Secondary Battery Pouch Structure for Internal Pressure Equalization

The patent converts the harmful effect of gas generation into a beneficial feature by designing an expansion chamber that accommodates gas volume increases during charge/discharge cycles. The gas generation, previously a reliability issue, becomes a controlled phenomenon that tests and validates the pouch's pressure management capabilities, ultimately improving operational reliability through controlled pressure equalization.

The expansion chamber is designed beforehand to accommodate potential gas generation during battery operation. By providing pre-calculated headspace and pressure management features before gas accumulation occurs, the system prevents operational failures while allowing normal charge/discharge cycles to proceed, resolving the contradiction between reliability and cycle flexibility.

The pouch is segmented into a battery accommodation chamber and a separate expansion chamber. This segmentation allows the battery chamber to maintain its structural integrity and mechanical stability while the expansion chamber absorbs pressure increases through controlled deformation, resolving the contradiction between maintaining pouch stability and managing internal pressure.

The pouch design changes the parameter of chamber volume distribution, creating a larger expansion chamber that can accommodate pressure increases without requiring increased overall pouch thickness. This parameter change allows the battery chamber to remain structurally stable while the expansion chamber manages pressure through controlled volume changes.