Wound Secondary Battery Separator Buffer for Impact Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary batteries face challenges in effectively absorbing impact, which can lead to short circuits and exposure of electrodes, and there is a risk of the separator being caught between exterior body members during sealing.
Innovation Solution
A secondary battery design featuring a wound electrode assembly with a separator extension portion that is bent to protrude outward, forming a flexible molded body that absorbs impact and reduces the risk of electrode exposure and separator entrapment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the separator extension portion is bent in one direction (thickness direction) to form a buffer portion, then impact absorption is improved, but the electrode may be exposed and the separator may be caught between exterior body members during sealing
Solution Approach 1:
The separator extension portion is bent not only in the thickness direction but also in the radial direction to protrude outward, creating a three-dimensional buffer structure. This multi-directional bending transforms the flat separator extension into a volumetric buffer that effectively absorbs impact while maintaining proper positioning within the exterior body, preventing both electrode exposure and separator entrapment during sealing.
Solution Approach 2:
The separator extension portion is formed with a curved or protruding shape that extends radially outward from the wound electrode assembly. This curvature creates a rounded buffer structure that distributes impact forces more effectively and prevents sharp edges that could cause electrode exposure or separator entrapment during the sealing process.
2Device complexity
If the separator extension portion is not extended, then the structure is simpler, but impact absorption is insufficient and short circuits may occur
Solution Approach 1:
The separator is extended beyond the electrode ends during the winding process, creating a buffer portion before the battery is assembled into the exterior body. This preliminary extension ensures that when impact occurs, the separator is already in position to absorb the force and prevent electrode contact, avoiding short circuits without requiring additional components or complex structures.
3Object-affected harmful factors
If the separator extension portion is bent to protrude outward, then impact absorption is enhanced, but the sealing process may become more difficult
Solution Approach 1:
The separator extension portion is designed with flexible bending characteristics that allow it to be shaped during assembly. The separator can be bent to protrude outward to create the buffer structure, and this dynamic shaping capability enables the buffer to adapt to the interior space of the exterior body, ensuring proper sealing without requiring excessive force or complex sealing mechanisms.
Data Source
AI summary
A secondary battery that includes a wound electrode assembly in which a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode are wound about a winding axis; and a current collecting tab at a first end of the wound electrode assembly along a direction of the winding axis, wherein the wound electrode assembly has a separator extension portion in which the separator extends more than the positive electrode and the negative electrode toward a second end of the wound electrode assembly along the direction of the winding axis, the second end being opposite the first end, and the separator has a bent shape that protrudes toward an outer peripheral side of the wound electrode assembly at least at a part of the separator extension portion in a sectional view passing through the winding axis.