Ion Diffusion Coefficient Research Articles

Durable Perovskite Solar Cells with 24.5% Average Efficiency: The Role of Rigid Conjugated Core in Molecular Semiconductors.

Efficient and robust n-i-p perovskite solar cells necessitate superior organic hole-transport materials with both mechanical and electronic prowess. Deciphering the structure-property relationship of these materials is crucial for practical perovskite solar cell applications. Through direct arylation, two high glass transition temperature molecular semiconductors, DBC-ETPA (202°C) and TPE-ETPA (180°C) are synthesized, using dibenzo[g,p]chrysene (DBC) and 1,1,2,2-tetraphenylethene (TPE) tetrabromides with triphenylene-ethylenedioxythiophene-dimethoxytriphenylamine (ETPA). In comparison to spiro-OMeTAD, both semiconductors exhibit shallower HOMO energy levels, resulting in increased hole densities (generated by air oxidation doping) and accelerated hole extraction from photoexcited perovskite. Experimental and theoretical studies highlight the more rigid DBC core, enhancing hole mobility due to reduced reorganization energy and lower energy disorder. Importantly, DBC-ETPA possesses a higher cohesive energy density, leading to lower ion diffusion coefficients and higher Young's moduli. Leveraging these attributes, DBC-ETPA is employed as the primary hole-transport layer component, yielding perovskite solar cells with an average efficiency of 24.5%, surpassing spiro-OMeTAD reference cells (24.0%). Furthermore, DBC-ETPA-based cells exhibit superior operational stability and 85°C thermal storage stability.

The effect of copper doping in α-MnO2 as cathode material for aqueous Zinc-ion batteries

Copper-doped Manganese Dioxide has been synthesised through a simple hydrothermal method at different doping levels. The synthesised materials have been characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) to determine the composition, structure, and morphology. All the Cu doped MnO2 are found to be single phased. Their electrochemical properties as cathode for Zinc-ion batteries are studied by cyclic voltammetry (CV), galvano-static charge / discharge (GCD) and electrochemical impedance spectroscopy (EIS), using 3 M ZnSO4 + 0.3 MnSO4 solution as the electrolyte. 3.8% Cu doped MnO2 has shown the highest initial capacity of 379.5 mAh g−1 at 0.02 A·g−1, and 304.4 mA h g−1 at 0.5 A g−1, but experienced fast fading with a poor capacity retention of 56.8% after 100 cycles. 7.4% Cu doping gives lower capacity, while 5.9% doping shows a higher discharging capacity (320.0 mAh·g−1 at 0.02 A·g−1 and 269.3 mAh·g−1 at 0.5 A·g−1) and improved stability (85.8% capacity retention after 100 cycles), better than non-doped MnO2 electrode (284.4 mAh g−1 at 0.02 A g−1 and 252.1 mAh·g−1 at 0.5 A g−1, capacity retention 76.7%). The samples show satisfactory capacity and rate capability while the cycling stability is not ideal, which may relate to the needle like morphology and nanoscale particle size. CV tests revealed that the electrochemical process is mainly diffusion controlled. The zinc ion diffusion coefficient is tested to be in the range of 10−12 cm2·s−1 from both CV and EIS tests and showed the same trend in their electrochemical capacity. Doping of Copper in MnO2 reduced the polarization on electrode, improved the electrochemical reversibility, as evidenced by the reduction of the redox peak potential difference from 0.31 to 0.24 V at 1.1 mV·s−1, and from 0.45 V to 0.31 V at 5 mV·s−1. Whilst the cell resistance of non-doped MnO2 increased from 1.78 Ω to 7.39 Ω after cycling, the cell resistances of all Cu-doped cathodes reduced, indicating improved electronic conductivities after cycling. These results indicate that Cu-doping is effective to increase the conductivity of the materials, reduce the polarization during charge and discharge, and improve the cycling stability of MnO2 cathode.

