Gel Electrolyte Separator Composition for Conductivity and Ductility

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Solution Overview

Problem

Current gel polymer electrolytes in lithium-ion batteries suffer from poor room-temperature conductivity and mechanical properties due to the addition of inorganic fillers, which reduces their safety and effectiveness.

Innovation Solution

A modified gel electrolyte separator is prepared using a slurry comprising nano-scale silica as an inert filler, polyethylene oxide (PEO) as a high polymer, a modified high block copolymer as a dispersant, an acrylic binder with N-methyl-2-pyrrolidone (NMP) as a solvent, and dichloromethane (DCM) as an organic solvent, enhancing mechanical and electrochemical properties while providing high-temperature heat resistance and flame retardancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inorganic fillers are added to gel polymer electrolyte to improve room-temperature conductivity, then ionic conductivity increases, but mechanical properties deteriorate and the material becomes brittle

Engineering Contradiction:
Improveionic conductivityVSAvoidmechanical properties
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses a composite structure combining gel polymer electrolyte with inorganic fillers (Al2O3, SiO2, TiO2) and lubricating additives (graphite, MoS2). This composite approach allows the inorganic fillers to enhance ionic conductivity while the lubricating additives compensate for mechanical brittleness, achieving both improved conductivity and maintained mechanical flexibility

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces lubricating additives as intermediary substances between the gel polymer matrix and inorganic fillers. These additives act as mediators that reduce the brittleness induced by fillers while maintaining the conductive pathways, thus resolving the contradiction between conductivity enhancement and mechanical integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If inorganic fillers are added to gel polymer electrolyte to increase ionic transference number, then electrochemical performance improves, but production difficulty increases due to brittleness

Engineering Contradiction:
Improveionic transference numberVSAvoidproduction difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The composite formulation with lubricating additives makes the electrolyte less brittle and more processable during manufacturing, while still achieving high ionic transference number through the inorganic filler content, thus improving both electrochemical performance and ease of manufacture

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the particle size parameters of inorganic fillers (5-50 μm) and controls the content ratios of various components to achieve the right balance between ionic transference number and mechanical flexibility for manufacturability

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If gel polymer electrolyte is used to replace liquid electrolyte to avoid leakage, then safety improves, but room-temperature conductivity decreases

Engineering Contradiction:
Improveelectrolyte leakageVSAvoidroom-temperature conductivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The gel polymer electrolyte is formulated as a composite material containing inorganic fillers and lubricating additives, which creates conductive pathways within the gel matrix to maintain high room-temperature conductivity while preserving the leakage-free advantage of gel electrolytes over liquid electrolytes

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The gel polymer electrolyte utilizes a porous gel matrix structure that accommodates ionic conduction pathways, allowing high conductivity at room temperature while maintaining the physical containment benefits of gel structure that prevent leakage

Inventive Principle:
Principle #31Porous materials

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 modified gel electrolyte separator exhibits improved mechanical and electrochemical properties, high-temperature heat resistance, and flame retardancy, making it suitable for lithium-ion batteries with enhanced safety and performance.

Implementation Method 1

a dispersant: 5‰ to 2%... the dispersant is a modified high block copolymer

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

a binder: 5‰ to 3%... the binder is an acrylic binder with N-methyl-2-pyrrolidone (NMP) as a solvent

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

an organic solvent: 85% to 97%... the organic solvent is dichloromethane (DCM)

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 4

electrolytes play an important role in conducting lithium ions in the battery

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentEP4475317A1Modified gel electrolyte separator, and preparation method and use thereof
Publication Date: 2024.12.11 CANGZHOU ZHONGFU NEW ENERGY MATERIALS CO LTD
  • EP4475317A1 patent drawingFigure 1
  • EP4475317A1 patent drawingFigure 2
  • EP4475317A1 patent drawingFigure 3

AI summary

Disclosed are a modified gel electrolyte separator, and a preparation method and use thereof, belonging to the technical field of novel battery separator materials. The modified gel electrolyte separator is prepared through impregnation in a modifying slurry including: in weight fraction, a nano functional material: 2% to 12%; a high polymer: 2‰ to 1%; a dispersant: 5%o to 2%; a binder: 5%o to 3%; and an organic solvent: 85% to 97%, wherein the nano functional material is silica; the high polymer is polyethylene oxide; the dispersant is a modified high block copolymer; the binder is an acrylic binder with N-methyl-2-pyrrolidone as a solvent; and the organic solvent is dichloromethane. The modified gel electrolyte separator shows high-temperature heat resistance, flame retardancy, and high ductility, as well as significantly improved mechanical and electrochemical properties, and exhibits broad application prospects in the preparation of lithium-ion batteries.