Peter Kritzer

Corrosion in high-temperature and supercritical water and aqueous solutions: a review

Abstract The aim of the present article is to review some of the common corrosion phenomena and describe the predominant corrosion mechanisms in high-temperature and supercritical water. Corrosion in aqueous systems up to supercritical temperatures is determined by several solution-dependent and material-dependent factors. Solution-depending factors are the density, the temperature, the pH value, and the electrochemical potential of the solution, and the aggressiveness of the attacking anions. Material-dependent parameters include alloy composition, surface condition, material purity, and heat treatment. Corrosion phenomena that are observed include intergranular corrosion, pitting, general corrosion, and stress corrosion cracking. The solubility and dissociation of both attacking species and corrosion products play the most important role for corrosion in high-temperature water. Both solubility and dissociation processes are strongly influenced by the density, or the ionic product, respectively, of the solvent. High values of both parameters favor ionic reactions, and thus, accelerate electrochemical forms of corrosion. At low densities, water behaves like a non-polar solvent, and thus, ions associate. In these cases, the concentation of e.g. aggressive H + drops down and thus, solutions containing species such as HCl become neutral and thus less aggressive. Further, corrosion products plug the surface and material loss stops. Materials parameters have influence especially on the initiation of corrosion. In the present article, these factors are linked with the physical and chemical properties of high-temperature and supercritical water. An outlook is also given for future research needs.

Dichtungs- und Elastomerkomponenten für Lithium-Batteriesysteme

An automobile Lithium-Batterien werden extrem hohe Anforderungen hinsichtlich Sicherheit und Lebensdauer gestellt. Dichtungskomponenten - sowohl auf Zell- als auch auf Systemebene - konnen erheblich dazu beitragen, diese Anforderungen zu losen.

Components for improved lithium battery systems: pressure regulation and fluid control

An essential characteristic of battery systems used in automotive and industrial applications is their long-term durability. One thing that has to be prevented is the occurrence of free fluids inside the battery system. This can be caused by leakage and by the “breathing interaction” between the battery housing and its surrounding environment – leading to condensation of air humidity forming inside the battery housing. This article describes approaches to pressure regulation of battery systems and to reducing and/or preventing fluids from occurring inside them.

Sealing and elastomer components for lithium battery systems

Lithium batteries dominate todays consumer market. In the year 2014, around two billion lithium cells were produced for cell phones only. Off-the-shelf usage of lithium-based battery systems in vehicles began in the year 2009 with Daimler AGs S400 hybrid. In 2011, the first purely electric vehicles with lithium batteries were produced in series. As of today, all battery-driven and plug-in hybrid vehicles contain lithium-based energy storage systems. Table 10.1 compares consumer lithium batteries with automotive lithium batteries.