Lithium-Sulfur Battery Electrolyte with Alkyl Vinyl Ether Additive

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Solution Overview

Problem

Lithium-sulfur batteries face issues with instability and reduced capacity due to the formation of lithium dendrites and passivation layers on the negative electrode, leading to short circuits and decreased cycle lifetime, which existing electrolyte additives and protective layers have not adequately addressed.

Innovation Solution

An electrolyte for lithium-sulfur batteries comprising a lithium salt, a non-aqueous organic solvent, and an alkyl vinyl ether compound as an additive, which improves the efficiency and stability of the negative electrode by enhancing the stripping/plating process and preventing lithium polysulfide migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium metal is used as a negative electrode active material to achieve high capacity and high energy density, then the theoretical specific capacity reaches 3,860 mAh/g and energy density is improved, but lithium dendrite forms on the surface causing short circuit and reducing battery stability and cycle lifetime

Engineering Contradiction:

Improveenergy densityVSAvoidbattery stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A protective layer comprising a polymer matrix and a lithium dendrite absorbing material is introduced as an intermediary between the lithium metal negative electrode and the electrolyte. This protective layer prevents direct contact between lithium metal and electrolyte, suppressing dendrite formation and improving battery reliability while maintaining high energy density

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A flexible protective layer in the form of a polymer matrix with integrated lithium dendrite absorbing material is applied on the lithium metal surface. This thin film structure provides mechanical flexibility while effectively absorbing dendrites and preventing short circuits

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If a protective layer is formed on the surface of lithium metal to prevent dendrite formation, then battery stability is improved, but the protective layer undergoes degeneration such as hardening or swelling during charging/discharging

Engineering Contradiction:

Improvebattery stabilityVSAvoidprotective layer stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The protective layer is designed as a composite material system consisting of a polymer matrix combined with lithium dendrite absorbing material. This composite structure provides both mechanical integrity and dendrite absorption capability, preventing hardening and swelling during battery operation

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The composition and physical properties of the protective layer are optimized by selecting appropriate polymer matrices and dendrite absorbing materials. The protective layer maintains stable mechanical and chemical properties during charging/discharging cycles, preventing degeneration

Inventive Principle:

Principle #35Parameter changes

3Reliability

If existing electrolyte additives or protective layers are used to suppress lithium dendrite formation, then some dendrite growth is inhibited, but the effect is not sufficient and capacity and lifetime characteristics are still reduced

Engineering Contradiction:

Improvedendrite suppressionVSAvoidcycle lifetime

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

A specifically designed protective layer with integrated lithium dendrite absorbing material is introduced as an intermediary between the lithium metal negative electrode and the electrolyte. This protective layer provides superior dendrite suppression capability compared to existing additives, significantly extending battery cycle lifetime

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Inventive Principle:

Principle #30Flexible shells and thin films

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 electrolyte enhances the capacity and lifetime of lithium-sulfur batteries by improving negative electrode stability and maximizing positive electrode capacity, while minimizing side reactions and maintaining high charging/discharging efficiency.

Implementation Method 1

improves the efficiency and stability of the negative electrode by enhancing the stripping/plating process

Methodology Applied

Scientific EffectStripping/plating process: Electroplating

Implementation Method 2

preventing lithium polysulfide migration

Methodology Applied

Scientific EffectMigration prevention: Diffusion Barrier

Implementation Method 3

the conversion reaction of lithium ions and sulfur (S 8 +16Li

Methodology Applied

Scientific EffectConversion reaction: Redox Reactions

Data Source

PatentEP4044314B1Electrolyte for lithium-sulfur battery, and lithium-sulfur battery including the same

Publication Date: 2025.09.24 LG ENERGY SOLUTION LTD

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AI summary

The present invention relates to an electrolyte for a lithium-sulfur battery and a lithium-sulfur battery comprising the same, more particularly to an electrolyte for a lithium-sulfur battery comprising a lithium salt, a non-aqueous organic solvent, and an additive, wherein the additive comprises an alkyl vinyl ether compound. The electrolyte for the lithium-sulfur battery of the present invention improves the efficiency and stability of the negative electrode, thereby improving the capacity and lifetime characteristics of the lithium-sulfur battery.