Solid Electrolyte Bonding Layer for Low-Impedance Cathode Contact
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Solution Overview
Problem
Solid electrolytes used in lithium-ion batteries face challenges such as delamination and insufficient electrical contact between electrodes, leading to increased interfacial impedance, which reduces battery power and capacity, especially when paired with a lithium metal negative electrode.
Innovation Solution
A bonding layer comprising a lithium salt, a polymer, and a solvent, such as a gel electrolyte, is introduced between the lithium-stuffed garnet electrolyte separator and the positive electrode to enhance adhesion and reduce interfacial impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a solid electrolyte separator is directly laminated to solid electrodes, then the battery structure is simple and device complexity is low, but interfacial impedance increases and electrical contact is insufficient
Solution Approach 1:
The patent introduces a bonding agent layer as an intermediary substance between the solid electrolyte separator and the solid electrodes. This bonding agent improves interfacial adhesion and reduces interfacial impedance, ensuring sufficient electrical contact while maintaining the simplicity of the overall battery structure. The bonding agent acts as a mediator that facilitates better contact without adding complex structural elements.
2Reliability
If a bonding layer is added between the electrolyte separator and positive electrode, then interfacial impedance decreases by a factor of at least 10, but device complexity increases
Solution Approach 1:
The patent applies the bonding agent layer locally at the critical interfaces between the solid electrolyte separator and the electrodes, rather than throughout the entire battery structure. This localized application reduces interfacial impedance where it matters most while minimizing the overall increase in device complexity. The bonding agent is specifically positioned at the positive electrode interface and selectively applied only where improved contact is needed.
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 bonding layer significantly lowers interfacial impedance by a factor of at least 10, improving the electrochemical performance and maintaining direct contact between the electrolyte separator and the positive electrode, thereby enhancing the battery's power and capacity.
Implementation Method 1
the bonding layer, the electrolyte or the catholyte in the positive electrode, do not detrimentally react with the Li metal in a lithium metal negative electrode but still provide a conduction medium for Li+
Implementation Method 2
A bonding layer comprising a lithium salt, a polymer, and a solvent, such as a gel electrolyte, is introduced between the lithium-stuffed garnet electrolyte separator and the positive electrode
Implementation Method 3
A bonding layer comprising a lithium salt, a polymer, and a solvent, such as a gel electrolyte, is introduced between the lithium-stuffed garnet electrolyte separator and the positive electrode to enhance adhesion
Data Source
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AI summary
Set forth herein are electrochemical cells which include a negative electrode current collector, a lithium metal negative electrode, an oxide electrolyte membrane, a bonding agent layer, a positive electrode, and a positive electrode current collector. The bonding agent layer advantageously lowers the interfacial impedance of the oxide electrolyte at least at the positive electrode interface and also optionally acts as an adhesive between the solid electrolyte separator and the positive electrode interface. Also set forth herein are methods of making these bonding agent layers including, but not limited to, methods of preparing and depositing precursor solutions which form these bonding agent layers. Set forth herein, additionally, are methods of using these electrochemical cells.