LLTO Solid Electrolyte Impurity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solid electrolytes for lithium batteries, such as lithium ion and lithium air batteries, face challenges in achieving high lithium ion conductivity, which is essential for enhancing battery performance and output.
Innovation Solution
A lithium-lanthanum-titanium oxide sintered material with reduced Al2O3 and SiO2 impurities, specifically formulated to have a lithium ion conductivity of 5.0 x 10^-4 Scm^-1 or more at 27°C, is developed by controlling the composition and sintering conditions, resulting in a material suitable for use as a solid electrolyte in lithium air and all-solid lithium ion batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid electrolyte materials are used, then battery assembly is simplified, but lithium ion conductivity is insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the solid electrolyte material. Specifically, it limits Al2O3 to 0.35 mass% or less and SiO2 to 0.1 mass% or less, while maintaining the base composition of La0.57Li0.29TiO3. This parameter optimization directly improves lithium ion conductivity to 5.0×10^-4 S/cm or more at 27°C, resolving the contradiction between material simplicity and performance requirements.
2Reliability
If impurity levels are reduced to increase conductivity, then lithium ion conductivity improves, but manufacturing complexity increases
Solution Approach 1:
The patent establishes specific parameter thresholds for impurity control: Al2O3 at 0.35 mass% or less and SiO2 at 0.1 mass% or less. These quantified parameters provide clear manufacturing targets that balance conductivity improvement with manufacturing feasibility. The patent demonstrates that achieving these parameter specifications enables lithium ion conductivity of 5.0×10^-4 S/cm or more at 27°C.
Solution Approach 2:
The patent replaces complex mechanical purification processes with optimized sintering conditions and composition control. By substituting extensive mechanical cleaning and separation operations with precise compositional formulation and controlled thermal processing, the patent achieves the required impurity levels while simplifying the overall manufacturing system.
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 optimized lithium-lanthanum-titanium oxide sintered material exhibits improved lithium ion conductivity, making it suitable for high-performance lithium air and all-solid lithium ion batteries, with applications in various devices requiring reliable and efficient energy storage.
Implementation Method 1
A material having high lithium ion conductivity is necessary as the solid electrolyte for the air battery and the all-solid lithium ion battery. As such material having high lithium ion conductivity, lithium-lanthanum-titanium oxides are the focus of attention
Implementation Method 2
Document 'H. Geng, et al., Electrochimica Acta 3406-3414 (2011) 56' discloses the effect of sintering temperature on microstructure and transport properties of Li3xLa2/3-xTiO3 (LLTO)
Data Source
Figure 1~2
AI summary
A lithium-lanthanum-titanium oxide sintered material has a lithium ion conductivity 3.0 x 10-4 Scm-1 or more at a measuring temperature of 27 °C, the material is described by one of general formulas (1-a)LaxLi2-3xTiO3-aSrTiO3, (1-a)LaxLi2-3xTiO3-aLa0.5K0.5TiO3, LaxLi2-3xTi1-aMaO3-a, Srx-1.5aLaaLi1.5-2xTi0.5Ta0.5O3 (0.55 ≤ x ≤ 0.59, 0 ≤ a ≤ 0.2, M = at least one of Fe or Ga), amount of Al contained is 0.35 mass% or less as Al2O3, amount of Si contained is 0.1 mass% or less as SiO2, and average particle diameter is 18 µm or more.