Abstract: The temperature rise and thermal stress in lithium-ion battery charging and discharging processes
may affect battery performances. This paper gives the temperature field and thermal stress field for a square
lithium-ion battery using theoretical calculation and simulation method, and analyzes relationship factors. The
results show that the highest temperature in the geometric center increases linearly with the heat generation
rate. The maximum temperature difference increases linearly the square of battery sizes. The battery center
area, the high-temperature region, has compressive stress; battery side center has tensile stress. Thermal
stress concentration occurs at the center of the sides. The maximum compressive stress is 2 times the
maximum compressive stress.

Key words: lithium-ion batteries, temperature field, thermo-stress, simulation, analytic solutions, laminated
material model