Protective Coatings for Lithium Metal Anodes Against Dendrites

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Solution Overview

Problem

Conventional lithium-ion batteries with graphite anodes have reached their theoretical capacity, limiting further performance improvements, and lithium metal anodes pose safety concerns due to dendrite formation, reactivity, and low Coulombic efficiency, necessitating the development of advanced lithium-free anodes for enhanced safety and longevity.

Innovation Solution

A metal anode with a protective coating comprising a composite material like lithium fluoride, lithium oxide, or hafnium oxide, applied using techniques such as atomic layer deposition, which suppresses dendrite growth and reduces electrolyte consumption, facilitating stable lithium ion transportation and prolonged battery life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium metal is used as anode to achieve ultrahigh capacity, then energy density is improved, but dendrite formation occurs causing safety issues and battery failure

Engineering Contradiction:

Improveenergy densityVSAvoidsafety

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A protective coating layer comprising lithium fluoride, lithium oxide, or hafnium oxide is applied as an intermediary between the lithium metal anode and the electrolyte. This coating prevents direct contact and harmful interactions while allowing lithium ion transport, thereby maintaining high energy density while eliminating safety risks associated with dendrite formation and reactivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If lithium metal anode is used to achieve high capacity, then energy density is improved, but reactivity with electrolyte increases causing side reactions and reduced battery life

Engineering Contradiction:

Improveenergy densityVSAvoidbattery life

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of stationary object

Solution Approach 1:

The protective coating acts as a stable intermediary barrier that prevents direct reactivity between lithium metal and the electrolyte. This eliminates parasitic side reactions and electrolyte consumption, thereby extending battery life while preserving the ultrahigh capacity advantage of lithium metal anodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If lithium metal anode is used to achieve ultrahigh capacity, then energy density is improved, but Coulombic efficiency decreases due to parasitic reactions

Engineering Contradiction:

Improveenergy densityVSAvoidCoulombic efficiency

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The protective coating comprising lithium fluoride, lithium oxide, or hafnium oxide serves as an inert intermediary that blocks parasitic reactions between lithium metal and electrolyte. This eliminates energy loss through side reactions and formation of solid electrolyte interphase, thereby achieving high Coulombic efficiency while maintaining ultrahigh energy density.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If protective coating is applied to prevent dendrite formation, then safety is improved, but manufacturing complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protective coating is applied using atomic layer deposition, a manufacturing technique that deposits ultra-thin, uniform layers at controlled thicknesses and compositions. This process achieves high safety performance while maintaining manufacturing simplicity through precise parameter control rather than complex multi-step procedures.

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 coated anodes achieve extended cycle life, maintaining 80% capacity for over 50 cycles and high energy density, with the protective coating preventing lithium dendrite formation and reducing electrolyte consumption, thereby enhancing safety and performance.

Implementation Method 1

a protective coating on the metal layer, wherein the protective coating comprises a composite material, and the composite material comprises an oxide or fluoride of lithium, sodium, or potassium

Methodology Applied

Scientific EffectPhysical barrier formation: Coatings

Implementation Method 2

applied using techniques such as atomic layer deposition

Methodology Applied

Scientific EffectAtomic layer deposition: Chemical Vapour Deposition

Implementation Method 3

facilitating stable lithium ion transportation

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS20230402612A1Materials and methods for components of lithium batteries

Publication Date: 2023.12.14 SHENZHEN INX ENERGY TECHNOLOGY CO LTD

AI summary

The present invention relates to materials and methods for components of lithium batteries, such as metal anodes having a protective coating.