Flexible Battery Expansion Sensor for Rechargeable Battery

A battery pack comprises a housing, at least a first battery cell, in particular a pouch cell, arranged within said housing and at least one expansion sensor, wherein an outer shell of said first battery cell comprises an electrically conductive material. The at least one expansion sensor is arranged between the electrically conductive material of said outer shell of said first battery cell and an abutting surface adjacent to said first battery cell and comprises at least one flat inductor circuit arranged on a flexible substrate, said at least one flat inductor circuit being arranged in a contact zone between the first battery cell and said abutting surface adjacent to said first battery cell, at least a first compressible buffer layer arranged between the flexible substrate with the inductor circuit and the electrically conductive material of said outer shell of said first battery cell and a detection circuit coupled to said at least one flat inductor circuit by means of respective connector lines arranged on said flexible substrate for detecting a change in inductance of said at least one flat inductor circuit.