To understand the thermal behavior of lithium-ion secondary batteries, distributed information related to local heat generation across the entire electrode plane, which is caused by the electrochemical reaction that results from lithium-ion intercalation or deintercalation, is required. To accomplish this, we first developed an enhanced single particle (ESP) model for lithium-ion batteries that provides a cost effective, timely, and accurate method for estimating the local heat generation rates without excessive computation costs. This model accounts for all the physical processes, including the solution phase limitation. Next, a two-way electrochemical-thermal coupled simulation method was established. In this method, the three dimensional (3D) thermal solver is coupled with the quasi-3D porous electrode solver that is applied to the unrolled plane of spirally wound electrodes, which allows both thermal and electrochemical behaviors to be reproduced simultaneously at every computational time-step. The quasi-3D porous electrode solver implements the ESP model. This two-way coupled simulation method was applied to a thermal behavior analysis of 18650-type lithium-ion cells where it was found that temperature estimates of the electrode interior and on the cell can wall obtained via the ESP model were in good agreement with actual experimental measurements.