Laminated Battery Cladding Deep Drawing via Differential Temperature Control

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Solution Overview

Problem

Existing methods for manufacturing external claddings for laminate batteries face challenges in increasing battery capacity and preventing contamination from impurities, as they often result in molding defects and allow lubricating oil to infiltrate the battery, leading to malfunctions.

Innovation Solution

The method involves using austenitic stainless steel foil with a thermoplastic resin layer on one surface and a lubricating film on the other, drawn under specific temperature conditions without lubricating oil, where the annular region is cooled and the exterior region is heated, allowing for deep drawing and reducing contamination risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If drawing is implemented on stainless steel foil at room temperature, then a strong and lightweight laminate battery can be constructed, but molding defects such as cracks occur when forming a deep projecting portion

Engineering Contradiction:
Improvestrength of laminate batteryVSAvoidmolding quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent changes the temperature parameter from room temperature to warm temperature (heating the stainless steel foil to 50-150°C before drawing). This parameter change enables deep drawing without cracks while maintaining the strength benefits of stainless steel foil, resolving the contradiction between strength and molding quality.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If lubricating oil is supplied during drawing, then deep drawing can be realized, but the lubricating oil and dust may infiltrate the battery interior causing malfunction

Engineering Contradiction:
Improvedeep drawing capabilityVSAvoidcontamination infiltration
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful element (lubricating oil) from the drawing process. By using warm working without lubricating oil, the patent achieves deep drawing capability while preventing oil infiltration into the battery, thus resolving the contradiction between deep drawing capability and contamination prevention.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a substitute intermediary (warm temperature treatment) to replace the harmful lubricating oil. The heated stainless steel foil becomes more formable, enabling deep drawing without requiring lubricating oil, thereby preventing contamination while achieving the desired drawing depth.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If lubricating oil is not used during drawing, then contamination infiltration is prevented, but the material cannot be moved smoothly and deep drawing cannot be realized

Engineering Contradiction:
Improvecontamination infiltrationVSAvoiddeep drawing processability
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the temperature parameter of the stainless steel foil to warm conditions (50-150°C), which fundamentally alters the material's formability. This parameter change enables smooth material movement and deep drawing without lubricating oil, resolving the contradiction between preventing contamination and achieving deep drawing processability.

Inventive Principle:
Principle #35Parameter changes

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 enables increased battery capacity by preventing infiltration of impurities and allowing for successful deep drawing without lubricating oil, reducing the risk of contamination and improving the manufacturing process.

Implementation Method 1

an exterior region on an exterior of the annular region is set at a temperature between 40°C and 100°C

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

an annular region of the stainless steel foil, which is contacted by a shoulder portion of the punch, is set at a temperature of 0 - 20°C

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP2693512B1Method of manufacturing cladding for laminated battery
Publication Date: 2018.05.02 NISSHIN STEEL CO LTD
  • EP2693512B1 patent drawingFigure 1~2
  • EP2693512B1 patent drawingFigure 3~4
  • EP2693512B1 patent drawingFigure 5~6

AI summary

In method for manufacturing an external cladding for a laminate battery according to the present invention, austenitic stainless steel foil 32 having a thermoplastic resin layer 30 on one of a front surface and a rear surface and a lubricating film 31 on the other surface is used as a material, the stainless steel foil 32 is disposed such that the surface provided with the thermoplastic resin layer 30 opposes a punch 42, and drawing is implemented on the stainless steel foil 32 without using lubricating oil in a condition where an annular region 32a of the stainless steel foil 32, which is contacted by a shoulder portion 42d of the punch 42, is set at a temperature of 20°C or lower, and an exterior region 32b on an exterior of the annular region 32a is set at a temperature between 40°C and 100°C.