Secondary Battery Hard Case Using Thermal Adhesion Layer

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Solution Overview

Problem

Conventional secondary batteries face challenges in achieving both high resistance against external impacts and low weight, with existing case materials either being heavy or lacking in strength, and also have inefficiencies in sealing.

Innovation Solution

A secondary battery design featuring a hard case formed from lightweight and impact-resistant plastic resins, with a two-part case structure coupled by a thermal adhesion layer for enhanced sealing efficiency, replacing traditional aluminum cans or composite pouches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an aluminum can is used as the case material, then the strength and resistance against external impacts is improved, but the weight increases

Engineering Contradiction:
Improveresistance against external impactsVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent employs a composite case structure consisting of a plastic resin base layer combined with an aluminum foil layer. This composite material approach allows the case to achieve the high strength and impact resistance of aluminum while significantly reducing the overall weight compared to a solid aluminum can. The plastic resin provides structural integrity and the aluminum foil reinforces strength, creating a lightweight yet durable case.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The case is designed with a multi-layer construction where different materials are applied in specific locations and thicknesses. The aluminum foil is applied as a thin layer (5-20 μm) on the plastic resin base, providing localized reinforcement where needed while maintaining overall lightness. This local application of materials optimizes the strength-to-weight ratio by placing material only where it is most needed for structural support.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If a composite aluminum pouch is used as the case material, then the weight is reduced, but the strength and resistance against external impacts deteriorates

Engineering Contradiction:
ImproveweightVSAvoidresistance against external impacts
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent uses a composite structure of plastic resin and aluminum foil to overcome the limitations of conventional aluminum pouches. While maintaining the lightweight advantage of the pouch design, the added aluminum foil layer provides enhanced strength and impact resistance. The plastic resin base maintains flexibility and light weight, while the aluminum reinforcement layer provides the necessary mechanical strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The case is divided into functional layers: a plastic resin base layer providing structural form and light weight, and an aluminum foil layer providing strength and barrier properties. This segmentation of functions allows each material to contribute its optimal properties without the drawbacks of using a single material for the entire case structure.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If a single-piece case structure is used, then the manufacturing process is simplified, but the sealing efficiency deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsealing efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The case is constructed from multiple separate components (case body, cap, and sealing members) that are assembled together. This segmentation allows for specialized sealing elements to be incorporated at the joints between components, significantly improving sealing efficiency. The separate components can be optimized for their specific functions while maintaining a relatively simple overall manufacturing process through modular assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Sealing members are introduced as intermediary elements between the case body and cap components. These sealing members specifically address the sealing requirement at the joint interfaces, allowing the main case structure to remain simple while achieving high sealing efficiency through the specialized sealing components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design provides improved resistance to external impacts, maintains lightness, and enhances sealing efficiency, addressing the limitations of conventional battery case materials.

Implementation Method 1

a case constituted by a first case portion and a second case portion, which are coupled to each other by an adhesion layer

Methodology Applied
Scientific EffectThermal adhesion: Adhesive

Data Source

PatentEP2367218B1Secondary battery
Publication Date: 2019.12.25 SAMSUNG SDI CO LTD
  • EP2367218B1 patent drawingFigure 1
  • EP2367218B1 patent drawingFigure 2
  • EP2367218B1 patent drawingFigure 3~5

AI summary

A secondary battery comprising an electrode assembly; a case accommodating the electrode assembly and comprising first and second case portions; and an adhesion layer interposed between the first and second case portions and adhering to a respective surface of each of the case portions in such a manner as to secure a connection between them.