Stacked Electrode Assembly Edge Insulation Against Battery Short Circuits

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Solution Overview

Problem

Lithium secondary batteries face safety risks due to short circuits caused by contact between electrodes, particularly in lithium metal batteries where dendrites form, leading to potential ignition or explosion, and existing insulation methods are inadequate.

Innovation Solution

An electrode assembly with an insulation layer formed on the tab and edge portions of electrodes, larger than the counter electrode, using a combination of insulation films, organic layers, or organic-inorganic mixed layers to prevent short circuits and dendrite growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If insulation tape is attached only on tab portion, then manufacturing cost is reduced, but short circuit prevention capability is insufficient

Engineering Contradiction:
Improvemanufacturing costVSAvoidshort circuit prevention capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies different insulation measures to different locations based on risk assessment. Insulation layers are specifically applied to edge portions and tab portions where short circuits are most likely to occur, rather than uniformly insulating the entire electrode. This localized approach optimizes the balance between safety and manufacturing cost.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The insulation solution is divided into separate components: insulation layers applied to edge portions and insulation tapes applied to tab portions. This segmentation allows each component to address specific short circuit risks at different locations, improving overall effectiveness while maintaining cost efficiency.

Inventive Principle:
Principle #1Segmentation

2Reliability

If insulation layer is formed on entire electrode surface, then short circuit prevention is maximized, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveshort circuit preventionVSAvoidinsulation structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of uniform insulation across the entire electrode surface, the patent selectively applies insulation layers only to edge portions and tab portions where short circuit risks are concentrated. This reduces material usage and structural complexity while maintaining adequate protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial insulation coverage focusing on critical areas rather than complete coverage. This partial action approach provides sufficient protection against the most common short circuit modes while avoiding the excessive complexity and cost of full-surface insulation.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3726637B1Stack type electrode assembly comprising electrode with insulation layer and lithium secondary battery comprising same
Publication Date: 2025.10.29 LG ENERGY SOLUTION LTD
  • EP3726637B1 patent drawingFigure 1
  • EP3726637B1 patent drawingFigure 2

AI summary

The present disclosure relates to an electrode assembly having a stack form of an electrode, a separator and a counter electrode, in which each of the electrode and the counter electrode includes a tab extending from a current collector; the electrode is larger than the counter electrode at four sides including a side from which the tap extends thereof, to have an exposed portion; and an insulation layer is formed on a tab portion of the electrode and on an edge portion of the electrode.