Enhanced diffusion kinetics in Y-doped SnO2 anodes for low-temperature lithium-ion batteries: A combined theoretical and experimental study

In recent years, there has been an increasing demand for lithium-ion batteries suitable for low temperatures in various fields. SnO2, with its high theoretical specific capacity, has emerged as an ideal candidate for low-temperature lithium-ion batteries. However, tin oxide exhibits inherent issues such as poor conductivity and limited cycle reversibility. Enhancing the diffusion rate of lithium ions in tin oxide is crucial for improving its low-temperature performance. We use first-principles calculations based on Density Functional Theory (DFT) to investigate the doping models of various transition metal elements (Sc, Y, Ti, Zr, V, Nb, Gr, Mo, Mn, Fe, Co, Ni) with a rational ratio of 4 % in SnO2. The results indicate that Y doping decreases the band gap of SnO2 by 0.253 eV, leading to a significant reduction in the Li-ion diffusion barrier of α-Sn. Furthermore, the synthesized SnO2 doped with Y (Y-SnO2) electrode exhibited excellent cyclic stability as an anode and achieved a high reversible capacity of 672 mAh g−1 at −10°C, surpassing that of the pure SnO2 (450 mAh g−1). Moreover, it demonstrated a higher diffusion coefficient of lithium ions and lower charge transfer impedance at both low and room temperatures.

Pillar[5]arene-supported viologen networks with enhanced rate capability and cycling stability for rechargeable organic batteries

Organic redox-active compounds are promising alternatives to traditional inorganic counterparts because of their sustainable resources and highly tunable properties. However, their solubility in organic electrolyte solvents and the sluggish electrode reactions hinder their further development. Herein, an intrinsically microporous decabromopropyl pillar[5]arene (P5Br) was used to support the methyl viologen (MV) functionality to yield two non-crosslinked and crosslinked organic electrode materials, namely MV-P5Br and CMV-P5Br, respectively. When evaluating against Li metal counter electrode, the MV-P5Br and CMV-P5Br electrodes delivered high discharge capacities of 87.9 and 92.7 mAh g−1 at 0.1 C, respectively, which are close to their theoretical values. After galvanostatic cycling at 0.1 C for 100 cycles, the CMV-P5Br electrode maintained a discharge capacity of 82.3 mAh g−1, much higher than the 43.7 mAh g−1 of the MV-P5Br electrode. When the current rate was increased to 10 C, the CMV-P5Br electrode delivered a discharge capacity of 60.7 mAh g−1, also higher than the 41.3 mAh g−1 of the MV-P5Br electrode. The increased cycling stability and rate performance of the CMV-P5Br electrode were attributed to the diminished solubility and the enhanced ion diffusion coefficient of the active material. When the counter electrode was changed to Na metal, similar results were obtained, suggesting that the CMV-P5Br electrode can also be used in Na-ion systems. This study demonstrates that the combination of crosslinked and microporous structure is highly effective to boost the electrochemical performance of organic redox-active compounds for rechargeable batteries.

The impact of membrane orientation on ion flux in bipolar membranes

Bipolar membranes (BPMs) are asymmetric, layered ion exchange membranes that are increasingly being explored for use in electrochemical devices. This study aims to investigate the effect that the direction of a diffusive driving force across a salt solution concentration gradient has on the flux through a BPM due to its asymmetric nature. BPMs were fabricated using PiperION poly(aryl piperidinium) A40 as the anion exchange layer (AEL) and Nafion 212 as the cation exchange layer (CEL) with no interfacial junction catalyst. The permeability of sodium chloride through the BPM membranes was measured across a 0.5molL-1 concentration differential for both orientations of the membrane, e.g. AEL facing the 0.5molL-1 NaCl solution versus the CEL facing the 0.5molL-1 NaCl solution. A flux differential of (76.3 ± 4.8)% was measured for the BPM depending on the direction of the driving force. A model based on Fick’s law and the Donnan equilibrium was developed and used to show that the flux differential results from changes in the ionic environment at the AEL–CEL junction due to differences in the ion diffusion coefficients and fixed charge concentrations of the two layers.

Femtosecond laser fabrication of 3D vertically aligned micro-pore network on thick-film Li4Ti5O12 electrode for high-performance lithium storage

The development of energy storage devices with high energy density relies heavily on thick film electrodes, but it is challenging due to the limited ion transport kinetics inherent in thick electrodes. Here, we report on the preparation of a directional vertical array of micro-porous transport networks on LTO electrodes using a femtosecond laser processing strategy, enabling directional ion rapid transport and achieving good electrochemical performance in thick film electrodes. Various three-dimensional (3D) vertically aligned micro-pore networks are innovatively designed, and the structure, kinetics characteristics, and electrochemical performance of the prepared ion transport channels are analyzed and discussed by multiple characterization and testing methods. Furthermore, the rational mechanisms of electrode performance improvement are studied experimentally and simulated from two aspects of structural mechanics and transmission kinetics. The ion diffusion coefficient, rate performance at 60 C, and electrode interface area of the laser-optimized 60-15% micro-porous transport network electrodes increase by 25.2 times, 2.2 times, and 2.15 times, respectively than those of untreated electrodes. Therefore, the preparation of 3D micro-porous transport networks by femtosecond laser on ultra-thick electrodes is a feasible way to develop high-energy batteries. In addition, the unique micro-porous transport network structure can be widely extended to design and explore other high-performance energy materials.

