Controlling the temperature build-up in electrode-sealed coin-shaped batteries via designing central heat dissipator

Abstract

Nowadays, the ever-increasing demand for the computational power in the calculators, watches and LED lights require higher consumption rate from their portable energy source, which is typically coin-shaped batteries. The required power generates and accumulates a large amount of heat, which is a critical safety concern due to flammability of the included organic electrolytes. When heat dissipation is minimal from the electrode surface, the packaging boundary remains the sole heat transfer medium. In such case, although the center carries a minimal real estate compared to the rest of the electrode surface, the heat gets trapped, due to having the lowest reach to the heat-dissipating boundaries. For this purpose, a central heat sink component is anticipated for the coin-shaped batteries and the temperature profile across the cell is analytically derived. Subsequently, the role of the sink thermal conductivity and its scale as well as the thermal conduction of the boundary on the formation of steady state temperature profile has been analyzed. More specifically, the location of the maximum temperature rmax and its value Tmax is obtained and verified versus the extreme values of the thermal conductivities, the areal ratio of the heat sink, and the current density. The obtained results could be useful for the cost-effective design of the packaging materials (i.e. sustainable plastics and bio-degradable) with limited heat dissipation for the rechargeable batteries, particularly during the high power applications, in the presence of highly flammable electrolytes.