Fluid Sealing Challenges in Solid Oxide Electrolysis Cells and Rapid Swap Battery Systems

Abstract

This thesis explores the design and development of several mechanical elements relevant to two technologies Important to a global transition to green energy, hydrogen and electric vehicles. The portion of the thesis relating to hydrogen focuses on preloading mechanisms and high temperature seals, two design spaces crucial to the implementation of solid oxide hydrogen generation. Due to the high operating temperatures (600°C - 800°C), seal materials commonly used in other applications are inadequate and glass or vermiculite based seals must be used. The delicateness of these seals makes them a common failure point, and consistent application of a preloading force is key to mitigating this. The concept of a variable-bypass piston is proposed as a preloading mechanism suitable for the high temperatures present inside solid oxide electrolyzer systems, and the development of seal geometries as well as flow characterization of porous steel wool seals to enable parametric design is documented. As an alternative to current sealing methods, initial development of a composite seal utilizing materials and manufacturing methods originating in the semiconductor industry was also conducted. The final section of the thesis proposes the concept and covers initial testing of fluid transfer through a kinematic coupling, a topic of potential interest for implementing liquid pack cooling in a system of rapidly swappable batteries for electric vehicles.