DEVELOPMENT OF THIN FILM SOLID OXIDE FUEL CELLS

单电池的制备及其叠层技术的研究是固体氧化物燃料电池发展的关键。本研究的主要目的是开发薄膜平板电池的叠层技术并进行组装，即研究叠层平板电池的机械强度、温度分布、对该材料的热膨胀和气密性进行了深入的研究，结果如下：1）平面堆中产生的热应力分析为了缓解平面SOFC堆中的热应力，测量合金隔板和氧化锆板之间的摩擦系数的温度依赖性。利用摩擦力的测量结果模拟了一种新的平板电池叠层方法，包括对薄膜电池的保护。2）空气电极柔性集流体的研制了一种减小平板SOFC空气电极热应力的柔性集流体。它们是由La（Sr）MnO_3细颗粒包覆的耐热合金丝组成。将柔性集流体与1）中提到的应力分析相结合，新开发了用于平面薄膜电池的堆叠方法。该单元栈被命名为Soft Stack。在软叠层中，薄膜电池由氧化锆环支撑，氧化锆环减少了由耐热合金和氧化锆之间的热膨胀系数差异引起的热应力。采用镍铬合金箔制备柔性集流体。

Preparation of single cells and studies of their stacking technologies are the most important for the development of solid oxide fuel cells. In this study, the main objective is to develop stacking technologies for thin film planar cells and to assembled them, that is, the major problems on the stackings of planar cells such as the mechanical strength, temperature distributions, thermal expansion and gas sealing were intensively investigated.The results are as follows.1) Analysis of thermal stresses developed in planar stacksIn order to relax the thermal stresses in planar SOFC stacks, the temperature dependence of the coefficient of friction between alloy separators and zirconia plates was measured. A new stacking method for planar cells including the protection of thin film cells are simulated using the results of the friction measurement.2) Development of flexible current collectors for air electrodesFlexible current collectors which reduce the thermal stresses developed in air electrodes of planar SOFCs are developed. They consist of heat resisting alloy wires coated withLa (Sr) MnO_3fine particles. The flexible current collector was combined with the stress analysis mentioned in 1) , and a stack method for planar thin film cells was newly developed. The cell stack was named Soft Stack. In the Soft Stack, the thin film cells were supported with zirconia rings which reduced the thermal stresses induced by the difference in thermal expansion coefficient between the heat resisting alloy and zirconia. The flexible current collectors were prepared with nickel-chromium alloy foils.