Battery Pack Electrode Tab Load Reduction

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Solution Overview

Problem

The existing battery pack designs face issues with fatigue fracture and joint separation of electrode tabs due to deformation of busbar modules caused by battery expansion and contraction, leading to increased load on electrodes and potential damage.

Innovation Solution

A battery pack design that includes multiple batteries with electrodes protruding from both ends, a substrate with insertion holes, and a fixing plate arranged between adjacent batteries, which reduces the load on electrodes by allowing the busbar modules to move with the batteries without being fixed to end plates, thereby minimizing position offset and stress on the electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If busbar modules are fastened to both end plates to prevent deformation, then structural stability is improved, but electrode tabs experience increased load and position offset due to battery expansion and contraction

Engineering Contradiction:
Improvestructural stabilityVSAvoidelectrode tab reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The battery pack structure is segmented into multiple independent battery units, each with its own busbar module and electrode tabs. This segmentation allows each battery unit to expand and contract independently without transmitting stress to adjacent units, reducing the load on individual electrode tabs while maintaining overall structural stability through the modular arrangement.

Inventive Principle:
Principle #1Segmentation

2Shape

If busbar modules are fastened to both end plates, then deformation of busbar modules is limited, but position offset between electrode tabs and slits increases during battery expansion and contraction

Engineering Contradiction:
Improvebusbar module shapeVSAvoidposition offset
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent employs flexible connection structures between the busbar modules and end plates, allowing the busbar modules to move slightly with battery expansion and contraction. This flexibility accommodates position offset between electrode tabs and slits while preventing excessive deformation of the busbar modules, resolving the contradiction between maintaining shape and allowing positional adjustment.

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If busbar modules are fastened to both end plates, then mechanical support is improved, but fatigue fracture and joint separation of electrode tabs occur due to repeated stress

Engineering Contradiction:
Improvemechanical supportVSAvoidjoint reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent transitions from a static fastening system to a dynamic one where busbar modules can move with battery expansion and contraction. This dynamic design allows the system to adapt to changing dimensions during charge-discharge cycles, reducing repeated stress on electrode tabs and preventing fatigue fracture and joint separation while maintaining adequate mechanical support.

Inventive Principle:
Principle #15Dynamics

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 effectively reduces the load on electrodes during battery expansion and contraction, minimizing fatigue fracture and joint separation risks while allowing busbar modules to move with the batteries, and provides a cooling effect using an aluminum fixing plate.

Implementation Method 1

provides a cooling effect using an aluminum fixing plate

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3591740A1Battery pack
Publication Date: 2020.01.08 YAZAKI CORP
  • EP3591740A1 patent drawingFigure 1
  • EP3591740A1 patent drawingFigure 2
  • EP3591740A1 patent drawingFigure 3

AI summary

A battery pack is provided which enables a reduction of a load on the electrodes which occurs with expansion or contraction of the batteries. Multiple batteries (21-26) have electrode tabs (202) protruding from both ends, and are stacked in a stacking direction (D1) orthogonal to a protrusion direction (D2) of the electrode tabs (202). Busbar modules (41, 42) are jointed to the electrode tabs (202) and comprise busbars (402) for connecting the batteries (21-26). An aluminum plate (5) is arranged between batteries (23, 24) of the multiple batteries (21-26) which are adjacent to a center. This aluminum plate (5) and the busbar modules (41, 42) are fixed.