Under fast charging conditions, the thermal properties of a lithium ion battery can greatly affect its charging speed, charging efficiency, cycle life, and security. To investigate the thermal properties of a prismatic nickel-manganese-cobalt (NMC) cell under fast charging conditions, an electrochemical-thermal coupled finite element model was created, and the heat generated by the tabs was taken into account. Constant current charging processes at 1 C, 3 C, and 6 C were performed through calculations and experiments, separately, and the validity of the model was proven. The electrochemical properties and thermal properties of the cell during 3-6 C charging were analyzed and compared. By changing the particle radii in the electrodes, the porosities of the active layers, and the separator, the effects of the these material parameters on the average volumetric heat generation rates and average temperatures of the cell under 3 and 6 C charging conditions were investigated. The method and results could provide technical assistance in the material design of lithium ion batteries toward fast charging applications.