Zigzag Film Packaging for Compact Power Storage Modules

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Solution Overview

Problem

Energy storage modules face a trade-off between reducing weight and maintaining high sealing properties, which affects energy density, as increasing the sealing area widens the interval between electrode assemblies, leading to increased size and reduced energy density.

Innovation Solution

The use of a film outer body that wraps and seals electrode assemblies in a zigzag manner, with alternating connectors and overlapping inclined portions, allows for a compact design while maintaining sealing integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the area of the sealing portion is increased to ensure high sealing property, then the sealing reliability is improved, but the interval between adjacent electrode assemblies is widened, leading to increased outer dimension and reduced energy density

Engineering Contradiction:
Improvesealing propertyVSAvoidouter dimension
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The film outer body is bent or curved between adjacent housing portions to extend in a zigzag manner, utilizing spatial arrangement in multiple dimensions to reduce the linear interval between electrode assemblies while preserving sealing area, thereby improving energy density without compromising sealing reliability

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

Solution Approach 2:

The film outer body incorporates curved or bent sections between housing portions, using curvature to efficiently pack the sealing structure within a compact volume, reducing the overall outer dimension while maintaining adequate sealing portion area

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Weight of moving object

If outer cans housing electrode assemblies are eliminated to reduce weight, then the weight of the energy storage module is reduced, but the sealing property of electrode assemblies must be maintained at high level

Engineering Contradiction:
ImproveweightVSAvoidsealing property
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent replaces rigid outer cans with a flexible film outer body that individually wraps and seals each electrode assembly, significantly reducing weight while maintaining sealing integrity through the film's continuous sealing structure and connector design

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

Multiple housing portions are connected by sealing portions formed from a single continuous film outer body, creating an integrated structure that provides both weight reduction and reliable sealing across all electrode assemblies

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4191626B1Power storage device and power storage module
Publication Date: 2026.03.11 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4191626B1 patent drawingFigure 1
  • EP4191626B1 patent drawingFigure 2A~2B
  • EP4191626B1 patent drawingFigure 3A~3C

AI summary

A power storage device 1 is provided with a plurality of cylindrical electrode bodies and a film outer package 4. The film outer package 4 comprises a plurality of containers 12 and a seal 14. The plurality of containers 12 individually encase the plurality of electrode bodies, and the seal 14 seals the containers 12 and connects the plurality of containers 12 to each other. The film outer package 4 extends in a zig-zag manner with bends or curves between adjacent containers 12.