Effect of nano-metakaolin on the chloride diffusion resistance of cement mortar with addition of fly ash

This study examines the improvement of nano-metakaolin (NMK) on the chloride ion diffusion resistance (CDR) of fly ash (FA) cement-based materials. The rapid chloride diffusion (RCM) method was employed to compare the effects of nano Al2O3, nano CaCO3, nano SiO2, nano attapulgite clay, and NMK on the CDR of cement mortar, and a suitable nanomaterial was identified. Subsequently, the influence of NMK on the CDR, flexural and compressive strengths of FA cement mortar was examined. The chloride ion concentration of NMK/FA cement paste under simulated salt environment were measured. The action mechanism of NMK on the CDR of FA cement mortar was explored through mercury intrusion porosimetry and scanning electron microscopy tests. The results reveal that among these nanomaterials, NMK exhibited the highest cost-effectiveness in enhancing CDR of cement mortar, with a suitable content of 5 wt%. NMK demonstrated a significant improvement in the CDR of FA cement mortar, particularly at a hydration age of 7d. Incorporating 5 wt% NMK into the cement mortar with addition of 30 wt% FA resulted in a 73% reduction in chloride ion diffusion coefficient (Dcl) compared to the cement mortar with the addition of 30 wt% FA at 7d. NMK enhances both flexural and compressive strengths of FA cement mortar at various hydration ages (3, 7, 14, 28 d). The addition of 5 wt% NMK makes a increment of about 10% for the flexural strength of cement mortar with 30 wt% FA at 7d. Moreover, NMK results in a denser internal structure of FA cement mortar, facilitates the generation of C–S–H gel, and reduces the more-harmful pores and harmful pores while increasing harmless and of less-harmful pores cement paste. Additionally, NMK exhibited the most substantial reduction in chloride ion concentration within FA cement paste at 7d. In general, NMK significantly enhances CDR, flexural and compressive strengths of FA cement mortar, especially at a hydration age of 7d.

Non-destructive characterization of pore structure and chloride diffusion coefficient of cementitious materials with modified non-contact electrical resistivity method

The intricate pore structure of cement-based materials passively influences chloride ion transport and mechanical properties. Existing non-contact electrical resistivity measurement (NC-ERM) methods lack precision for rigorous studies. the NC-ERM was upgraded in this research, which is suitable for assessing the pore structure and transport characteristics of hardened cementitious substrates. The results obtained from this method closely correspond to those obtained from CEMHYD3D, Mercury intrusion porosimetry (MIP), and other methods. Additionally, the impact of mixture proportions on the resistivity, pore structure parameters, and chloride ion diffusion coefficient of cementitious materials is discussed. With an increase in sand ratio and sand-to-stone ratio, the resistivity exhibits an initial rise followed by a decline. Chloride diffusion of 5 wt% NaCl-saturated specimens is 1.2–1.3 times higher than 3.5 wt% NaCl. This study provides a novel non-destructive, convenient and accurate method for characterising the pore structure and testing the transport properties of cementitious materials.

Vinasse-based hard carbon: Preparation and study on its compatibility with ester/ether-based electrolyte for sodium ion storage

In this work, a simple method was used to prepare vinasse based hard carbon (HC) for sodium ion storage. The interlayer spacing and closed pore structure of the materials were regulated by different pyrolysis temperature, and the electrochemical evaluations were conducted in ether-based and ester-based electrolytes, respectively. The initial coulombic efficiency (ICE) of 91.1 %, capacity retention rate of 63.1 % at high rate of 10 A g-1 (platform capacity of 121.7mAh g-1), and ultra-long cycle stability of 93.7 % after 8000 cycles at 5 A g-1 fully shows better compatibility in the ether-based electrolyte. The coordination number, de-solvation energy, and diffusion rate of Na+ in the two electrolytes were simulated and calculated by molecular dynamics (MD) combined with density functional theory (DFT). It was elucidated that Na+ partially co-embeds in ether-based electrolytes, avoiding slow de-solvation processes, in addition, when Na+ is embedded alone, it has a lower de-solvation free energy than that in ester-based electrolytes, therefore, the ion diffusion coefficient obtained in ether-based electrolytes is above three times than that in ester-based electrolytes. The ultrafast dynamics achievements excellent rate performance and cycling stability for the sample of optimal structure. This research has a promoting effect on the commercial application of biomass-based hard carbon for sodium ions storage.

