A Study on the Thermal Deformation of Current Collectors by Burning Heat Pellets in Thermal Batteries

Abstract

Thermal batteries are primary batteries that use molten salts as an electrolyte and employ an internal pyrotechnic source to heat the battery stack to operating temperatures, typically between 450 and 550 ℃. The unit cell of thermal batteries consists of an anode, an electrolyte, a cathode, a heat pellet and a current collector. The heat source for such batteries is typically heat pellets based on Fe/KClO4. The elevated temperature by combustion of heat pellet is supposed to cause a flatness non-uniformity, buckling, with a lateral extension diameter of current collector. This paper mainly focused on the combustion and buckling model of current collector to simulate the effect of heat source. Mechanical stresses in the current collector caused by thermal stress is a critical design consideration of thermal batteries because the internal short circuit could be occurred.

Analytical Study of Insulation Characteristics of Thermal Batteries with Vacuum Insulation

“…A thermal battery is a battery that uses a chemical heat source to instantaneously raise the temperature above the melting point of the electrolyte to convert the electrolyte to a liquid state for operation. Thermal batteries have the advantage that there is no self-discharge when they are inactive with the electrolyte in a solid state, which allows for more than 15 years of storage [1,2,3]. Figure 1 shows the internal structure of a typical thermal battery, where the unit cell consists of a current collector, heat source, cathode, anode, and electrolyte.…”