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Understanding the behavior of Li-ion cells during thermal runaway is critical to evaluate the safety of these energy storage devices under outstanding conditions. Li-ion cells possess a high energy density and are used to store and supply energy to many aerospace applications. Incidents related to the overheating or thermal runaway of these cells can cause catastrophic damages that could end up costly space missions; therefore, thermal studies of Li-ion cells are very important for ensuring safety and reliability of space missions. This work evaluates the thermal behavior of Li-ion cells before and after storage degradation at high temperature using accelerating rate calorimeter (ARC) equipment to analyze the thermal behavior of Li-ion cells under adiabatic conditions. Onset temperature points of self-heating and thermal runaway reactions are obtained. The onset points are used to identify non-self-heating, self-heating and thermal runaway regions as a function of state of charge. The results obtained can be useful to develop accurate thermo-electrochemical models of Li-ion cells.

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The realization of fusion reactors rests on the function of the blanket systems with high thermal ef ciency consisting of armor and structural materials. The fabrication of the blanket requires upgrade of bonding technology which makes the components reliable. The combination of tungsten and oxide dispersion strengthened ferritic steel (ODS-FS) is considered to be adequate for the application to the fusion diverter components. The issue of diffusion bonding of tungsten with ODS-FS is to reduce thermal stresses caused by a large difference in thermal expansion coef cient between the two materials. In this study, an innovative thermal stress relaxation methodology during cooling has been newly proposed as a key technology in joining, which is based on the phenomenon of γ→α phase transformation-induced creep deformation of low carbon steel inserted between tungsten and ODS-FS. In the cooling pattern where the joint was slowly cooled at a rate of approximately 1.6 C/min from 800 C to 600 C. The application of the technology to the diffusion bonding of tungsten/ODS-FS resulted in a very high bonding strength of 480 MPa, which has never been achieved so far by the conventional bonding methodologies.