Cathodes properties

Copper Corrosion Inhibitors. The most effective corrosion inhibitors for copper and its alloys are the aromatic triazoles, such as benzotriazole (BZT) and tolyltriazole (TTA). These compounds bond direcdy with cuprous oxide (CU2O) at the metal surface, forming a "chemisorbed" film. The plane of the triazole Hes parallel to the metal surface, thus each molecule covers a relatively large surface area. The exact mechanism of inhibition is unknown. Various studies indicate anodic inhibition, cathodic inhibition, or a combination of the two. Other studies indicate the formation of an insulating layer between the water surface and the metal surface. A recent study supports the idea of an electronic stabilization mechanism. The protective cuprous oxide layer is prevented from oxidizing to the nonprotective cupric oxide. This is an anodic mechanism. However, the triazole film exhibits some cathodic properties as well. 

Surprisingly there are relatively few data on the cathodic or anodic behaviour of sulfoxides 77. It is quite interesting to consider that the sulphoxide function is intermediate between the corresponding thioether and sulphone. Thus data concerning the cathodic properties of sulphoxides derive both from the basicity of the S=0 group and from their capability to allow the formation of the corresponding thioether, while cleavage reactions on the C—S bond are quite unusual. On the other hand, oxidation may provide sulphones. 

SEI formation control is the key to good performance and the safety of the whole lithium ion battery, as not only anode operation but also cathode properties are strongly affected by the SEI formation process (the cathode is the lithium cation source of lithium ion cells). Apart from control of the graphite (surface) properties, an appropriate composition of the electrolyte is usually helpful for creation of an effective SEI. 

The primary challenge in commercialization of MCFC remains in the proper selection of materials for the cathode. The life expectancy of the electrode structure is aimed toward 40,000 hr for successful commercialization of MCFC. The following cathode properties were recognized as of fundamental importance with respect to the cell performance 1) high electronic conductivity at 650°C (cr > 1 S/cm) 2) low chemical reactivity and solubility in the electrolyte 3) thermodynamic stability at 650°C in carbonate electrolyte at different partial pressures of O2/CO2 mixtures 4) high electrocatalytic activity for the oxygen reduction reaction and 5) suitability for the fabrication of porous electrodes. ... 

Many of the differences have been explained by Moore, Sumner. Wyatt [1-7] and Kirshenbaum [8, 9], They showed that the electrical circuit, spark-gap-explosive geometry, cathode properties, and nature of the explosive all play important roles. The circuit components and spark-gap geometry affect the rate of energy delivery, efficiency of energy transfer, and character of the spark. One of the problems is differentiation between the contributions to the observed results made by the spark and by the explosive. 

A summary of anode and cathode properties for both cell types is contained in the table below. 

R. Holthe, E. Bradal, P.O. Gartland, Time dependence of cathodic properties of materials in seawater, Mater. Performance 28 (1989) 16-23. 

Johnsen R, Bardal E. Cathodic properties of different stainless steels in natural seawater. Corrosion 41,1985, 296. 

Okada S, Sawa S, Egashira M, Yamaki J-I, Tabuchi M, Kageyama H, Konishi T, Yoshino A (2001) Cathode properties of phospho-olivine LiMP04 for lithium secondary batteries. J Power Sources 97-98 430-432... 

Two different cathodes were used in these commercial solid-state cells. The original battery system used a mixture of Pbl2 and Pb for the cathode. This was replaced by a mixture of Pbl2, PbS, and Pb. A newer system, with increased energy density, used a mixture of TiS2 and S as the cathode. " Properties of these battery systems are summarized in Table 15.4. Other cathode materials have also been investigated in cells of this type. They include AS2S3 and various other metal sulfides. ... 

Chihara K, Chujo N, Kitajou A et al (2013) Cathode properties of Na2C606 for sodium-ion batteries. Electrochim Acta 110 240-246... 

New cathode materials for IT-SOFC phase stability, oxygen exchange and cathode properties of La2-xNi04+g, Solid State Ionics, Vol. 179, pp. 2000-2005... 

Wakihara M (2005) Lithium manganese oxides with spinel structure and their cathode properties for lithium ion battery. Electrochem 73 328-335... 

---