Battery Separator Ridge Design for Sputter Adhesion Prevention
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Solution Overview
Problem
Existing power storage devices face issues with reliability due to separator deterioration and sputter adhesion during current collector welding, leading to reduced battery capacity and performance degradation.
Innovation Solution
The power storage device incorporates a separator with a ridge portion protruding past the active material layers and a heat resistant layer, which enhances heat capacity and prevents sputter adhesion, improving reliability and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separator is extended further outward to prevent sputter adhesion and improve reliability, then the separator's protective function is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The separator is divided into two functional regions: a stacked portion (first region) that contacts the active material layers and a protruding portion (second region) that extends outward to prevent sputter adhesion. This segmentation allows each region to be optimized independently for its specific function while simplifying the overall design approach.
Solution Approach 2:
Different regions of the separator are given different properties and functions. The stacked portion is optimized for thermal stability and contact with active material, while the protruding portion is optimized for sputter prevention. This local differentiation resolves the contradiction by making the separator structure functionally optimized rather than uniformly complex.
2Reliability
If the separator protrudes outward past the active material layers to prevent sputter adhesion, then the reliability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The separator is pre-formed with the protruding portion extending beyond the active material layers before assembly. This preliminary configuration ensures that the sputter prevention function is already in place during welding operations, eliminating the need for post-assembly adjustments and reducing precision requirements during final assembly.
Solution Approach 2:
The protruding portion of the separator acts as an intermediary barrier between the welding area and the active material layers. By providing this intermediate protective structure, the design reduces the precision requirements for direct positioning of welding components relative to the active material, as the separator protrusion provides a buffer zone.
3Reliability
If the separator structure is enhanced with additional layers and protrusions to prevent deterioration, then the reliability is improved, but the ease of manufacture decreases
Solution Approach 1:
The separator is segmented into a stacked portion and a protruding portion, each with specific functions. This segmentation allows for standardized manufacturing processes where each segment can be produced and then assembled, improving ease of manufacture compared to creating a single complex integrated structure.
Solution Approach 2:
The separator structure serves multiple functions: thermal stability through the stacked portion and sputter prevention through the protruding portion. By designing a single component that performs both functions, the invention improves ease of manufacture compared to using multiple separate components, while maintaining high reliability.
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 ridge portion and heat resistant layer design effectively suppresses separator deterioration and sputter adhesion, enhancing the device's reliability and maintaining battery capacity.
Implementation Method 1
the separator includes a stacked portion in a region sandwiched between the positive electrode active material layer and the negative electrode active material layer and a protruding portion protruding outward past the positive electrode active material layer and the negative electrode active material layer... the stacked portion includes the substrate and a first heat resistant layer formed on the positive electrode side surface of the substrate, at least one portion of the protruding portion includes the substrate and a second heat resistant layer formed on the negative electrode side surface of the substrate
Implementation Method 2
A first ridge portion having insulating properties is formed on the positive electrode side surface of the substrate, and the first ridge portion is formed along at least a part of an end portion of the first heat resistant layer on the protruding portion side
Data Source
Figure 1
Figure 2
Figure 3~4A
AI summary
A disclosed power storage device includes an electrode group that includes a positive electrode (10), a negative electrode (20), and a separator (30). In the electrode group, the positive electrode (10), the negative electrode (20), and the separator (30) are stacked in a stacking direction such that the separator (30) is between the positive electrode (10) and the negative electrode (20). The positive electrode (10) includes a positive electrode current collector (11) and a positive electrode active material layer (12). The negative electrode (20) includes a negative electrode current collector (21) and a negative electrode active material layer (22). The separator (30) includes a protruding portion (30x) protruding outward past the positive electrode active material layer (12) and the negative electrode active material layer (22). The separator (30) includes a substrate (31) and a ridge portion (32) formed on the substrate (31). The ridge portion (32) is formed like a ridge along at least a part of an edge of the protruding portion (30x).