Chloride ion permeability of concrete containing recycled composite powder from building demolition waste

Buildings in the marine environment are vulnerable to chloride ion erosion, which threatens the service life of concrete structures. To facilitate the application of concrete containing construction demolition waste in the marine environment, recycled composite powder concrete (RCPC) was prepared using recycled composite powder as cement substitute. The chloride ion permeability of RCPC was evaluated by chloride ion diffusion test and rapid chloride ion migration test (RCM). The chloride ion permeability of RCPC continued to enhance with growing content of recycled composite powder. During the immersion age, the surface chloride ion content of the samples containing recycled composite powder increased by an average of 18.3–65.3% over the control group, with a corresponding average increase in chloride ion diffusion coefficients ranging from 17.0% to 31.5%. The chloride ion migration coefficients in the RCM test raised by 9.5–24.7%. A series of microscopic tests such as nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS) suggested that the total porosity increased by 11.9–29.5% with the addition of recycled composite powder. The chloride ion diffusion coefficients exhibited a linear increase with growing total porosity and porosity of capillary pores, whereas an exponential increase with the porosity of transitional pores. The poor reactivity of the recycled composite powder resulted in a looser microstructure and weakened chloride binding capacity, and these factors boosted chloride ion transport. A chloride ion diffusion model of RCPC considering the time dependence of chloride ion transport was developed, and the reliability of the model was verified by experimental data.

Preparation of Na3V2(PO4)3 Cathode Materials by Hydrothermal Assisted Sol-Gel Method for Sodium -Ion Batteries

Na3V2(PO4)3 (NVP) cathode material of the sodium ion battery (1 C=117 mAh g-1) has a NASICON-type structure, which not only facilitates the rapid migration of sodium ions, but also has a small volume deformation during sodium ion de-intercalation and the main frame mechanism remains unchanged, and thus is seen as an energy storage material for a wide range of applications, but has a limited electronic conductivity due to its structure. In this paper, NVP cathode materials with finer primary particles are successfully prepared using a simple hydrothermal treatment-assisted sol-gel method. The increased pore size of the NVP materials prepared under the hydrothermal process allows for more active sites and more effective resistance to the volume deformation of sodium ions during insertion/extraction processes, effectively facilitating the diffusion of ions and electrons. The Na3V2(PO4)3 material obtained by the optimized process exhibited good crystallinity in XRD characterization, as well as superior electrochemical properties in a series of electrochemical tests. A specific capacitance of 106.3 mAh g-1 at 0.2 C is demonstrated, compared to 96.5 mAh g-1 for Na3V2(PO4)3 without hydrothermal treatment, and cycling performance is also improved with 93% capacity retention. The calculated sodium ion diffusion coefficient (DNa = 5.68 × 10-14) obtained after EIS curve fitting of the improved sample illustrates that the pore structure is beneficial to the performance of the Na3V2(PO4)3 cathode material.

Relationship between chloride ingress and concrete cover quality of inland structures exposed to deicing salts

The apparent diffusion coefficient of chloride ions is used to evaluate the durability of existing concrete structures against chloride attack. The coefficient requires in situ measurements of chloride profiles, which use destructive sampling techniques, such as core drilling. In this study, the relationship between the apparent diffusion coefficient of chloride ions obtained from destructive tests and the air-permeability coefficient obtained from a non-nodestructive Torrent method in the existing road bridges exposed to deicing salts was analyzed. The obtained relationship was different from the common trends obtained from laboratory chloride-immersion tests and in situ measurements in marine/coastal concrete structures. Additional cyclic wetting and drying tests in a laboratory revealed the effects of environmental differences on the apparent diffusion coefficient of chloride ions. A higher ratio of the drying period, in the case of deicing salts, reduced the apparent diffusion coefficient.

