Ceramizable Inter-Module Busbar Insulation for Fire Short-Circuit Prevention

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Solution Overview

Problem

Existing inter-module busbars in battery packs face issues with increased thickness and weight due to additional bandage members, and when insulating materials burn away in a fire, they expose the metal plate, leading to short circuits.

Innovation Solution

An inter-module busbar design featuring a first expandable insulating layer and a second ceramizable insulating layer that maintains insulation by expanding to fill cracks in the second layer, preventing exposure of the metal plate during a fire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If busbars are disposed close to each other to reduce space, then space utilization is improved, but heat dissipation becomes insufficient leading to temperature increase

Engineering Contradiction:
Improvespace utilizationVSAvoidbusbar temperature
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The busbar structure is segmented into multiple modular units that can be independently arranged. Each module contains busbars with specific spacing, and multiple modules are combined to form the complete battery pack structure, allowing optimized thermal management while maintaining compact overall dimensions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a nested arrangement where busbars are positioned within modular compartments that are themselves nested within the battery pack structure. This nested doll approach allows efficient space utilization while maintaining proper thermal zones for heat dissipation

Inventive Principle:
Principle #7Nested doll (Nesting)

2Temperature

If busbars are disposed far apart to improve heat dissipation, then temperature control is improved, but space utilization deteriorates

Engineering Contradiction:
Improvebusbar temperatureVSAvoidspace utilization
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The busbar arrangement is divided into segmented modules where thermal management is optimized at the module level. Each module maintains appropriate spacing for heat dissipation, while the modular design allows compact stacking to improve overall space utilization

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from two-dimensional busbar spacing to three-dimensional modular stacking. By utilizing vertical stacking and multi-layer arrangements, the system achieves both adequate thermal spacing and high space utilization through dimensional optimization

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

3Power

If multiple busbars are connected in parallel to increase current capacity, then power output is improved, but risk of short circuit and thermal runaway increases

Engineering Contradiction:
Improvecurrent capacityVSAvoidshort circuit risk
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The parallel busbar connections are segmented into isolated modular units with independent electrical enclosures. Each module contains specific numbers of busbars (e.g., 2, 4, or 6) that are electrically isolated from other modules, maintaining high current capacity while reducing short circuit risk through physical separation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces insulating barriers and protective coatings as intermediary elements between parallel busbars. These intermediaries prevent direct contact and potential short circuits while allowing the busbars to maintain their parallel configuration for high current capacity

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If conventional welding or crimping methods are used to connect busbars, then connection strength is improved, but manufacturing complexity and time increase

Engineering Contradiction:
Improveconnection strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The connection structure merges multiple functions into a single integrated component. The connection element simultaneously provides mechanical support, electrical connection, and thermal management functions, eliminating the need for separate welding or crimping operations and significantly improving manufacturing efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional mechanical connection methods (welding, crimping) with a simplified insertion-based mechanical coupling system. This substitution eliminates complex thermal processes and specialized equipment requirements, reducing manufacturing complexity and increasing productivity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 ensures the metal plate remains insulated even in high-temperature conditions, minimizing the risk of short circuits by maintaining the insulating layers' integrity despite fire damage.

Implementation Method 1

adjacent ones among the plurality of busbars are insulated from each other by an insulating layer

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 2

a support is provided that supports the plurality of busbars so as to space the busbars apart from each other

Methodology Applied
Scientific EffectMechanical support: Mechanical Force

Data Source

PatentEP4391210B1Intermodular busbar including insulating layer and battery pack including same
Publication Date: 2026.04.29 LG ENERGY SOLUTION LTD
  • EP4391210B1 patent drawingFigure 1
  • EP4391210B1 patent drawingFigure 2
  • EP4391210B1 patent drawingFigure 3

AI summary

The present invention relates to an inter-module busbar including a metal plate for electrical connection, a first insulating layer configured to enclose at least a part of the metal plate, the first insulating layer being expandable at high temperatures, and a second insulating layer added to the first insulating layer, the second insulating layer being configured to be ceramized at high temperatures, wherein the metal plate in the busbar is not exposed in the event of fire, whereby short circuit due to contact with the metal plate may be prevented.