Polarization Resistance Values Research Articles

Enhanced oxygen reduction reaction activity and electrochemical performance of A-site deficient (La0.6Sr0.4)1-xFe0.8Ni0.2O3−δ cathode for solid oxide fuel cells

In this work, (La0.6Sr0.4)0.9Fe0.8Ni0.2O3-δ (LSFN90), a stable, highly ORR-active and cost-efficient perovskite oxide, is developed as cathode materials for solid oxide fuel cell (SOFC). The introduction of A-site deficiency results in the crystal expansion of the cubic perovskite phase and an increase in oxygen vacancy concentration at operating temperature. The LSFN90 cathode displays good oxygen reduction reaction activity and low polarization resistance values. The A-site deficiency facilitates the diffusion of oxygen ions in the electrode and accelerates the surface oxygen exchange reaction. LSFN90 is used as cathode materials for SOFC to prepare anode-supported single cells, achieving maximum power densities of 1.51, 1.27, 0.95 and 0.63 W cm−2 under wet hydrogen (3%H2O–97%H2) atmosphere at 850, 800, 750 and 700 °C, respectively. The introduction of A-site deficiency can greatly enhance the oxygen reduction reaction activity and electrochemical performance of the cathode, demonstrating that LSFN90 has significant potential as a cathode material for practical applications in solid oxide fuel cells.

Improving the performance of titanium bipolar plate in proton exchange membrane water electrolysis environment by nitrogen-chromium composite cathode plasma electrolytic deposition

In the proton exchange membrane water electrolysis (PEMWE), the titanium bipolar plate coated with noble metals is usually used, which puts forward higher requirements for costs. This study investigates the cathode plasma electrolytic deposition (CPED) for the titanium and obtains TiN and TiN/CrN coatings. The TiN coating exhibits the diffusion resistance in the anode PEMWE environment, resulting in an increase in the interfacial contact resistance (ICR). The denser TiN/CrN coating eliminates the diffusion resistance and increases the polarization resistance (Rp) value from 3873 Ω cm2 of TiN coating to 12,320 Ω cm2 of TiN/CrN. After long-term potentiostatic polarization, the ICR of TiN/CrN coating is 8.5 mΩ cm2, which is 3.5 times lower than that of TiN coating. Therefore, the low-cost TiN/CrN coating obtained by CPED has brought a good application prospect for bipolar plates in PEMWE.

Corrosion of metal parts in the power plant

AbstractThe AISI 304 (X5CrNi19‐10) stainless steel is widely used for the production of various metal parts in power plants. A procedure for testing the influence of the dust from a power plant on resistance to general and pitting corrosion of the AISI 304 stainless steel is developed and performed. The quantitative (XRD method) and qualitative (Fourier–transform infrared spectroscopy [FTIR] method) composition of the dust present in the power plant is determined. Applying the Mott–Schottky method, the properties of the passive layer are analyzed, while a degree of chromium depletion of the grain boundary is determined by the electrochemical potentiokinetic reactivation method with double loop method. Values of polarization resistance (linear polarization resistance and electrochemical impedance spectroscopy methods) and the corrosion current density (polarization measurements) indicate that the stainless steel has a higher resistance to general corrosion in the dust solutions than in the etalon solution. Also, based on the measured value of the pitting potential (Epit) and the difference between the values of the pitting potential and the corrosion potential (Epit – Ecorr), it can be seen that stainless steel has a higher resistance to localized types of corrosion, such as pitting corrosion, in dust solutions than in the etalon solution.