Multiscale modeling of smectite illitization in bentonite buffer of engineered barrier system

With the increasing usage of nuclear energy, how to properly dispose nuclear waste becomes a critical issue. In this study, a multiscale modeling approach combining the experimental findings is presented to address the illitization process, its impact on transport properties, and system behavior of bentonite buffer in engineered barrier systems (EBS). Through the pore-scale modeling, reactive transport properties such as illite generation rate and effective diffusion coefficient of potassium ion as a function of porosity and temperature are quantified by employing the findings of hydrothermal reaction experiments of Bentonil-WRK. The capability of pore-scale modeling has been developed based on the Darcy-Brinkmann-Stokes equation, involving the processes of smectite illitization and clay swelling. Obtained reactive transport properties are utilized as input parameters for the macroscale modeling to predict the long-term behavior of bentonite buffer in EBS. As such, this study involves the whole workflow of quantifying the reaction parameters of smectite illitization through the hydrothermal reaction experiments, and numerically modeling the reactive transport process of smectite illitization in bentonite buffer of EBS from pore-scale to macroscale. The presented multiscale modeling findings are expected to provide reliable solution for safe nuclear waste disposal with EBS.

High‐Areal‐Capacity and Long‐Cycle‐Life All‐Solid‐State Lithium‐Metal Battery by Mixed‐Conduction Interface Layer

AbstractThe rapid growth of lithium dendrites has seriously hindered the development and practical application of high‐energy‐density all‐solid‐state lithium metal batteries (ASSLMBs). Herein, a soft carbon (SC)‐nano Li6.4La3Zr1.4Ta0.6O12 (LLZTO) (with high ionic conductivity and diffusion coefficient) mixed ionic and electronic conducting interface layer is designed to promote the rapid migration of Li+ at the interfacial layer, induce the uniform deposition of lithium metal on nanoscale (nano) LLZTO ion‐conducting network inside the interface layer, effectively suppress the growth of lithium dendrites, and significantly improve the electrochemical performance of ASSLMBs. LiZrO2@LiCoO2(LZO@LCO)/Li6PS5Cl(LPSCl)‐nano LLZTO/Li ASSLMB achieves high current density (12.5 mA cm−2), ultra‐high areal capacity (15 mAh cm−2, corresponding to LZO@LCO mass loadings of 111.11 mg cm−2), and ultra‐long cycle life (20 000 cycles). Therefore, the introduction of SC‐nano LLZTO mixed conducting interface layer can greatly improve the interfacial stability between solid‐state electrolyte (SSE) and lithium metal anode to enable dendrite‐free ASSLMBs.

Structure and electrochromic properties of polypyrrole films synthesized by AC electrochemical impedance spectroscopy under different amplitude

Alternating current (AC) electrochemical impedance spectroscopy (EIS) was employed to synthesize polypyrrole (PPy) electrochromic films on fluorine-doped tin oxide (FTO) transparent conductive glasses. When depositing the PPy films, a fixed initial voltage was 700 mV and AC of different amplitudes was applied. The influence of AC voltage amplitude on the structure and electrochromic performance of PPy films was investigated. Scanning electron microscope (SEM) observation reveals that the PPy films prepared under AC are composed of uniform-distributed nanospheres when the AC amplitude is below 400 mV, which is different from the submicron structure displayed by PPy films prepared under direct current (DC). This kind of nanospherical structure is helpful to ion transport, resulting in improved electrochromic properties of the PPy films prepared under AC compared with the PPy film prepared under DC. In particular, the PPy film prepared under 100 mV amplitude AC shows ideal electrochromic properties, with an ion diffusion coefficient of 8.13 × 10−10 cm2·s−1, a coloring efficiency of 137.4 cm2·C−1, quick coloration and bleaching switching times of 5.0 s and 6.5 s, respectively, and retains 65.7% of its optical modulation after 100 cycles.

Determination of the Diffusion Coefficient in Electrodeposition Reactions by Electrochemical Impedance Spectroscopy: A Case Study of Cobalt in Molten LiCl-KCl Salt

Compared to direct current (DC) techniques, electrochemical impedance spectroscopy (EIS) allows for a more accurate determination of the diffusion coefficient of metal ions in electrodeposition reactions. However, its actual application has been less attempted due to the difficulty in determining complex parameters, such as the concentration of deposited species in the electrode matrix. Here, we introduce a simplified approach to facilitate the EIS application to electrodeposition reactions, using the Co(II)/Co(0) reaction in molten LiCl-KCl salt as a case study. The working electrode surface area was determined by the photography of the electrochemical cell taken in situ. The diffusion coefficients of Co(II) in the LiCl-KCl salt, determined by EIS, were found to be (3.56 ± 0.49) × 10−5 cm2/s and (1.61 ± 0.12) × 10−5 cm2/s for the tungsten and liquid bismuth electrodes, respectively. The possible reasons for the observed discrepancy in the diffusion coefficients of Co(II) obtained from the two different electrodes were discussed.

