Solid-State Electrolyte Ion Exchange for Dendrite-Resistant Batteries

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Solution Overview

Problem

Lithium metal batteries face challenges with low critical current densities due to lithium filament growth and penetration through solid electrolytes, primarily attributed to defects and tensile stresses, which lead to dendrite formation and mechanical failure.

Innovation Solution

Introducing residual compressive stresses in the solid electrolyte by exchanging lithium ions with larger ionic radius ions like potassium, silver, or sodium through ion exchange methods, inhibiting filament growth and enhancing fracture resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If lithium ions are exchanged with larger ions (e.g., potassium, silver, sodium), then residual compressive stresses are induced and fracture resistance is enhanced, but lithium ion diffusivity may be reduced

Engineering Contradiction:

Improvefracture resistanceVSAvoidlithium ion diffusivity

Core Design Contradiction:

StrengthVSSpeed

Solution Approach 1:

The patent applies local quality by performing ion exchange only in the near-surface region of the solid electrolyte, creating a compressed layer with enhanced fracture resistance while keeping the bulk material unchanged to maintain lithium ion diffusivity. This localized treatment resolves the contradiction by confining the stress-inducing modification to only where it is needed for preventing filament penetration.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the ionic radius parameter by exchanging lithium ions with larger ions (potassium, silver, or sodium), which induces residual compressive stresses. This parameter change enhances fracture resistance while the controlled extent of exchange maintains sufficient lithium ion diffusivity for battery performance.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the solid electrolyte is made more resistant to filament penetration through stress induction, then reliability is improved, but the complexity of the manufacturing process increases

Engineering Contradiction:

Improveresistance to filament penetrationVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by performing ion exchange treatment before battery assembly to induce residual compressive stresses in advance. This preliminary stress induction prevents filament penetration during battery operation without requiring additional components or complex manufacturing steps during assembly.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical reinforcement methods with a chemical ion exchange process that induces residual compressive stresses. This substitution achieves enhanced reliability against filament penetration through chemical modification rather than mechanical structuring, simplifying the overall manufacturing approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If residual compressive stresses are induced to prevent crack growth, then the solid electrolyte can withstand higher current densities, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvecurrent density capabilityVSAvoidion exchange control precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies partial action by performing ion exchange to a controlled depth in the near-surface region, creating sufficient compressive stress to prevent crack growth and enable higher current densities, while avoiding excessive exchange that would overly complicate manufacturing precision requirements.

Inventive Principle:

Principle #16Partial or excessive action

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 induced residual compressive stresses significantly reduce lithium filament penetration and dendrite formation, increasing fracture toughness and preventing mechanical failure, while maintaining sufficient lithium ion diffusivity for battery performance.

Implementation Method 1

exchanging lithium ions with larger ionic radius ions like potassium, silver, or sodium through ion exchange methods

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

Introducing residual compressive stresses in the solid electrolyte by exchanging lithium ions with larger ionic radius ions

Methodology Applied

Scientific EffectResidual stress:

Implementation Method 3

maintaining sufficient lithium ion diffusivity for battery performance

Methodology Applied

Scientific EffectIon diffusion: Diffusion

Data Source

PatentUS20250096310A1Lithium-Based Solid-State Electrolyte with Lithium Ions Exchanged by Ions Having a Larger Ionic Radius

Publication Date: 2025.03.20 BROWN UNIVERSITY

AI summary

The present disclosure describes a method of providing residual compressive stress to a lithium-based solid electrolyte by ion exchanging lithium ions with ions having a larger ionic radius that the lithium ions.