Laminate Pouch Battery Case Venting for Electrode Deformation Control

Solution Overview

Problem

Existing pouch-type lithium secondary batteries face deformation of the electrode assembly due to internal gas generation during the activation process, which hinders efficient handling and transfer of the battery cells.

Innovation Solution

A battery case with a laminate sheet structure that includes a first region without a barrier layer or with slits in the barrier layer, allowing easy discharge of internal gas, and a second region with conventional laminate sheet properties to maintain structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional laminate sheet with barrier layer is used for the entire battery case, then the battery case has good strength and protection, but gas generated during activation process causes electrode assembly deformation

Engineering Contradiction:

Improvebattery case strengthVSAvoidelectrode assembly deformation

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The battery case is divided into two distinct regions: a first region without a barrier layer (or with slit-formed barrier layer) that allows gas discharge, and a second region with a conventional barrier layer that provides strength and protection. This segmentation resolves the contradiction by localizing the gas discharge function to specific areas while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the battery case are assigned different functional properties: the first region has gas-permeable characteristics (no barrier layer or slit-formed barrier layer) to enable gas discharge, while the second region has gas-impermeable characteristics (conventional barrier layer) to provide strength and protection. This local differentiation allows simultaneous achievement of gas discharge and structural strength.

Inventive Principle:

Principle #3Local quality

2Object-generated harmful factors

If a laminate sheet without barrier layer is used for the entire battery case, then gas can be easily discharged, but the battery case loses strength and protection

Engineering Contradiction:

Improvegas discharge easeVSAvoidbattery case strength

Core Design Contradiction:

Object-generated harmful factorsVSStrength

Solution Approach 1:

The battery case is divided into two distinct regions: a first region without a barrier layer (or with slit-formed barrier layer) that allows gas discharge, and a second region with a conventional barrier layer that provides strength and protection. This segmentation resolves the contradiction by localizing the gas discharge function to specific areas while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the battery case are assigned different functional properties: the first region has gas-permeable characteristics (no barrier layer or slit-formed barrier layer) to enable gas discharge, while the second region has gas-impermeable characteristics (conventional barrier layer) to provide strength and protection. This local differentiation allows simultaneous achievement of gas discharge and structural strength.

Inventive Principle:

Principle #3Local quality

3Object-generated harmful factors

If gas pocket unit is expanded to collect gas, then gas can be collected, but pickup of battery cell using transfer member becomes difficult

Engineering Contradiction:

Improvegas collection capabilityVSAvoidbattery cell pickup ease

Core Design Contradiction:

Object-generated harmful factorsVSEase of operation

Solution Approach 1:

The battery case is divided into two distinct regions: a first region without a barrier layer (or with slit-formed barrier layer) that allows gas discharge, and a second region with a conventional barrier layer that provides strength and protection. This segmentation resolves the contradiction by localizing the gas discharge function to specific areas while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents electrode assembly deformation by facilitating gas discharge, reducing swelling, and enabling easy handling of battery cells during transfer processes.

Implementation Method 1

the laminate sheet constituting the first region does not include a barrier layer or includes a barrier layer in which a slit is formed

Methodology Applied

Scientific EffectGas discharge through laminate sheet: Permeation

Data Source

PatentUS12614789B2Lithium secondary battery case for suppressing deformation of electrode assembly

Publication Date: 2026.04.28 LG ENERGY SOLUTION LTD

AI summary

A lithium secondary battery case composed of laminate sheet including an outer layer/barrier layer/inner layer structure is provided. The case includes a first region in which gas discharge is easier or expansion is relatively easier compared to a second region. The second region is a remaining region that excludes the first region. The laminate sheet forms the first region by either not including the barrier layer or including a barrier layer having a slit therein.