Experimental Investigation on Reversible Swelling Mechanisms of Lithium-Ion Batteries under a Varying Preload Force

The safety of lithium-ion batteries has to be guaranteed over the complete lifetime considering geometry changes caused by reversible and irreversible swellings degradation mechanisms. An understanding pressure distribution gradients is necessary optimize battery modules avoid local bearing risk safety-relevant changes. In this study, two fresh pouch cells was measured with an initial preload force 300 or 4000 N. Four identical were electrochemically aged a N force. thickness change during aging. After aging, swelling behavior investigated draw conclusions on how affected aging behavior. A novel test setup developed measure cell without contact high precision. results suggested that applied surface. found affect locality swelling. Positions suffering from large variations increased strongly in terms their particular, edges showed strong increase peaks.