Secondary Battery Case Structure to Eliminate Bat-Ear Dead Space
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Solution Overview
Problem
The related art pouch type secondary batteries suffer from a dead space due to the bat-ear deviation in the sealing part, leading to reduced energy density.
Innovation Solution
A case design with symmetrical recessed parts and inclined connection surfaces that minimize the bat-ear when unfolded, allowing for a V-shaped configuration that reduces dead space and minimizes deformation during folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional pouch structure with sealing parts is used, then the battery can be manufactured with standard processes, but dead space occurs due to bat-ear deviation reducing energy density
Solution Approach 1:
The invention applies asymmetry by designing the connection part with inclined surfaces (first and second connection surfaces) that are not symmetrical, allowing the sealing part to align precisely with the cup width and eliminate bat-ear deviation while maintaining manufacturability
Solution Approach 2:
The invention changes the geometric parameters of the connection part by introducing inclined surfaces with specific angles, transforming the conventional horizontal connection into a sloped configuration that prevents dead space formation and improves sealing alignment
2Reliability
If the sealing part area is increased to ensure proper sealing, then sealing reliability improves, but the bat-ear protrusion increases creating more dead space
Solution Approach 1:
The invention uses curved surfaces in the connection part, replacing sharp angles with smooth transitions between the recessed parts and connection surfaces, which distributes stress evenly and maintains sealing reliability while minimizing protrusion and dead space
3Ease of manufacture
If the case structure is simplified for ease of manufacture, then manufacturing cost decreases, but the ability to minimize bat-ear and dead space is reduced
Solution Approach 1:
The invention segments the case into distinct functional parts: first and second recessed parts for accommodating electrode assembly ends, a connection part with inclined surfaces for bridging the gap, and circumferential parts for structural support. This segmentation allows each part to be optimized independently while maintaining overall simplicity and manufacturability
Data Source
AI summary
Disclosed are a secondary battery and a secondary battery case.According to one aspect of the present invention, provided is a case for a secondary battery including: a first recess part having a recessed shape; a second recess part opposite the first recess part and having a recessed shape; a circumferential part configured to surround a circumference of each of the first recess part and the second recess part when the case is unfolded; and a connection part provided between the first recess part and the second recess part to connect the first recess part to the second recess part, wherein, when the case is unfolded, the connection part includes: a first connection surface inclined in a first direction from one end of the first recess part; and a second connection surface inclined in the first direction from one end of the second recess part.