Cylindrical Battery Foldback Sealing for Larger Electrode Space
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Solution Overview
Problem
Conventional cylindrical batteries are limited in increasing the size of the housing portion and battery capacity due to the restriction imposed by the grooved portion in the exterior housing can.
Innovation Solution
The cylindrical battery design incorporates a foldback portion in the exterior housing can and a second foldback portion in the sealing assembly, allowing for a larger housing portion and increased battery capacity without the need for a grooved portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grooved portion is formed in the exterior housing can to fix the sealing assembly, then the sealing assembly can be securely fixed, but the housing portion of the electrode assembly is restricted in size and battery capacity cannot be increased
Solution Approach 1:
The invention transitions from a radial groove structure to an axial foldback structure. Instead of using a grooved portion that radially recesses into the housing can, the invention uses a foldback portion that extends axially and folds back to engage with the sealing assembly. This dimensional change allows the housing portion to extend further axially without being constrained by radial groove limitations, thereby increasing battery capacity while maintaining secure sealing assembly fixation.
Solution Approach 2:
The invention inverts the conventional approach by having the exterior housing can fold back onto itself (first foldback portion) and the sealing assembly fold back onto itself (second foldback portion), rather than using a grooved recess. This inversion allows both components to engage each other through foldback structures, eliminating the need for space-consuming grooves and enabling increased housing portion size.
2Ease of manufacture
If a grooved portion is formed in the exterior housing can, then the sealing assembly can be fixed by caulking, but the axial height available for the electrode assembly is reduced
Solution Approach 1:
The invention replaces the radial groove approach with axial foldback structures. The first foldback portion of the exterior housing can and the second foldback portion of the sealing assembly engage through axial folding rather than radial recessing. This dimensional change maximizes the utilization of axial height for the electrode assembly while maintaining ease of manufacture through caulking fixation.
3Volume of moving object
If the housing portion size is increased to increase battery capacity, then more electrode assembly space is available, but the sealing assembly cannot be securely fixed without a grooved portion
Solution Approach 1:
The invention inverts the conventional groove-based fixation approach by using mutual foldback structures. The first foldback portion of the exterior housing can folds back to engage with the second foldback portion of the sealing assembly, creating a secure fixation mechanism that does not require space-consuming grooves. This allows the housing portion size to be increased while maintaining reliable sealing assembly fixation.
Solution Approach 2:
The invention transitions from radial groove fixation to axial foldback engagement. By utilizing axial folding rather than radial recesses, the housing portion can extend to maximize battery capacity while the foldback structures provide secure fixation of the sealing assembly through a different dimensional approach.
Data Source
AI summary
A cylindrical battery comprises an outer case can, an electrode body that is accommodated in the outer case can, and a sealing body that covers an opening portion of the outer case can. The outer case can comprises: a bottom plate portion; a cylinder portion that is connected to the bottom plate portion via an annular corner portion that is positioned outward in the radial direction, and extends in the axial direction; and a rolled-back portion that is connected to an end portion of the cylinder portion that is on the opposite side from the corner portion in the axial direction. The sealing body comprises a rolled-back portion that has an end portion on the outside in the radial direction, the end portion being secured to the rolled-back portion.