In-vehicle Battery Module Structural Support for Vibration Reliability

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Solution Overview

Problem

Conventional in-vehicle battery modules with cylindrical cells lack sufficient structural integrity to maintain performance when components, such as adhesives, are damaged or degraded, leading to impaired electrical connections and poor reliability due to vibrations during vehicle travel.

Innovation Solution

The in-vehicle battery module design includes a battery cell holder, protective case, vent cover, bus bars, and a support member that maintains the axial position of cylindrical battery cells, ensuring electrical connections remain intact even if adhesives fail, with elastic members and integrated support structures to absorb height tolerance and distribute load effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If adhesive is used to fix cylindrical battery cells to battery cell holder, then assembly is simplified, but reliability deteriorates when adhesive is damaged or degraded due to vibrations

Engineering Contradiction:
Improveassembly simplicityVSAvoidelectrical connection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The support function is segmented from the adhesive bonding function. The battery cell holder provides mechanical support and positioning through its structure, while adhesive provides bonding. This segmentation means that if adhesive fails, the structural support remains intact, maintaining reliability while keeping assembly simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The battery cell holder is designed with beforehand cushioning features such as recesses and protrusions that compensate for potential adhesive failure. These structural elements are built in advance to prevent battery cell movement even when adhesive degrades from vibrations, thus cushioning against future reliability issues.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If side plates are used to hold cylindrical battery cells, then structural support is provided, but electrical connection reliability deteriorates when side plates are damaged or bent

Engineering Contradiction:
Improvestructural supportVSAvoidelectrical connection reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

Instead of relying on the entire side plate structure for both support and electrical connection, the invention uses local quality features: specific recesses and protrusions at critical locations provide localized support and alignment. This means damage to other parts of the side plate doesn't necessarily compromise electrical connections, improving reliability while maintaining structural strength.

Inventive Principle:
Principle #3Local quality

3Reliability

If multiple components are used to hold battery cells, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvebattery module reliabilityVSAvoidholding structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into the battery cell holder itself: mechanical support, positioning, alignment, and electrical connection maintenance are all integrated into this single component through features like recesses, protrusions, and bus bar integration. This reduces the number of separate holding components needed, thereby reducing device complexity while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

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

This design enhances the reliability of the battery module by maintaining electrical connections and reducing the risk of bus bar damage, even when adhesives are compromised, thereby ensuring consistent performance during vibrations.

Implementation Method 1

an elastic member disposed at least one of between the end faces on the first-electrode sides of the cylindrical battery cells and the protective case and between the end faces on the second-electrode sides of the cylindrical battery cells and the second-electrode bus bar such that the elastic member elastically deforms to absorb an axial height tolerance of the cylindrical battery cells

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3249716B1In-vehicle battery module
Publication Date: 2020.01.08 TOYOTA JIDOSHA KK
  • EP3249716B1 patent drawingFigure 1
  • EP3249716B1 patent drawingFigure 2
  • EP3249716B1 patent drawingFigure 3

AI summary

An in-vehicle battery module includes a plurality of cylindrical battery cells (12), a battery cell holder (14), a protective case (16), a vent cover (20) provided such that the battery cell holder is positioned between the protective case and the vent cover, the vent cover and the battery cell holder disposed such that a vent space in which gas discharged from an end face on a second-electrode side of the cylindrical battery cell flows is provided between the vent cover and the battery cell holder, at least one first-electrode bus bar (23), at least one second-electrode bus bar (25) provided in the vent space, and a support member (50) disposed partially in the vent space and the support member being configured to support the second-electrode bus bar from the vent cover side.