Ni, Cr, and Fe surfaces corroded by molten ZnCl<sub>2</sub>

Wang, Xueliang; Liu, Wenguan; Yu, Ge; He, Jie; Tang, Zhongfeng; Liu, Yan

doi:10.1002/maco.201911346

Cited by 12 publications

(4 citation statements)

References 33 publications

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“…In any case, localized corrosion attack is a classical scenario, described also for many other electrode/electrolyte systems. [39][40][41] Our analysis explains the faster dis-/charge kinetics and higher rate capability observed for the iron electrode in Figures 1d and 2d as crack formation "supplies" continuously fresh iron surface for metal dissolution and chlorination as shown in Figure 5e,f.…”

Section: Resultsmentioning

confidence: 93%

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

et al. 2022

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Sodium‐metal chloride batteries are considered a sustainable and safe alternative to lithium‐ion batteries for large‐scale stationary electricity storage, but exhibit disadvantages in rate capability. Several studies identify metal‐ion migration through the metal chloride conversion layer on the positive electrode as the rate‐limiting step, limiting charge and discharge rates in sodium‐metal chloride batteries. Here the authors present electrochemical nickel and iron chlorination with planar model electrodes in molten sodium tetrachloroaluminate electrolyte at 300 °C. It is discovered that, instead of metal‐ion migration through the metal chloride conversion layer, it is metal‐ion diffusion in sodium tetrachloroaluminate which limits chlorination of both the nickel and iron electrodes. Upon charge, chlorination of the nickel electrode proceeds via uniform oxidation of nickel and the formation of NiCl2 platelets on the surface of the electrode. In contrast, the oxidation of the iron electrodes proceeds via localized corrosion attacks, resulting in nonuniform iron oxidation and pulverization of the iron electrode. The transition from planar model electrodes to porous high‐capacity electrodes, where sodium‐ion migration along the tortuous path in the porous electrode can become rate limiting, is further discussed. These mechanistic insights are important for the design of competitive next‐generation sodium‐metal chloride batteries with improved rate performance.

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Section: Resultsmentioning

confidence: 93%

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

et al. 2022

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“…The Gibbs free energy of formation for divalent alloy element chlorides increases in the order of Cr < Ni [24], a trend that corresponds to the relative stability of these metal elements in molten chloride salts. Hence, it can be concluded that since CrCl 2 has the highest negative Gibbs free energy of formation, Cr will be preferentially attacked.…”

Section: Discussionmentioning

confidence: 99%

Corrosion Behavior of Ni-Cr Alloys with Different Cr Contents in NaCl-KCl-MgCl2

Lei,

Zhou,

Zhang

et al. 2024

Materials

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This study investigates the corrosion behavior of Ni-Cr binary alloys, including Ni-10Cr, Ni-15Cr, Ni-20Cr, Ni-25Cr, and Ni-30Cr, in a NaCl-KCl-MgCl2 molten salt mixture through gravimetric analysis. Corrosion tests were conducted at 700 °C, with the maximum immersion time reaching up to 100 h. The corrosion rate was determined by measuring the mass loss of the specimens at various time intervals. Verifying corrosion rates by combining mass loss results with the determination of element dissolution in molten salts using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Detailed examinations of the corrosion products and morphology were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Micro-area elemental analysis on the corroded surfaces was performed using an energy dispersive spectrometer (EDS), and the elemental distribution across the corrosion cross-sections was mapped. The results indicate that alloys with lower Cr content exhibit superior corrosion resistance in the NaCl-KCl-MgCl2 molten salt under an argon atmosphere compared to those with higher Cr content; no corrosion products were retained on the surfaces of the lower Cr alloys (Ni-10Cr, Ni-15Cr). For the higher Cr alloys (Ni-20Cr, Ni-25Cr, Ni-30Cr), after 20 h of corrosion, a protective layer was observed in certain areas. The formation of a stable Cr2O3 layer in the initial stages of corrosion for high-Cr content alloys, which reacts with MgO in the molten salt to form a stable MgCr2O4 spinel structure, provides additional protection for the alloys. However, over time, even under argon protection, the MgCr2O4 protective layer gradually degrades due to chloride ion infiltration and chemical reactions at high temperatures. Further analysis revealed that chloride ions play a pivotal role in the corrosion process, not only facilitating the destruction of the Cr2O3 layer on the alloy surfaces but also possibly accelerating the corrosion of the metallic matrix through electrochemical reactions. In conclusion, the corrosion behavior of Ni-Cr alloys in the NaCl-KCl-MgCl2 molten salt environment is influenced by a combination of factors, including Cr content, chloride ion activity, and the formation and degradation of protective layers. This study not only provides new insights into the corrosion resistance of Ni-Cr alloys in high-temperature molten salt environments but also offers significant theoretical support for the design and optimization of corrosion-resistant alloy materials.

