Integral Separator-Electrode with Protective Edge Coating

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Solution Overview

Problem

Lithium-ion batteries face challenges in forming a continuous separator coating larger than the electrode substrate, leading to potential internal short circuits due to incomplete edge coverage.

Innovation Solution

A method involving a continuous electrode sheet with an active material on a current collector, where the sheet is cut into individual electrodes with center and edge regions, and a uniform separator coating is applied to both, ensuring edge protection and forming an integral separator-electrode with protective edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a separator coating is formed directly on an electrode substrate to reduce battery cost, then manufacturing cost is reduced, but the separator coating size matches the electrode substrate size which causes incomplete edge coverage and internal battery short circuits

Engineering Contradiction:

Improvemanufacturing costVSAvoidbattery safety

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The separator coating is extended beyond the two-dimensional boundary of the electrode substrate into the third dimension by forming it on carrier belts that extend beyond the electrode edges. This allows the separator coating to wrap around and cover the edges of the electrode, providing complete coverage while maintaining cost-effective direct formation processes.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The separator coating process is divided into distinct regions: a first separator coating applied to the center region of the electrode and a second separator coating applied to the edges. This segmentation allows each region to be optimized independently, ensuring proper coverage and functionality while maintaining manufacturing efficiency.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If a separator coating is applied only to the center region of the electrode, then manufacturing process is simplified, but the edges remain unprotected causing internal short circuits

Engineering Contradiction:

Improvecoating process complexityVSAvoidedge coverage precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Different separator coating configurations are applied to different regions of the electrode: the center region receives a first separator coating while the edges receive a second separator coating. This local differentiation ensures that each region receives the appropriate level of protection and functionality, with edges getting enhanced coverage to prevent shorts.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The separator coating is pre-formed on carrier belts before the electrode is fully assembled into the battery. This preliminary formation allows the separator to be precisely positioned and shaped to extend beyond the electrode edges, ensuring complete coverage is achieved before the battery is sealed and assembled.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the separator coating size is made larger than the electrode substrate to ensure edge coverage, then battery safety is improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improveedge protectionVSAvoidseparator formation process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Carrier belts are introduced as intermediary elements that carry the separator coating material. These carrier belts extend beyond the electrode substrate and allow the separator coating to be formed larger than the electrode itself. The carrier belts act as a mediating structure that enables complete edge coverage without requiring complex direct formation processes on the electrode.

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

This approach enhances lithium-ion battery performance by providing a continuous separator coating that covers the entire electrode, including edges, thereby preventing internal shorts and improving battery reliability and safety.

Implementation Method 1

A substantially uniform thickness separator coating is then applied to each electrode. The separator coating is applied to at least a portion of the center region and the plurality of edges

Methodology Applied

Scientific EffectCoating/Deposition: Deposition (physical)

Data Source

PatentUS9324984B2Direct formation of a separator with a protective edge on an electrode

Publication Date: 2016.04.26 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for forming integral separator-electrodes for a battery. The method comprises providing a continuous electrode sheet having an electrode active material deposited on a current collector. The method includes forming a plurality of individual electrodes from the continuous electrode sheet. Each electrode is formed having a center region and a plurality of edges. A separator coating having a substantially uniform thickness is applied to the center region and the plurality of edges of each electrode. The separator coating layer is larger in size than the electrode active material coated area.