In this work, nanocomposite HA/chitosan coatings were electrophoretically deposited (EPD) on a near-β Ti-13Nb-13Zr alloy. The influence of the state of the HA particles introduced to the colloidal ...solution of chitosan (nc-HA-p as a nanopowder and nc-HA-s as nanoparticles suspended in ethanol), as well as the chemical composition of a multi-component HA-chitosan suspension and EPD parameters, on the homogeneity of coatings has been studied. It was established that the pH value and the chemical composition of the suspension have a substantial effect on the electrokinetic properties of suspended HA and chitosan particles. These are also influenced by the deposition kinetics of EPD and the uniformity of as-deposited coatings. The thickness of the nc-HA-p/chitosan and nc-HA-s/chitosan coatings was up to 750nm and 1.5μm, respectively. The nc-HA-s/chitosan coating microstructure consisted of HA nanoparticles, homogeneously embedded in an amorphous chitosan matrix. The nc-HA-p/chitosan coating microstructure was non-homogeneous, composed of HA agglomerates in a chitosan matrix. The presence of thin oxide layer was observed on the coatings/titanium alloy interface. The nc-HA-s/chitosan coating exhibited better adhesion to the titanium alloy substrate than the nc-HA-p/chitosan coating. It was found that the nc-HA-s/chitosan coating improves the electrochemical corrosion resistance of the Ti-13Nb-13Zr alloy in Ringer's solution, as well as its bioactivity and other biological properties.
Display omitted
•Uniform nc-HA/chitosan coatings were produced on the Ti-13Nb-13Zr alloy by EPD.•Coating homogeneity depends on the HA state introduced to the suspension.•The nc-HA-s/chitosan coatings exhibited good adhesion to the alloy.•The nc-HA-s/chitosan coatings improved corrosion resistance of titanium alloy.•Bioactivity of the alloy was enhanced by nc-HA-s/chitosan coatings.
In this study, a NiCoCrAlY + lanthanum zirconate multilayer thermal barrier coating was deposited on Inconel 738 through the thermal plasma spray technique. The coated samples subjected to hot ...corrosion testing at 900 °C for 240 h after coating them with 90 wt.% Na2SO4 + 5 wt.% NaCl + 5 wt.% V2O5. The corroded samples were evaluated using SEM, SED, XRD, microhardness and electrochemical study. The dominance of vanadium was observed in the form of LaVO4 phase formation at the plates on the coating surface. The as-received coating sample, sample after the electrochemical test, sample after hot corrosion and hot-corroded sample after electrochemical test were tested for hardness. A significant decrease of 23.8% in hardness was measured after the electrochemical test of the corroded sample.
With the rapid development of consumer electronics, electric vehicles and grid-scale stationary energy storage, high-energy batteries are urgently demanded at present. Lithium metal batteries (LMBs) ...are considered to be one of the most promising high-energy density energy storage devices at present and have received much attention due to their ultra-high theoretical capacity, extremely low electrochemical potential and light mass. However, critical issues, such as uncontrollable lithium dendrite growth, dynamic changes in volume, interfacial impedance, severe chemical and electrochemical corrosion, remain huge challenges for Li metal anodes, which not only lead to low Columbic efficiency of LMBs, but also pose the risk of internal short circuit, causing serious side reactions and safety concerns that hinder LMBs from practical applications. Nevertheless, lithium metal is gradually poised for a revival after decades of oblivion, due to the development of research tools and nanotechnology-based solutions. In this review, various recent material designs for lithium metal anodes are reviewed based on previous theoretical understanding and analysis. Suppressing Li dendrites and ensuring the long life span of practical batteries through limited Li metal anodes design are still challenges. Multi-scale modeling methods are concerned, requiring the application of electrode material development. Hybrid multi-scale modeling application methods with machine learning technology are proposed based on the cloud computing platform. Computational material designs for Li metal anodes on model information are integrated with artificial intelligence. Finally, this review provides a novel framework for next-generation lithium metal anode design methods with a digital solution based on multi-scale data-driven models and machine learning techniques.
Graphical Abstract
Aqueous rechargeable Na-ion batteries (ARNBs) hold great promise for grid-scale electric energy storage because of their outstanding merits of low cost and resource abundance; however, their low ...energy density and poor cycling stability limit practical application. In this work, we reported a Prussian Blue (PB) analogue Na2Zn3Fe(CN)62 as a high-voltage aqueous cathode for ARNBs and achieved its stable cycling at a high operation potential of 1.13 V (vs SHE) by using of a highly concentrated NaClO4 electrolyte. Raman spectroscopy, in situ XRD, and DFT calculations have been utilized to study the underlying mechanism of electrode performance as a function of electrolyte concentration. It was revealed that in the concentrated 17 m NaClO4 electrolyte almost all the water molecules are coordinated with Na+ ions, and the solvation energy of PB materials increases considerably with increasing salt concentrations, which broadens the electrochemical stability window of the electrolyte and greatly alleviates the dissolution of the materials. An aqueous rechargeable Na-ion battery was constructed by using a Na2Zn3Fe(CN)62 cathode, a NaTi2(PO4)3 anode, and 17 m NaClO4 electrolyte. This full cell demonstrates a high-voltage output of 1.6 V and an energy density of 55 Wh kg–1 (based on the total mass of the electrode-active materials), offering a viable alternative to commercial aqueous batteries for large-scale EES applications.
