Lithium Battery Active Material Passivation for Thermal Runaway

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Solution Overview

Problem

Existing methods for suppressing thermal runaway in lithium batteries primarily focus on passively blocking ion/electron migration pathways without addressing the main source of thermal energy generation, namely the active materials, leading to incomplete safety solutions.

Innovation Solution

Applying a non-lithium alkali metal ion and an amphoteric metal ion to the positive and negative active material layers of lithium batteries when a predetermined temperature is reached, transforming these layers into a passivated state to block electrochemical reactions and reduce thermal energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If physical or chemical methods are used to block ion/electron migration pathways, then thermal runaway is suppressed, but the active materials remain vulnerable to exothermic reactions

Engineering Contradiction:

Improvethermal runaway suppressionVSAvoidexothermic reactions in active materials

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A coating layer comprising metal fluoride, metal oxide, or metal oxyfluoride is applied to the surface of the active materials. This coating layer acts as an intermediary barrier between the active materials and the electrolyte, preventing direct contact and reducing exothermic reactions at the interface while maintaining electrochemical performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface properties of active materials are modified by forming a protective coating layer with specific chemical composition (metal fluoride, oxide, or oxyfluoride). This changes the surface energy, chemical reactivity, and thermal stability parameters of the active material surface, reducing its susceptibility to exothermic decomposition.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If flame retardant is added into the electrolyte, then the scale of thermal runaway is controlled, but the root cause in active materials is not addressed

Engineering Contradiction:

Improvethermal runaway scale controlVSAvoidexothermic reactions in active materials

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The coating layer serves as a protective intermediary on the active material surface, preventing direct exothermic reactions between active materials and electrolyte. This addresses the root cause rather than just controlling the scale of thermal runaway after it initiates.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective coating layer is formed on the active material surface before thermal runaway can occur. This preliminary protective action prevents exothermic reactions at their source, rather than attempting to control or suppress them after initiation.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a coating layer is formed on the positive active material, then charge transfer resistance increases at elevated temperature, but the mechanism is not fully understood

Engineering Contradiction:

Improvethermal runaway suppressionVSAvoidcoating layer formation mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A coating layer comprising metal fluoride, metal oxide, or metal oxyfluoride is formed on the positive active material surface. This coating layer acts as a stable intermediary that increases charge transfer resistance at elevated temperatures, preventing thermal runaway while the specific formation mechanism can be optimized through material selection.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Effectively prevents thermal runaway by transforming active materials into lower energy states, thereby reducing the risk of fire or explosion in lithium batteries.

Implementation Method 1

applying a metal ion (A) and an amphoteric metal ion (B) to a positive active material layer and a negative active material layer to passivate the positive active material layer and the negative active material layer

Methodology Applied

Scientific EffectPassivation:

Implementation Method 2

block the electrochemical reaction pathway to effectively avoid the thermal runaway of the battery

Methodology Applied

Scientific EffectIon migration blocking:

Data Source

PatentEP3945619B1Method for suppressing thermal runaway of lithium batteries

Publication Date: 2026.04.15 PROLOGIUM TECHNOLOGY CO LTD

Figure 1
Figure 2
Figure 3A~3B

AI summary

The invention provides a method for suppressing thermal runaway of lithium batteries, which is included a step of providing a lithium battery capable of performing charging and discharging, which includes an electrochemical reaction system. When the temperature of the lithium battery reaches to a predetermined temperature, a metal ion (A) and an amphoteric metal ion (B) are applied to the positive active material layer and the negative active material layer of the lithium battery to passivate the positive active material layer and the negative active material layer. The metal ion (A) is selected from a non-lithium alkali metal ion, an alkaline earth metal ion or a combination thereof to prevent the thermal runaway from occurring.