focuses on the optimization of the removal percentage of Chromium (VI) from a real tannery effluent by electrocoagulation process (EC). The influence of high efficiency cathodic materials (titanium and nickel) was also investigated in this work. The tannery effluent is from the town of Maroua in the Far North Region in Cameroon. The effectiveness of the main operational parameters such as current intensity, initial Cr (VI) concentration, initial pH as well as solution conductivity was examined. All experiments were carried out in an electrocoagulation cell with an effective volume of 400 mL using two electrode combinations as anode/cathode (Al/Ti and Al/Ni). It was found that the Al/Ti combination exhibits higher removal efficiency than Al/Ni under the same operational conditions. Cr (VI) removal efficiencies of 90.93 % and 84.30 % were respectively observed for the Al/Ti and Al/Ni electrodes with an optimal initial pH (pH=6). The maximum current intensity, the maximum initial Cr (VI) concentration as well as the NaCl concentration were 0.4 A, 10 mg/L Cr(VI) and 1.5 g/L respectively. Response surface methodology by the mean of central composite design was performed. The influence of current intensity (100–300 mA), electrolysis time (10–30 min) and interelectrode spacing (1–3 cm), the probability and the mathematical model were highly discussed. According to the experimental design results, the removal of Cr (VI) in the real tannery effluent was up to 99.58 %. For the aforementioned efficiency it requires the optimum values of 211.891 mA, 36.8179 min and 1.609 cm for current intensity, time and the interelectrode spacing, respectively. EC has shown to be easy to operate, to be economic by using cheaper electrodes and efficient for the treatment of real tannery effluent.

Physical confinement versus adsorption driven reconstruction: The case of sulfate anion interaction with vicinal Cu(111) surfaces

Nano-electrochemistry, i.e., the research of the properties of nano-(structured) electrodes and their influence on electrochemical processes when immersed inside an electrolyte, represents a hot topic in view of applications in nano-electronics, electro-catalysis and energy storage devices. The role of physical confinement in the electrochemical fabrication and performances of the respective systems have been recently addressed in the context of metal-organic networks on surfaces, but rarely of nano-structured bare metal surfaces, for instance, regularly stepped (vicinal) surfaces. In this work we investigate the interplay between physical confinement and adsorbate induced restructuring by the electrochemical adsorption of sulfate anions on the flat and two distinctly different vicinal Cu(111) surfaces. Sulfate adsorption on the flat Cu(111) surface is known to create a long-range ordered Moiré-superstructure with lattice parameters in the 2–4 nm range due to an expansion of the topmost layer of copper atoms with respect to the underlying crystal planes. This restructuring is also observed on a vicinal Cu(111) surface whose original terrace width is considerably smaller than the lattice vectors of the sulfate induced Moiré-structure. The results clearly indicate not only that the Moiré formation lifts the physical confinement imposed by the initial terrace width, but also shine more light on the Moiré formation process itself. Such adsorbate induced restructuring, of course, depends on the respective adsorbate – electrode combination, but must, in principle, always be taken into account in order to understand electrochemical processes at nano-structured (and nano-sized) electrode surfaces.

Performance of pharmaceutical products removal in a bioelectrochemical system at low temperatures and changes in microbial communities and antibiotic resistance genes.

Biological methods do not effectively remove pharmaceutical products (PPs) and antibiotic resistance genes (ARGs) from wastewater at low temperatures, leading to environmental pollution. Therefore, anaerobic-aerobic-coupled upflow bioelectrochemical reactors (AO-UBERs) were designed to improve the removal of PPs at low temperatures (10 ± 2 °C). The result shows that diclofenac (DIC) and ibuprofen (IBU) removals in the system with aerobic anodic and anaerobic cathodic chambers were 91.7% and 94.7%, higher than that in the control system (12.2 ± 1.5%, 36.5 ± 5.9%), and aerobic zone favors DIC and IBU removal; fluoroquinolone antibiotics (FQs) removals in the system with aerobic cathodic and anaerobic anodic chambers were 17.5-22.4% higher than that in the control system (9.1-22.4%), and anaerobic zone favors FQs removal. Analysis of microbial community structure and ARGs showed that different electrotrophic microbes (Flavobacterium, Acinetobacter, and Delftia) with cold-resistant ability to degrade PPs were enriched in different electrode combinations, and the aerobic cathodic chambers could remove certain ARGs. These results showed that AO-UBERs under intermittent electrical stimulation mode are an alternative method for the effective removal of PPs and ARGs at low temperatures.

