Battery Module Bus Bar Frame Sealing Against Thermal Runaway

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Solution Overview

Problem

Existing battery modules are prone to damage and thermal runaway due to high-temperature gases and flames discharged through slots in the bus bar frame during thermal events, risking fire or explosion and serial thermal runaway of adjacent cells.

Innovation Solution

A battery module design featuring a guide portion on the bus bar frame that expands to block gas discharge and includes an elastic guide structure with a filling space for fire extinguishing, along with an insulating cover to prevent electrical shorts and enhance safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrode leads pass through slots in the bus bar frame to connect to bus bars, then electrical connection is achieved, but high-temperature gases and flames can discharge through the slots during thermal runaway, damaging bus bars and terminals

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidthermal damage to bus bar
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A guide structure is introduced as an intermediary component between the electrode lead and the bus bar frame slot. This guide structure seals the slot opening while allowing the electrode lead to pass through, thereby preventing high-temperature gases and flames from reaching the bus bar while maintaining electrical connectivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The guide structure is installed in advance to prevent thermal runaway propagation before it can occur. By sealing the slot openings beforehand, the system prepares countermeasures against potential thermal damage, preventing high-temperature gases and flames from damaging the bus bar during thermal runaway events.

Inventive Principle:
Principle #9Preliminary anti-action

2Quantity of substance

If battery cells are densely disposed to increase energy density, then energy density improves, but control of gas discharge direction becomes more difficult, increasing risk of thermal runaway spread

Engineering Contradiction:
Improveenergy densityVSAvoidthermal runaway propagation
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The harmful function of the slot (allowing gas discharge) is extracted and separated from its useful function (allowing electrode lead passage). The guide structure retains the electrical connection function while removing the gas discharge pathway, thereby preventing thermal runaway spread even when battery cells are densely packed.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a sealing structure is added to block gas discharge through slots, then thermal safety improves, but manufacturing complexity and assembly difficulty increase

Engineering Contradiction:
Improvethermal safetyVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The guide structure is designed as a flexible component that can be easily deformed during assembly to accommodate electrode leads, then returns to its sealed position. This flexibility simplifies the assembly process while maintaining the sealing function to block gas discharge.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The guide structure automatically seals the slot opening when the electrode lead passes through, without requiring additional sealing operations or complex assembly steps. The structure serves both the electrical connection and thermal protection functions through its own design, reducing manufacturing complexity.

Inventive Principle:
Principle #25Self-service

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

Prevents damage to bus bars and terminals, suppresses fires, and delays serial thermal runaway by blocking gas discharge and extinguishing flames, enhancing electrical safety and module integrity.

Implementation Method 1

a guide portion configured to guide an electrode lead of the battery cell to an entrance of a slot of the bus bar frame and expand after the electrode lead is inserted into the slot

Methodology Applied
Scientific EffectElastic expansion: Elasticity

Implementation Method 2

the filling space is filled with a filling material in a gel or liquid state, thereby extinguishing or suppressing a fire that occurs in the battery module

Methodology Applied
Scientific EffectFire suppression through gel/liquid material: Gel

Data Source

PatentEP4415152B1Battery module, and battery pack and vehicle including same
Publication Date: 2026.02.04 LG ENERGY SOLUTION LTD
  • EP4415152B1 patent drawingFigure 1
  • EP4415152B1 patent drawingFigure 2
  • EP4415152B1 patent drawingFigure 3

AI summary

A battery module according to an embodiment of the present disclosure may include: a battery cell including an electrode lead extending a predetermined length; a bus bar frame having a slot into which the electrode lead is inserted and a guide portion configured to guide the electrode lead to the entrance of the slot; and a bus bar coupled to the bus bar frame and connected to an end of the electrode lead inserted into the slot.