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Linear polarization is a potentiodynamic method used for electrochemical characterization of materials. Obtained values of corrosion potential and corrosion current density offer information about material behavior in corrosion environments from the thermodynamic and kinetic points of view, respectively. The present study offers a comparison of applications of the linear polarization method (from −100 mV to +200 mV vs. EOCP), the cathodic polarization of the specimen (−100 mV vs. EOCP), and the anodic polarization of the specimen (+100 mV vs. EOCP), and a discussion of the differences in the obtained values of the electrochemical characteristics of cast AZ91 magnesium alloy. The corrosion current density obtained by cathodic polarization was similar to the corrosion current density obtained by linear polarization, while a lower value was obtained by anodic polarization. Signs of corrosion attack were observed only in the case of linear polarization including cathodic and anodic polarization of the specimen.

The effects of cathodic polarisation switch-off on the passivation of AISI 304L stainless steel in air and its crevice corrosion susceptibility in 3.5 wt.% NaCl aqueous electrolyte were investigated. Scanning Kelvin probe (SKP) data showed that the oxide film is significantly destabilised and the rate of steel passivation in air is slowed down. Thermal desorption analysis (TDA) highlighted that hydrogen absorption is proportional to the applied cathodic current density. A special crevice corrosion set-up was designed to realise simultaneous reproducible monitoring of potential and galvanic current to study the impact of prior cathodic polarisation on crevice corrosion onset.

Electrochemical reduction of CO₂ using renewable sources of electrical energy holds promise for converting CO₂ to fuels and chemicals. Since this process is complex and involves a large number of species and physical phenomena, a comprehensive understanding of the factors controlling product distribution is required. While the most plausible reaction pathway is usually identified from quantum-chemical calculation of the lowest free-energy pathway, this approach can be misleading when coverages of adsorbed species determined for alternative mechanism differ significantly, since elementary reaction rates depend on the product of the rate coefficient and the coverage of species involved in the reaction. Moreover, cathode polarization can influence the kinetics of CO₂ reduction. Here, we present a multiscale framework for ab initio simulation of the electrochemical reduction of CO₂ over an Ag(110) surface. A continuum model for species transport is combined with a microkinetic model for the cathode reaction dynamics. Free energies of activation for all elementary reactions are determined from density functional theory calculations. Using this approach, three alternative mechanisms for CO₂ reduction were examined. The rate-limiting step in each mechanism is **COOH formation at higher negative potentials. However, only via the multiscale simulation was it possible to identify the mechanism that leads to a dependence of the rate of CO formation on the partial pressure of CO₂ that is consistent with experiments. Simulations based on this mechanism also describe the dependence of the H₂ and CO current densities on cathode voltage that are in strikingly good agreement with experimental observation.

To enhance both the electrical conductivity and long-term stability of manganese dioxide (MnO2) as the cathode of AZIBs, a stabilized cathode of Cu-intercalated MnO2 was designed in this paper. Tests showed that the Cu-MnO2 electrode possessed a smaller polarization voltage with higher reversibility. The capacity of Cu-MnO2 was 356.2 mAh g−1, which was higher compared to the capacity of original MnO2 (255.6 mAh g−1) under 100 mA g−1. Furthermore, the Cu-MnO2 possesses a capacity retention of 65.9% even after 100 turns under 100 mA g−1. This work may provide important insights into the development of AZIBs.

Understanding the local electrochemical processes is of key importance for efficient energy storage applications, including electrochemical double layer capacitors. In this work, we studied the charge storage mechanism of a model material - reduced graphene oxide (rGO) - in aqueous electrolyte using the combination of cavity micro-electrode, operando electrochemical quartz crystal microbalance (EQCM) and operando electrochemical dilatometry (ECD) tools. We evidence two regions with different charge storage mechanisms, depending on the cation-carbon interaction. Notably, under high cathodic polarization (region II), we report an important capacitance increase in Zn 2+ containing electrolyte with minimum volume expansion, which is associated with Zn 2+ desolvation resulting from strong electrostatic Zn 2+ -rGO interactions. These results highlight the significant role of ion-electrode interaction strength and cation desolvation in modulating the charging mechanisms, offering potential pathways for optimized capacitive energy storage. As a broader perspective, understanding confined electrochemical systems and the coupling between chemical, electrochemical and transport processes in confinement may open tremendous opportunities for energy, catalysis or water treatment applications in the future. Understanding local electrochemical processes can help improve electrochemical energy storage. Here, the authors report a charge storage mechanism in aqueous electrolyte for reduced graphene oxide using an electrochemical quartz crystal microbalance.

This review paper provides an overview of inorganic corrosion inhibitors, including their types, mechanisms of action, applications, recent advances, and future directions. Inorganic corrosion inhibitors have been widely used to protect metals and alloys from corrosion in various industries, such as oil and gas, chemical, and construction industries. The different types of inorganic corrosion inhibitors discussed in this review include metal-based, metal oxide-based, phosphate-based, silicate-based, and other inorganic inhibitors. The mechanisms of action of inorganic corrosion inhibitors are mainly related to their adsorption on metal surfaces, formation of protective films, and cathodic and anodic polarization. The paper also highlights the applications of inorganic corrosion inhibitors in different industries and discusses their effectiveness and limitations. Recent advances in the field of inorganic corrosion inhibitors, such as nanotechnology-based inhibitors, green inhibitors, combination inhibitors, and computational studies, are also reviewed. In conclusion, this paper summarizes the key findings of the review and provides a future outlook for the development of inorganic corrosion inhibitors. The review concludes that further research is needed to develop more effective, environmentally friendly, and economical inorganic corrosion inhibitors for various industrial applications.

