Gel Polymer Electrolyte with Acetonitrile for Lithium Dendrite Control

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Solution Overview

Problem

Lithium secondary batteries using carbon-based anode active materials face limitations in capacity, while lithium metal anodes cause dendrite formation leading to short circuits and degradation, and existing solid electrolytes, including gel polymer electrolytes, have insufficient ion conductivity and transfer rates.

Innovation Solution

A gel polymer electrolyte composed of a crosslinked product of multifunctional acryl-based and urethane acryl-based monomers with a PFPE unit, combined with a liquid electrolyte containing acetonitrile, enhances lithium ion mobility and distribution, preventing dendrite formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium metal anode is used to increase capacity, then battery capacity is improved, but lithium dendrite formation occurs causing short circuits and degradation

Engineering Contradiction:
Improvebattery capacityVSAvoidshort circuit prevention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

A gel polymer electrolyte is introduced as an intermediary layer between the lithium metal anode and the cathode. This gel polymer electrolyte contains a crosslinked polymer matrix that physically restrains lithium dendrite growth while maintaining lithium ion conductivity, thus preventing short circuits while enabling the use of high-capacity lithium metal anodes

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrolyte system uses a composite structure combining gel polymer electrolyte with liquid electrolyte containing acetonitrile. The gel polymer provides mechanical strength and dendrite suppression, while the liquid electrolyte component ensures high lithium ion conductivity, creating a synergistic system that addresses both capacity and safety requirements

Inventive Principle:
Principle #40Composite materials

2Reliability

If solid electrolytes are used to control lithium dendrites, then dendrite growth is suppressed, but ion conductivity and transfer rate are insufficient

Engineering Contradiction:
Improvedendrite controlVSAvoidion conductivity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the physical and chemical parameters of the solid electrolyte by incorporating a gel polymer matrix with specific crosslinking density and combining it with liquid electrolyte components. This creates a semi-solid gel electrolyte with optimized parameters that simultaneously provides dendrite suppression capability and high lithium ion conductivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The electrolyte combines gel polymer electrolyte and liquid electrolyte in a composite structure, where the gel polymer provides mechanical integrity for dendrite control and the liquid electrolyte component (with acetonitrile) provides high ion conductivity, achieving both reliability and performance

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If gel polymer electrolyte is used for easy manufacture, then manufacturing ease is improved, but ion transfer rate is insufficient

Engineering Contradiction:
Improvemanufacturing easeVSAvoidion transfer rate
Core Design Contradiction:
Ease of manufactureVSSpeed

Solution Approach 1:

The invention optimizes the composition parameters of the gel polymer electrolyte by selecting specific monomers (multifunctional acryl-based monomer with three or more polymerizable functional groups) and controlling crosslinking density, while also optimizing the liquid electrolyte composition including acetonitrile content, to achieve both ease of manufacture and high ion transfer rate

Inventive Principle:
Principle #35Parameter changes

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 gel polymer electrolyte improves lithium ion mobility, leading to increased battery capacity, extended lifespan, and reduced resistance by uniformly distributing lithium ions, thus enhancing the performance of lithium secondary batteries.

Implementation Method 1

a gel polymer electrolyte for a lithium secondary battery... mobility of lithium ions is improved

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

the gel polymer is i) a crosslinked product of a multifunctional acryl-based monomer having three or more polymerizable functional groups

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 3

the liquid electrolyte includes a lithium salt, an organic solvent, and acetonitrile

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP4614640A1Gel electrolyte for lithium secondary battery and lithium secondary battery including the same
Publication Date: 2025.09.10 SAMSUNG SDI CO LTD
  • EP4614640A1 patent drawingFigure 1
  • EP4614640A1 patent drawingFigure 2
  • EP4614640A1 patent drawingFigure 3

AI summary

A lithium secondary battery including a gel polymer electrolyte. The gel polymer electrolyte includes a gel polymer and a liquid electrolyte, wherein the gel polymer is i) a crosslinked product of a multifunctional acryl-based monomer having three or more polymerizable functional groups, or ii) a crosslinked product of a first polymerizable monomer and a second polymerizable monomer, wherein the first polymerizable monomer is a multifunctional acryl-based monomer having three or more polymerizable functional groups, and the second polymerizable monomer is at least one selected from among a urethane acryl-based monomer having two or more polymerizable functional groups and a polymerizable monomer including a perfluoropolyether (PFPE) unit and having two or more polymerizable functional groups, and the liquid electrolyte includes a lithium salt, an organic solvent, and acetonitrile.