High-throughput battery materials testing based on test cell arrays and dispense/jet printed electrodes

A cost effective and reliable technology for the fabrication of electrochemical test-cell arrays for battery materials research, based on batch-fabricated glass micro packages was developed and tested. Jet dispensing was investigated for the first time as a process for fabricating battery electrode arrays and separators and compared to micro dispense printing. The process shows the reproducibility over the whole range of investigated materials and battery cell structures that is required for battery materials research. Such setup gives rise to a significantly improved reliability and reproducibility of electrochemical experiments. Cost-effective fabrication of our test chips by batch processing allows for their single-use in electrochemical experiments, thereby preventing contamination issues due to repeated use as in conventional laboratory test cells. In addition, the integration of micro pseudo reference electrodes is demonstrated. Thus, the test cell array together with the developed electrode/electrolyte deposition technology provide a highly efficient tool for speedy combinatorial and high throughput testing of battery materials on a system level (full cell tests). Experimental results are shown for the microfabrication of lithium-ion test cells with help of several electrode and binder materials. The influence of jetting parameters on electrode lateral dimensions and thickness, reproducibility of the electrode mass as well as the use of integrated micro-reference electrodes for impedance spectroscopy and cyclic voltammetry measurements in micro cells are presented in detail.

     

Porous FeAl alloys via powder sintering:Phase transformation,microstructure and aqueous corrosion behavior

This study investigates the phase transformation and microstructure of porous FeAl parts sintered from elemental powder mixtures using in-situ neutron diffraction and in-situ thermal dilatometry.A single B2 structured FeAl phase was determined in the sintered FeAl alloy.The combined effects of the Kirk-endall porosity,transient liquid phase,and phase transformations associated with powder sintering all contribute to the swelling phenomenon of the final sintered part.The aqueous corrosion test indicates that the corrosion products include iron oxides in the porous FeAl parts.The accumulation of corrosion products blocks the pore channel and decreases pore size and permeability over the soaking time.     

The organization of Patent databanks at the Ilmenau Institute of Technology

With the establishment of the Polytechnical Patent Library at the Ilmenau Institute of Technology in April 1981, an efficient patent information centre was set up for the southern districts of the German Democratic Republic (Suhl, Gera, Erfurt). First, the manual methods of search were complemented by two subsystems of the automized patent pre-search system, namely the selective dissemination of information and the field-oriented patent family service. In 1985, the set-up of patent databanks was begun. The present paper explains their specific features, thus complementing the conception of the patent pre-search system presented in previous papers.^(1,2) The information services are rendered by order of the Inventions and Patent Office.     

Neutron Diffraction and Neutron Radiography Investigation into Powder Sintering of Ti/Al and TiH2/Al Compacts

Metallurgical and Materials Transactions B - Sintering behaviors of two types of powder compact, i.e., Ti/Al and TiH2/Al, under vacuum were studied using in situ neutron diffraction, in situ...     

Kinetik der VC-polymerisation: Ein Modellvergleich,II. Anwendungsbeispiele

A selection of several kinetic models for vinyl chloride polymerization in part I of this paper¹ was performed and has resulted in an optimal mathematical model, which exhibits numerous advantages for the practical work of chemical engineers, e.g. in the analysis of experimental results, in the modelling, and the optimization of polymerization reactors. Some examples are shown in this paper.     

Novel method to produce cobalt–polypyrrole catalysts for oxygen reduction reaction by dual plasma process

Platinum-free electrocatalysts based on cobalt and polypyrrole were successfully produced with a dual plasma process and characterised for the oxygen reduction reaction by cyclic voltammetry (CV). The results show that composites with catalytic activity were obtained. Furthermore, by varying the plasma process parameters, the activity of the samples was changed. Structural properties were also investigated by means of energy dispersive X-Ray spectroscopy (EDX), to obtain the elemental contents, and Fourier transform infrared spectroscopy (FT-IR) to identify the chemical structure of the films. The results indicate that, with increasing magnetron power, more and more cobalt nitrogen bonds are formed. The formation of these complexes correlates with the increase in catalytic activity.