Electrochemical impedance study on the low temperature of Li-ion batteries

About a century ago, researchers first recognized a connection between the activity of environmental microorganisms and cases of anaerobic iron corrosion. Since then, such microbially influenced corrosion (MIC) has gained prominence and its technical and economic implications are now widely recognized. Under anoxic conditions (e.g., in oil and gas pipelines), sulfate-reducing bacteria (SRB) are commonly considered the main culprits of MIC. This perception largely stems from three recurrent observations. First, anoxic sulfate-rich environments (e.g., anoxic seawater) are particularly corrosive. Second, SRB and their characteristic corrosion product iron sulfide are ubiquitously associated with anaerobic corrosion damage, and third, no other physiological group produces comparably severe corrosion damage in laboratory-grown pure cultures. However, there remain many open questions as to the underlying mechanisms and their relative contributions to corrosion. On the one hand, SRB damage iron constructions indirectly through a corrosive chemical agent, hydrogen sulfide, formed by the organisms as a dissimilatory product from sulfate reduction with organic compounds or hydrogen ("chemical microbially influenced corrosion"; CMIC). On the other hand, certain SRB can also attack iron via withdrawal of electrons ("electrical microbially influenced corrosion"; EMIC), viz., directly by metabolic coupling. Corrosion of iron by SRB is typically associated with the formation of iron sulfides (FeS) which, paradoxically, may reduce corrosion in some cases while they increase it in others. This brief review traces the historical twists in the perception of SRB-induced corrosion, considering the presently most plausible explanations as well as possible early misconceptions in the understanding of severe corrosion in anoxic, sulfate-rich environments.

Corrosion of Iron by Sulfate-Reducing Bacteria: New Views of an Old Problem

The low temperature performance of Li-ion batteries

The influence of hydrogen sulfide on corrosion of iron under different conditions

Asymmetrical Schiff bases as inhibitors of mild steel corrosion in sulphuric acid media

The inhibitive action of three Schiff bases, N,N′-o-phenylen-bis(3-methoxysalicylidenimine) (V–o-Ph–V), N,N′-p-phenylen-bis (3-methoxysalicylidenimine) (V–p-Ph–V) and N-[(2-hydroxy-3-methoxyphenyl)methylene]-histidine (V-His), on copper corrosion in aerated 0.5 mol dm−3 NaCl and NaBr solutions was investigated using EIS and steady-state polarization techniques. The inhibitor effectiveness depended strongly on the geometric structure of the Schiff bases. Among the three kinds of Schiff base used, the inhibition efficiency of V–o-Ph–V on copper corrosion was the highest, V–p-Ph–V the next and V-His the lowest. The Schiff bases inhibited the cathodic current more significantly than the anodic current. The different influences of V–o-Ph–V or V–p-Ph–V on the anodic and cathodic reactions led to the appearance of a low frequency capacitive loop in the impedance spectra. The inhibition action of the Schiff bases was due to their adsorption on the copper surface followed by complexation with Cu(I) or Cu(II) ions, forming a blocking barrier to copper corrosion.

Inhibition of copper corrosion by several Schiff bases in aerated halide solutions

Electrochemical behaviour of chromium in acid solutions with H2S

The electrochemical behavior of copper in the aerated 0.5 mol dm 3 sodium bromide solutions with or without a Schiff base, N,N'-o-phenylen-bis(3-methoxysalicylidenimine) (V-o-Ph-V) were investigated by means of the steady-state polarization and impedance techniques. V-o-Ph-V acted as a mixed-type inhibitor in NaBr media, and it adsorbed easily on the copper surface at potentials near the corrosion potential. The adsorbed V-o-Ph-V formed a thin protective film which reduced both anodic and cathodic teaction rates significantly. The impedance spectra for copper measured at the corrosion potentials in the presence of V-o-Ph-V displayed two capacitive loops due to different influences of the protective film on the anodic and cathodic reactions occurring at the copper surface. V-o-Ph-V could self-assemble on the copper surface and the self-assembled film also exhibited a good inhibition on copper in halide solutions. The dissolution mechanism of copper and the inhibition mechanism of V-o-Ph-V on the copper in NaBr solution are interpreted. In addition, the inhibiting action of V-o-Ph-V is compared with that of the other two Schiff bases, N,N'-o-phenylen-bis (3-methoxysalicylidenimine) (V-p-Ph-V) and N-[(2-hydroxy-3-methoxyphenyl)methylene]-histidine (V-His) in order to investigate the effect of Schiff bases' geometric structures on their inhibition ability.

Lin Niu

Papers

The influence of hydrogen sulfide on corrosion of iron under different conditions

Inhibition of copper corrosion by several Schiff bases in aerated halide solutions

Electrochemical behaviour of chromium in acid solutions with H2S

Studies on electrochemical behavior of copper in aerated NaBr solutions with Schiff base, N, N' -o -phenylen-bis(3-methoxysalicylidenimine)