The findings reveal that soil constituents significantly affect the corrosion process. Moisture content and pH promote the formation of corrosion products, while high chloride concentrations ...accelerate corrosion. Conversely, high organic matter content inhibits corrosion by limiting oxygen diffusion to the metal surface. The effectiveness of conservation treatments, particularly wax or oil-based coatings, varied with soil conditions, showing reduced efficacy in soils with high chloride concentrations. This study underscores the importance of understanding soil constituents for developing effective corrosion and conservation strategies for buried bronze statuettes. The results offer valuable insights for customizing preservation approaches based on soil types. X-ray diffraction (XRD) analysis revealed that mineralogical compositions in soil significantly influence corrosion processes, providing critical insights for effective preservation strategies. pH measurements indicated varying soil acidity and alkalinity levels, crucial in determining corrosion rates and mechanisms, offering essential data for targeted preservation strategies. Additionally, the identification of brochantite and antlerite through Micro-Raman spectroscopy suggests a link to sulfur pollutants from the decomposition of organic matter by sulfate-reducing bacteria, highlighting the potential environmental impact of microbial activity in the soil ecosystem.
•A 45-degree elbow results in a region of low velocity, high pressure and high turbulence energy.•The change in the flow state leads to the condensation of water vapor.•The synergistic effect of ...electrochemical corrosion and stress corrosion evokes the incident.•Changing the structure will reduce the condensation of vapor can improve the life of pipeline.
A bursting incident occurred in a 45-degree elbow of a natural gas gathering pipeline in an oilfield. The failure analysis was performed by means of corrosion morphology observation, corrosion products analysis, and computational fluid dynamics (CFD) simulations. The results showed that a radical change in the fluid state at the 45-degree elbow due to its climbing structure and formation a region of low flow velocity, high pressure and high turbulence kinetic energy, which promoted the condensation of water vapor containing CO2. Then the corrosive water droplets flowed back under the action of gravity and accumulated at the junction between the elbow and horizontal pipeline. In such a corrosive medium, electrochemical corrosion was preferred for 20 steel. In addition, the junction of the horizontal pipe and the inclined pipe exhibits higher structural stress concentration, resulting in increased corrosion thinning. Finally, the failure of the pipeline can be attributed to the synergistic effect of electrochemical corrosion and stress accelerated corrosion.
Photovoltaic silicon waste (WSi) can be used to manufacture Si-based anodes for lithium-ion batteries as a means of reducing production costs as well as achieving the high-value recycling of ...secondary resources. However, the mechanism by which trace metal impurities in WSi affect battery performance remains unclear. The present work quantitatively analyzed the key role of metal impurities physically doped into WSi in determining the performance of Si-based anodes. A paradoxical phenomenon in which metal impurities in WSi powders decreased the conductivity of the material was identified. Doping with magnetic metal impurities was also found to increase the magnetic strength of WSi powders while significantly enhancing the self-discharge effect of Si-based anodes. The mechanism responsible for this effect was revealed based on in situ monitoring and quantitative characterization. Trace metal impurities in WSi-based anodes were shown to spontaneously undergo electrochemical corrosion reactions, resulting in the formation of metal dendrites in the battery and the decomposition of the electrolyte. As a result, the battery performance became unstable and prone to safety hazard. The results of this research provide theoretical support for the value-added recycling of WSi based on manufacturing highly stable, safe Si-based anodes for lithium-ion batteries.
CNTs are decorated uniformly with nano Ni through electroless plating method (CNTs@Ni). Average contact angle with 2024 aluminum alloy reduces from 138.6° to 81.2°, significantly improving wetting of ...CNTs. CNTs@Ni are used as the reinforcement to fabricate 2024-CNTs@Ni composites via high-intensity ultrasonic-assisted casting method. The appropriate content of CNTs@Ni assists 2024-CNTs@Ni composites to obtain excellent microstructure, mechanical properties and electrochemical corrosion resistance. When the CNTs@Ni content is 1.5 wt%, CNTs@Ni are uniformly dispersed, uniform organization and grain refinement is most significant according to the results of scanning electron microscopy. CNTs@Ni composites exhibit more excellent mechanical properties than cast 2024 aluminum alloy. This results from a synergy of grain refinement strengthening, thermal mismatch strengthening, Orowan strengthening and load-bearing strengthening. The percentage contribution of each strengthening mechanism is calculated for composites with different CNTs@Ni content. In addition, 2024–1.5 wt% CNTs@Ni composites show better electrochemical characteristic with higher corrosion potential of −603.792 mv and lower corrosion current density of 102.332 μA·cm−2. Cl− ions are more resisted because of Ni introduction. The large number of dislocations accelerates the diffusion of elements, which expedites formation of thicker protective films to resist corrosion. The phenomenon of “large anode - small cathode” improves the electrochemical corrosion resistance.
Display omitted
•CNTs decorated uniformly with nano Ni via electroless plating method were used as reinforcement for CNTs/Al composites. Average contact angle with 2024 aluminum alloy reduced from 138.6° to 81.2•With addition CNTs@Ni, the mechanical properties of 2024-CNTs@Ni composites were significantly improved. Load-bearing strengthening contribution gradually dominated.•2024–1.5 wt.% CNTs@Ni composite exhibited excellent corrosion resistance due to the Ni resistance to Cl− ions and enhancement of “large anode - small cathode”.
