Lithium-Metal Unit Cell Edge-Bonded Separator for Electrode Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Achieving precise alignment of positive and negative electrodes in lithium-metal batteries is challenging, particularly in stacked cells, due to factors like high-speed operations, dimensional variability, and the fragility of electrodes, which can lead to internal shorts and catastrophic failures.
Innovation Solution
The development of lithium-metal unit cells with a negative electrode, positive electrode, and a separator sheet, where the electrodes are integrated with polymer bases and current collectors, and the separator is bonded to the edges, ensuring precise alignment and support without the need for external wrapping or folding, allowing for improved handling and stacking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrodes are handled in high-speed operations during battery assembly, then productivity is improved, but manufacturing precision deteriorates due to dimensional variability and electrode fragility
Solution Approach 1:
The battery assembly is divided into modular unit cells, each with self-contained electrode stacks and separator sheets. This segmentation allows for pre-assembly and quality control of individual units before final stacking, maintaining precision while enabling high-speed final assembly through modular integration.
Solution Approach 2:
Separator sheets serve as intermediary components between positive and negative electrodes, providing mechanical support and maintaining alignment. The separator sheets are specifically designed to bridge dimensional variability and prevent electrode misalignment during high-speed handling operations.
2Manufacturing precision
If separator sheet is bonded to electrode edges, then electrode alignment is improved, but device complexity increases
Solution Approach 1:
The separator sheet performs multiple functions simultaneously: it provides ionic conductivity between electrodes, maintains electrode alignment through edge bonding, and serves as a mechanical support structure. This multi-functionality reduces the need for additional alignment components, thereby managing complexity while achieving precise alignment.
Solution Approach 2:
The alignment function is merged into the separator sheet itself through edge bonding, rather than being a separate process or component. This integration simplifies the overall structure by combining separation and alignment functions into a single element.
Data Source
AI summary
Described herein are lithium-metal unit cells and methods of fabricating such cells. A lithium-metal unit cell comprises a negative electrode, a positive electrode, and a separator sheet. The negative electrode comprises a negative polymer base and a negative active material layer adhered to and supported on the negative polymer base and comprising lithium metal. The positive electrode comprises a positive polymer base, a positive current collector adhered to and supported on the positive polymer base, and a positive active material layer adhered to and supported on the positive polymer base such that the positive current collector is positioned between the positive polymer base and the positive active material layer. The separator sheet is positioned between the negative active material layer and the positive active material layer and bonded to the negative base side edges and the positive base side edges.