This study explores how external mechanical pressure affects the performance of commercial prismatic lithium-ion cells over their lifespan. While previous research has focused on pressure effects in pristine cells, this work emphasizes the changes that occur as the cells age. High-capacity NMC/graphite prismatic cells are used, and various levels of external pressure are aplied while electrochemical characterization tests are applied, such as qOCV, capacity tests, HPPC and dQ/dV analysis. Results show that while pristine cells show minimal change, aged cells benefit significantly from increased pressure, with up to 2% capacity recovery and reduced internal resistance.

The improvements are attributed to pressure restoring contact between degraded internal components, enhancing electron and ion transport. These findings suggest that mechanical compression can counteract structural degradation, particularly in aged cells, by improving internal contact and restoring electrochemical pathways. The study concludes that external pressure should be considered a valuable design parameter in battery systems, especially for long-life applications, as it can enhance both static and dynamic performance of aged cells.