Fast-Cure Gel Polymer Electrolytes for Lithium Battery Conductivity

Solution Overview

Problem

Lithium batteries using traditional organic carbonates as electrolytes face issues with volatility, flammability, toxicity, and chemical reactivity, while solid polymer electrolytes (SPEs) have poor room temperature ionic conductivity due to their crystalline structure, limiting their application in electrochemical cells.

Innovation Solution

Fast-cure gel polymer electrolytes are developed by trapping oligo(alkylene glycol)siloxane or silane in a three-dimensional polymer matrix, using a combination of oligo(alkylene glycol)silane, cross-linking agents, salts, initiators, and stabilizing additives, which provide improved conductivity and stability, suitable for use in lithium batteries and other electrochemical cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If PEO is used as the polymer matrix, then film strength is improved, but crystallinity increases and ionic conductivity decreases

Engineering Contradiction:

Improvefilm strengthVSAvoidionic conductivity

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent introduces oligo(ethylene glycol) monomers with different chain lengths and cross-linking densities at local regions within the polymer matrix. This creates local amorphous zones with enhanced ionic conductivity while maintaining overall film strength through the cross-linked network structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the molecular weight distribution, cross-linking density, and compositional ratios of PEO and oligo(ethylene glycol) components to suppress crystallization. These parameter modifications enable the formation of an amorphous gel structure that maintains film integrity while enhancing ionic transport.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If oligo(ethylene glycol)siloxanes are used as electrolyte components, then ionic conductivity is improved, but dimensional stability deteriorates

Engineering Contradiction:

Improveionic conductivityVSAvoiddimensional stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent combines oligo(ethylene glycol)siloxane components with a cross-linked poly(ethylene glycol) matrix to create a composite gel structure. The cross-linked network provides dimensional stability and mechanical strength, while the oligo(ethylene glycol)siloxane phases provide channels for ionic conduction, resolving the contradiction between conductivity and stability.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The cross-linked polymer matrix acts as an intermediary structure that constrains the oligo(ethylene glycol)siloxane chains, preventing excessive chain mobility and dimensional changes. This intermediary network maintains structural integrity while allowing sufficient ionic transport through the gel phase.

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

The fast-cure gel polymer electrolytes offer enhanced room temperature conductivity, stability, and safety, enabling wider application in lithium batteries and electrochemical cells with improved performance and reduced processing challenges.

Implementation Method 1

Fast-cure gel polymer electrolytes are developed by trapping oligo(alkylene glycol)siloxane or silane in a three-dimensional polymer matrix

Methodology Applied

Scientific EffectGel formation: Gel

Implementation Method 2

Fast-cure gel polymer electrolytes are developed by trapping oligo(alkylene glycol)siloxane or silane in a three-dimensional polymer matrix, using a combination of oligo(alkylene glycol)silane, cross-linking agents, salts, initiators, and stabilizing additives

Methodology Applied

Scientific EffectCross-linking: Chemical Bonding

Implementation Method 3

Fast-cure gel polymer electrolytes are developed by trapping oligo(alkylene glycol)siloxane or silane in a three-dimensional polymer matrix, using a combination of oligo(alkylene glycol)silane, cross-linking agents, salts, initiators, and stabilizing additives

Methodology Applied

Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS8492033B2Fast cure gel polymer electrolytes

Publication Date: 2013.07.23 UCHICAGO ARGONNE LLC

AI summary

Fast-cure gel polymer electrolytes are prepared by trapping an oligo(alkylene glycol)siloxane or silane in a three dimensional polymer matrix. An ion-conducting phase of the electrolyte contains a siloxane or silane compound and a lithium salt. Such siloxanes or silanes include a silicon or silicon oxide group having four or less substituents that is an oligo(alkylene glycol), or cyclic carbonate moiety.