Modeling Degradation in Solid Oxide Electrolysis Cells

Manohar S. Sohal ; Anil V. Virkar ; Sergey N. Rashkeev ; Michael V. Glazoff

关键词: DIFFUSION;    ELECTRODES;    ELECTROLYSIS;    ELECTROLYTES;    HYDROGEN;    LTE;    OXIDES;    OXYGEN;    RECOMMENDATIONS;    SIMULATION;    STEAM;    THERMODYNAMICS degradation;    electrochemical model;    hydrogen;    NGNP;    solid oxide electrolysis cel;   

DOI  :  10.2172/993195
RP-ID  :  INL/EXT-10-19691
PID  :  OSTI ID: 993195
Others  :  TRN: US1008066

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.