Vapor-Deposited Silane Composite Coating for Lithium Anode Dendrite Control

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Solution Overview

Problem

Lithium metal batteries face performance degradation due to side reactions with electrolyte species and the formation of lithium dendrites, which can lead to premature failure and reduced cycling lifetime.

Innovation Solution

A method of forming an inorganic-organic composite surface coating on lithium-containing negative electrodes using vapor deposition of mercapto-containing silanes and inorganic silanes, such as 3-mercaptopropyltrimethoxysilane and tetraethyl orthosilicate, to suppress dendrite growth and enhance electrochemical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium metal is used in the negative electrode to achieve high energy density, then the battery storage capacity increases, but lithium dendrite formation occurs leading to cell failure

Engineering Contradiction:

Improvestorage capacityVSAvoidcell stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

An inorganic-organic composite coating is introduced as an intermediary layer between the lithium metal anode and the electrolyte. This coating acts as a mediator that allows lithium ion transport while preventing direct contact between lithium metal and electrolyte species, thereby suppressing dendrite formation and side reactions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite coating material comprising both inorganic components (such as metal oxides, metal phosphates, or metal sulfides) and organic components (such as polymers or small molecules). This composite structure combines the advantages of both material types to achieve effective dendrite suppression while maintaining ion conductivity.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If lithium metal anode is used to achieve high energy density, then storage capacity doubles, but side reactions with electrolyte species occur compromising coulombic efficiency

Engineering Contradiction:

Improvestorage capacityVSAvoidcoulombic efficiency

Core Design Contradiction:

Quantity of substanceVSLoss of energy

Solution Approach 1:

The composite coating serves as an intermediary barrier that prevents direct side reactions between lithium metal and electrolyte species. This mediator layer allows selective lithium ion transport while blocking other electrolyte components, thereby improving coulombic efficiency by reducing parasitic reactions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the interface properties between the lithium anode and electrolyte by introducing a coating with specific chemical and physical properties. The coating's composition, thickness, and structure are optimized to achieve the desired balance between ion conductivity and reaction suppression.

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If lithium metal anode is used to achieve high energy density, then battery size is reduced, but dendrite growth causes internal short circuit and thermal runaway

Engineering Contradiction:

Improvebattery sizeVSAvoiddendrite formation

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The composite coating acts as a protective intermediary layer that physically constrains dendrite growth. This mediator prevents dendrites from developing sharp protrusions that could puncture the separator, thereby eliminating the risk of internal short circuits and thermal runaway while maintaining the compact battery design.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating is applied beforehand to the lithium metal anode surface, providing a protective cushion that prevents dendrite formation before it can cause harmful effects. This preventive measure addresses potential failures before they occur, ensuring safe operation throughout the battery's lifecycle.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 surface coating effectively minimizes lithium dendrite formation, improving the cycling life and stability of lithium metal batteries by providing a robust and flexible interface for lithium ion transport, leading to doubled cycling lifetime and reduced capacity degradation.

Implementation Method 1

a vapor deposition process of at least two distinct precursors on one or more surface regions of a negative electrode material comprising lithium

Methodology Applied

Scientific EffectVapor deposition: Physical Vapour Deposition

Implementation Method 2

The first precursor and the second precursor react to form an inorganic-organic composite surface coating

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS10608249B2Conformal coating of lithium anode via vapor deposition for rechargeable lithium ion batteries

Publication Date: 2020.03.31 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A negative lithium-containing electrode for an electrochemical cell is provided, along with methods of making such a negative lithium-containing electrode. The method includes depositing a first precursor and a second precursor in a vapor deposition process onto one or more surface regions of a negative electrode material comprising lithium. The first precursor and the second precursor react to form an inorganic-organic composite surface coating on the one or more surface regions. The first precursor comprises an organic mercapto-containing silane and the second precursor comprises an inorganic silane.