Electrochromic nickel-oxide-based thin films in KOH electrolyte: Ionic and electronic effects elucidated by impedance spectroscopy

Ni-oxide-based thin films, prepared by sputtering, are investigated by electrochemical impedance spectroscopy in a KOH electrolyte. The films are electrochromic, and an increase of the applied potential leads to a variation from a bleached to a colored state as a result of proton (H+) extraction together with extraction of electrons from the valence band. The complex frequency-dependent impedance displays different features in different potential ranges. At low potentials, where coloration is weak, the spectra give evidence for a constant-phase element in parallel with a leak resistance. At intermediate and high potentials, the impedance spectra indicate the presence of a diffusion process, and a model for anomalous diffusion gives excellent fits to the spectra except in a crossover region. The applicability of this model in a significant part of the studied potential range suggests the presence of a multiple-trapping process for the ions. The potential dependence of the chemical capacitance, as well as the diffusion coefficient of un-trapped ions, are analyzed. The electrochemical density-of-states of the charge-compensating electrons gives indications of the top of the valence band and of a band tail extending into the band gap. Diffusion coefficients are found to increase steeply in the crossover potential region to very high values at high potentials. These features are discussed and related to the electrochromic behavior of Ni-oxide-based thin films.

Effectiveness of Biological Mortars with Bacterial Glycocalyx on Service Life of Concrete Structures Exposed to Salt Attack

This study investigated the effectiveness and limitations of newly developed biological mortars regarding chloride ion diffusion resistance. Through several tests on the glycocalyx production capacity and growth potentials of bacteria cells under marine environments, Bacillus licheniformis was isolated and immobilized in the expanded vermiculites together with a bacterial culture medium for producing biological mortars. The chloride ion diffusion coefficient of the mortars up to 91 days was determined through natural diffusion cell tests. Subsequently, the service life of RC structure repaired with biological mortars under chloride attack was evaluated considering multilayer theory and time-dependent diffusion. The addition of expanded vermiculites immobilizing Bacillus licheniformis significantly reduced the chloride ion diffusion coefficient. When its addition increased from 10 to 30%, the chloride ion diffusion coefficient decreased by 50–90% compared to that of mortars without bacteria. The service life of reinforced concrete structures repaired with biological mortars containing 30% expanded vermiculite concentration and thickness of 50 mm was evaluated to be six times longer than that of repaired with conventional mortar. Overall, this novel approach holds significant potential in addressing the salt-induced deterioration challenges faced by RC structures.

Corrosion Resistance of Shotcrete under the Influence of Salt Solutions

The article describes the relevance of new scientific research on the corrosion resistance of shotcrete applied as a protective coating on building structures. A formulation has been developed for five compositions of shotcrete, consisting of a basic and additional binder, fillers and hardening accelerators. The size and nature of the pores of the manufactured samples, the development of destruction by changes in mass and strength are investigated. The physicochemical features of the corrosive destruction of some shotcrete compositions in solutions of sodium sulfate and sodium chloride have been established, and the diffusion coefficients of chloride ions and sulfate ions have been determined. The numerical values of the parameters limiting the mass transfer of calcium hydroxide during corrosion of shotcrete are determined: the coefficients of mass conductivity and mass transfer.

Experimental Study on the Effect of Corrosion-inhibiting Admixtures on Chloride Corrosion Resistance of Concrete

Compared to the different types of rust inhibitors, The effects of the internal and external coating corrosion inhibitors on the corrosion resistance of concrete were studied. The impact of the mixed rust inhibitor on the working performance, compressive strength and chloride ion permeability coefficient of concrete was investigated. The results show that the working performance, late mechanical properties, and resistance to chlorine salt erosion of concrete are better than those of reference concrete after adding the anti-rust agent. Comparing the effects of 2% and 4% internal rust inhibitors on the corrosion resistance of chloride ions, based on the control group, the chloride ion diffusion coefficient of concrete with 2% and 4% rust inhibitors decreases to the original 15.1% and 37.0%, respectively. Concrete’s chloride ion diffusion coefficient with external rust inhibitor decreases to 62.5%. In addition, the internal corrosion inhibitor has a specific water-reducing component, which reduces the water consumption of concrete and improves the compactness of concrete itself, thus improving the corrosion resistance of concrete.