(Digital Presentation) Au-Mo-Fe-Ni/CeO2(Gd2O3) As Potential Fuel Electrodes for Internal CO2 Reforming of CH4 in Single SOFCs

In this study the catalytic and electro-catalytic performance, as well as the coking resistance of un-modified and modified Ni/CeO2(Gd2O3) with 3 wt.% Au−0.4 wt.% Mo and 3 wt.% Au−0.5 wt.% Fe electrocatalysts were studied as half and full electrolyte supported cells under internal CO2 reforming of CH4 in single SOFCs, at 750-900 oC. The aim was to elucidate their activity towards the consumption of CH4, CO2, the production of H2, H2O, CO and the production of carbon, as a function of temperature and the applied current density under a biogas fuel mixture of CH4/CO2=1. Additionally, the cells comprising the electrocatalysts as fuel electrodes, 8 mol% Y2O3 stabilized ZrO2 (8YSZ) as electrolyte and La0.6Sr0.4Co0.8Fe0.2O3- δ (LSCoF) as oxygen electrode were characterized using I-V measurements and Electrochemical Impedance Spectra (EIS) analysis in order to investigate the evolution of the ohmic and polarization resistance values as a reflection of current.

Corrosion resistance of Aluminium steel in 1N Sodium Hydroxide solution by an aqueous extract of Thespesia populnea plant leaves

Corrosion resistance effect of aluminium steel in 1N sodium hydroxide by an aqueous extract of Thespesia populnea plant leaves has been investigated by mass loss method. It is observed that as the concentration of the inhibitor increases, the inhibition efficiency increases. The mechanistic aspects of corrosion resistance have been studied by potentiodynamic polarization technique and electrochemical impedance spectroscopy. A maximum inhibition efficiency of 78.70% is achieved by this inhibitor system. Potentiodynamic polarization technique reveals that the inhibitor system functions as a mixed type of inhibitor, controlling anodic and cathodic reactions. It is noted that in the presence of inhibitor, linear polarization resistance value increases and corrosion current decreases. Electrochemical impedance studies reveal that a protective film is formed on the Al steel surface, since in the presence of inhibitor system, the charge transfer resistance value increases and double layer capacitance value decreases. This is due to adsorption of the molecules of the active ingredients of the extract on the Al steel surface. The inhibition efficiency increases due to adsorption of hetero atoms present in TP plant leaves extract on the Al steel surface. The maximum inhibition efficiency and the lower corrosion rate are obtained at high concentration 1200 ppm for TP plant leaves extract. By further increase in inhibitor concentration above 1200 ppm, the inhibition efficiency and corrosion rate almost remained constant. So, the 1200 ppm concentration is fixed as the maximum inhibition for the investigative aqueous extract of plant leaves as corrosion inhibitor. This concentration corresponds to the attainment of a saturation value in surface coverage of Al steel. The protective film formed over the Al steel surface has been characterized by Fourier Transform infra-red spectroscopy. The surface morphology of the protective film of carbon steel immersed in sodium hydroxide in the absence and presence of inhibitor has been studied by Scanning electron microscopy. The outcome of the study can be used in pickling industry wherein sodium hydroxide is used to remove the rust on the Al steel surface.

Surface Modification of Pure Mg for Enhanced Biocompatibility and Controlled Biodegradation: A Study on Graphene Oxide (GO)/Strontium Apatite (SrAp) Biocomposite Coatings

Magnesium alloys have excellent biodegradability but suffer from high corrosion rates and unfavorable biological responses. Thus, a surface modification strategy to regulate the corrosion rate and enhance biocompatibility is required. In this study, pure Mg substrate surfaces were coated with strontium apatite (SrAp) and graphene oxide (GO) biocomposite structures using the hydrothermal method to increase the biocompatibility of the surface of the Mg and obtain a moderate biodegradation rate. The effect of the GO concentration (0, 2, 4, and 6 wt.%) on the surface microstructure and its corrosion behavior were systematically studied. The corrosion behavior of the coatings was characterized in-vitro using the electrochemical polarization method in Hank’s solution. An EDS-connected SEM was used to examine the coatings’ surface properties. The functional groups of the coatings were identified using ATR-IR spectroscopy. To determine the degree of crystallization and examine the elemental distribution of the coatings, an XRD was used with a grazing incidence attachment. The XRD and SEM-EDS results showed that increasing the GO ratio in the SrAp-based coatings significantly enhanced the homogeneity and crystallinity, and the ATR-IR spectroscopy revealed that the SrAp/GO coatings were rich in functional groups, including hydroxyl, phosphate, and carbonate groups, that are known to promote bone formation and regeneration. The results of the electrochemical polarization tests demonstrated a considerable decrease in the corrosion rates for the samples with SrAp matrix and GO coatings. Additionally, the coatings containing GO exhibited higher polarization resistance (Rp) values, indicating their potential as a promising surface modification technique for biodegradable implants. These findings suggest that incorporating GO into the SrAp coatings could enhance their biocompatibility and provide a moderate biodegradation rate, which is desirable for biomedical applications.

