Composite Electrode Coating With Eutectic Electrolyte for Thermal Stability

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Solution Overview

Problem

Lithium-ion battery electrode materials face issues with thermal runaway, poor ionic conductivity, and structural instability due to temperature rise during cycling, leading to safety concerns and reduced performance.

Innovation Solution

A composite pole is developed comprising a current collector coated with a eutectic electrolyte and active electrode material, where the eutectic electrolyte has a melting point and phase transition temperature of at least 60°C, enhancing safety and ionic conductivity by absorbing heat and maintaining structural stability through phase change properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flame retardant is added to the electrode material to suppress oxygen release, then safety of the battery is improved, but ion transmission capability is reduced

Engineering Contradiction:
ImprovesafetyVSAvoidion transmission capability
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a eutectic electrolyte as an intermediary substance between the electrode material and the external environment. This eutectic electrolyte forms a protective layer that suppresses oxygen release and improves safety, while simultaneously maintaining ion transmission capability through its unique eutectic composition and phase change properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the phase change parameters of the eutectic electrolyte (melting point, phase transition temperature) to dynamically adjust the protective function. At normal operating temperatures, the eutectic electrolyte maintains a stable protective layer; when temperature rises during thermal runaway, the phase change absorbs heat and maintains the integrity of the protective barrier, ensuring both safety and ion transmission are preserved.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If phase change materials (e.g., paraffin) are coated on the electrode, then safety is improved, but ion transmission capability is reduced due to inability to conduct ions

Engineering Contradiction:
ImprovesafetyVSAvoidion transmission capability
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent creates a composite structure by combining electrode material with a eutectic electrolyte system. This composite material integrates the safety benefits of phase change materials with the ionic conductivity of electrolyte components, overcoming the limitation of conventional phase change materials like paraffin that cannot conduct ions. The eutectic composition enables both thermal protection and ion transport functions simultaneously.

Inventive Principle:
Principle #40Composite materials

3Reliability

If modified materials are coated on the electrode, then initial safety is improved, but structural stability deteriorates due to separation and fracture during reaction process

Engineering Contradiction:
ImprovesafetyVSAvoidstructural stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent exploits the phase transition characteristics of the eutectic electrolyte to maintain structural stability. The specific melting point and phase transition temperature of the eutectic system are designed to match the thermal behavior of the electrode material during cycling. This synchronized phase transition prevents differential expansion and contraction that causes separation and fracture, thereby maintaining both safety and structural integrity over long-term operation.

Inventive Principle:
Principle #36Phase transitions

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 pole effectively improves the safety and electrochemical performance of lithium-ion batteries by reducing heat generation and enhancing ionic conductivity, particularly improving rate capability and structural stability.

Implementation Method 1

the composite pole utilizes the phase change character of an electrolyte to improve the safety performance

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

the eutectic electrolyte absorbs heat by dissolving at high temperature

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Implementation Method 3

the development of a material having high ionic conductivity and suppressing temperature rise is a current trend

Methodology Applied
Scientific EffectIonic conductivity: Conduction (electrical)

Data Source

PatentEP4362126A1Composite pole and preparation method and use thereof, and lithium ion battery
Publication Date: 2024.05.01 BEIJING WELION NEW ENERGY TECH CO LTD
  • EP4362126A1 patent drawingFigure 1~2
  • EP4362126A1 patent drawingFigure 3~4
  • EP4362126A1 patent drawingFigure 5

AI summary

The present disclosure relates to the technical field of lithium-ion batteries, in particular to a composite pole, a preparation method and use thereof, and a lithium-ion battery containing the composite pole. The composite pole comprising a current collector and coating disposed on surface of the current collector; wherein the coating comprises active electrode material and a eutectic electrolyte; wherein the melting point and the phase transition temperature of the eutectic electrolyte are respectively higher than or equal to 60°C. The composite pole provided by the present disclosure has higher safety, structural stability, and ionic conductivity; meanwhile, when the composite pole is used lithium-ion battery, the safety and electrochemical performance of the battery can be effectively improved.