Anode Protective Layer for Lithium-Sulfur Cells Against Polysulfides

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Solution Overview

Problem

Lithium-sulfur batteries face issues with polysulfide diffusion leading to capacity decay and cell failure due to the generation of soluble polysulfide species that migrate through the electrolyte, causing loss of active material and reducing battery performance.

Innovation Solution

A protective layer composed of fluorinated poly(meth)acrylates and functionalized graphene moieties is applied on the anode to prevent polysulfide contact, combined with a 3D scaffold cathode structure featuring graded porosity and interconnected channels to confine elemental sulfur, and a protective sheath to inhibit polysulfide migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective layer is applied on the anode to prevent polysulfide contact, then battery cyclability is improved, but device complexity increases

Engineering Contradiction:

Improvebattery cyclabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A protective layer comprising fluorinated poly(meth)acrylates and functionalized graphene moieties is applied on the anode to act as an intermediary barrier that prevents polysulfide contact with the lithium anode, thereby improving cyclability while maintaining a relatively simple overall device structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective layer utilizes composite materials combining fluorinated poly(meth)acrylates with functionalized graphene moieties to achieve effective polysulfide blocking while maintaining structural integrity and electrochemical performance

Inventive Principle:

Principle #40Composite materials

2Reliability

If a 3D scaffold cathode structure with graded porosity is used to confine elemental sulfur, then capacity retention is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecapacity retentionVSAvoidmanufacturing precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The cathode employs graded porosity where pore size and distribution vary locally throughout the structure, with larger pores near the sulfur loading region and smaller pores toward the electrolyte interface, optimizing sulfur confinement while accommodating manufacturing tolerances

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

A 3D scaffold cathode structure with controlled porosity is used to physically confine elemental sulfur, preventing polysulfide dissolution and maintaining high capacity retention during cycling

Inventive Principle:

Principle #31Porous materials

3Loss of substance

If a protective sheath is applied to inhibit polysulfide migration, then active material loss is reduced, but device complexity increases

Engineering Contradiction:

Improveactive material lossVSAvoiddevice complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

A protective sheath is applied to the cathode structure to act as an intermediary barrier that inhibits polysulfide migration through the electrolyte, reducing active material loss while maintaining a relatively simple overall device architecture

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 solution effectively reduces polysulfide diffusion, enhancing battery performance by maintaining lithium ion transport and preventing dendrite formation, thereby increasing cyclability and energy density.

Implementation Method 1

A protective layer composed of fluorinated poly(meth)acrylates and functionalized graphene moieties is applied on the anode to prevent polysulfide contact

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

a 3D scaffold cathode structure featuring graded porosity and interconnected channels to confine elemental sulfur

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Implementation Method 3

The anode may be formed as a single layer of solid lithium, and thereby may output lithium cations (Li+) during operational discharge cycling of the lithium-sulfur battery

Methodology Applied

Scientific EffectElectrochemical reaction: Redox Reactions

Data Source

PatentUS12444749B2Anode protective layer for lithium-sulfur cylindrical cells

Publication Date: 2025.10.14 LYTEN INC

AI summary

A lithium-sulfur battery including an anode, a cathode, a separator, and an electrolyte is provided. The lithium-sulfur battery may be formed as a jelly roll. The anode may output lithium cations (Li+) and a solid-electrolyte interphase (SEI) may be formed on the anode. A protective layer may be formed at least partially within and on the SEI. In addition, the protective layer may be positioned proximal to the anode and include wrinkled graphene nanoplatelets and fluorinated poly(meth)acrylates. For example, multiple wrinkled graphene nanoplatelets may be adjoined to one another by flexure points, where each flexure point may provide exposed carbon atoms. In this way, the fluorinated poly(meth)acrylates may be grafted onto at least some exposed carbon atoms. At least some fluorinated poly(meth)acrylates may be compatible with polymerization and cross-linking with one another responsive to exposure to one or more of free-radical initiators or an ultraviolet (UV) energetic environment.