Battery Cell Manufacturing Device Gravity-Assisted Stacking

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Solution Overview

Problem

Current battery cell manufacturing processes are complex and costly, particularly for prismatic and pouch-shaped batteries, due to issues with stress concentration and short circuits in stack type electrode assemblies, and require significant space and equipment investment for stack/folding type electrode assemblies.

Innovation Solution

A battery cell manufacturing device that stacks unit cells with a separator in between, using a hopper-type unit cell stacking unit to facilitate gravity-assisted stacking, followed by wrapping with a separation film and thermal shrinking to improve processability and quality, while minimizing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If stack type electrode assembly is used, then prismatic structure is achieved, but manufacturing process becomes complicated and short circuits may occur due to electrode pushing under external impact

Engineering Contradiction:
Improveprismatic structureVSAvoidmanufacturing process complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The electrode assembly is segmented into multiple independent pouch-shaped cells that are stacked together. Each pouch cell contains folded electrode plates with separators, creating discrete units that are less prone to short circuits while maintaining the overall prismatic shape of the battery pack.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention combines elements of both jelly-roll and stack type assemblies by using folded electrode plates within pouch cells, creating a composite structure that leverages the advantages of both types while mitigating their respective disadvantages.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If stack/folding type electrode assembly is used, then manufacturing complexity is reduced, but significant space and equipment investment are required

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidmanufacturing space requirement
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The manufacturing process is segmented into independent steps for each pouch cell, allowing for compact, modular equipment layouts. Unit cells are assembled, folded, and sealed in separate stations that can be arranged in a space-efficient manner, reducing the overall manufacturing footprint.

Inventive Principle:
Principle #1Segmentation

3Productivity

If unit cells are stacked with physical pushing, then stacking is achieved, but stress concentrates on battery causing electrode detachment and deformation

Engineering Contradiction:
Improvestacking efficiencyVSAvoidelectrode integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A separator film is introduced as an intermediary element between stacked unit cells. This film distributes the stacking force uniformly across the electrode surfaces, preventing stress concentration and electrode detachment while maintaining effective stacking.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The separator film acts as a flexible intermediary layer that conforms to the electrode surfaces, distributing mechanical stress evenly during stacking operations and preventing deformation and detachment of electrode materials.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If separator film is wrapped and thermally shrunk, then unit cell stack is protected, but manufacturing process time increases

Engineering Contradiction:
Improveunit cell stack protectionVSAvoidmanufacturing cycle time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The separator film undergoes a thermal phase transition during shrinking, rapidly changing from a relaxed state to a tightly conforming state around the unit cell stack. This rapid phase change provides efficient protection without requiring prolonged processing time.

Inventive Principle:
Principle #36Phase transitions

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 approach simplifies the manufacturing process, enhances battery cell quality and capacity, and reduces costs by allowing for efficient stacking and protection of unit cells without physical pushing, thereby improving the integration and reliability of battery cells.

Implementation Method 1

a heating unit to thermally shrink the separation film wrapping the outside of the unit cell stack

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 2

a hopper-type unit cell stacking unit to facilitate gravity-assisted stacking

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2648263B1Device for manufacturing battery cell
Publication Date: 2020.03.18 LG CHEM LTD
  • EP2648263B1 patent drawingFigure 1~2
  • EP2648263B1 patent drawingFigure 3
  • EP2648263B1 patent drawingFigure 4

AI summary

Disclosed herein is a battery cell manufacturing device configured to manufacture a battery cell including two or more unit cells. The battery cell manufacturing device includes a unit cell stacking unit into which unit cells are introduced from above and in which the unit cells are sequentially stacked, a wrapping unit to wrap an outside of the unit cell stack discharged from the unit cell stacking unit with a separation film, and a heating unit to thermally shrink the separation film wrapping the outside of the unit cell stack.