Amorphous Garnet Electrolyte Precursor for Low-Temperature Cubic Phase
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Synthesizing garnet oxide solid electrolytes at high temperatures leads to lithium evaporation and difficulty in achieving a pure cubic phase, while using sintering agents only partially improves the sintering temperature and can cause interface formations and side reactions.
Innovation Solution
A solid electrolyte precursor with an amorphous phase content of at least 50% and specific X-ray diffraction characteristics, prepared through high-energy mechanical milling and heat treatment at 600°C or less, forms a crystalline solid electrolyte with a cubic phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high temperature heat treatment (900°C or greater) is used to synthesize garnet oxide solid electrolytes, then ionic conductivity is improved, but lithium evaporation occurs and pure cubic phase formation becomes difficult
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperature (900°C or greater) to low temperature (600°C or lower) synthesis. This parameter change enables the formation of garnet oxide solid electrolyte with pure cubic phase while preventing lithium evaporation, thus resolving the contradiction between achieving high ionic conductivity and preventing lithium loss.
Solution Approach 2:
The patent utilizes phase transition from amorphous precursor to crystalline garnet phase at low temperature. The amorphous precursor undergoes phase transition to form the desired cubic garnet structure at 600°C or lower, avoiding the need for high temperature treatment that causes lithium evaporation while still achieving the required crystalline phase for high ionic conductivity.
2Temperature
If sintering agents are introduced to lower sintering temperature, then sintering temperature is partially improved, but interface formations and side reactions occur
Solution Approach 1:
The patent removes sintering agents from the synthesis system entirely. By using an amorphous precursor that can be directly converted to crystalline phase at low temperature without sintering agents, the harmful interface formations and side reactions caused by sintering agents are eliminated, while still achieving low temperature synthesis.
Solution Approach 2:
The amorphous precursor acts as an intermediary state that enables low temperature crystallization. This intermediate amorphous phase allows the system to bypass the need for sintering agents, facilitating phase transition at 600°C or lower without introducing harmful interfaces or side reactions.
3Stability of the object's composition
If high temperature heat treatment is used to form crystalline phase, then crystalline structure is achieved, but lithium loss increases and preparation reliability decreases
Solution Approach 1:
The patent changes the temperature parameter from high (900°C or greater) to low (600°C or lower), enabling crystalline phase formation while preventing lithium loss. This parameter change simultaneously achieves reliable crystalline structure formation and maintains preparation reliability by avoiding lithium evaporation.
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 method allows for the synthesis of a garnet crystal structure at lower temperatures, reducing lithium loss and minimizing interface reactions, resulting in improved ionic conductivity and uniform interfacial characteristics in lithium batteries.
Implementation Method 1
a phase change from an amorphous structure to a garnet crystal structure may be observed at a temperature of 600° C. or less
Implementation Method 2
high-energy mechanical milling and heat treatment at 600°C or less, forms a crystalline solid electrolyte with a cubic phase
Data Source
AI summary
A solid electrolyte precursor, a solid electrolyte, and a method of preparing the solid electrolyte. The solid electrolyte precursor includes a compound represented by Formula 1 and has an amorphous phase and the amorphous phase is contained in an amount of at least 50 volume percent based on the total volume of the solid electrolyte precursor. When the solid electrolyte precursor is analyzed by X-ray diffraction using Cu Kα radiation at a diffraction angle of 10° 2θ to 90° 2θ, a proportion of an area Pb of peaks having a full width at half maximum of 0.01° to 0.5° to a total area Pa of all peaks is 10% or less:(LixAa)(LayB′b)(ZrzC′c)O12+δ.