Rechargeable sodium-chlorine (Na-Cl 2 ) batteries show high theoretical specific energy density and excellent adaptability for extreme environmental applications. However, the reported cycle life is mostly less than 500 cycles, and the understanding of battery failure mechanisms is quite limited. In this work, we demonstrate that the substantially increased voltage polarization plays a critical role in the battery failure. Typically, the passivation on the porous cathode caused by the deposition of insulated sodium chloride (NaCl) is a crucial factor, significantly influencing the three-phase chlorine (NaCl/Na + , Cl - /Cl 2 ) conversion kinetics. Here, a self-depassivation strategy enabled by iodine anion (I - )-tuned NaCl deposition was implemented to enhance the chlorine reversibility. The nucleation and growth of NaCl crystals are well balanced through strong coordination of the NaI deposition-dissolution process, achieving depassivation on the cathode and improving the reoxidation efficiency of solid NaCl. Consequently, the resultant Na-Cl 2 battery delivers a super-long cycle life up to 2000 cycles. An iodine-induced self-depassivation strategy extends Na-Cl 2 battery life to 2000 cycles by forming high-reactivity NaCl and lowering the chlorine conversion polarization, which successfully solves a key failure mechanism for superior reversibility.

The breakthrough in electrolyte technology stands as a pivotal factor driving the battery revolution forward. The colloidal electrolytes, as one of the emerging electrolytes, will arise gushing research interest due to their complex colloidal behaviors and mechanistic actions at different conditions (aqueous/nonaqueous solvents, salt concentrations etc.). Herein, we show “beyond aqueous” colloidal electrolytes with ultralow salt concentration and inherent low freezing points to investigate its underlying mechanistic principles to stabilize cryogenic Zn metal batteries. Impressively, the “seemingly undesired” concentration polarization at the interface would disrupt the coalescence stability of the electrolyte, leading to a mechanically rigid interphase of colloidal particle-rich layer, positively inhibiting side reactions on either side of the electrodes. Importantly, the multi-layered pouch cells with cathode loading of 10 mg cm –2 exhibit undecayed capacity at various temperatures, and a relatively high capacity of 50 mAh g –1 could be well maintained at −80 °C. Here, the authors design a “beyond aqueous” colloidal electrolyte with ultralow salt concentration and inherent low freezing point and investigate its colloidal behaviors and underlying mechanistic principles to stabilize cryogenic Zn metal battery.

Electrochemical CO 2 reduction reaction (CO 2 RR) occurring at the electrode/electrolyte interface is sensitive to both the potential and concentration polarization. Compared to static electrolysis at a fixed potential, pulsed electrolysis with alternating anodic and cathodic potentials is an intriguing approach that not only reconstructs the surface structure, but also regulates the local pH and mass transport from the electrolyte side in the immediate vicinity of the cathode. Herein, via a combined online mass spectrometry investigation with sub-second temporal resolution and 1-dimensional diffusion profile simulations, we reveal that heightened surface CO 2 concentration promotes CO 2 RR over H 2 evolution for both polycrystalline Ag and Cu electrodes after anodic pulses. Moreover, mild oxidative pulses generate a roughened surface topology with under-coordinated Ag or Cu sites, delivering the best CO 2 -to-CO and CO 2 -to-C 2+ performance, respectively. Surface-enhanced infrared absorption spectroscopy elucidates the potential dependence of *CO and *OCHO species on Ag as well as the gradually improved *CO consumption rate over under-coordinated Cu after oxidative pulses, directly correlating apparent CO 2 RR selectivity with dynamic interfacial chemistry at the molecular level. How pulsed electrolysis impacts the electrochemical CO2 reduction reaction remains unclear. Here, authors present a molecular-level picture on the complex interactions between cathode surfaces, adsorbates, and local reaction environment to elucidate the promotional effect of pulsed electrolysis.

Lithium solid-state batteries offer improved safety and energy density. However, the limited stability of solid electrolytes (SEs), as well as irreversible structural and chemical changes in the cathode active material, can result in inferior electrochemical performance, particularly during high-voltage cycling (>4.3 V vs Li/Li + ). Therefore, new materials and strategies are needed to stabilize the cathode/SE interface and preserve the cathode material structure during high-voltage cycling. Here, we introduce a thin (~5 nm) conformal coating of amorphous Nb 2 O 5 on single-crystal LiNi 0.5 Mn 0.3 Co 0.2 O 2 cathode particles using rotary-bed atomic layer deposition (ALD). Full cells with Li 4 Ti 5 O 12 anodes and Nb 2 O 5 -coated cathodes demonstrate a higher initial Coulombic efficiency of 91.6% ± 0.5% compared to 82.2% ± 0.3% for the uncoated samples, along with improved rate capability (10x higher accessible capacity at 2C rate) and remarkable capacity retention during extended cycling (99.4% after 500 cycles at 4.7 V vs Li/Li + ). These improvements are associated with reduced cell polarization and interfacial impedance for the coated samples. Post-cycling electron microscopy analysis reveals that the Nb 2 O 5 coating remains intact and prevents the formation of spinel and rock-salt phases, which eliminates intra-particle cracking of the single-crystal cathode material. These findings demonstrate a potential pathway towards stable and high-performance solid-state batteries during high-voltage operation. Improving interfacial stability during high-voltage cycling is essential for lithium solid-state batteries. Here, authors develop a thin, conformal Nb 2 O 5 coating on LiNi 0.5 Mn 0.3 Co 0.2 O 2 particles using atomic layer deposition to limit chemo-mechanical degradation during high-voltage cycling.