Garnet-Type Li-Ion Ceramic Material for Thin Solid Electrolytes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current all-solid lithium ion secondary batteries with garnet-type oxide ceramic solid electrolytes face challenges in achieving high ion conductivity due to limited ion mobility and conductivity contributed by grain boundaries, particularly in devices with thin solid electrolyte layers.
Innovation Solution
Incorporating rare-earth elements into the Li-ion conductive oxide ceramic material with a garnet-type or similar crystal structure, specifically in the composition formula Li7+xLa3Zr2−xAxO12, where A is a rare-earth element, to increase transgranular ion conductivity by expanding the lattice constant and optimizing Li ion mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If thin solid electrolyte layers are used to reduce grain boundaries, then device complexity is reduced, but ion conductivity contribution from grain boundaries becomes limiting
Solution Approach 1:
The patent changes the material parameters by incorporating rare-earth elements that modify the grain boundary properties. The rare-earth element content (0.01-0.10 mol ratio) and specific composition ratios are optimized to reduce grain boundary resistance, enabling thin electrolyte layers to maintain high ion conductivity despite reduced grain boundary contribution.
Solution Approach 2:
The patent applies local quality by targeting specific regions (grain boundaries) for improvement through rare-earth element doping. The rare-earth elements preferentially segregate to grain boundaries, locally modifying their electrical properties and reducing resistance, which allows thin films to achieve high overall conductivity even with fewer grain boundaries.
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
This approach enhances overall ion conductivity in ceramic materials with a reduced number of grain boundaries, making them suitable for applications in thin solid electrolyte layers, particularly in stacked secondary batteries, with demonstrated ion conductivities exceeding 1.00×10−3 S/cm.
Implementation Method 1
increase transgranular ion conductivity by expanding the lattice constant and optimizing Li ion mobility
Data Source
AI summary
A Li-ion conductive oxide ceramic material including a garnet-type or similar crystal structure according to an aspect of the present disclosure contains Li, La, Zr, and O, the material further containing one or more elements selected from the group consisting of rare-earth elements. A Li-ion conductive oxide ceramic material including a garnet-type or similar crystal structure according to the other aspects of the present disclosure is represented by the following composition formula (1) Li7+xLa3Zr2−xAxO12 where A is one or more elements selected from the group consisting of rare-earth elements, and x is a number such that 0<x≤0.5.