A novel distributed electric resistance model is used to describe the heat generation characteristics of a cell with the electric resistance of a cell is divided into three parts: the main body, two current collectors, and two electrode tabs. This model was used to simulate the effects of natural convection cooling and forced air convection cooling on tabs of a lithium-ion pouch battery, and the effects of dry air and wet air on the cooling effect. The parameter of the module cooling coefficient (MCC) was introduced to evaluate the effect of thermal management. The results show that wet air has a better cooling effect than dry air, but the cooling effect of wet air with 15% and 75% relative humidity is almost the same, and increasing the inlet air velocity can significantly improve the cooling effect. In addition, the index MCC of positive and negative tabs and the heat flux during cooling process are quantified, so as to provide better service for thermal management design.