Battery Pack Bus Bar Layout for Thermal Runaway Isolation

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Solution Overview

Problem

Existing battery packs face safety concerns due to potential internal short circuits during thermal runaway events, which can compromise their safety and performance.

Innovation Solution

The battery pack design disperses positive and negative terminals of multiple cell assemblies, utilizing inter-bus bars to connect them in specific configurations, along with a center beam and cross-beams to maintain spacing and prevent internal short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If battery cell assemblies are arranged closely to improve energy density, then the energy density increases, but the risk of internal short circuits during thermal runaway events increases

Engineering Contradiction:
Improveenergy densityVSAvoidsafety
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The battery pack is divided into multiple groups (first to sixth battery cell assemblies) arranged in a specific pattern with inter-bus bars spaced apart. This segmentation creates physical separation between positive and negative terminals, preventing thermal runaway propagation while maintaining high cell density within each group.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Inter-bus bars serve as intermediary components that electrically connect battery cells while maintaining spatial separation. The inter-bus bars are positioned to connect adjacent cells in each group but are spaced apart from each other, acting as controlled conduits for electrical connection while preventing direct thermal contact between opposing terminals.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If inter-bus bars are positioned close together to reduce pack size, then the compactness improves, but the risk of internal short circuits increases

Engineering Contradiction:
Improvepack sizeVSAvoidinternal short circuit risk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

Different regions of the battery pack have different inter-bus bar spacing configurations. Within each group of battery cell assemblies, inter-bus bars are positioned close together to minimize local volume. However, between groups (specifically between first-third and fourth-sixth assemblies), the inter-bus bars are spaced apart to prevent harmful thermal and electrical interactions.

Inventive Principle:
Principle #3Local quality

3Power

If positive and negative terminals are positioned close together to improve electrical connectivity, then the electrical resistance decreases, but the vulnerability to thermal runaway propagation increases

Engineering Contradiction:
Improveelectrical connectivityVSAvoidthermal runaway propagation
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The battery pack arrangement utilizes three-dimensional spatial configuration to resolve the contradiction. Within each group, terminals are positioned for optimal electrical connectivity. Between groups arranged in the second direction, the inter-bus bars are positioned at different heights or depths, creating vertical or depth-wise separation that prevents thermal runaway propagation while maintaining electrical connectivity through the inter-bus bar design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4679618A1Battery pack
Publication Date: 2026.01.14 LG ENERGY SOLUTION LTD
  • EP4679618A1 patent drawingFigure 1
  • EP4679618A1 patent drawingFigure 2
  • EP4679618A1 patent drawingFigure 3

AI summary

A battery pack including first to third battery cell assemblies arranged in a first direction; fourth to sixth battery cell assemblies arranged in the first direction, the fourth to sixth battery cell assemblies being spaced apart from the first to third battery cell assemblies in a second direction that is perpendicular to the first direction; and first to fifth inter-bus bars, wherein the first inter-bus bar and the second inter-bus bar are spaced apart from each other in the second direction.