Battery cell having structure for prevention of swelling

A battery cell, comprising:

• a jelly-roll type electrode assembly;
• a battery casing extending along a longitudinal axis between upper and lower surfaces, and having a sidewall extending therebetween, the jelly-roll type electrode assembly being accommodated in the battery casing;
• and
• an isolation wall offset inwardly towards the longitudinal axis from the sidewall such that the isolation wall is not in contact with the sidewall in an undeformed state, the isolation wall being in direct physical contact with the battery casing in the undeformed state, and the isolation wall extending alongside the sidewall along the longitudinal axis so as to define a buffer space between the sidewall and the isolation wall, the buffer space configured to accommodate deformation of the electrode assembly when the electrode assembly is expanded by allowing the electrode assembly to deform the isolation wall outwardly into the buffer space towards the sidewall, such that deformation of the sidewall of the battery casing is prevented from occurring, wherein the buffer space extends around a complete perimeter of the battery casing that extends about the longitudinal axis.