Composite Membrane for Lithium Air Battery Ion Conductivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Lithium air batteries require an effective separating membrane that blocks moisture and gases while allowing lithium ions to pass through, which existing membranes fail to achieve efficiently, limiting their performance and stability.

Innovation Solution

A composite membrane with an organic polymer layer and ion conductive inorganic particles, where the particles have a hydrophobic coating and are dispersed within the polymer layer, forming a bicontinuous structure that allows lithium ion conductivity while blocking oxygen and moisture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a separating membrane is used to block moisture and gases, then protection against harmful factors is improved, but ion conductivity deteriorates

Engineering Contradiction:
Improvemoisture and gas blockingVSAvoidlithium ion conductivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent employs a composite membrane structure combining organic polymer materials with inorganic ion-conductive particles (such as lithium phosphorus oxynitride or lithium aluminum phosphate). This composite approach allows the membrane to simultaneously block moisture and gases through the polymer matrix while maintaining lithium ion conductivity through the inorganic particles that provide dedicated ion transport pathways.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The membrane structure is designed with local differentiation where inorganic ion-conductive particles are dispersed within the polymer matrix, creating regions with specialized functions. The polymer regions provide barrier properties against moisture and gases, while the inorganic particle regions provide ion conductivity, allowing each material to perform its optimal function in its designated location.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a dense membrane structure is used to block gases and moisture, then protection against harmful factors is improved, but ion conductivity deteriorates

Engineering Contradiction:
Improvegas and moisture barrierVSAvoidion conductivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The composite membrane combines the dense structure of the polymer matrix (which provides excellent barrier properties against gases and moisture) with dispersed inorganic ion-conductive particles (which create continuous pathways for lithium ion transport). This resolves the contradiction by allowing the polymer to form a dense barrier while the inorganic particles maintain ion conductivity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The membrane incorporates a porous or composite structure where inorganic particles are distributed within the polymer matrix, creating a network of ion-conductive channels. This porous architecture allows lithium ions to pass through while the overall dense structure maintains barrier properties against larger molecules like water and oxygen.

Inventive Principle:
Principle #31Porous materials

3Reliability

If inorganic particles are added to improve ion conductivity, then ion conductivity is improved, but mechanical strength deteriorates

Engineering Contradiction:
Improveion conductivityVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The composite membrane uses the polymer matrix as a continuous phase that provides mechanical strength and flexibility, while inorganic particles are dispersed as a secondary phase that provides ion conductivity. The polymer binder holds the inorganic particles together, creating a composite structure where each component contributes its superior properties without compromising the other.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The polymer matrix acts as an intermediary material that binds the inorganic particles together, providing mechanical cohesion while allowing ion transport. The polymer serves as a matrix that holds the inorganic particles in place, transferring mechanical loads, and maintaining structural integrity while the inorganic particles provide the ion-conductive pathways.

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 composite membrane enhances the ion conductivity and mechanical strength of lithium air batteries, improving their performance and lifespan by allowing lithium ions to pass through while effectively blocking gases and moisture, thus overcoming the limitations of existing membranes.

Implementation Method 1

a hydrophobic coating is on at least a portion of the plurality of ion conductive inorganic material particles

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

an excellent separating membrane capable of blocking moisture and gas while allowing the passage of lithium ions

Methodology Applied
Scientific EffectSelective permeability: Semipermeable Membrane

Data Source

PatentEP3147965B1Composite membrane, preparing method thereof, negative electrode structure including the composite membrane, and lithium secondary battery including the negative electrode structure
Publication Date: 2018.11.21 SAMSUNG ELECTRONICS CO LTD
  • EP3147965B1 patent drawingFigure 1A~1B
  • EP3147965B1 patent drawingFigure 2
  • EP3147965B1 patent drawingFigure 3A~3B

AI summary

A composite membrane including an organic membrane including a plurality of through holes, and a plurality of ion conductive inorganic material particles in the through holes, wherein a contact angle of the composite membrane or the ion conductive inorganic material particles is about 30° to about 90°.