Electrode Assembly Separation Film Folding Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrode assemblies face challenges in preventing the separation film from unfolding and exposing electrodes during the folding of unit cells, which can lead to instability and damage in secondary batteries.
Innovation Solution
The electrode assembly incorporates a separation film that is folded multiple times to surround unit cells, with specific folding patterns and adhesion layers to ensure the film remains in place and covers the electrodes, preventing exposure and unfolding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the separation film is folded once to surround unit cells, then the manufacturing process is simple, but the film may unfold and electrodes may be exposed
Solution Approach 1:
The separation film is divided into multiple folding parts (first folding part and second folding part) that fold at different stages. The first folding part folds once to provide initial coverage, while the second folding part folds again to provide additional coverage and prevent unfolding, thereby resolving the contradiction between manufacturing simplicity and reliability.
Solution Approach 2:
The first folding part is folded in advance to surround a portion of the unit cells before the second folding part is applied. This preliminary action provides initial protection and stability, preventing the film from unfolding during subsequent handling and assembly processes.
2Reliability
If the separation film is folded multiple times to surround unit cells, then the film stability is improved, but the manufacturing complexity increases
Solution Approach 1:
The separation film is segmented into distinct folding parts (first folding part and second folding part) with clearly defined folding locations. This segmentation allows each part to perform a specific function (first part provides initial coverage, second part provides additional coverage), improving reliability without requiring a completely complex new structure.
Solution Approach 2:
The multiple folding parts extend the separation film's coverage in different spatial dimensions around the unit cells. The first folding part covers one dimension while the second folding part covers another dimension, providing comprehensive protection without requiring excessive material or complex three-dimensional structures.
3Reliability
If adhesion layers are applied to the separation film, then the film adherence to unit cells is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The adhesion layer is applied in advance to the outer surface of the first folding part before the folding process. This preliminary application of adhesion material ensures that when the first folding part folds to surround the unit cells, the adhesion is already established, improving reliability without requiring additional adhesion steps after folding.
Solution Approach 2:
The adhesion layer on the first folding part automatically adheres to the unit cells when the folding occurs, utilizing the folding action itself to bring the adhesive surface into contact with the target surface. This self-adhesion mechanism reduces the need for separate adhesion application steps and external bonding processes.
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
This configuration enhances the stability and protection of the electrodes, preventing damage and ensuring a secure assembly that maintains energy density and performance in secondary batteries.
Implementation Method 1
the first folding part that adheres to a portion of the separation film, which faces the first folding part when folded, by applying an adhesion layer to an exterior surface thereof in a folding direction
Data Source
AI summary
An electrode assembly and a method for manufacturing the electrode assembly comprises a plurality of unit cells comprising a positive electrode, a negative electrode, and a separator, respectively, and a separation film folded to be disposed between the plurality of unit cells. The separation film is folded two times or more to come into contact with and surround a first unit cell, which is disposed at an initial position of the separation film, of the plurality of unit cells.