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Abstract. The operation principle of a commercially available solid electrolyte sensor was modified with respect to applications in flowing gaseous mixtures containing H 2 and O 2 . For this purpose the generally applied coulometric or potentiometric operation mode was replaced by cyclic voltammetry. By varying the sensor temperature, electrode area and potential scan rate, the conditions for the characteristic peak formation for every gas component were determined. While hydrogen oxidation peaks arise at potential scan rates up to 100 mV s −1 , oxygen reduction peaks develop between 200 and 1000 mV s −1 . A linear relationship between peak area/peak height and concentration was found at concentrations φ(H 2 ) < 100 vol. ppm and φ(O 2 ) ≤ 500 vol. ppm. It could be demonstrated that hydrogen can be measured selectively at catalytically highly active Pt electrodes even in gas mixtures with comparably high oxygen concentrations by using cyclic voltammetry.

To reduce the ecological footprint and to increase the lifetime of lithium‐ion batteries (LIBs), it is necessary to understand aging phenomena inside the cells during cycling. In this study, the positive effect of external pressure through bracing the cells on aging is investigated for automotive battery cells with more than 7000 cycles. After cycling, the aged cells are studied by using post‐mortem analysis. It is shown that bracing does not affect the anode and cathode in the same manner. A lack of external pressure results in lithium plating due to contact losses on the anode. Such a loss of lithium inventory plays only a small role in the braced cells. However, the structural and morphological degradation, such as particle cracking at the cathode, is significant. Half‐cell tests of aged and unaged anode samples extracted from the automotive cells confirm the post‐mortem findings, where only minimal differences can be seen for the braced cell. In contrast, the aged cathodes from braced cells demonstrate substantial capacity fade in half‐cell measurements as compared to the cathodes extracted from the unbraced cell. Finally, a new concept of the mechanical state of health (mechanical SOH) is introduced to correlate mechanical effects with electrode degradation.

The generation of hydrogen as a chemical energy storage for power generation via fuel cells or for the synthesis of fuels has attained a strong interest in recent years. By way of example this is realized using electrolysis of water with the help of excess electricity of wind power plants. However with low temperature grade waste heat as it could be found in many industrial and household applications, there is another source of usable energy for this purpose. In a first pragmatic experimentation we investigated the pyroelectric effect of ferroelectric BaTiO3 combined with a temperature cycling to generate hydrogen from water. Therefore, single crystals ground to powder were brought into contact with distilled water and set to a cyclical temperature change from 40 °C to 70 °C. With the help of a highly selective and sensitive measuring system based on a coulometric solid electrolyte detector we could provide a first indication of pyroelectric generated hydrogen by a fraction of 300 Vol.-ppb in the sample gas.

Spray‐assisted layer‐by‐layer assembly is applied to the fabrication of functional thin film composites based on colloidal semiconductor nanocrystals (see picture). The technique is capable of handling various material combinations, yielding varying functional architectures. Light‐emitting devices, including those of all‐inorganic design, are generated in order to demonstrate the potential applicability and versatility of this approach.