Garnet Ceramic Powder Pore Control for Solid Electrolyte Pulverization

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Solution Overview

Problem

Current methods for producing fine particles of LLZ-based garnet-type compounds for solid electrolytes in lithium-ion batteries require strong mechanical crushing, which damages the material and is costly and environmentally unfriendly, and result in high-density particles that are difficult to pulverize further.

Innovation Solution

A ceramic powder material with controlled pore characteristics, specifically a pore volume of 0.4 mL/g or more and average pore size of 0.5 um to 5 um, allowing for easy pulverization into fine particles without the need for strong crushing methods, achieved through a method involving calcination and mixing of precursor oxides.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If wet pulverization with strong mechanical crushing force is used to obtain fine particles, then particle size is reduced to 1 um or less, but material properties are impaired due to moisture absorption and Li desorption when water is used as solvent

Engineering Contradiction:
Improveparticle sizeVSAvoidmaterial properties
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent replaces the mechanical wet pulverization system with a chemical synthesis system. Instead of mechanically crushing synthesized powder, the invention synthesizes the garnet-type compound directly in a desired fine particle size range (0.1-10 μm) through controlled chemical reactions, thereby avoiding the need for strong mechanical crushing that damages material properties.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the synthesis parameters to directly produce fine particles. By controlling synthesis temperature (500-900°C), precursor composition, and calcination conditions, the invention achieves direct formation of garnet-type compounds with particle sizes of 0.1-10 μm, eliminating the need for subsequent size reduction that would compromise material integrity.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If wet pulverization with organic solvent is used to obtain fine particles, then particle size is reduced, but large amount of organic solvent is required making the method costly and environmentally burdensome

Engineering Contradiction:
Improveparticle sizeVSAvoidproduction cost and environmental load
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical pulverization process requiring organic solvents with a chemical synthesis process using aqueous solutions. The synthesis method employs water-based solutions for precursor preparation and calcination, completely eliminating the need for large amounts of organic solvents and their associated environmental and cost issues.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses inexpensive, easily removable water as the processing medium instead of costly organic solvents. Water can be completely evaporated or dried without leaving harmful residues, making the process economically viable and environmentally friendly compared to organic solvent-based methods.

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

3Reliability

If conventional synthesis method is used to produce garnet-type compound, then high-density particles are obtained, but the particles are very strong and difficult to atomize without strong crushing method

Engineering Contradiction:
ImprovedensityVSAvoidpulverizability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent optimizes synthesis parameters including calcination temperature (500-900°C), holding time, and atmospheric conditions to control particle density and structure. By carefully controlling these parameters, the invention produces particles with optimized density that maintain structural integrity while being sufficiently friable for easy size reduction to fine particles.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary size reduction by controlling the synthesis process itself to directly form fine particles (0.1-10 μm) rather than producing dense particles that require subsequent crushing. The synthesis conditions are predetermined to yield particles of the desired size range, eliminating the need for post-synthesis size reduction.

Inventive Principle:
Principle #10Preliminary 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 resulting ceramic powder material can be easily formed into fine particles under gentle conditions, enhancing the production efficiency and reducing environmental impact while maintaining high ionic conductivity for lithium-ion batteries.

Implementation Method 1

a pore volume of 0.4 mL/g or more and 1.0 mL/g or less

Methodology Applied
Scientific EffectPore structure: Porosity

Implementation Method 2

a third step of calcining the precipitate B at a temperature of 500°C or more and 900°C or less to obtain a precursor oxide

Methodology Applied
Scientific EffectCalcination: Heat Treatment

Data Source

PatentEP4005999B1Ceramic powder material and method for producing ceramic powder material
Publication Date: 2023.07.26 DAIICHI KIGENSO KAGAKU KOGYO CO LTD
  • EP4005999B1 patent drawingFigure 1
  • EP4005999B1 patent drawingFigure 2

AI summary

A ceramic powder material containing a garnet-type compound containing Li, wherein the ceramic powder material has a pore volume of 0.4 mL/g or more and 1.0 mL/g or less.