Pouch Cell Foam Pad Structure for Uniform Swelling Pressure

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Solution Overview

Problem

Existing battery modules struggle to effectively manage cell swelling, leading to uneven pressure distribution and deformation among battery cells when swelling occurs.

Innovation Solution

A battery module design featuring a pouch case with a foam pad layer as the outermost layer, comprising inner and outer resin layers and a metal layer, which absorbs swelling and ensures uniform pressure distribution across the battery cell stack.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a compression pad is formed between the module frame and battery cells to manage swelling, then swelling control is improved, but the compression pad reaches a minimum compression thickness where it can no longer perform compression, making it difficult to flexibly cope with swelling

Engineering Contradiction:
Improveswelling controlVSAvoidflexibility to cope with swelling
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the material parameter of the compression element from a conventional solid foam pad to a braid structure with inherent elasticity. This braided configuration allows the material to dynamically adjust its compression force based on swelling程度, maintaining effective compression across varying swelling conditions without reaching a minimum effective thickness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure combining the braid layer with the pouch case, creating a hybrid system that integrates the structural integrity of the pouch with the elastic compression properties of the braid. This composite approach enables both swelling control and continuous adaptability.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If battery cells are stacked in a multi-module structure to increase capacity, then energy storage capacity is improved, but uneven pressure distribution and deformation occur among battery cells when swelling happens

Engineering Contradiction:
Improvebattery capacityVSAvoidpressure distribution uniformity
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies the braid layer locally at specific positions within the pouch case structure, allowing different regions to have differentiated functions. The braid provides localized elastic compression where needed, ensuring uniform pressure distribution across the battery cell stack while maintaining the overall multi-module high-capacity structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The braid structure introduces dynamic elasticity to the pouch case system, enabling it to automatically adjust and redistribute pressure in response to swelling. This dynamic response ensures that pressure remains evenly distributed across all battery cells in the stack, preventing deformation even as capacity increases through multi-module configuration.

Inventive Principle:
Principle #15Dynamics

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 foam pad layer effectively controls cell swelling, ensuring uniform pressure distribution and deformation across the battery cell stack, eliminating the need for separate compression pads and enhancing overall module stability.

Implementation Method 1

a foam pad layer for controlling cell swelling is located at the outermost part of the pouch case

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4040582B1Battery module and battery pack including the same
Publication Date: 2025.12.24 LG ENERGY SOLUTION LTD
  • EP4040582B1 patent drawingFigure 1
  • EP4040582B1 patent drawingFigure 2
  • EP4040582B1 patent drawingFigure 3

AI summary

A battery module according to an embodiment of the present disclosure includes a battery cell stack in which a plurality of battery cells are stacked, and a module frame for housing the battery cell stack, wherein the battery cell comprises a pouch case and an electrode assembly housed in the pouch case, and wherein a foam pad layer for controlling cell swelling is located at the outermost part of the pouch case.