Impact of multi-pass friction stir alloying on the characterization of Mg based bio-ceramic nano composites

Multi-pass friction stir alloying is performed to incorporate bio-ceramic Nano-powders with MB3 magnesium alloy. The reinforcement bio-ceramic particles were hydroxyapatite (HA), tri-calcium phosphate (TCP) and aluminum oxide (Al2O3) Nano powders. The results revealed that the increased number of FSP passes caused a refinement in the grain structure, resulting in increasing average microhardness values in the stirred zone. Furthermore, all processed samples revealed tensile and yield strength values lower than that of the base material, with an enhancement in their ductility. While, the electrochemical impedance spectroscopy (EIS) results showed a higher radius capacitive loop of the 4-pass manufactured composites, and the best corrosion behavior was achieved at the 4-pass Mg-HA composite. Moreover, the potentiodynamic polarization (PDP) results showed lower current density with higher polarization resistance values (Rb) of the manufactured composites compared to the base material which reflects the improvement in the corrosion behavior. Moreover, the immersion test results displayed also lower corrosion rates of all processed samples, where the lowest corrosion rate was achieved at 4 passes Mg-HA composite with a reduction of about 27 % of the BM after 7 days of immersion in simulated body fluid (SBF).

Corrosion behavior of anodized Ti-Ta binary surface alloys in various physiological fluids for implant applications

In this study, corrosion-resistant surface-modified biometals were developed by coating titanium-tantalum alloy thin films onto titanium substrates, followed by anodization. These films were systematically investigated for their crystal structure, morphology, and microstructure. Electrochemical studies were carried out in 0.9% NaCl, PBS, and SBF. EIS data was evaluated using equivalent circuit models and a physical model is proposed to describe the corrosion process. The polarization resistance values suggest that the anodized Ti-Ta thin film alloy possesses favorable corrosion resistance properties, thereby indicating its potential for use in orthopedic applications.

Influence of A-Site Modifications on the Properties of La0.21Sr0.74−xCaxTi0.95Fe0.05O3−δ Based Fuel Electrode for Solid Oxide Cell

To make solid oxide fuel cell (SOFC) systems commercially attractive it’s essential to reduce manufacturing cost and improve the stability of membrane electrode assembly (MEA). In this research, the influence of A-site modification on electrical and electrochemical performance of 5% A-site deficient La0.21Sr0.74−xCaxTi0.95Fe0.05O3−δ (x = 0.26 − 0.69) (LSCTF5-x) hydrogen electrode has been studied. Results indicate that the magnitude of A-site deficiency and Ca concentration in A-site influence the conductivity, catalytic activity and stability of the electrodes considerably. The highest stability was observed in the case of La0.21Sr0.26Ca0.48Ti0.95Fe0.05O3−δ anode composition. The maximal total electrical conductivity of porous electrode layer made of LSCFT5-x was 3.5 S cm−1 at 850 °C characteristic of the La0.211Sr0.26Ca0.48Ti0.95Fe0.05O3−δ material in 97% H2 + 3% H2O atmosphere. The best electrochemical performance was observed in the case of La0.21Sr0.37Ca0.37Ti0.95Fe0.05O3−δ , which showed polarization resistance value equal to 0.44 Ω cm2 after 100 h of stabilization at 800 °C in humidified (1.7% H2O) H2 atmosphere. During the stability test the fuel cell with optimal anode composition 50 wt% La0.21Sr0.26Ca0.48Ti0.95Fe0.05O3−δ + 50 wt% Ce0.9Gd0.1O2-δ showed power density of 437 mW cm−2 at 850 °C in 98.3% H2 + 1.7% H2O atmosphere.

