Electrode Assembly Separator Bonding for Short-Circuit Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The lamination & stack type electrode assembly has weak adhesive force between unit cells, leading to misalignment risks and potential short-circuits due to external forces or heat, and lacks sufficient bonding between separators.
Innovation Solution
A method involving the alternately stacking first and second electrodes with separators, forming a bonding part by bonding protruding separators outward, and using heated rolls to bond them, ensuring the separators protrude appropriately to prevent short-circuits and maintain energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separators are made to protrude outward to enable bonding, then short-circuit prevention is improved, but assembly width increases reducing energy density
Solution Approach 1:
The bonding part is folded back onto itself in a nested configuration, with the protruding separators being bent back toward the cell stack. This nesting approach allows the separators to extend beyond the electrode edges for bonding purposes while returning to occupy minimal space, thus preventing short-circuits without significantly increasing the final assembly width.
Solution Approach 2:
The bonding part is configured to extend in the width direction initially for bonding purposes, then folded back to extend primarily in the length direction. This dimensional transformation allows the separator to serve its bonding function while minimizing its impact on the width dimension, thereby maintaining energy density.
2Productivity
If lamination & stack type is used for quick manufacturing, then productivity is improved, but adhesive force between unit cells becomes weak leading to misalignment
Solution Approach 1:
The separators are configured to protrude outward beyond the electrode edges before the stacking process, creating preliminary bonding protrusions that extend into the next unit cell. This preliminary configuration ensures that when unit cells are stacked, the separators are already positioned to provide bonding force, maintaining alignment accuracy during the quick manufacturing process.
Solution Approach 2:
The bonding part is designed with sufficient protrusion length and bonding strength to compensate for potential misalignment forces during stacking. This beforehand cushioning provides a safety margin that prevents misalignment even when manufacturing speed is increased, maintaining precision despite higher productivity.
3Ease of manufacture
If separator protrusion length is increased for easy bonding, then ease of manufacture is improved, but energy density decreases due to larger assembly size
Solution Approach 1:
The bonding part is folded back onto itself in a nested configuration, allowing sufficient protrusion length for easy bonding operations while returning to occupy minimal space. This nested structure provides the necessary length for bonding ease without permanently increasing the assembly width, thereby maintaining energy density.
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 solution effectively prevents short-circuits between electrodes, maintains energy density, and minimizes assembly width, enhancing the electrode assembly's performance and efficiency.
Implementation Method 1
the plurality of separators may pass between a first roll and a second roll, of which at least one is heated, and be bonded to each other
Data Source
AI summary
A method for manufacturing an electrode assembly includes preparing a cell stack and forming a bonding part. In the preparing, a first electrode and a second electrode having a width greater than that of the first electrode are alternately stacked with a separator therebetween. In the forming, a bonding part is folded toward the cell stack by bonding the plurality of separators protruding outward further than the first electrode and the second electrode to each other. An electrode assembly is also provided.