Battery Cell Degassing Channels for Thermal Runaway Venting

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Solution Overview

Problem

Current battery cell designs lack features that allow for controlled degassing during thermal runaway, leading to increased risk of explosion due to pressure buildup between electrode layers.

Innovation Solution

Incorporating degassing channels and weakened portions within the electrode and coating layers of the battery cell stack to facilitate controlled gas release during thermal runaway events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If energy density is increased to meet power requirements, then battery performance improves, but thermal runaway severity increases exponentially

Engineering Contradiction:

Improveenergy densityVSAvoidthermal runaway severity

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The cell stack is segmented into multiple layers with integrated degassing channels and paths of weakness, dividing the gas accumulation problem into manageable segments that can release pressure locally rather than allowing system-wide pressure buildup

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Degassing channels and paths of weakness are pre-defined during cell manufacturing, establishing gas release pathways before thermal runaway occurs, so that when gas is generated during thermal runaway, it can immediately escape through pre-positioned channels rather than accumulating

Inventive Principle:

Principle #10Preliminary action

2Object-affected harmful factors

If gas accumulates between electrode layers during thermal runaway, then pressure increases, but explosion-type reaction is prevented

Engineering Contradiction:

Improvepressure buildupVSAvoidexplosion risk

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

Gas is extracted from the confined space between electrode layers through degassing channels that lead to paths of weakness, removing the harmful gas accumulation that would otherwise lead to explosive pressure buildup

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The harmful gas generated during thermal runaway is converted into a beneficial release mechanism by channeling it through predefined paths of weakness, transforming a potential explosion hazard into a controlled degassing process that protects the cell structure

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If coating layers are applied to electrode layers to improve safety, then thermal runaway controllability improves, but interfacial resistance increases and performance decreases

Engineering Contradiction:

Improvethermal runaway controllabilityVSAvoidelectrochemical performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The coating layers are segmented with integrated degassing channels and uncoated areas, creating localized regions where gas can escape without requiring continuous coating coverage, thus maintaining electrochemical performance while providing thermal runaway protection

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the coating layers have different properties - some areas have full coating for protection, while uncoated areas and degassing channels provide gas release pathways, creating local quality variations that balance safety and performance

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250038348A1Battery cell comprising degassing channels and/or paths of weakness

Publication Date: 2025.01.30 ARCHER AVIATION INC

AI summary

The present invention relates to a high-performance battery cell (10) for driving an electric aircraft, comprising a plurality of layers (12) stacked one to another to form a cell stack (100; 200; 300; 400), the cell stack (100; 200; 300; 400) comprising at least two electrode layers (102, 104; 202, 204; 302, 304; 402, 404) comprising a cathode layer and an anode layer, and coating layers (120, 122, 124; 220, 222, 224; 320, 322, 324; 420, 422, 424) applied to the electrode layers (102, 104; 202, 204; 302, 304; 402, 404), wherein at least one of the electrode layers (102, 104; 202, 204; 302, 304; 402, 404) and/or at least one of the coating layers (120, 122, 124; 220, 222, 224; 320, 322, 324; 420, 422, 424) comprises at least one degassing channel (16) connecting an inner portion of the cell stack (100; 300; 400) with an edge portion of the cell stack (100; 300; 400), and/or at least one weakened portion (202a,b, 204a,b; 302a,b, 304a,b) pre-defining at least one path of weakness connecting an inner portion of the cell stack (200:300; 400) with an edge portion of the cell stack (200; 300; 400).