Lars Röntzsch

Rapidly solidified Fe-base alloys as electrode materials for water electrolysis

Abstract Amorphous ribbons of the systems Fe60Co20Si10B10 and Fe50Co20V10Si10B10 have been prepared via melt spinning to be used as electrode materials in alkaline water electrolysis. It turned out that the gas atmosphere during melt-spinning has a significant impact on the surface morphology and microstructure of the ribbons. Furthermore, a comprehensive characterization of the microstructure depending on the peripheral speeds of the cooling wheel was conducted. Moreover, the transition from the amorphous to the crystalline state was investigated via differential scanning calorimetry measurements. Preliminary electrochemical investigations suggest a noticeable improvement of the electrocatalytic activity of the melt-spun amorphous ribbons after an anodic–cathodic pretreatment.

Highly efficient and long-term stable micro fuel cell system based on ceramic multilayer technology

This contribution shows the development of a micro fuel cell system based on the ceramic multilayer technology. All necessary components, like the hydrogen reservoir based on metal hydrides, the planar fuel cell stack, as well as all necessary micro valves were manufactured in ceramic multilayers. The target size of the system is similar to rechargeable lithium button cell batteries (CR2450) and can substitute these. By use of metal hydrides as hydrogen storage medium, a power density of up to 290 Wh / l can be achieved that exceeds the lithium battery (CR2450) by more than 50% in combination with extended operating temperatures and increased cycle stability. By the potential of miniaturization of the ceramic energy system and the scalability to the specific application dimensions and performance, completely new possibilities are offered as a long-term stable energy storage, for example, in the field of autonomous sensor systems for the Internet of Things (IoT).