Composite Battery Cover With Nitrogen Release for Arc Mitigation

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Solution Overview

Problem

Battery enclosures face challenges in preventing thermal runaway propagation and arcing during thermal events, as the increased temperature and pressure lead to vent gas bursts and ionic particle arcs between cells and conducting structures, which can cause further thermal runaway and damage.

Innovation Solution

The enclosure features a composite battery cover with a metallic layer, a composite layer containing reinforcing fibers and a molecular nitrogen releasing agent, and a metallic mesh layer, which increases the molecular nitrogen concentration during thermal events, reducing the speed of ionic particles and likelihood of arcs, while ultraviolet sensors detect arcing and a controller takes mitigation actions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional battery enclosure is used, then the structure is simple and manufacturing is easy, but thermal runaway propagation and arcing cannot be effectively prevented

Engineering Contradiction:

Improveprevention of thermal runaway propagation and arcingVSAvoidcomplexity of composite cover structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining multiple layers with distinct functions: an outer metallic layer for structural strength and arc containment, a composite layer with reinforcing fibers for mechanical integrity, and a coating layer containing molecular nitrogen releasing agents for arc mitigation. This multi-material composite structure resolves the contradiction by providing superior thermal and electrical protection while maintaining a manageable structural complexity through functional layering.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The cover is segmented into multiple functional layers, each addressing specific protection needs. The outer metallic layer handles structural support and arc containment, the composite layer provides mechanical reinforcement, and the coating layer releases nitrogen to suppress arcing. This segmentation allows each layer to be optimized for its specific function while collectively providing comprehensive protection against thermal runaway and arcing.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the enclosure uses advanced composite materials and multiple layers, then protection against thermal runaway and arcing is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improvesafety during thermal eventsVSAvoidease of manufacturing composite cover

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The coating layer containing molecular nitrogen releasing agents is applied in advance to the composite structure. During thermal events, this pre-applied coating automatically releases nitrogen gas to suppress arcing without requiring additional active components or complex control systems. This preliminary action simplifies manufacturing by integrating the arc mitigation function directly into the passive structure rather than requiring separate active systems.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a metallic layer is used in the cover, then arc containment is improved, but thermal conduction may accelerate thermal runaway propagation

Engineering Contradiction:

Improvearc containment capabilityVSAvoidthermal propagation risk

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The metallic layer is positioned specifically at the outer surface of the cover where arc containment is most critical. The composite layer with nitrogen-releasing coating is placed adjacent to the battery cells where thermal protection is needed. This local quality assignment allows the metallic layer to provide arc containment where needed while the composite layer provides thermal insulation and active arc suppression near the batteries, resolving the contradiction between arc containment and thermal propagation prevention.

Inventive Principle:

Principle #3Local quality

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 solution effectively reduces the likelihood of arcing and thermal runaway propagation by creating a high dielectric medium with increased nitrogen concentration, enhancing safety and preventing damage to adjacent cells during thermal events.

Implementation Method 1

A coating layer is arranged on an inner surface of the composite layer and including a molecular nitrogen releasing agent

Methodology Applied

Scientific EffectMolecular nitrogen release: Decomposition (biological)

Implementation Method 2

increases the molecular nitrogen concentration during thermal events, reducing the speed of ionic particles and likelihood of arcs

Methodology Applied

Scientific EffectDielectric effect: Dielectric

Data Source

PatentUS20250023169A1Composite cover for a battery pack or a battery module for reducing thermal propagation runaway and mitigating arcing

Publication Date: 2025.01.16 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An enclosure for one of a battery module or battery pack includes a body configured to receive at least one of a plurality of battery modules and a plurality of battery cells. A cover is arranged over the body and includes an outer metallic layer, a composite layer arranged adjacent to an inner surface of the outer metallic layer and including reinforcing fibers encapsulated in resin, and a coating layer arranged on an inner surface of the composite layer and including a molecular nitrogen releasing agent.