Multi-layer organic-inorganic hybrid anticorrosive coatings for protection of medium carbon steel

In the current study, sol-gel technology was used to produce organic-inorganic hybrid coatings onto AISI 1045 carbon steel as a means of corrosion protection. The organic-inorganic hybrid coatings were prepared using tetraethylorthosilicate (TEOS) and 3-(trimethoxysilyl)propyl methacrylate precursors. The coatings were thermally treated and the effect of temperature and time was studied. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated that the coatings possess homogeneous morphologies and that their thickness decreases with increasing heat treatment temperatures. At the highest treatment the coating was 20% thinner and more than 25% more scratch resistant compared with the untreated coating. According to thermalgravimetric analysis the coating mass loss was approximately 15% up to 150 °C and 2.7% between 150 and 400 °C. The electrochemical measurements, in 3.5% NaCl aqueous solution, determined that the coatings treated at 100 °C have polarization resistance values on the order of 60 kΩ cm2 after 72 h of exposure time in saline solution. The phase angle at high frequency (close to −90° at 103-105 Hz) demonstrated that the coating presented capacitive behavior related to less aggressive corrosion in this electrolyte. Further increasing the temperature beyong 100 °C reduced the performance of the coatings as demonstrated by a decrease of the polarization resistance by about one order of magnitude and the shift of the corrosion potential to more negative values.

Evaluation of perovskite-type contact paste materials for reversible solid oxide fuel cell stacks

At the electrode/interconnect interface in reversible solid oxide fuel cells (RSOFC), a contact paste is applied during stack fabrication. Careful selection of a contact paste material (CPM) is essential for improving the robustness of the RSOFC stack. For the successful industrialization of RSOFC technology, development of optimized CPM is required. Herein, three lanthanum-based perovskite compositions, LaNi0.6Fe0.2Cu0.2O3-δ (LNFCu), LaNi0.6Fe0.3Cr0.1O3-δ (LNFCr), and LaNi0.5Co0.2Cu0.3O3-δ (LNCCu) were investigated as air electrode CPMs employed in between Crofer 22 APU interconnect (IC) and La0.3Ca0.7Fe0.7Cr0.3O3-δ (LCFCr) electrode. More specifically, the three candidates were screened for thermal expansion coefficient (TEC), chemical compatibility with adjacent stack components, area specific resistance (ASR), and their performance as an air electrode CPM in a symmetrical LCFCr RSOFC. All three materials show good chemical compatibility with both the IC and LCFCr, excellent match of TEC with cell components, as well as markedly low ASR values. Most notably, from electrochemical impedance spectroscopy (EIS) study, LNFCr, and LNCCu CPMs exhibit polarization resistance values (Rp), at 800 °C, of ca. 0.83 Ω cm2, which is comparable to that of Au (0.63 Ω cm2), a material commonly regarded as the state-of-the-art. Of the three CPMs studied, it was concluded that LNFCr is the best candidate.

