Lithium-ion battery is nowadays used for vehicle and stationary application due to several advantages. Among all the available formats for lithium-ion batteries, pouch format is one of the preferred choices for automotive manufactory thanks to packaging efficiency. Many studies focused on the effect of electric and thermal parameters for lithium-ion battery performance, as the state of charge (SOC), the discharge/charge rate, the operation temperature and self-heating. However, swelling is sometimes observed in pouch packs for automotive application. The mechanical parameter must be considered for pouch format. This paper attempts to show how external pressure influences the performance of lithium-ion pouch battery according to static and dynamic external pressures, mainly used electrochemical impedance spectroscopy and power cycle techniques. The results of our investigations show that static pressure has a little impact on impedance of lithium-ion pouch battery, dynamic pressure generates during discharging/charging which looks like “cell breathing”. Moreover, this pressure links to current amplitude. It would be interesting to use a dynamic pressure indicator to monitor the electric characterizations of lithium-ion pouch cells in future applications.