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“…This explains that the 316 SS alloy experienced a corrosion attack after being corroded by the NaCl–KCl–FeCl 3 vapor at 300°C, and the Fe, Ni, and Cr elements were depleted attributing to the reaction of HCl with oxides and alloy elements Fe, Ni, and Cr of 316 SS (Equations ). [ 27 ] However, the corroded 316 SS was in the NaCl–KCl–FeCl 3 vapor but was not in contact with the oxidizing compound FeCl 3 due to the high stability of molten salt at the corrosion temperature (Figure 2); thus the corrosion attack of the corroded 316 SS in the NaCl–KCl–FeCl 3 vapor is lesser than that in the NaCl–KCl–FeCl 3 molten salt

{{\rm{F}}\text{eCl}}_{3}+{3{\rm{H}}}_{2}{\rm{O}}={\text{Fe}(\text{OH})}_{3}+3\text{HCl}({\rm{g}}),

6{\rm{H}}\text{Cl}+{\text{Cr}}_{2}{{\rm{O}}}_{3}={2\text{CrCl}}_{3}+{3{\rm{H}}}_{2}{\rm{O}},

\text{HCl}+\text{Me}(\text{Me}=\text{Fe},\text{Ni},\text{Cr})={\text{MeCl}}_{2}+{{\rm{H}}}_{2}({\rm{g}}).

…”

Section: Discussionmentioning

confidence: 99%

Corrosion behavior and mechanism of 316 stainless steel in NaCl–KCl–FeCl₃ molten salt and vapor at 300°C

Yang

Guo

Chen

et al. 2023

Materials & Corrosion

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The corrosion behavior of 316 stainless steel (316 SS) in NaCl–KCl–FeCl3 molten salt and vapor was studied at 300°C for 150, 300, and 500 h in Ar. The weight change, the micromorphology, element distribution, and crystal structure of the 316 SS alloy were analyzed by scanning electron microscopy, energy‐dispersive spectroscopy, and X‐ray diffraction. 316 SS alloys suffered from weight loss, significant visible corrosion shedding, and corrosion holes. The corrosion holes and corrosion shedding block of the 316 SS alloys become more and more serious with the increase in corrosion time. The corrosion depth of the corroded 316 SS alloys in NaCl–KCl–FeCl3 molten salt and vapor for 500 h can even reach up to 20.0 and 14.0 μm, respectively. 316 SS alloys in NaCl–KCl–FeCl3 molten salts underwent a more serious corrosion attack than that in the NaCl–KCl–FeCl3 vapor at 300°C due to the strong oxidizing compound FeCl3 in the molten salt. It not only offers a new insight into the corrosion behavior of 316 SS alloys in the chloride salts and corresponding vapor but also enriches the corrosion databases of the chloride salts.

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Ni, Cr, and Fe surfaces corroded by molten ZnCl₂

Cited by 12 publications

References 33 publications

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

Corrosion Behavior of Ni-Cr Alloys with Different Cr Contents in NaCl-KCl-MgCl2

Corrosion behavior and mechanism of 316 stainless steel in NaCl–KCl–FeCl₃ molten salt and vapor at 300°C

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Ni, Cr, and Fe surfaces corroded by molten ZnCl2

Cited by 12 publications

References 33 publications

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

Elucidating the Rate‐Limiting Processes in High‐Temperature Sodium‐Metal Chloride Batteries

Corrosion Behavior of Ni-Cr Alloys with Different Cr Contents in NaCl-KCl-MgCl2

Corrosion behavior and mechanism of 316 stainless steel in NaCl–KCl–FeCl3 molten salt and vapor at 300°C

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Ni, Cr, and Fe surfaces corroded by molten ZnCl₂

Corrosion behavior and mechanism of 316 stainless steel in NaCl–KCl–FeCl₃ molten salt and vapor at 300°C