Cylindrical Cell Housing Structure for Stronger End-Cap Welding
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Solution Overview
Problem
The welding quality of cylindrical cell housings and end caps in battery manufacturing is poor, leading to low assembly qualification rates and safety risks due to manufacturing tolerances and difficulty in controlling the roundness of openings and end caps.
Innovation Solution
Incorporating a second wall portion with a greater thickness than the first wall portion in the cylindrical cell housing, which is welded to the end cap, increasing the overlap area and improving the roundness and strength of the welding interface, thereby enhancing the assembly qualification rate and safety performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the housing wall thickness is increased to improve welding quality with the end cap, then the welding strength and assembly qualification rate improve, but the overall cell volume increases and energy density decreases
Solution Approach 1:
The patent applies local quality by creating a second wall portion with greater thickness specifically at the welding interface with the end cap, while the rest of the housing maintains its original thickness. This localized thickening provides sufficient welding area and strength without increasing the overall cell volume, thereby resolving the contradiction between welding strength and cell volume.
2Manufacturing precision
If the housing wall thickness is increased to provide sufficient welding area, then the assembly qualification rate improves, but the manufacturing complexity increases
Solution Approach 1:
The housing is segmented into two distinct wall portions: a first wall portion with standard thickness and a second wall portion with increased thickness at the welding interface. This segmentation allows the structure to meet welding area requirements while maintaining manufacturing simplicity through a straightforward geometric modification rather than a completely complex redesign.
3Strength
If the second wall portion protrudes outward to increase welding area, then the welding quality improves, but the cell outer dimensions increase and energy density decreases
Solution Approach 1:
The second wall portion with greater thickness is nested within the overall cell structure, effectively utilizing the space between the first wall portion's outer surface and the electrode assembly. This nesting approach provides the necessary welding area without increasing the cell's outer dimensions, thereby maintaining energy density while improving welding quality.
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
This solution improves the welding quality and safety performance of cylindrical cells by increasing the overlap area between the housing and end cap, reducing the risk of laser leakage and enhancing structural strength while maintaining energy density.
Implementation Method 1
the second wall portion is welded to the end cap
Data Source
AI summary
The present application relates to a cylindrical cell, a battery, and a power consuming device, and belongs to the field of battery manufacturing technology. The present application provides a cylindrical cell, comprising: a housing, the housing having an opening at an end in a first direction; and an end cap, covering the opening; wherein the housing comprises a side wall, the side wall comprises a first wall portion and a second wall portion disposed in the first direction, the second wall portion is located on a side of the first wall portion close to the opening, the second wall portion has a thickness greater than the thickness of the first wall portion, and the second wall portion is welded to the end cap.