Thermal runaway is a critical safety concern in lithium-ion battery systems, emphasising the necessity to comprehend its behaviour in various modular setups. This research compares thermal runaway propagation in different modular configurations of lithium-ion batteries by analysing parameters such as cell spacing and distribution, application of phase change materials (PCMs), and implementing insulating materials. The study at the module level includes experimental validation and employs a comprehensive model considering heat transfer due to electrical performance and thermal runaway phenomena. It aims to identify the most effective modular configuration for mitigating thermal runaway risks and enhancing battery safety. The findings provide valuable insights into the design and operation of modular lithium-ion battery systems, guiding engineers and researchers in implementing best practices to improve safety and performance across various applications.
In this paper, water droplet dynamics in FC channels were investigated by applying numerical and experimental methodologies. Specifically, digital imaging with high-spatial resolution was applied for characterising the micro-channel surface and defining the texture of the Gas Diffusion Layer (GDL) of a Membrane electrode assembly (MEA). The optical results allowed the definition of a 3D geometry of the GDL to use in CFD simulations. Moreover, a custom procedure of image processing permitted the estimation of the contact angles of droplets deposited on the GDL (123°) and channel walls (50°-60°) for a wide range of droplet size (0.3-1.2mm). The determined specifications were used as boundary conditions for a 3D CFD two phase simulation employing the Volume of Fluid (VOF) model. Droplets were initialized on the walls and their dynamics were studied under increasing air flow, up to 20 m/s.
To satisfy recent stringent exhaust gas regulations, large amounts of Rh and Pd have been often employed in three-way catalysts (TWCs) as main active components. However, application of Pt-based TWCs are limited due to their lower thermal stability than Pd. Previously, we found that Pt-based TWCs with a small amount of CeO2 showed high catalytic performance in gasoline vehicles test. Especially, calcined CeO2 at high temperature before Pt loading (cal-CeO2) showed higher catalytic activity than untreated CeO2 after endurance at 1000 degree centigrade. This result could be attributed to higher redox performance and Pt dispersion derived from strong interaction between Ce and Pt. Even though cal-CeO2 has low specific surface area (SSA) given by preliminary calcination, it shows strong effects on catalytic performance. In other word, improvement of its SSA could be the most powerful way to prepare highly active Pt catalysts.