Construction of three-dimensional thermal simulation model of lithium-ion secondary battery

We are developing a large-capacity lithium-ion secondary battery as a backup power supply for next generation communications. The lithium-ion secondary battery has the advantage of very high energy density. However, the temperature of the battery rises when overcharge or internal short-circuit occurs. If the temperature of the battery exceeds a constant value, there is a danger that the positive electrode’s active material may decompose, oxygen may be discharged, the electrolysis liquid may burn, and rapid ignition (thermal runaway) may occur. In general, lithium-ion secondary batteries come in three shapes (cylinder, flat, and accumulating). A structural examination of the temperature increase is indispensable to develop a large-capacity lithium-ion secondary battery. We developed a highly accurate three-dimensional thermal simulation model using the finite-element method.