Bus Bar Flame Blocking Structure for Pouch Cell Thermal Runaway

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Solution Overview

Problem

Existing battery cell assemblies face challenges in preventing thermal runaway and flame propagation from spreading to adjacent cells, with current solutions increasing module size or not effectively blocking flame propagation to electrode leads.

Innovation Solution

A battery cell assembly with a bus bar and a flame blocking member, comprising a mesh net made of high rigidity and heat-resistant materials, integrated into the bus bar to prevent flame, particles, and gas from spreading, while maintaining a compact design by using overlapping net structures and a through-hole configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thermal insulation pad is added to cover the portion where the electrode lead and the bus bar are welded, then heat propagation to adjacent battery cells is prevented, but the battery module size increases by the thickness of the thermal insulation pad

Engineering Contradiction:

Improveheat propagation preventionVSAvoidbattery module size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The flame blocking member is integrated with the bus bar to form a single combined structure. The bus bar serves both its electrical conduction function and the flame blocking function, eliminating the need for separate thermal insulation components and thereby preventing battery module size increase

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bus bar is designed to perform multiple functions: electrical connection and flame blocking. By making the bus bar multi-functional, the patent avoids adding extra components that would increase the battery module size while still achieving heat propagation prevention

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a flame prevention net is added to the inside or outside of the pouch-type secondary battery, then flame propagation is blocked, but the overall volume increases and the configuration for blocking flame propagation to electrode leads is not disclosed

Engineering Contradiction:

Improveflame propagation blockingVSAvoidoverall volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The flame blocking member is merged with the bus bar structure, creating an integrated component that blocks flame propagation to the electrode leads without requiring separate flame prevention nets that would increase overall volume

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The flame blocking member acts as an intermediary structure between the battery cell and the electrode lead connection point. It intercepts and blocks flame propagation before it can reach the electrode leads, preventing fire spread without adding external volume

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If a mesh net with high rigidity and heat resistance is coupled to the bus bar, then flame, particles, and gas are blocked from spreading to adjacent cells, but the device complexity increases

Engineering Contradiction:

Improveflame and particle blockingVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The mesh net is coupled to and integrated with the bus bar, forming a unified structure. This merging approach blocks flame, particles, and gas spread while minimizing device complexity by combining safety functions with the existing electrical connection structure

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The flame blocking member uses a composite structure combining the mesh net material with the bus bar material. This composite approach provides both flame blocking capability and structural integrity without requiring completely separate complex components

Inventive Principle:

Principle #40Composite materials

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

Effectively reduces the risk of external ignition and propagation of heat sources, protects soft pouch-type battery cells from impact, and controls discharge direction of thermal events, thereby preventing thermal runaway between adjacent cells.

Implementation Method 1

a flame blocking member including a mesh net formed of a material with high rigidity and high heat resistance coupled to a body of the bus bar

Methodology Applied

Scientific EffectPhysical Containment: Physical Containment

Implementation Method 2

a flame blocking member including a mesh net formed of a material with high rigidity and high heat resistance coupled to a body of the bus bar

Methodology Applied

Scientific EffectHeat Exchange: Heat Exchanger

Data Source

PatentUS20240396158A1Battery cell assembly including bus bar with flame blocking member and battery cell assembly structure

Publication Date: 2024.11.28 LG ENERGY SOLUTION LTD

AI summary

A battery cell assembly is provided. The battery cell assembly includes at least one pouch-type battery cell including an electrode lead, a cell cover surrounding the at least one pouch-type battery cell and having a front open end or a rear open end, a bus bar connected to the electrode lead of the at least one pouch-type battery cell, a bus bar frame supporting the bus bar and covering the front open end or the rear open end of the cell cover where the electrode lead is located, and a flame blocking member including a mesh net formed of a material with high rigidity and high heat resistance coupled to a body of the bus bar.