Assembled Battery Swell Control via Segmented End Plates

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Solution Overview

Problem

Conventional assembled batteries experience significant elongation due to swelling lithium ion secondary batteries, which is problematic for vehicles with limited mounting space, as it can interfere with surrounding components and is challenging to manage with increasing battery capacity.

Innovation Solution

The battery cells are arranged in series with end plates divided into small plates, connected by metal bands, which relax the reaction force from swelling and minimize elongation by distributing the load effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If bar-shaped spacers are continuously connected to suppress battery cell swells, then the swell amount is controlled, but the assembled battery elongates due to reaction force from constraining

Engineering Contradiction:
Improvebattery cell swell controlVSAvoidassembled battery elongation
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The end plates are divided into multiple small plates arranged in a matrix pattern, which segments the constraint structure to reduce localized reaction forces that cause elongation while maintaining overall swell control

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The small plates are positioned at specific locations corresponding to terminal positions, creating non-uniform constraint distribution that allows swell accommodation in critical areas while maintaining control where needed

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If the capacity of battery cells is increased, then higher energy storage is achieved, but the swell amount becomes bigger causing difficulty in maintaining spaces between cells

Engineering Contradiction:
Improvebattery capacityVSAvoidspace maintenance between cells
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

Dividing end plates into small plates distributed across the battery cell surfaces provides multiple discrete constraint points that can accommodate larger overall swell while maintaining proper spacing between adjacent cells

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The constraint structure is distributed across two dimensions (width and length) rather than concentrated at edges, allowing the battery to swell uniformly in the thickness direction without compromising inter-cell spacing

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

3Volume of moving object

If the assembled battery size is confined within predetermined limits, then mounting space requirements are met, but deformation of battery cells due to swell must be suppressed

Engineering Contradiction:
Improveassembled battery size confinementVSAvoidbattery cell deformation
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

Small plates are strategically positioned at terminal locations where electrical connections are made, providing localized constraint that prevents deformation at critical areas while allowing controlled swell in non-critical regions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The distributed small plate configuration segments the constraint function across multiple locations, maintaining overall size confinement while accommodating local deformation needs of high-capacity battery cells

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3285310B1Assembled battery
Publication Date: 2020.03.11 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3285310B1 patent drawingFigure 1A
  • EP3285310B1 patent drawingFigure 1B
  • EP3285310B1 patent drawingFigure 1C

AI summary

In a state where battery cells (2) are sandwiched from both ends by a pair of end plates (3) comprising a plurality of plates, the pair of end plates (3) are secured by metal bands (4). The end plates (3) are secured by bolts to a base, at the inside end of the plates as seen from the battery cells (2). Then, elongation of the assembled battery (1) can be kept to a small range, even when the battery cells (2) are swollen.