Hybrid dual-mode high-output triboelectric nanogenerator for achieving alternating current/direct current collaborative output

The large-scale practical application of triboelectric nanogenerators (TENGs) mainly depends on the limitations of output performance. On the basis of previous theory, this paper proposes a comprehensive strategy on the coupling of triboelectrification, corona discharge, volume effect, and space volume utilization of charge capture to enhance TENGs’ output. Thereby, a hybrid dual-mode high-output TENG (HDH-TENG) is proposed to efficiently harvest natural mechanical energy through a rotation-driven sliding-TENG (RS-TENG) and a magnetic-driven contact-separation TENG (MC-TENG). The simplified sliding-TENG with the combination of PU foam and vertical-radial electrodes achieves AC/DC collaborative output with charge density of 173.3 and 175.2 µC m−2, respectively. The simplified contact-separation TENG with the PU foam achieves AC output with charge density of 108.8 µC m−2. Furthermore, the integrated RS-TENG and MC-TENG achieve efficient collaborative output of DC with power density of 6.4 W m−2 Hz−1 and AC with power density of 128.6 mW m−2 Hz−1 through persistent directional sliding and contact separation, respectively, where a record-high constant current density output reached 1.9 mA m−2 Hz−1. The HDH-TENG can drive 6575 LEDs and 12 incandescent lamps, and continuously and stably power 52 hygrothermographs. This work further provides a new strategy for charge density enhancement of TENGs.

High-order brain interactions in ketamine during rest and task: a double-blinded cross-over design using portable EEG on male participants

Ketamine is a dissociative anesthetic that induces a shift in global consciousness states and related brain dynamics. Portable low-density EEG systems could be used to monitor these effects. However, previous evidence is almost null and lacks adequate methods to address global dynamics with a small number of electrodes. This study delves into brain high-order interactions (HOI) to explore the effects of ketamine using portable EEG. In a double-blinded cross-over design, 30 male adults (mean age = 25.57, SD = 3.74) were administered racemic ketamine and compared against saline infusion as a control. Both task-driven (auditory oddball paradigm) and resting-state EEG were recorded. HOI were computed using advanced multivariate information theory tools, allowing us to quantify nonlinear statistical dependencies between all possible electrode combinations. Ketamine induced an increase in redundancy in brain dynamics (copies of the same information that can be retrieved from 3 or more electrodes), most significantly in the alpha frequency band. Redundancy was more evident during resting state, associated with a shift in conscious states towards more dissociative tendencies. Furthermore, in the task-driven context (auditory oddball), the impact of ketamine on redundancy was more significant for predictable (standard stimuli) compared to deviant ones. Finally, associations were observed between ketamine’s HOI and experiences of derealization. Ketamine appears to increase redundancy and HOI across psychometric measures, suggesting these effects are correlated with alterations in consciousness towards dissociation. In comparisons with event-related potential (ERP) or standard functional connectivity metrics, HOI represent an innovative method to combine all signal spatial interactions obtained from low-density dry EEG in drug interventions, as it is the only approach that exploits all possible combinations between electrodes. This research emphasizes the potential of complexity measures coupled with portable EEG devices in monitoring shifts in consciousness, especially when paired with low-density configurations, paving the way for better understanding and monitoring of pharmacological-induced changes.

NRV: An open framework for in silico evaluation of peripheral nerve electrical stimulation strategies.

Electrical stimulation of peripheral nerves has been used in various pathological contexts for rehabilitation purposes or to alleviate the symptoms of neuropathologies, thus improving the overall quality of life of patients. However, the development of novel therapeutic strategies is still a challenging issue requiring extensive in vivo experimental campaigns and technical development. To facilitate the design of new stimulation strategies, we provide a fully open source and self-contained software framework for the in silico evaluation of peripheral nerve electrical stimulation. Our modeling approach, developed in the popular and well-established Python language, uses an object-oriented paradigm to map the physiological and electrical context. The framework is designed to facilitate multi-scale analysis, from single fiber stimulation to whole multifascicular nerves. It also allows the simulation of complex strategies such as multiple electrode combinations and waveforms ranging from conventional biphasic pulses to more complex modulated kHz stimuli. In addition, we provide automated support for stimulation strategy optimization and handle the computational backend transparently to the user. Our framework has been extensively tested and validated with several existing results in the literature.

