Composite Battery Separator With Fire-Suppression Ceramic Layers

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Solution Overview

Problem

Existing lithium-ion batteries face issues with thermal stability due to manufacturing defects, aging, and abuse conditions, which can lead to undesirable heat generation and combustion chain reactions, necessitating materials that inhibit combustion propagation.

Innovation Solution

A composite separator for lithium-ion batteries comprising a microporous layer with fire suppression layers containing ceramic material and cyclophosphazene, which are integrated into the battery structure to quench and suppress combustion chain reactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional porous separators made of ionically conductive polymers are used, then ion conduction is enabled, but thermal stability and fire suppression are insufficient

Engineering Contradiction:

Improvethermal stabilityVSAvoidcombustion propagation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The separator is constructed as a composite material system combining a polyolefin microporous base layer with fire suppression layers containing ceramic particles (alumina, silica, or dehydrated zeolite) and cyclophosphazene compounds. This composite structure integrates the ion conduction capability of the polymer matrix with the thermal stability of ceramic materials and the combustion-inhibiting properties of cyclophosphazene, thereby simultaneously achieving reliable ion transport and fire suppression functionality.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The fire suppression layers are designed with porous structures that allow cyclophosphazene compounds to be distributed within the pore network of ceramic materials. The porous architecture maintains ion conductivity pathways while providing sufficient surface area and volume for the cyclophosphazene to effectively quench combustion chain reactions when thermal runaway occurs.

Inventive Principle:

Principle #31Porous materials

2Reliability

If fire suppression layers with high ceramic material content are added, then thermal stability improves, but device complexity increases

Engineering Contradiction:

Improvethermal stabilityVSAvoidseparator structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The separator is divided into functionally distinct segments: a microporous polyolefin base layer for ion conduction and discrete fire suppression layers containing ceramic particles and cyclophosphazene. This segmentation allows each layer to be optimized for its specific function while maintaining overall system simplicity. The fire suppression layers can be applied as coatings or laminates on the base layer, avoiding the need for complex multi-component mixing or processing.

Inventive Principle:

Principle #1Segmentation

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 composite separator effectively prevents and inhibits combustion chain reactions during thermal runaway events, maintaining thermal stability and mechanical integrity of the battery.

Implementation Method 1

the cyclophosphazene may effectively quench, suppress, and/or terminate combustion chain reactions

Methodology Applied

Scientific EffectCombustion suppression:

Implementation Method 2

The one or more fire suppression layers comprise a ceramic material having interconnected open pores

Methodology Applied

Scientific EffectThermal stability:

Implementation Method 3

Porous separators of lithium batteries are generally made of ionically conductive and electrically insulating polymers

Methodology Applied

Scientific EffectIonic conduction:

Data Source

PatentUS12438236B2Composite separator including fire suppression layer containing ceramic material and cyclophosphazene and electrochemical cell including the same

Publication Date: 2025.10.07 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A separator for an electrochemical cell that cycles lithium ions includes a microporous layer and one or more fire suppression layers disposed on at least one of a first side or an opposite second side of the microporous layer. The one or more fire suppression layers include a ceramic material having interconnected open pores and a cyclophosphazene disposed within the interconnected open pores of the ceramic material.