Beta-Alumina Solid Electrolyte Sheet With Low Voidage for Ion Conduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The ion conduction value of beta-alumina-based solid electrolyte sheets decreases when manufactured using conventional methods, likely due to insufficient adhesion and denseness of particles during the production process.
Innovation Solution
A beta-alumina-based solid electrolyte sheet with a thickness of 1 mm or less and voidage of 20% or less is produced using isostatic pressing and controlled composition, including 65 to 98% Al2O3, 2 to 20% Na2O, 0.3 to 15% MgO+Li2O, and optionally ZrO2 and Y2O3, to enhance adhesion and denseness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If beta-alumina-based solid electrolyte sheet is manufactured by conventional green sheet method, then manufacturing process is simple, but ion conduction value decreases
Solution Approach 1:
The invention changes the composition parameters of the solid electrolyte by adding specific amounts of Li2O (0.1-5 wt%) and MgO (0.1-5 wt%) to the conventional beta-alumina system. This compositional modification transforms the material properties to achieve higher ion conduction values (1.0 S/cm or more at 25°C) while maintaining the conventional green sheet manufacturing process, thus resolving the contradiction between manufacturing simplicity and ion conduction performance.
2Quantity of substance
If solid electrolyte sheet thickness is reduced to increase energy density, then energy density per unit volume increases, but ion conduction value decreases
Solution Approach 1:
The invention modifies the chemical composition parameters of the solid electrolyte by incorporating Li2O and MgO additives, which fundamentally changes the ion conduction characteristics of the material. This enables thin sheets (1 mm or less) to maintain high ion conduction values (1.0 S/cm or more) despite reduced thickness, thereby achieving high energy density without sacrificing ion conduction performance.
Solution Approach 2:
The invention creates a composite solid electrolyte system by combining beta-alumina with Li2O-MgO additives. This composite material approach allows the thin sheet structure to achieve enhanced ion conduction properties that would not be possible with conventional beta-alumina alone, resolving the contradiction between thickness reduction and ion conduction maintenance.
3Reliability
If voidage is reduced to increase particle denseness, then ion conductivity improves, but manufacturing difficulty increases
Solution Approach 1:
The invention changes the compositional parameters by adding Li2O and MgO, which modify the sintering behavior and particle packing characteristics of the green sheet. This enables achieving low voidage (20% or less) and high particle denseness through conventional firing processes, maintaining ease of manufacture while improving ion conductivity.
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 solid electrolyte sheet exhibits high ion conductivity, with an ion conduction value of 1 S or more, suitable for sodium ion all-solid-state secondary cells, enhancing energy density per unit volume.
Implementation Method 1
beta-alumina-based solid electrolytes, including β-alumina and β′′-alumina, are also known to exhibit high sodium ion conductivity
Implementation Method 2
The solid electrolyte sheet according to the present invention has a small thickness of 1 mm or less and a voidage of 20% or less, and has excellent ion conductivity
Data Source
AI summary
Provided is a thin beta-alumina-based solid electrolyte sheet having a high ion conduction value. The solid electrolyte sheet containing β-alumina and/or β″-alumina and having a thickness of 1 mm or less and a voidage of 20% or less.