Electrode Assembly Cushioning for Pouch Film Puncture Resistance

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Solution Overview

Problem

Lithium ion batteries face issues with the puncture of the polypropylene layer in laminated aluminum films due to the sharp edges of anode current collectors, leading to battery leakage and corrosion, as the existing thickness of the polypropylene layer is insufficient and burrs on copper foils can pierce through the separator and film.

Innovation Solution

An electrode assembly with an anti-puncture cushion covering the edges of the anode sheet, which is wrapped by a laminated aluminum film, preventing direct contact and potential puncture by the anode current collector, thereby isolating the anode sheet from the film and reducing the risk of leakage and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the thickness of the polypropylene layer is reduced to increase energy density, then the energy density is improved, but the anti-puncture strength deteriorates

Engineering Contradiction:

Improveenergy densityVSAvoidanti-puncture strength

Core Design Contradiction:

Use of energy by moving objectVSStrength

Solution Approach 1:

The patent applies beforehand cushioning by introducing a cushioning layer made of soft material (such as polyethylene or polypropylene foam) between the anode current collector and the polypropylene layer. This cushioning layer is positioned in advance to prevent puncture, allowing the polypropylene layer to be thinner while maintaining sufficient anti-puncture strength. The soft material absorbs potential mechanical stress and prevents direct contact between sharp edges and the thin polypropylene layer.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Use of energy by moving object

If the thickness of the anode current collector is reduced to increase energy density, then the energy density is improved, but the sharpness of edges increases which raises puncture probability

Engineering Contradiction:

Improveenergy densityVSAvoidpuncture probability

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies the intermediary principle by introducing a cushioning layer as a mediator between the anode current collector and the polypropylene layer. This intermediate layer, made of soft material, prevents direct interaction between the sharp edges of the thinned current collector and the polypropylene layer, thereby eliminating the harmful puncture effect while allowing the current collector to be thinner for higher energy density.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If burrs are present on the copper foil to maintain manufacturing simplicity, then the ease of manufacture is improved, but the reliability deteriorates due to potential puncture of separator and film

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidbattery safety

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The cushioning layer serves as an intermediary that protects against burrs on the copper foil. Instead of requiring complex deburring processes to eliminate manufacturing defects, the soft cushioning material absorbs the potential damage from burrs, preventing them from puncturing the separator and polypropylene layer. This maintains manufacturing simplicity while significantly improving battery safety and reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Device complexity

If the polypropylene layer is punctured to reduce manufacturing complexity, then the device complexity is reduced, but the harmful effects increase due to battery leakage and corrosion

Engineering Contradiction:

Improvestructure complexityVSAvoidbattery leakage and corrosion

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent prevents the harmful effects of puncture by applying beforehand cushioning with a protective layer of soft material. This cushioning layer is positioned before assembly to prevent puncture of the polypropylene layer, thereby eliminating battery leakage and corrosion risks without requiring complex sealing systems or multiple protective layers. The solution maintains simple device structure while preventing harmful effects.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS12166181B2Electrode assembly, and lithium ion electric roll using the electrode assembly

Publication Date: 2024.12.10 DONGGUAN AMPEREX TECH

AI summary

An electrode assembly and a lithium ion electric roll having the same are provided. Also provided is a battery, which includes: a first layer; a second layer located at the side of a surface of the first layer, exposed from the first layer in a first direction view which is perpendicular to a first surface of the first layer; a third layer tucking at least one portion of the second layer with the first layer in the first direction view, being exposed from the second layer in the first direction view; and a conductive plate protruding from a second side of the first layer in the first direction view.