Elastic Pressing Housing for Pouch Cell Swelling Suppression

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Solution Overview

Problem

Existing battery modules face issues with structural stability due to swelling phenomena in lithium-polymer pouch-type secondary battery cells, which can lead to performance deterioration and require additional components like compression pads or straps that reduce energy density and complicate assembly.

Innovation Solution

A method of manufacturing a battery module where pouch-type battery cells are accommodated in a module housing in a strongly pressurized state without separate components, using a metal housing with elastic pressing plates that compress the cells, thereby minimizing swelling and simplifying assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compression pads are inserted between secondary battery cells to suppress swelling, then the swelling phenomenon is suppressed, but the space for accommodating secondary battery cells is reduced and energy density per unit volume decreases

Engineering Contradiction:
Improveswelling suppressionVSAvoidenergy density per unit volume
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The pressing plates are integrated into the module housing structure itself, eliminating the need for separate compression pads. The housing's side walls function as pressing plates that directly compress the battery cells, merging the structural support function with the compression function, thereby suppressing swelling without sacrificing cell accommodation space

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The module housing serves multiple functions: it provides structural protection, accommodates battery cells, and simultaneously acts as a compression mechanism through its side walls functioning as pressing plates. This multi-functionality eliminates the need for dedicated compression components that would reduce energy density

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If straps are used to tighten the battery module to suppress swelling, then the swelling phenomenon is suppressed, but the pressure is irregularly applied and additional assembly processes and components are required

Engineering Contradiction:
Improveswelling suppressionVSAvoidassembly structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressing plates are formed as integral parts of the module housing structure, combining the compression mechanism with the housing itself. This eliminates the need for separate straps and their associated assembly processes, reducing device complexity while maintaining uniform compression force application

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The module housing structure itself provides the compression function through its side walls acting as pressing plates. The housing design inherently includes the compression mechanism, eliminating the need for external compression components and simplifying the overall assembly structure

Inventive Principle:
Principle #25Self-service

3Reliability

If the module housing strongly compresses the cell assembly from the early assembling state to suppress swelling, then the swelling phenomenon is suppressed, but the assembling process becomes more difficult

Engineering Contradiction:
Improveswelling suppressionVSAvoidassembling ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The pressing plates are designed to be movable relative to the cell assembly during the assembly process, allowing cells to be inserted first and then compressed. This dynamic design enables a two-stage process: easy assembly followed by strong compression, resolving the contradiction between assembly ease and swelling suppression

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cell assembly is inserted into the housing first in an uncompressed state, allowing easy assembly. After assembly is complete, the pressing plates are then activated to apply strong compression. This preliminary insertion before compression maintains ease of manufacture while achieving swelling suppression

Inventive Principle:
Principle #10Preliminary action

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

This approach suppresses volume expansion during charging and discharging, reduces manufacturing costs, and simplifies the assembly process by eliminating the need for additional components, while maintaining or improving energy density.

Implementation Method 1

a first module housing (310) formed of an elastic material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3629396B1Method for manufacturing a battery module having initial pressing force strengthening structure for cell assembly
Publication Date: 2024.08.28 LG ENERGY SOLUTION LTD
  • EP3629396B1 patent drawingFigure 1
  • EP3629396B1 patent drawingFigure 2~3
  • EP3629396B1 patent drawingFigure 4(a)~4(b)

AI summary

Disclosed is a battery module, which includes a cell stack having pouch-type battery cells provided to stand side by side and stacked in a horizontal direction, and a module housing configured to accommodate the cell stack. The module housing includes a lower plate provided in a rectangular plate form to support the cell stack at a lower portion of the cell stack; and a first left pressing plate and a first right pressing plate having elasticity and extending upwards at both side edge regions of the lower plate, which are provided side by side, to form an acute angle with respect to a vertically upper direction so that a gap between the first left pressing plate and the first right pressing plate becomes narrowed upwards. The first left pressing plate and the first right pressing plate are elastically biased to press both side surfaces of the cell stack.