Battery Module Housing Structure for Cell Swelling Constraint

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Solution Overview

Problem

Battery modules experience performance degradation and durability issues due to a swelling phenomenon caused by charging and discharging, leading to electrical disconnections and damage to the battery case.

Innovation Solution

A battery module design with support portions on the left and right plates that uniformly pressurize the cell assembly during volume expansion, using adhesives and elastic pads to stabilize the cells and prevent excessive movement, and incorporating a module housing with recesses and tubes to manage volume changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the cell assembly is fixed rigidly to the module housing, then the battery cells are stable during charging and discharging, but the battery case may be damaged due to forced movement during swelling phenomenon

Engineering Contradiction:
Improvestability of battery cellsVSAvoidbattery case durability
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The module housing is designed with a flexible pressing structure that can dynamically adapt to the swelling and contraction of the cell assembly during charging and discharging cycles, rather than using rigid fixation that causes damage

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The module housing includes a pressing structure that applies predetermined pressing force to the cell assembly in advance, preventing excessive swelling and potential damage to the battery case while accommodating normal volume changes

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Stability of the object's composition

If the middle part of the cell assembly is intensively pressurized by the module housing during swelling, then the cell assembly is constrained, but damage to the electrode assembly inside the battery cell becomes severer

Engineering Contradiction:
Improveconstraint of cell assemblyVSAvoiddamage to electrode assembly
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The pressing structure of the module housing is designed to apply different pressing forces to different regions of the cell assembly, with reduced pressing force on the middle part to avoid severe damage to the electrode assembly while maintaining constraint

Inventive Principle:
Principle #3Local quality

3Strength

If the battery cells are not pressed during swelling phenomenon, then the battery case and electrode assembly are protected from damage, but the battery cells may move excessively and cause electrical disconnection

Engineering Contradiction:
Improvebattery case integrityVSAvoidelectrical connection reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The pressing structure is designed to apply appropriate pressing force that changes with the swelling state of the cell assembly, maintaining electrical connections while preventing damage to the battery case and electrode assembly

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4135108B1Battery module, battery pack comprising same, and vehicle
Publication Date: 2026.01.07 LG ENERGY SOLUTION LTD
  • EP4135108B1 patent drawingFigure 1
  • EP4135108B1 patent drawingFigure 2
  • EP4135108B1 patent drawingFigure 3

AI summary

Provided is a battery module that prevents performance degradation due to a swelling phenomenon caused by charging and discharging and increases durability. The battery module includes a cell assembly comprising a plurality of battery cells stacked in a left-right direction; and a module housing configured to accommodate the cell assembly therein. The module housing includes an upper plate covering an upper portion of the cell assembly, a left plate covering a left portion of the cell assembly, a right plate covering a right portion of the cell assembly, and a lower plate covering a lower portion of the cell assembly, and at least one of the left plate and the right plate includes a support portion having a shape protruding toward the cell assembly from an inner surface facing the plurality of battery cells to pressurize at least a part of the cell assembly with a relatively small volume expansion.