Stacked Secondary Battery Separator Wrap for Impact Protection

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Solution Overview

Problem

The enlargement of secondary batteries for battery electric vehicles increases the weight of the electrode body, leading to a higher risk of damage from impact and vibration during manufacturing, compromising the reliability of the battery.

Innovation Solution

A secondary battery design featuring a stacked-type electrode body with a zigzag-bent separator that is wound around the outer periphery of the electrode plates, providing a zigzag-bent part and a wound part, and includes an extension part to protect the electrodes from impact and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the size of the secondary battery is enlarged to extend the cruising distance of BEV, then the battery capacity is improved, but the weight of the electrode body increases leading to higher risk of damage from impact and vibration

Engineering Contradiction:
Improvebattery capacityVSAvoidresistance to impact and vibration damage
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The separator is designed with a specific configuration where it extends beyond the electrode plates at both ends in the stacking direction, creating a protective structure that cushions the electrodes against impact and vibration before damage can occur. This beforehand cushioning approach addresses the reliability issue by preemptively protecting the electrodes in the enlarged battery design.

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

2Weight of moving object

If the weight of the electrode body is increased to provide sufficient battery capacity, then the cruising distance is improved, but the damage risk from impact and vibration during manufacture increases

Engineering Contradiction:
Improveelectrode body weightVSAvoidresistance to impact and vibration damage
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The separator configuration creates a protective cushioning structure that mitigates the increased vulnerability of heavier electrode bodies to impact and vibration damage during manufacturing processes.

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

Solution Approach 2:

The separator acts as an intermediary protective element between the heavy electrode plates and external impact forces, reducing the transmission of mechanical stress to the electrodes during handling and assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a conventional separator configuration is used, then the battery structure is simple, but the outermost surfaces and corners of the electrodes are exposed and vulnerable to damage

Engineering Contradiction:
Improveseparator configuration complexityVSAvoidprotection of electrode outer surfaces
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The separator extends beyond the electrode plates at both ends in the stacking direction, creating a protective overhang that shields the outermost surfaces and corners of the electrodes before impact can occur. This configuration provides beforehand protection without requiring complex additional structures.

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

Solution Approach 2:

The separator, as a flexible thin film structure, is configured to extend beyond the electrodes and wrap around corners, providing protective coverage of vulnerable electrode surfaces through its adaptable geometry rather than rigid shielding.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP4632857A1Secondary battery
Publication Date: 2025.10.15 PRIME PLANET ENERGY & SOLUTIONS INC
  • EP4632857A1 patent drawingFigure 1~2
  • EP4632857A1 patent drawingFigure 3~4
  • EP4632857A1 patent drawingFigure 5

AI summary

A secondary battery in which a problem in a conventional art is solved is provided. A secondary battery according to the present disclosure includes: a stacked-type electrode body that includes a plurality of first electrode plates, a plurality of second electrode plates, and a separator with a band-like shape; and a battery case. The separator includes a zigzag-bent part that is bent in a zigzag manner so that the separator is disposed between the first electrode plate and the second electrode plate, and a wound part that is wound to an outer periphery of a part where the first electrode plates, the second electrode plates, and the zigzag-bent part are stacked. The separator includes a start end part corresponding to an end part on one side in a longitudinal direction and a terminal end part corresponding to an end part on the other side. The terminal end part is positioned at a winding terminal end of the wound part. The zigzag-bent part includes a first bent part and a second bent part. The separator includes an extension part that is positioned on a side of the start end part relative to the zigzag-bent part, and disposed between the second bent part and the wound part. In the stacking direction of the first electrode plate and the second electrode plate, outer surfaces of both electrode plates that are positioned at the outermost surface sides are covered with the separator.