APPLICATION OF LANTHANUM GALLATE BASED OXIDE ELECTROLYTE IN SOLID OXIDE FUEL CELL STACK

Mitsubishi Materials Corporation (MMC) and The Kansai Electric Power Co., Inc. (KEPCO) have been collaborating to develop intermediate temperature SOFC (IT-SOFC) modules, which use lanthanum gallate based electrolyte, for stationary power generation since FY2001. The fourth generation 1-kW class module with internal manifolds was developed and the electrical efficiency of 54% HHV on DC output was achieved in 2005. The long-term durability test of the 1 kW-class module was conducted. The degradation rate of the terminal voltage was about 0.5% per 1,000 hours. In order to test the durability of the module against variation of operating conditions, the cyclic loading experiments were conducted. As a proof of concept for a multi-stack module, the 10 kW-class module has been designed and manufactured. In evaluation tests, the module achieved the electrical efficiency of 50%HHV with 12.6 kW-DC output power at thermally self-sustained operation using town gas. Another program to increase the output power density of cell-membrane has been started with optimizing the electrolyte, fuel and air electrodes, and the current collectors.