Solid-State Battery Electrolyte Layout for Interface Crack Suppression
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Solution Overview
Problem
Solid-state batteries experience decreased cycle characteristics due to volume changes in negative electrode active materials during charging and discharging, leading to peeling or cracking at interfaces and increased resistance, particularly when using a combination of inorganic and polymer electrolytes.
Innovation Solution
A solid-state battery design that incorporates a polymer electrolyte for the negative electrode layer and an inorganic electrolyte for the positive electrode layer, with a solid electrolyte layer covering three sides of the current collector and active material layers to prevent deformation and internal short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a sulfide solid electrolyte is used in the solid-state battery, then high ionic conductivity is achieved, but peeling or cracking occurs at interfaces due to volume change of negative electrode active material during charging and discharging
Solution Approach 1:
The patent applies different electrolyte materials to different locations: a polymer electrolyte is used in the negative electrode layer where volume change occurs during charging/discharging, while an inorganic solid electrolyte is used in the positive electrode layer. This local differentiation allows each region to have properties optimized for its specific functional requirements, preventing interface degradation in the negative electrode while maintaining high ionic conductivity in the positive electrode.
Solution Approach 2:
The patent employs a composite electrolyte structure combining polymer electrolyte and inorganic solid electrolyte in different layers. The polymer electrolyte component accommodates volume changes in the negative electrode, while the inorganic solid electrolyte provides high ionic conductivity in the positive electrode, creating a composite system that overcomes the limitations of using either material alone throughout the entire battery.
2Reliability
If a polymer electrolyte is used for the negative electrode layer to suppress peeling and cracking, then interface bonding stability is improved, but ionic conductivity is lower compared to inorganic solid electrolyte
Solution Approach 1:
The patent applies different electrolyte materials to different locations: a polymer electrolyte is used in the negative electrode layer where volume change occurs during charging/discharging, while an inorganic solid electrolyte is used in the positive electrode layer. This local differentiation allows each region to have properties optimized for its specific functional requirements, preventing interface degradation in the negative electrode while maintaining high ionic conductivity in the positive electrode.
Solution Approach 2:
The patent employs a composite electrolyte structure combining polymer electrolyte and inorganic solid electrolyte in different layers. The polymer electrolyte component accommodates volume changes in the negative electrode, while the inorganic solid electrolyte provides high ionic conductivity in the positive electrode, creating a composite system that overcomes the limitations of using either material alone throughout the entire battery.
3Ease of manufacture
If the solid electrolyte layer covers only the necessary area, then manufacturing complexity is reduced, but deformation and internal short circuits occur during pressing
Solution Approach 1:
The patent extends the solid electrolyte layer to cover the end surfaces of the current collector and active material layers before the pressing process. This preliminary extension ensures that when pressing occurs, the electrolyte layer is already in position to prevent deformation and short circuits, eliminating the need for complex post-pressing adjustments or additional protective structures.
Solution Approach 2:
The solid electrolyte layer functions as a protective thin film that conforms to the structure of the current collector and active material layers. By covering the end surfaces, it acts as a flexible protective barrier that prevents short circuits during pressing while maintaining the overall structural integrity and simplicity of the battery design.
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 design suppresses peeling and cracking, maintaining excellent cycle characteristics by using a polymer electrolyte for the negative electrode, reducing the occurrence of short circuits and enhancing battery performance.
Implementation Method 1
it is possible to suppress peeling or cracking inside of a negative electrode layer or at an interface between the negative electrode layer and a solid electrolyte layer during charging and discharging
Implementation Method 2
ions and electrons are conducted by using an interface between a solid and a solid
Implementation Method 3
the inorganic solid electrolyte is used for a positive electrode layer from the viewpoint of improving the battery performance
Data Source
AI summary
A solid-state battery includes: a first current collector layer having a first current collector tab protruding from one side of a quadrilateral; a first active material layer laminated on the first current collector layer; a second current collector layer having a second current collector tab protruding from one side of a quadrilateral; a second active material layer laminated on the second current collector layer; and a solid electrolyte layer arranged between the first active material layer and the second active material layer and including a polymer electrolyte, wherein, in three sides other than the one side where the first current collector tab is arranged, the solid electrolyte layer is arranged so as to cover end surfaces of the first current collector layer and the first active material layer.