Wound Battery Cell Layout to Prevent Separator Damage and Shorts
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Solution Overview
Problem
Conventional batteries with winding electrode bodies are prone to short circuits due to vibration or shock, which can damage the separator and cause electrical shorts between the positive and negative electrodes.
Innovation Solution
The battery design includes a winding electrode body with a flat shape and curvature parts that face the battery case and sealing plate, ensuring that the negative electrode's outermost periphery faces the inner peripheral side via the separator, preventing direct contact with the positive electrode. Additionally, a spacer is used between the sealing plate and the winding electrode body to reduce stress and prevent separator damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the winding electrode body is covered with a separator and the tabs are bundled together, then the battery structure is simplified and manufacturing is easier, but the tabs have play and can move during use, causing the winding electrode body to contact the battery case or components, potentially damaging the separator and causing short circuits
Solution Approach 1:
The patent applies preliminary action by pre-positioning the winding electrode body in a specific orientation within the battery case during manufacturing. The curvature parts are deliberately positioned to face the bottom wall and sealing plate, and the negative electrode's outermost periphery is arranged to face the inner peripheral side via the separator. This pre-established configuration prevents tabs from having excessive play and moving during use, thereby preventing short circuits while maintaining manufacturing simplicity.
2Ease of operation
If the tabs are made movable to accommodate assembly variations, then ease of assembly is improved, but the winding electrode body may contact external components causing separator damage and short circuits
Solution Approach 1:
The patent applies preliminary anti-action by pre-configuring the winding electrode body orientation to counteract potential harmful movements. The specific arrangement where curvature parts face the bottom wall and sealing plate, and the negative electrode's outermost periphery faces the inner peripheral side via the separator, creates a geometric constraint that prevents tabs from moving in directions that would cause separator damage or short circuits, while still allowing necessary assembly tolerances.
3Stability of the object's composition
If the winding electrode body is positioned with curvature parts facing the bottom wall and sealing plate, then the structure is more stable and short circuit risk is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies asymmetry by utilizing the inherent asymmetric geometry of the winding electrode body with its curvature parts. By positioning these curvature parts to face specific reference surfaces (bottom wall and sealing plate), the design creates a unique, stable orientation that is self-aligning. This asymmetric configuration enhances structural stability and prevents short circuits while the self-aligning nature reduces the actual manufacturing precision requirements compared to a symmetric design that would require precise centering.
Data Source
AI summary
Disclosed here is a battery including: an exterior body having a bottom wall; and a winding electrode body in which positive electrode, negative electrode and separator are wound about a winding axis. The winding electrode body has a flat shape having a pair of curvature parts having a curved outside surface and a flat part that connects the pair of curvature parts to each other and has a flat outside surface. When a line perpendicular to the winding axis of the winding electrode body and perpendicular to the bottom wall of the exterior body is assumed as L1, a portion positioned at an outermost periphery of the negative electrode in at least one of the pair of the curvature parts faces a portion positioned on a winding inner peripheral side of the negative electrode via the separator and not via the positive electrode on the line L1.