Search

staxera GmbH is a manufacturer of commercial available solid oxide fuel cell (SOFC) stacks and Integrated Stack Modules (ISM). The aim of development and testing is to meet the requirements of existing customers and the needs of the market. Besides high power densities, low degradation rates in long term operation and thermal cycling capability, the possibility for oxidation and reduction (redox) cycles as a requirement of system operation or in case of a system failure is a big challenge in today's SOFC stack development. In this publication, data for different types of redox cycles at stack level is reported, including system relevant combined thermal and redox cycling.

Reliable performance of SOFC stacks and Integrated Stack Modules (ISM) are determined by a robust stack design as well as an optimized operation regime. The following paper gives insight to some of the test methods Staxera has established to develop operation procedures that will allow a robust and long term stable performance of stacks and ISMs. As a result more than 12000h of operation and more than 50 thermal cycles could be demonstrated.

Development and progress in manufacturing of high power density electrolyte supported cell based on a thin (50 µm) 3YSZ substrate is presented. The cells with improved cathode based on LSMM’/ScSZ and the multilayer anode based on Ni/GDC cermet show very good electrochemical performance. The maximum power density increases up to 750 mW/cm2at 0.7V@860 °C for developed cell without additional contact layer and is greater than one of the commercial cells based on partially scandia stabilized zirconia electrolytes as well as 95µm 3YSZ. The changes in polarization resistance of tested cells under different operating conditions as well as during redox-cycling and durability tests were performed and are discussed on basis of analysis of impedance spectra. The developed cells show a good long-term stability (proved for >1300 h) under high current density (500mA/cm²@850°C, N2:H2:H2O=55:40:5, air). The estimated power degradation rate is below 0.5%/1000 h.