Solid Electrolyte MO2 Distribution for Battery Ionic Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In all solid batteries, the diffusion of MO2 from the solid electrolyte layers into the electrode layers disrupts the composition of Li—Al-M-PO4-based phosphoric acid salts, reducing ionic conductivity due to decreased ion conduction paths and increased interface resistance.
Innovation Solution
The battery design includes a solid electrolyte layer with a Li—Al-M-PO4-based phosphoric acid salt as the main component, where the ratio of MO2 is unevenly distributed from the center to 0.4 A in the thickness of the electrolyte layer, achieved by adding MO2 particles and adjusting the firing conditions during the manufacturing process, ensuring high ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MO2 is added to the solid electrolyte layer, then ionic conductivity is improved, but MO2 diffuses into electrode layers causing composition fluctuation and reduced ionic conductivity
Solution Approach 1:
The patent applies local quality by creating a non-uniform distribution of MO2 within the solid electrolyte layer. Specifically, MO2 is concentrated in a first region (closer to one electrode) while maintaining lower concentrations in a second region (closer to the other electrode). This spatially differentiated composition optimizes ionic conductivity in different zones while preventing excessive MO2 diffusion to either electrode interface, thereby resolving the contradiction between achieving high ionic conductivity and maintaining compositional stability.
2Reliability
If MO2 diffuses into electrode layers, then interface resistance increases, but uniform distribution of MO2 is difficult to achieve
Solution Approach 1:
The patent implements local quality by specifying different MO2 concentration zones within the solid electrolyte layer. The first region contains higher MO2 content to enhance ionic conductivity where needed, while the second region maintains lower MO2 content to prevent interface resistance increase. This controlled non-uniform distribution is achieved through specific manufacturing parameters during the sintering process, resolving the contradiction between optimizing interface resistance and achieving precise distribution control.
Solution Approach 2:
The patent applies parameter changes by controlling the sintering temperature and atmosphere during manufacturing to achieve the desired MO2 distribution. By optimizing these thermal processing parameters, the patent enables selective formation of MO2-rich and MO2-poor regions within the solid electrolyte layer, thereby achieving both low interface resistance and controlled distribution uniformity simultaneously.
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 secures high ionic conductivity by maintaining the composition of the solid electrolyte layer and reducing interface resistance between the electrolyte and electrode layers, enhancing the battery's performance and rate characteristics.
Implementation Method 1
MO2, an oxide of 'M ', may diffuse into electrode layers
Implementation Method 2
High ionic conductivity can be achieved by using phosphoric acid salt having a NASICON structure, as solid electrolyte layers of an all solid battery
Data Source
AI summary
An all solid battery includes a solid electrolyte layer of which a main component is a Li—Al-M-PO4-based phosphoric acid salt, a first electrode layer that is provided on a first main face of the solid electrolyte layer and includes an active material, and a second electrode layer that is provided on a second main face of the solid electrolyte layer and includes an active material. “M” is at least one of Ge, Ti, and Zr. A region in which a ratio of MO2 with respect to Li—Al-M-PO4 is 5% or more is unevenly distributed from a center in a thickness of the solid electrolyte layer to 0.4 A downward and to 0.4 A upward, when the thickness of the solid electrolyte layer is expressed by “A”.