3D All-Solid-State Lithium-Ion Battery Cathode Protection Layer
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Solution Overview
Problem
Three-dimensional all-solid-state lithium ion batteries face issues with non-uniform lithium composition in the solid state electrolyte layer, leading to lithium deficient regions, reduced reversible capacity, increased interfacial resistance, and accelerated degradation due to lithium ion migration during the deposition process.
Innovation Solution
Incorporating a cathode protection layer between the cathode and the solid state electrolyte, formed by processes like sputtering or chemical vapor deposition, to prevent lithium migration and ensure uniform composition, using materials such as metal oxides like Al, Si, Ti, Zr, Sn, or Ca, and forming the cathode protection layer to have a thickness between 3 nm to 20 nm to optimize interfacial resistance and charge/discharge efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a solid state electrolyte layer is deposited on a cathode, then the battery structure is formed, but lithium ion migration during deposition causes non-uniform lithium composition and creates lithium deficient regions
Solution Approach 1:
A cathode protection layer is introduced as an intermediary between the cathode and the solid state electrolyte layer. This protection layer prevents lithium ion migration from the cathode to the electrolyte during the deposition process, thereby maintaining uniform lithium composition in the cathode and preventing lithium deficient regions. The protection layer acts as a barrier that mediates the interaction between the cathode and electrolyte during manufacturing.
Solution Approach 2:
The cathode protection layer is formed on the cathode surface before the solid state electrolyte layer is deposited. This preliminary action prevents lithium migration issues before they can occur during the electrolyte deposition process, ensuring uniform lithium composition is maintained from the outset rather than attempting to correct it afterward.
2Reliability
If the cathode protection layer thickness is increased to prevent lithium migration, then interfacial resistance decreases, but the battery structure becomes more complex and manufacturing becomes difficult
Solution Approach 1:
The thickness of the cathode protection layer is optimized to a specific range (3 nm to 20 nm) to achieve the desired balance. This parameter optimization ensures the layer is thick enough to effectively prevent lithium migration and reduce interfacial resistance, while remaining thin enough to maintain structural simplicity and ease of manufacturing. The specific thickness range represents an optimized parameter that resolves the contradiction between protection effectiveness and structural complexity.
3Productivity
If different materials are used for cathode protection layer and solid state electrolyte layer to optimize performance, then battery efficiency improves, but manufacturing process becomes more complex
Solution Approach 1:
The cathode protection layer can be formed using the same material as the solid state electrolyte layer, allowing a single material system to serve multiple functions: as the protection layer during deposition and as the functional electrolyte layer. This multi-functionality approach simplifies the manufacturing process by reducing the number of different materials that need to be handled and processed, while still achieving the desired charge/discharge efficiency through proper layer configuration and thickness optimization.
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 cathode protection layer enhances the performance and lifetime of the lithium ion battery by maintaining lithium distribution, reducing interfacial resistance, and stabilizing charge/discharge efficiency, while also simplifying the manufacturing process by potentially using the same material for both the cathode protection and solid state electrolyte layers.
Implementation Method 1
a cathode protection layer disposed on a surface of the cathodes and on the cathode current collector; wherein the cathode protection layer is between the cathode and the solid state electrolyte layer
Implementation Method 2
The cathode protection layer may be formed by a sputtering process
Implementation Method 3
the solid state electrolyte layer may be formed by a chemical vapor deposition (CVD) process
Implementation Method 4
A first part of the cathode protection layer contacting the surface of the cathode may include a solid solution formed by a reaction with the surface of the cathode
Data Source
AI summary
A three-dimensional all-solid-state lithium ion batteries including a cathode protection layer, the battery including: a cathode including a plurality of plates which are vertically disposed on a cathode current collector; a cathode protection layer disposed on a surfaces of the cathode and the cathode current collector; a solid state electrolyte layer disposed on the cathode protection layer; an anode disposed on the solid state electrolyte layer; and an anode current collector disposed on the anode, wherein the cathode protection layer is between the cathode and the solid state electrolyte layer, and wherein the solid state electrolyte layer is between the cathode protection layer and the anode.