Battery Pack Barrier Sealing at Bus Bar Connections

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Solution Overview

Problem

Conventional battery packs face challenges in effectively suppressing thermal propagation between modules, particularly at the bus bar connections, which can lead to failures, explosions, or fires.

Innovation Solution

A battery pack design incorporating a barrier unit with a bus bar unit that seals the electrical connection points between modules, using a bus bar unit with a conduction portion and a sealing portion to prevent thermal propagation, and optionally including a blocking portion for enhanced safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional barrier is provided between battery modules, then thermal propagation is partially suppressed, but thermal propagation cannot be completely blocked due to gaps at bus bar installation portions

Engineering Contradiction:
Improvethermal propagation suppressionVSAvoidbarrier structure completeness
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The barrier is divided into a barrier body and a separate cover portion. The cover portion specifically seals the bus bar installation portions, while the barrier body provides general thermal isolation. This segmentation allows each component to address specific thermal propagation paths without requiring complete redesign of the entire barrier structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover portion is designed to fit over and seal the bus bar installation portions on the barrier body. This nested configuration ensures that the bus bar connections, which are potential thermal propagation pathways, are enclosed within the barrier structure, preventing flame and gas from passing through these critical areas.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If battery modules are electrically connected through bus bar installation portions, then electrical connectivity is achieved, but thermal propagation occurs since flame or gas flows through these portions

Engineering Contradiction:
Improveelectrical connectionVSAvoidthermal propagation through bus bar portions
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cover portion acts as an intermediary element between the bus bar installation portions and the external environment. It provides a sealing interface that allows the bus bar to maintain electrical connectivity while preventing thermal propagation. The cover portion mediates between the need for electrical connection and the need for thermal isolation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the barrier structure is simplified without a cover portion, then device complexity is reduced, but thermal propagation prevention at bus bar portions is compromised

Engineering Contradiction:
Improvebarrier structureVSAvoidthermal propagation prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The barrier system is segmented into functional components: the barrier body for general thermal isolation and the cover portion for sealing bus bar areas. This segmentation allows the structure to remain relatively simple while addressing specific thermal propagation risks at critical locations without requiring complete structural redesign.

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 design effectively prevents the spread of gas or flame between battery modules, ensuring safer operation by sealing the connection points and reducing thermal propagation risks.

Implementation Method 1

a bus bar unit configured to electrically connect module terminals of different battery modules and located at an end or inside of the barrier unit to seal the end or inside of the barrier unit

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP4228083B1Battery pack with improved safety
Publication Date: 2025.10.29 LG ENERGY SOLUTION LTD
  • EP4228083B1 patent drawingFigure 1
  • EP4228083B1 patent drawingFigure 2
  • EP4228083B1 patent drawingFigure 3

AI summary

Disclosed is a battery pack with improved safety to more effectively prevent thermal propagation between battery modules. The battery pack includes a plurality of battery modules, each of which includes at least one battery cell and a module terminal; a barrier unit interposed between adjacent battery modules; and a bus bar unit configured to electrically connect module terminals of different battery modules and located at an end or inside of the barrier unit to seal the end or inside of the barrier unit.