Defluoridation by positive single-pulse current electrocoagulation from photovoltaic wastewater: Energy consumption assessment and mechanism analysis

The presence of fluoride ions (F−) in photovoltaic (PV) wastewater significantly affects the integrity of the ecological environment. In contrast to direct current electrocoagulation (DC-EC), positive single-pulse electrocoagulation (PSPC-EC) shows a significant reduction in both the formation of passivation films on electrodes and the consumption of electrical energy. Under the experimental conditions of an Al–Al–Al–Al electrode combination, an electrode spacing of 1.0 cm, a NaCl concentration of 0.05 mol L−1, an initial pH of 5.6, an initial F− concentration of 5 mg L−1, a current density of 5 A m−2, a pulse frequency of 500 Hz, and a 40 % duty cycle, the achieved equilibrium F− removal efficiencies were 84.0 % for DC-EC and 88.0 % for PSPC-EC, respectively, accompanied by power consumption of 0.0198 kWh·mg−1 and 0.0073 kWh·mg−1. The flocs produced in the PSPC-EC process were characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy and it is revealed that the F− removal mechanisms in the PSPC-EC process include co-precipitation, hydrogen bond complexation, and ion exchange. When the actual PV wastewater was finally subjected to treatment under the optimal PSPC-EC conditions, the F− concentration in the wastewater was reduced from 4.6 mg L−1 to 1.4 mg L−1. This paper provides both a theoretical framework and a technological basis for the application of PSPC-EC in the advanced treatment of PV wastewater.

Spatially resolved capacitance-based stress self-sensing in concrete

Spatially resolved capacitance-based stress self-sensing in unmodified concrete has been demonstrated. The spatial resolution is 45 mm in one dimension, which is in the direction of the capacitance measurement. Parallel coplanar component electrodes (aluminum, 5-mm wide), attached to the concrete using double-sided adhesive tape) separated by 45 mm are used to measure the in-plane capacitance in the direction perpendicular to the length of the electrodes. Combinations of component electrodes are electrically connected to form an electrode. The capacitance ranges from ∼200 pF to ∼750 pF. The greater is the number of component electrodes in an electrode, the higher is the capacitance. The compressive loading is applied at selected areas located between adjacent component electrodes. The stress (defined as load divided by the 300 ×300-mm2 concrete area) is up to 3000 Pa. The load decreases the capacitance monotonically and reversibly. The fractional decrease in capacitance ranges from ∼0.1 % to ∼0.5 %. More spatially concentrated loading, as for loading near the edges of the specimen, gives greater fractional decrease in capacitance. The capacitance decreases with increasing inter-electrode distance. Embedded steel rebars with a 20.0-mm concrete cover do not affect the capacitance or capacitance-based sensing.

Estimation of Li-ion battery SOH based on factors combination of FBG wavelength shift and charge-discharge process

For the purpose of daily battery maintenance, safety forecasting, and energy ladder use, it is crucial to accurately estimate the state of health (SOH) of Li-ion batteries. The external fiber Bragg grating (FBG) sensor is used in this work to collect the signal fluctuations of the wavelength shift in different areas during the Li-ion battery's charge-discharge cycle using a combination of feature analysis and data-driven method, and the characteristics of the wavelength shift and the charge- discharge process in different regions under 125 cycles are statistically analyzed. The reaction degree of Li-ion battery in different areas was compared by wavelength shift value. The wavelength shift factor and charge-discharge process factor related to battery SOH were extracted and trained in the NGO-BP regression model. The experimental results show that the combination of fiber Bragg grating wavelength shift factor and charge-discharge process factor can accurately estimate the SOH of Li-ion battery, and the prediction effect of three areas combination is the best, the goodness of fit R2 is 0.99958, the mean square error MSE is 2.71 × 10−4, the mean absolute error MAE is 1.3373 × 10−2, the root mean square error RMSE is 1.6462 × 10−2, and the mean absolute percentage error MAPE is 1.3679 × 10−2%.The combination of negative electrode and middle area uses fewer sensors to obtain higher prediction accuracy, and its cost performance is the highest. The utilization of fiber Bragg grating wavelength shift factor and charge-discharge process factor has essentially led to the accurate calculation of Li-ion battery SOH, which holds significance for battery health monitoring as well as the design and development of battery management systems.