Experimental studies of the inhibitory effect of thiamazole on copper corrosion in near neutral 3% sodium chloride solution

As the unused drugs which are disgracefully arranged can contaminate the environment, a conceivable application of unused pharmaceutical compounds as corrosion inhibitors was successfully implemented, in this context thiamazole was assessed as a potential copper corrosion inhibitor in near neutral 3% sodium chloride solution. Electrochemical methods, surface and solution analysis are used to explore copper corrosion and its resistance. Corrosion of copper and its inhibition by thiamazole have been investigated in 3% NaCl solution using Potentiodynamic polarization, Electrochemical impedance spectroscopy, X-rays diffraction analysis, Scanning electron microscopy (SEM) along with Energy dispersive X-ray spectroscopy(EDX),contact angle measurements, Inductively Coupled Plasma (ICP) and Ion chromatography(IC).According to polarization measures, thiamazole works as a mixed type inhibitor. The values of polarization resistance and inhibition efficiency increase with thiamazole concentration increase, according to electrochemical impedance spectroscopy data. After 24 h immersion time of copper sheets in free amd containing thiamazole solution, it was revealed that thiamazole behave as mixed-type inhibitor with an efficiency of 97%. SEM/EDX investigations confirm that thiamazole forms a protective and hydrophobic layer on copper surface, this finding was assessed by contact angle (CA) tests; these results are further supported by XRD patterns that show the removal of crystalline corrosion products. The results of inductively coupled plasmasolution analysis and ionic chromatography demonstrate that in the presence of 10-4 M thiamazole in the investigated solution, the concentration of chloride increased while the concentration of copper (II) ions decreased.The outlined findings infer that the used molecule plays a role of an environmentally friendly corrosion inhibitor.

Structural, particle size distribution, and electrochemical behavior of double perovskite oxide doped Ce0.8Sm0.2O1.9 for intermediate temperature solid oxide fuel cells

Double perovskite SmBa0.5Sr0.5Co2O5+δ(70%)+Ce0.8Sm0.2O1.9(30%) as SBSC70+SDC30 cathode was fabricated using solid-state reaction technique and investigated as cathode material for solid oxide fuel cells operating at intermediate temperature (IT-SOFC). This work aims to determine the effect of SDC electrolyte doping into double perovskite cathodes on SOFC performance. LS-POP carried out particle size distribution analysis, and the equipment operates on a light source (HE-Ne laser) basis. XRD was used to determine the structure of the cathode powder, and SEM was used to analyze the microstructure morphology. Symmetrical cells were tested using a potentiostat Voltalab PGZ 301. The distribution of particle size for the SBSC70+SDC30 cathode was in the range of 1.41-2.03 µm. The polarization resistance (Rp) value of SBSC70+SDC30 cathode decreases with increasing temperature from 1.22 cm2 at 600°C to 0.21 cm2 at 800°C. The SBSC70+SDC30 activation energy (Ea) for Rp was 117. 3 kJ mol−1. From the overall results, double perovskite SBSC70+SDC30 cathode has potential as a cathode of medium temperature SOFC cells.

An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates

A study of the corrosion behaviour of T91 steel in molten 60 wt% NaNO3-40%KNO3 has been carried out at 300, 400 and 500 °C during 1000 h. Employed techniques included potentiodynamic polarization tests, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. Experiments were complemented by detailed scanning electronic measurements and X-ray diffraction studies. Polarization curves revealed the existence of a passive layer formed onto the steel, composed mainly of Cr2O3, FeCr2O4, NaCrO4 and K2Fe2O4. Corrosion current density values increased, whereas the polarization resistance value decreased more than one order of magnitude as the testing temperature increased. EIS tests indicated a charge transfer controlled corrosion process, regardless of the testing temperature, and that the double electrochemical layer resistance decreased with the temperature.

