Battery Module Deformation Prevention for Cell Swelling

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Solution Overview

Problem

Existing battery modules and packs face challenges in minimizing displacement deviation between parts due to battery cell swelling, leading to potential deformation of the module housing and reduced lifespan.

Innovation Solution

A battery module with a deformation prevention structure comprising a housing plate, pressing plate, flat springs, and protruding portions, such as steel balls, to minimize deformation caused by swelling, ensuring the module housing maintains rigidity and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a battery module uses a fixed structure without expansion compensation, then the structural stability is maintained, but the battery cells cannot expand during charging which reduces battery life

Engineering Contradiction:
Improvebattery lifeVSAvoidstructural stability
Core Design Contradiction:
Duration of action of stationary objectVSStability of the object's composition

Solution Approach 1:

The battery module employs a dynamic support structure where support beams can move relative to the housing to accommodate battery cell expansion during charging. The support structure transitions from a fixed rigid configuration to a dynamic adjustable configuration that maintains contact with expanding cells while preserving overall structural integrity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The support structure is divided into multiple independent support beams that can move individually to accommodate localized expansion of different battery cells. This segmentation allows each beam to respond independently to expansion forces while maintaining overall module stability through the collective behavior of all support elements.

Inventive Principle:
Principle #1Segmentation

2Strength

If a battery module uses a rigid housing structure, then the mechanical strength is improved, but the battery cells cannot expand freely which reduces battery life

Engineering Contradiction:
Improvemechanical strengthVSAvoidbattery life
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

The housing structure implements local quality differentiation where specific regions contain movable support beams that allow localized expansion while other regions maintain rigid structural support. This creates zones of flexibility within an otherwise rigid housing, permitting cell expansion at critical interfaces while preserving overall mechanical strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Movable support beams act as intermediary elements between the rigid housing and the battery cells. These intermediaries absorb expansion forces through their own movement, protecting the rigid housing structure from direct expansion stresses while still allowing cells to expand freely during charging cycles.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of stationary object

If the battery module housing is made larger to accommodate expansion, then the expansion space is sufficient, but the energy density decreases

Engineering Contradiction:
Improvebattery lifeVSAvoidenergy density
Core Design Contradiction:
Duration of action of stationary objectVSQuantity of substance

Solution Approach 1:

The support structure uses dynamic movement rather than static expansion space to accommodate battery cell growth. The movable beams provide expansion accommodation through their displacement capability, eliminating the need for additional permanent volume in the housing, thereby maintaining high energy density while supporting full cell expansion cycles.

Inventive Principle:
Principle #15Dynamics

4Reliability

If a fixed support structure is used, then the device complexity is reduced, but the battery module cannot adapt to cell expansion which reduces reliability

Engineering Contradiction:
Improveadaptability to expansionVSAvoidsupport structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The support structure incorporates simple dynamic elements (movable beams on guides or rails) that provide adaptability to cell expansion without requiring complex active control systems. The movement is mechanically constrained to simple linear or rotational paths, maintaining structural simplicity while achieving the necessary adaptability for reliable operation throughout battery lifecycle.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4311003B1Battery module and battery pack including the same
Publication Date: 2026.05.06 LG ENERGY SOLUTION LTD
  • EP4311003B1 patent drawingFigure 1
  • EP4311003B1 patent drawingFigure 2
  • EP4311003B1 patent drawingFigure 3

AI summary

A battery module includes a battery cell stack including a plurality of battery cells arranged and stacked in a first direction; a module housing configured to accommodate the battery cell stack; and a deformation prevention structure disposed between the module housing and an outermost peripheral battery cell among the plurality of battery cells, in which the module housing includes a housing plate adjacent to the outermost peripheral battery cell, and in which the deformation prevention structure includes: a pressing plate fixed to the housing plate and supported on the battery cell stack; a flat spring disposed between the pressing plate and the housing plate; and a protruding portion supported on the pressing plate and protruding from an outer surface of the housing plate.