Garnet Solid Electrolyte Al2O3 Additive Sintering
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Solution Overview
Problem
Garnet-type solid electrolytes for all-solid-state batteries face challenges with low ionic conductivity, high grain boundary resistance, and inefficient production due to high-temperature sintering requirements, which limits their scalability and energy density.
Innovation Solution
A method involving the addition of a small amount of Al2O3 to a precursor containing hydroxide during the garnet-type solid electrolyte preparation process, enhancing sintered density and ionic conductivity while maintaining a pure cubic phase crystal structure without impurities, using a mixture of LiOH, La(OH)3, ZrO2, and Al2O3, and optimizing calcination conditions to produce a garnet-type solid electrolyte with improved properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature sintering (900-1400°C) is used to prepare oxide-based solid electrolyte, then sintered density is improved, but production efficiency deteriorates and large-area electrolyte membrane cannot be formed
Solution Approach 1:
The patent changes the chemical composition parameters by introducing Al2O3 as an additive (0.1-5 wt%) and using hydroxide precursors instead of conventional carbonates. This composition modification enables effective sintering at reduced temperatures (800-1000°C), resolving the contradiction between achieving high sintered density and maintaining production efficiency
Solution Approach 2:
The patent creates a composite solid electrolyte system by combining oxide-based electrolyte materials with Al2O3 additive. This composite formulation improves sinterability and enables formation of dense electrolyte membranes at lower temperatures, simultaneously achieving high sintered density and scalable production
2Stability of the object's composition
If long-time calcination (6 hours or longer) at high temperature (1000-1250°C) is used to prepare garnet-type electrolyte, then phase changes and composition uniformity are secured, but production time increases
Solution Approach 1:
The patent performs preliminary mixing and uniform distribution of hydroxide precursors (LiOH, La(OH)3) and Al2O3 additive before calcination. This preliminary homogenization of the precursor mixture enables faster and more uniform phase transformation during calcination, achieving composition uniformity in 2-4 hours instead of 6+ hours
Solution Approach 2:
The patent modifies the chemical parameters by using hydroxide precursors with higher reactivity compared to conventional carbonates. This chemical parameter change accelerates the decomposition and phase formation kinetics, reducing the required calcination time while maintaining composition uniformity
3Reliability
If pellet-covered garnet is used to prevent lithium volatilization, then phase changes are secured, but the proportion of garnet is less than 20% by weight which is inefficient
Solution Approach 1:
The patent introduces Al2O3 as an intermediary substance that prevents lithium volatilization during calcination without requiring pellet covering. The Al2O3 forms a protective matrix that retains lithium species in place, enabling high garnet phase purity (>80%) and efficient production
Solution Approach 2:
The patent extracts the function of lithium retention from the mechanical pellet covering method and transfers it to the chemical Al2O3 additive system. This eliminates the need for pellet formation and covering steps while achieving better lithium retention and higher garnet phase proportion
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 approach results in a garnet-type solid electrolyte with significantly increased ionic conductivity and sintered density, achieving up to 100 times higher conductivity than tetragonal phases and maintaining a pure cubic phase structure, thereby enhancing the performance and efficiency of all-solid-state batteries.
Implementation Method 1
the garnet-type solid electrolyte may be prepared by adding an aluminum oxide (Al2O3) to a precursor containing hydroxide, thereby enhancing sintered density and ionic conductivity
Implementation Method 2
adding a small amount of Al2O3 to a precursor containing hydroxide during the garnet-type solid electrolyte preparation process, enhancing sintered density and ionic conductivity
Implementation Method 3
optimizing calcination conditions to produce a garnet-type solid electrolyte with improved properties
Implementation Method 4
maintaining a pure cubic phase crystal structure without impurities
Data Source
AI summary
Disclosed are a garnet-type solid electrolyte and a method for preparing the same. The garnet-based solid electrolyte of the present invention is prepared by adding Al2O3 to a precursor containing hydroxide, thereby enhancing sintered density and ionic conductivity while having a pure cubic phase crystal structure without including impurities.