Electrophoretic deposition of dense anode barrier layers of doped ZrO2 and BaCeO3 on a supporting Ce0.8Sm0.2O2-δ solid electrolyte: Problems and search for solutions in SOFC technology

This work is aimed at the formation of dense anode coatings of yttria-stabilized zirconia (YSZ) and samarium-doped barium cerate BaCe0.8Sm0.2O3-δ (BCS) on the Ce0.8Sm0.2O2-δ electrolyte to increase the performance of a single fuel cell on its base. Materials are obtained by precipitation from a nitrate solution (YSZ-disp), by laser vaporization-condensation (YSZ-lec) and citrate-nitrate method (BCS). YSZ and BCS coatings on SDC substrates were obtained by electrophoretic deposition (EPD) followed by sintering at 1300–1500 °C. Two methods are applied to ensure surface conductivity of the SDC substrates for successful EPD: by synthesizing a conducting polymer - polypyrrole and by depositing a buffer layer of finely dispersed Pt. The main problem of the formation of the dense YSZ layers on the SDC substrates has been revealed, which is associated with their delamination during high-temperature sintering due to thermal expansion mismatch. It is shown that the use of a Pt buffer sublayer makes it possible to avoid delamination during sintering at a temperature of 1500 °C. The BCS barrier layers are shown to be completely compatible with SDC. The influence of the YSZ and BCS barrier layers on the ohmic and polarization resistance values and the open circuit voltage (OCV) values is discussed.

Influence of pulse current on the electrodeposition behaviors of CaCO3 scale in the industrial circulating water system

The deposition of the CaCO3 crystals in circulating cooling water is crucial to industrial water softening, which is beneficial to avoiding internal scaling and improving production efficiency. This paper focuses on the practicability of electrochemical techniques to analyze the influence of pulse current on the electrodeposition of CaCO3 in blank and high salinity conditions, including linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy tests. We assessed the coverage and compactness of the CaCO3 scale layer by obtaining residual current density (ir) and polarization resistance (Rp) values. Electrochemical results revealed that pulse electrodeposition can generate a more compact CaCO3 scale layer by Ostwald ripening, while the salt effect of NaCl can inhibit the nucleation and growth of CaCO3 crystals. Scanning electron microscope and X-ray diffractometer tests showed that unstable CaCO3 crystals can be dissolved and the size of calcites had changed with Ostwald ripening. Longer pulse-off time is beneficial to Ostwald ripening of CaCO3 crystals and nucleation in the first and second periods can influence the size of calcites formed under pulse current.

Magnesium-zinc-graphene oxide nanocomposite scaffolds for bone tissue engineering

The aim of this study was to fabricate and evaluate magnesium-zinc-graphene oxide nanocomposite scaffolds for bone tissue engineering. For this reason, Mg-6Zn, Mg-6Zn-1GO, and Mg-6Zn-2GO scaffolds were fabricated by the powder metallurgy method. The porosity level and also the pore size of the scaffolds were evaluated by SEM which varied from 40 to 46% and 200 to 500 μm, respectively. The chemical composition and microstructure of the scaffolds were characterized by XRD and SEM equipped with EDS; the presence of Mg, Zn, C, and O elements in the structure of the scaffolds was shown. Also, the elemental map confirmed the existence of magnesium, zinc, carbon, and oxygen in the structure of the scaffold. The mechanical properties of the scaffolds were investigated by the compression test; the results showed that by the addition of graphene oxide to the structure, the compressive strength of the samples increased from 5 to 8 MPa. Electrochemical corrosion polarization tests were conducted to evaluate the corrosion resistance of the samples immersed in simulated body fluid (SBF). Furthermore, the biodegradability of the scaffolds was determined by immersion of the samples in phosphate-buffered saline (PBS). The results demonstrated that the polarization resistance value and the corrosion rate for different formulations including Mg-6Zn, Mg-6Zn-1GO, and Mg-6Zn-2GO were 41.58, 35.48, and 55.40 Ω.cm2 followed by 10.60, 14.83, and 9.06 mm.year−1, respectively. Based on the results, the Mg-6Zn-2GO formulation presented the best corrosion resistance among the samples were investigated, which confirmed the results of the immersion test. Moreover, the MTT assay proved that the extract of Mg-6Zn-2GO scaffolds was not cytotoxic in contact with L-929 cells which validated the studied scaffolds for bone tissue applications.

