Garnet-Type Ceramic Solid Electrolyte for Lithium-Ion Batteries
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Solution Overview
Problem
The development of lithium-ion-conductive ceramic materials with high ion conductivity is hindered by the high cost and limited availability of expensive elements like Nb and Ta, which are used in existing garnet-type ceramic materials, such as Li7La3Zr2O12, making it challenging to produce these materials at a lower cost while maintaining high performance.
Innovation Solution
A lithium-ion-conductive ceramic material with a garnet-type or garnet-like crystal structure, composed of Li, La, Zr, and at least one of Mg and A (where A is Ca, Sr, or Ba), satisfying specific mole ratio conditions, which allows for higher ion conductivity and reduced production costs by utilizing more abundant and inexpensive elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If expensive elements like Nb and Ta are used to achieve high ion conductivity in garnet-type ceramic materials, then ion conductivity is improved, but production cost increases and material availability decreases
Solution Approach 1:
The patent replaces expensive, scarce elements (Nb, Ta) with cheaper, more abundant elements (Mg, Ca, Sr, Ba) as substitution elements in the garnet-type ceramic material. This substitution maintains high ion conductivity while significantly reducing production cost and improving material availability, directly resolving the technical contradiction between performance and manufacturing ease.
Solution Approach 2:
The patent optimizes the substitution ratio parameters, specifically setting the substitution ratio of Mg and/or A elements to be 0.01 to 0.50 (preferably 0.05 to 0.20) relative to the total mole sum of La and A elements. This parameter optimization ensures high ion conductivity is achieved while using abundant, inexpensive elements, thereby reducing production cost without sacrificing performance.
2Reliability
If expensive elements like Nb and Ta are used to achieve high ion conductivity in garnet-type ceramic materials, then ion conductivity is improved, but material availability decreases
Solution Approach 1:
The patent substitutes scarce elements (Nb, Ta) with abundant elements (Mg, Ca, Sr, Ba) in the garnet-type ceramic material. This substitution maintains high ion conductivity while using elements that are more readily available in nature, directly resolving the contradiction between achieving high performance and ensuring sufficient material availability.
Solution Approach 2:
The patent defines specific substitution ratio parameters (0.01 to 0.50, preferably 0.05 to 0.20) for Mg and/or A elements relative to La and A elements. This parameter control ensures optimal ion conductivity is achieved while using abundant elements, thereby guaranteeing both high performance and adequate material supply.
3Reliability
If Al is added to LLZ components to achieve high Li ion conductivity, then ion conductivity is improved, but production cost increases due to additional processing
Solution Approach 1:
The patent replaces Al substitution with Mg and/or A element substitution in the LLZ ceramic material. This approach achieves high Li ion conductivity while using simpler, more cost-effective raw materials and processing methods, thereby reducing production complexity and cost while maintaining or improving ion conductivity performance.
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 ceramic material achieves high ion conductivity and reduced production costs by using abundant elements like Mg and Sr, enhancing the mobility of Li ions and maintaining consistent ion conductivity, thus enabling the production of high-performance lithium batteries with lower internal resistance and increased capacity.
Implementation Method 1
a ceramic material having a garnet-type crystal structure is a promising material for producing solid electrolyte layer having high chemical stability... cubic-type LLZ exhibits high ion conductivity when a specific element thereof is substituted with another element
Data Source
AI summary
[OBJECTS]An object of the present invention is to provide a lithium-ion-conductive ceramic material having a target ion conductivity, while suppressing production cost. Another object is to provide a high-performance lithium battery, while suppressing production cost, by virtue of having the lithium-ion-conductive ceramic material.The lithium-ion-conductive ceramic material contains Li, La, and Zr, as well as at least one of Mg and A (wherein A represents at least one element selected from the group consisting of Ca, Sr, and Ba) and which has a garnet-type crystal structure, wherein the elements contained in the ceramic material satisfy the following mole ratio conditions (1) to (3): (1) 1.33≤Li/(La+A)≤3; (2) 0<Mg/(La+A)≤0.5; and (3) 0<A/(La+A)≤0.67, and a lithium battery employing the ceramic material.