LLZO Solid-State Electrolyte Membrane Air Degradation

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Solution Overview

Problem

Conventional solid-state LLZO electrolyte membranes for lithium-ion batteries degrade rapidly when exposed to air, limiting their performance and requiring hermetic packaging, which increases production costs and restricts assembly under controlled conditions.

Innovation Solution

A fused solid-state electrolyte membrane with a thickness of less than 5 mm, composed of a polycrystalline product with less than 3% amorphous phase and predominantly made of Li, La, Zr, and a dopant, is developed, featuring a microstructure with a high percentage of cubic and tetragonal LLZO phases and a specific composition that enhances resistance to air degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hermetic packaging under argon is used to store the membrane, then the membrane degradation is prevented, but production costs increase

Engineering Contradiction:
Improvemembrane stabilityVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent develops a fused LLZO membrane with specific composition (2.500≤a≤8.500, 1.000≤b≤3.500, 0.600≤c≤2.000, 0≤d≤1.900 in formula LiaLabZrcMdO12) that achieves adequate air stability without requiring expensive hermetic packaging, effectively replacing the need for costly protective packaging with an inherently more stable material composition

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent modifies the chemical composition parameters of the LLZO membrane by controlling the atomic indices (a, b, c, d) in the formula LiaLabZrcMdO12 and using specific dopants (Al, P, Sb, Sc, Ti, V, Y, Nb, Hf, Ta, lanthanides, Se, W, Bi, Si, Ge, Ga, Sn, Cr, Fe, Zn, Na, K, Rb, Cs, Fr, Mg, Ca, Sr, Ba), which changes the material's properties to achieve both air stability and high ionic conductivity without requiring hermetic packaging

Inventive Principle:
Principle #35Parameter changes

2Reliability

If hermetic packaging under argon is used to store the membrane, then the membrane degradation is prevented, but assembly under air becomes restricted

Engineering Contradiction:
Improvemembrane stabilityVSAvoidassembly flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent develops a fused LLZO membrane with specific composition (2.500≤a≤8.500, 1.000≤b≤3.500, 0.600≤c≤2.000, 0≤d≤1.900 in formula LiaLabZrcMdO12) that achieves adequate air stability without requiring hermetic packaging, enabling flexible assembly under air conditions

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent modifies the chemical composition parameters of the LLZO membrane by controlling the atomic indices (a, b, c, d) in the formula LiaLabZrcMdO12 and using specific dopants, which changes the material's properties to allow assembly under air while maintaining stability

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 fused membrane exhibits significantly improved resistance to aging in air, allowing for storage and assembly in air, reducing production costs and maintaining high ionic conductivity, thus enabling more flexible and cost-effective battery manufacturing and use.

Implementation Method 1

c) cooling until said liquid mass has completely solidified

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentUS20230253675A1Membrane made of a polycrystalline LLZO product
Publication Date: 2023.08.10 SAINT GOBAIN CENT DE RES & DEVS & DETUD EUROEN

AI summary

A fused solid-state electrolyte e membrane having a thickness less than 5 mm and intended for a lithium-ion battery. The membrane includes a polycrystalline product including at least 3.0% amorphous phase and including, for more than 95% of its mass, of the elements Li, La, Zr, M and O, M being a dopant chosen from the group formed by Al, P, Sb, Sc, Ti, V, Y, Nb, Hf, Ta, the lanthanides with the exception of La, Se, W, Bi, Si, Ge, Ga, Sn, Cr, Fe, Zn, Na, K, Rb, Cs, Fr, Mg, Ca, Sr, Ba and the mixtures thereof. The contents of these elements, measured after a decarbonatation operation without loss of lithium, being defined by the formula LiaLabZrcMdO12, wherein the atomic indices are such that: 2.500<a<8,500, and 1,000<b<3.500, and 0.600<c<2.000, and 0<d<2.000.