Battery Electrode Tab Insulation Layout to Prevent Internal Shorts

Solution Overview

Problem

Existing battery cell designs face challenges in reliability due to issues such as self-discharge and short-circuiting caused by bent tabs being extruded into electrode assemblies during manufacturing and use.

Innovation Solution

An electrode sheet design featuring a current collector with a first and second insulating layer, where the second insulating layer has a greater thickness than the first, reducing the bending ease of the tab and providing support, thereby minimizing the risk of tab insertion into the electrode assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the tab is made thin and flexible to facilitate bending during assembly, then the ease of operation is improved, but the reliability deteriorates due to increased risk of self-discharge and short-circuiting when the bent tab is extruded against the electrode assembly

Engineering Contradiction:

Improveease of bendingVSAvoidrisk of self-discharge and short-circuiting

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The insulating layer is applied selectively only to the first portion of the tab that is prone to bending and contact with the electrode assembly, rather than the entire tab. This localized insulation provides protection exactly where needed while maintaining the flexibility and electrical conductivity of the tab in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

An insulating layer is introduced as an intermediary substance between the tab and the electrode assembly. This intermediate layer prevents direct contact and potential short-circuiting when the tab bends and is extruded against the electrode assembly, while still allowing the tab to perform its electrical function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a thick insulating layer is applied to the tab to prevent contact with the electrode assembly, then the reliability is improved, but the device complexity and material usage increase

Engineering Contradiction:

Improveprotection against contactVSAvoidinsulating layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The insulating layer is applied selectively only to the first portion of the tab that is prone to bending and contact with the electrode assembly, rather than the entire tab. This localized insulation provides protection exactly where needed while maintaining the flexibility and electrical conductivity of the tab in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of applying insulation to the entire tab (excessive action), the insulating layer is applied only to the critical first portion where bending and contact risks exist (partial action). This optimized approach provides sufficient protection against short-circuiting while minimizing material usage and structural complexity.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If the insulating layer thickness is increased to provide better support during bending, then the reliability is improved, but the tab's flexibility and ease of bending deteriorates

Engineering Contradiction:

Improvesupport during bendingVSAvoidflexibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The insulating layer is applied selectively only to the first portion of the tab that is prone to bending and contact with the electrode assembly, rather than the entire tab. This localized insulation provides protection exactly where needed while maintaining the flexibility and electrical conductivity of the tab in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The thickness of the insulating layer is optimized to provide sufficient mechanical support during bending to prevent contact with the electrode assembly, while controlling it to not be so thick as to prevent necessary flexibility for assembly. This parameter optimization balances support and flexibility requirements.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250329900A1Electrode sheet and preparation method therefor, battery cell, battery, and electrical apparatus

Publication Date: 2025.10.23 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

AI summary

An electrode sheet and a manufacturing method therefor, a battery cell, a battery and an electrical apparatus. The electrode sheet includes a current collector, a first insulating layer and a second insulating layer, where the current collector includes a main body part and tabs, the tabs extend from the first end of the main body part, and the first end is one end of the main body part in a first direction. Each tab includes a first portion and a second portion, the first portion being close to the main body part with respect to the second portion, the surfaces of the two sides of the first portion are respectively provided with the first insulating layer and the second insulating layer, and the thickness d2 of the second insulating layer being greater than the thickness d1 of the first insulating layer.