Battery Cell Sealing Region Shortening to Eliminate Bat-Ears

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery cell manufacturing processes create bat-ears at the intersection of fold lines and sealing sections, which impair the dimensional stability and flatness of the cell housing, preventing it from resting properly on support structures.

Innovation Solution

A method involving plastic deformation of the sealing region's second section using a bending tool to introduce patterns like waves or zigzags, reducing the effective length and correcting bat-ears by applying heat and pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If material layers are bonded to form sealing sections using pressure and heat, then the receiving space is sealed, but bat-ears are formed at the intersection of fold lines and sealing sections

Engineering Contradiction:
Improvesealing qualityVSAvoidflatness of cell housing
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The method performs preliminary action by shortening the sealing section before final bonding. The material layers are pre-cut or pre-formed with reduced length in the sealing section, preventing excess material from forming bat-ears during the bonding process. This preliminary dimensioning ensures that when pressure and heat are applied to create the seal, no protruding material remains at the fold line intersections.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If excess material remains at the sealing section, then sealing coverage is increased, but dimensional stability of the battery cell is impaired

Engineering Contradiction:
Improvesealing coverageVSAvoiddimensional stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention applies parameter changes by precisely controlling the dimensions of the sealing section. The length of the sealing section is optimized to provide adequate sealing coverage while eliminating excess material. By adjusting the sealing section length parameter to match the exact required coverage, the method achieves both sufficient sealing and maintained dimensional stability, preventing bat-ear formation.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the cell housing has protruding bat-ears, then material coverage is maximized, but the bottom surface cannot rest flatly on support structures

Engineering Contradiction:
Improvematerial coverageVSAvoidflatness on support surface
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The method extracts the problematic excess material from the sealing section before the bonding process. By removing or reducing the material length in the sealing section preliminarily, the bat-ears are prevented from forming. This extraction of excess material ensures that the cell housing maintains proper geometry with a flat bottom surface that can rest evenly on module frames or cooling plates.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The method effectively eliminates or reduces bat-ears, ensuring the cell housing lies flat and maintains dimensional accuracy, enhancing thermal and mechanical stability.

Implementation Method 1

at least a second section of the sealing region is plastically deformed by a bending tool in order to shorten the length of the second section

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The material layers are then bonded to the sides of the receiving space using pressure and heat to form sealing sections

Methodology Applied
Scientific EffectHeat: Heating

Implementation Method 3

The material layers are then bonded to the sides of the receiving space using pressure and heat to form sealing sections

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4557464A1Method for shortening sealing portions
Publication Date: 2025.05.21 CELLFORCE GROUP GMBH
  • EP4557464A1 patent drawingFigure 1
  • EP4557464A1 patent drawingFigure 2A
  • EP4557464A1 patent drawingFigure 2B

AI summary

The invention relates to a method for producing or processing a sealing region of a cell housing of a battery cell, wherein the sealing region is formed from at least two superimposed material layers which at least partially delimit a receiving space of the cell housing. The sealing region and/or the cell housing are fixed in place, and at least a second section of the sealing region is plastically deformed by a bending tool to shorten the length of the second section. Furthermore, the invention relates to a battery cell.