Pouch Battery Electrode Lead Pressure-Responsive Safety Mechanism

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Solution Overview

Problem

Lithium secondary batteries face safety issues due to increased internal pressure from gas generation, which can lead to swelling, explosion, or fire, especially in large-scale applications like electric vehicles and power storage devices, where proper safety measures are crucial to prevent damage and injury.

Innovation Solution

An electrode lead design for pouch-type secondary batteries featuring an inner lead and an outer lead with a separable configuration, where the outer lead deforms and disconnects from the inner lead when internal pressure increases, blocking electrical connections and allowing gas discharge, thereby preventing further gas generation and potential hazards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electrode lead maintains continuous electrical connection for normal operation, then electrical conductivity is improved, but safety deteriorates when internal pressure increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidsafety hazard from internal pressure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The electrode lead employs a dynamic connection mechanism where the outer lead can deform and separate from the inner lead in response to internal pressure changes. This dynamic behavior allows the system to transition from a connected state during normal operation to a separated state when safety hazards arise, resolving the contradiction between maintaining reliable electrical connection and preventing safety hazards.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrode lead is divided into two separate components: an inner lead that maintains electrical connection with the electrode assembly and an outer lead that provides external connection. This segmentation allows the outer lead to deform and separate from the inner lead when internal pressure increases, blocking electrical connection to prevent safety hazards while maintaining the structure's electrical conductivity during normal operation.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If the outer lead is designed to deform and separate for safety, then safety is improved, but electrical conductivity deteriorates

Engineering Contradiction:
Improvesafety from internal pressureVSAvoidelectrical connection
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The electrode lead system dynamically adjusts its electrical conductivity based on internal pressure conditions. During normal operation, the outer lead remains in contact with the inner lead, maintaining electrical conductivity. When internal pressure increases to hazardous levels, the outer lead deforms and separates, automatically blocking electrical connection to prevent safety hazards, thus resolving the contradiction between safety and electrical conductivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The harmful electrical connection is extracted or blocked when safety hazards arise. The outer lead serves as a controllable electrical pathway that can be separated from the inner lead to block electrical connection, allowing the system to maintain conductivity during normal operation while preventing conductivity when safety hazards occur.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If the electrode lead structure is made complex with separable components, then safety is improved, but device complexity increases

Engineering Contradiction:
Improvesafety from internal pressureVSAvoidelectrode lead structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The electrode lead combines multiple functions into a single integrated structure. The outer lead serves both as an electrical connection component and as a pressure-responsive safety mechanism. By merging the electrical connection function and the safety protection function into one structure, the patent reduces overall device complexity while maintaining the separable components needed for safety.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The outer lead performs multiple functions: it provides external electrical connection, acts as a pressure sensor through its deformation behavior, and serves as a safety mechanism by separating to block electrical connection when internal pressure increases. This multi-functionality reduces the need for additional separate components, thereby reducing device complexity while improving safety.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 electrode lead design effectively blocks electrical connections and allows gas discharge when internal pressure rises, preventing explosions, fires, and ensuring safer operation of secondary batteries, especially in large-scale applications like electric vehicles and power storage devices.

Implementation Method 1

when an inner pressure of the pouch-type secondary battery increases, the outer lead is partially deformed and thus the portion of the outer lead is detached from the inner lead

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3293798B1Electrode lead and secondary battery having same
Publication Date: 2021.10.27 LG ENERGY SOLUTION LTD
  • EP3293798B1 patent drawingFigure 1
  • EP3293798B1 patent drawingFigure 2
  • EP3293798B1 patent drawingFigure 3

AI summary

The present disclosure provides an electrode lead that ensures safety of a secondary battery when gas is generated within the secondary battery. The electrode lead is included in a pouch-type secondary battery in which outer circumferential parts of a pouch casing are sealed and an electrode assembly is accommodated in a center part of the pouch casing. The electrode lead includes an inner lead at least partially formed of an electrically-conductive material, contacting an electrode tab of the electrode assembly, and interposed between the sealing parts of the pouch casing; and an outer lead disposed outside of the inner lead, at least partially formed of an electrically-conductive material, providing an external terminal connectable to an external device, interposed between the sealing parts of the pouch casing, and configured such that a portion of the outer lead contacts the inner lead and that, when an inner pressure of the pouch-type secondary battery increases, the outer lead is partially deformed and thus the portion of the outer lead is detached from the inner lead.