Garnet Ion-Conducting Oxide Inhibiting Lithium Carbonate Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Garnet-type ion-conducting oxides experience a decrease in ion conductivity when exposed to air due to lithium carbonate formation on their surface, which is difficult to prevent without using a glove box, leading to poor workability, low productivity, and high production costs.
Innovation Solution
A garnet-type ion-conducting oxide with a specific chemical formula (Lix-3y-z, Ey, Hz)LαMβOγ, where E is Al, Ga, or Si, and L is an alkaline-earth metal or lanthanoid element, with a half-width of a diffraction peak less than 0.164°, inhibiting lithium carbonate formation by increasing crystallinity and stabilizing the crystal structure, and a method involving sintering with a lithium-containing flux at a temperature above the flux's melting point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If garnet-type ion-conducting oxide is handled in a glove box to prevent lithium carbonate formation, then ion conductivity is maintained, but workability deteriorates and production cost increases
Solution Approach 1:
A protective coating layer is applied to the surface of the garnet-type ion-conducting oxide particles to act as an intermediary barrier that prevents direct contact between the oxide surface and atmospheric CO2, thereby preventing lithium carbonate formation without requiring a glove box environment
Solution Approach 2:
The oxide particles are stored and handled in an atmosphere with controlled CO2 concentration (e.g., nitrogen or argon atmosphere) to create an inert environment that prevents the chemical reaction between CO2 and the oxide surface, eliminating the need for expensive glove box equipment
2Reliability
If conventional sintering methods are used for garnet-type ion-conducting oxide, then dense sintered bodies can be obtained, but sintering temperature must be very high causing energy consumption and equipment requirements
Solution Approach 1:
The invention changes the chemical composition parameters of the garnet-type oxide by substituting cations at specific crystallographic sites with elements having different ionic radii and bonding characteristics, which modifies the sintering behavior and enables dense sintering at lower temperatures
Solution Approach 2:
The invention uses composite oxide materials combining multiple cations (e.g., Li, La, Zr, Al, Ta) in specific ratios to create a composite garnet structure that exhibits enhanced sinterability and achieves high density at reduced sintering temperatures compared to conventional single-phase garnet oxides
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 solution effectively inhibits lithium carbonate formation on the surface of the oxide particles, maintaining high lithium ion conductivity and reducing production costs by allowing sintering at lower temperatures, thus enhancing the workability and productivity of the oxide electrolyte sintered body.
Implementation Method 1
a half-width of a diffraction peak which has a highest intensity and which is observed at a diffraction angle (2θ) in a range of from 29° to 32° as a result of X-ray diffraction measurement using CuKα radiation, is 0.164° or less
Implementation Method 2
X-ray diffraction measurement using CuKα radiation
Implementation Method 3
sintering a mixture of the flux and the crystal particles of the garnet-type ion-conducting oxide by heating at a temperature equal to or more than a melting point of the flux
Implementation Method 4
sintering a mixture of the flux and the crystal particles of the garnet-type ion-conducting oxide by heating at a temperature equal to or more than a melting point of the flux
Data Source
AI summary
A garnet-type ion-conducting oxide configured to inhibit lithium carbonate formation on the surface of crystal particles thereof, and a method for producing an oxide electrolyte sintered body using the garnet-type ion-conducting oxide. The garnet-type ion-conducting oxide represented by a general formula (Lix-3y-z, Ey, Hz)LαMβOγ (where E is at least one kind of element selected from the group consisting of Al, Ga, Fe and Si; L is at least one kind of element selected from an alkaline-earth metal and a lanthanoid element: M is at least one kind of element selected from a transition element which be six-coordinated with oxygen and typical elements in groups 12 to 15 of the periodic table; 3≤x−3y−z≤; 0≤y≤0.22; C≤z≤2.8; 2.5≤α≤3.5; 1.5≤≈≤2.5; and 11≤γ≤13), wherein a half-width of a diffraction peak which has a highest intensity and which is observed at a diffraction angle (2θ) in a range of from 29° to 32° as a result of X-ray diffraction measurement using CuKα radiation, is 0.164° or less.