报告题目：NOVEL MATERIALS AND OPERANDO CHARACTERIZATION FOR SOLID STATE ELELCTROCHEMICAL CELLS
报告人：Prof. Peter Holtappels
Department of Energy Conversion and Storage, Technical University of Denmark
Frederiksborgvej 399, DK-4000 Roskilde, Denmark
The section “Electrochemical materials and Interfaces” is working on novel materials and characterization techniques for electrochemical cells with a strong focus on applying structraul and chemical characterization techniques such as XRD, Raman spectroscopy and atomic force microscopy to working electrodes and electrochemical cells for batteries, fuel and electrolysis cells.
The presentation will start with a brief overview on the related section activities.
The section has a strong background in investigating solid oxide fuel cells. These high temperatures, all solid state fuel cells can offer supply of electrical energy with a high efficiency and based on a wide range of fuels. While natural gas and/or bio methane is a commonly used fuel for combined heat and power supply, liquid fuels such as gasoline, Diesel and alcohols are interesting fuels, especially for remote fuel cell systems. For those applications, redox tolerant and sulphur resistant fuel electrode materials are advantageous in order to make the cells more tolerant against sudden system failures such as fuel cut off and reformer breakdown. Also for direct feeding of alcohols and higher hydrocarbons, coking tolerant electrodes are required. State-of art fuel electrodes are based on a nickel ceramic composite, a nickel cermet, which suffers from low redox stability, susceptibility for sulfur poisoning and coking. Operando Raman spectroscopy can reveal coke formation on these electrodes and thus help identifying critical operation regimes.
Redox stable anodes can be achieved by replacing the Ni-cermet fuel electrode by an electronically conducting ceramic, e.g. strontium titanate with incorporated nano-scaled electro catalysts.
Full cells using LSM/YSZ cathodes have been developed and tested as single 5 x 5 cm2 cells and up 100 cm2 circular cells. The initial performance exceeded 0.4 W/cm2 at 850 °C and redox tolerance has been proven in a 1 kW system environment.
The cell concept provides flexibility with respect to the used electro-catalysts and various metals including Ni and Ru infiltrated in a niobium modified strontium titanate have been studied as regards their electrochemical performance and stability. Stable power output has been observed for Ru and Ru/Gd modified ceria (CGO) as infiltrate. Promising low cost alternatives are Co and Fe nano catalysts have recently been investigated. Their initial performance and electro catalytic properties as well as the susceptibility to carbon formation will be discussed.
Peter Holtappels has studied Chemistry and obtained his doctoral degree in natural sciences from the University in Bonn, Germany, in 1997. He is professor at DTU Energy and Head of the Section for “Electrochemical Materials and Interfaces”. He has continuously been involved in high temperature electrochemistry activities at various institutions in Germany, Denmark and Switzerland. His research interests are sustainable energy technologies with focus on elelctrochemical energy conversion and storage technologies. During his career, Peter Holtappels has demonstrated novel electrode architectures and advanced in-situ and operando electrochemical testing of materials, electrodes and cell concepts for solid state electrochemical cells with emphasis on nano-structured materials. He has been involved in numerous national and international projects related to the development of ceramic electrochemical cells and coordinated the FCH JU project SCOTAS-SOFC. From 2009-2011 he was Vice Chair of the European COST Action 543 “Bioethanol” dealing with the processing and utilization of bioethanol for various fuel cell applications. Peter Holtappels was Chair for Cross Cutting Activities in the Board of NERGHY, the research grouping in the European Joint Technology Initiative for Fuel Cells and Hydrogen (FCH JU) (2014-16) and is coordinating the subprogramme “Electrodes and Catalysts” of the Joint Programme “Fuel cells and Hydrogen” of the European Research Alliance (EERA).