Stabilization of the cubic perovskite La0.8Pr0.2BaCo2-yO6-δ by introducing Co deficiency and its effect on thermal expansion, electrical conductivity and electrochemical properties

The effects of B site deficiency on crystal structure, phase relationships, surface and high temperature properties of the cubic perovskite La0.8Pr0.2BaCo2-yO6-δ (0.00 ≤ y ≤ 0.10) have been studied. From X-ray diffraction data the single cubic perovskite phase was obtained for the Co range 0.00 ≤ y ≤ 0.05. X-ray photoelectron spectroscopy (XPS) measurements indicated the presence of Co3+ and Pr3+ and confirmed a lower Co content for the y = 0.05 sample. High temperature X-ray diffraction and dilatometry revealed the formation of secondary phases related to CoOx compounds. The introduction of Co deficiency (y = 0.02 and 0.05) at the B site prevents the formation of these secondary phases while the crystal structure remains cubic. The polarization resistance values for the oxygen reduction reaction in La0.8Pr0.2BaCo2-yO6-δ (0.00 ≤ y ≤ 0.05) electrodes were as low as 0.05 Ω cm2 at 600°C. The impedance spectra as a function of T and pO2 reveal two arcs reproduced with (R, CPE) elements. The variation of the polarization resistance (Rp) with pO2 was analyzed by using the power law. For the low frequency contribution, 0.1 ≤ ν ≤ 3 Hz, the parameter n ∼ -1, corresponds to the oxygen molecule diffusion through the porous of the electrode. For the contribution at higher frequencies, 5 ≤ ν ≤ 500 Hz, the parameter n was in the range -0.17 ≤ n ≤ -0.33, which indicates the main rate-limiting process is the oxygen exchange at the surface of the electrode. The rate of change of Rp with time for the Co-deficient electrodes, 1RpdRpdt∼6×10−4h−1, was found to be slightly slower than that obtained for the stoichiometric sample.

Battery SOH Prediction Based on Multi-Dimensional Health Indicators

Battery capacity is an important metric for evaluating and predicting the health status of lithium-ion batteries. In order to determine the answer, the battery’s capacity must be, with some difficulty, directly measured online with existing methods. This paper proposes a multi-dimensional health indicator (HI) battery state of health (SOH) prediction method involving the analysis of the battery equivalent circuit model and constant current discharge characteristic curve. The values of polarization resistance, polarization capacitance, and initial discharge resistance are identified as the health indicators reflective of the battery’s state of health. Moreover, the retention strategy genetic algorithm (e-GA) selects the optimal voltage drop segment, and the corresponding equal voltage drop discharge time is also used as a health indicator. Based on the above health indicator selection strategy, a battery SOH prediction model based on particle swarm optimization (PSO) and LSTM neural network is constructed, and its accuracy is validated. The experimental results demonstrate that the suggested strategy is accurate and generalizable. Compared with the prediction model with single health indicator input, the accuracy is increased by 0.79%.

Effect of temperature on anti-corrosion properties of aluminum alloy anodized by sulphuric acid

Temperature is one of the most important parameters in anodizing treatments of aluminum alloys as it directly affects the quality of the anodic coatings. This research study has examined and investigated the effect of this important parameter on the anti-corrosion properties of the anodizing layers of aluminum alloy 5083.The morphology and crystalline structure of anodic oxide layers were characterized respectively by X-ray diffraction, scanning lectron microscopy and EDX analysis. The corrosion behaviour of the alloy, before and after anodization at different temperatures, was analyzed in chlorinated medium using different electrochemical techniques, namely open circuit potential measurement, potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that temperature has a significant influence on the quality of the anodic oxide layers. Therefore, for a relatively low treatment temperature, the developed anodic films show high surface roughness values and contain fewer pores and defects compared to the films obtained at 20°C. Electrochemical analysis indicates that these films also show good corrosion resistance in the chloride environment. This is reflected by relatively low corrosion current density values as well as relatively high polarization resistance values.