This work presents the design and simulation of a MEMS piezoelectric pressure sensor for early thermal runaway detection in electric vehicle (EV) batteries. Using IntelliSuite tools, the sensor was modeled and analyzed through structural design in IntelliDesigner, fabrication process simulation in IntelliFab, and 3D visualization in FabSim. The study focused on evaluating piezoelectric pressure sensor performance under high-temperature conditions by varying piezoelectric materials. Initial simulations were conducted with a square Lead Zirconate Titanate (PZT) diaphragm (150 µm × 2 µm), followed by multilayer configurations using Zinc Oxide (ZnO) and Silicon Dioxide (SiO₂). The simulation results show that ZnO produced the highest maximum displacement of 1.468 µm, while PZT and AlN recorded 0.058969 µm and 0.099251 µm, respectively. In terms of sensitivity, PZT demonstrated a stable increasing trend, reaching 0.00348 at 500 °C, whereas ZnO and AlN exhibited decreasing sensitivities of 0.362 and 0.000362, respectively, at the same temperature. These findings indicate that ZnO offers superior sensitivity at lower temperatures, while PZT provides robust performance under high-temperature conditions.