Battery End Cover Assembly With Laser-Shielded Pole Seam
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Solution Overview
Problem
The reliability of end cover assemblies in rechargeable batteries is compromised due to welding heat damage during assembly, leading to partial failures and reduced overall reliability.
Innovation Solution
The end cover assembly design includes a top cover unit, a pole with a base and connecting portion, an upper plastic member, and a fixing member. The pole's connecting portion has a step surface that abuts against the fixing member, covering the seam and preventing laser welding heat from damaging the upper plastic member. Additionally, a boss portion on the pole reduces welding layer interference and enhances connection strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is performed to connect the fixing member and the pole, then connection strength is improved, but the upper plastic member is damaged by welding heat causing localized functional failures
Solution Approach 1:
The pole is divided into multiple sections: base portion, connecting portion, and boss portion. This segmentation allows the welding process to be isolated to specific areas (seam between fixing member and connecting portion) while protecting other areas (upper plastic member) from heat damage through the shielding effect of the base portion's step surface
Solution Approach 2:
The base portion acts as an intermediary shielding structure. Its step surface surrounds the connecting portion and blocks welding heat from reaching the upper plastic member, thereby mediating between the welding process and the plastic member to prevent thermal damage while maintaining connection strength
2Ease of manufacture
If the connecting portion is directly welded to the fixing member, then assembly is simplified, but welding heat damages surrounding parts including the upper plastic member
Solution Approach 1:
The pole structure is segmented into base portion, connecting portion, and boss portion, creating a multi-layer configuration where the base portion's step surface provides automatic shielding during welding, simplifying the manufacturing process while protecting against heat damage
Solution Approach 2:
The step surface of the base portion, which could be seen as an additional structural element, actually serves as a beneficial shielding barrier that converts the potential harm of welding heat into a protected welding zone, allowing direct welding of the connecting portion to the fixing member without damaging surrounding parts
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 design effectively prevents localized functional failures of the upper plastic member due to welding heat, maintains normal function of the end cover assembly, and significantly improves the reliability of the entire assembly.
Implementation Method 1
welding heat will damage other parts in the end cover assembly
Implementation Method 2
laser welding heat from damaging the upper plastic member
Data Source
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AI summary
The present disclosure relates to an end cover assembly, a battery, an energy storage device, and an electric system. The end cover assembly includes a top cover unit, a pole, an upper plastic, and a fixing member. The pole penetrates the top cover unit and includes a base portion and a connecting portion. The connecting portion protrudes from an end surface of the base portion in an axial direction of the base portion, and a part of the end surface of the base portion outside a coverage area of the connecting portion is formed as a step surface surrounding the connecting portion. The upper plastic is at least partially sleeved on a peripheral side of the base portion. The upper plastic is partially located at a side of the top cover unit in a thickness direction of the top cover unit. The fixing member is partially located at the other side of the top cover unit in the thickness direction of the top cover unit. A seam is formed between the fixing member and the connecting portion and surrounds the connecting portion, and the step surface abuts against the fixing member and cover the seam. During welding by using a laser, the laser irradiates through the seam onto the step surface. Through a shielding effect of the step surface, the laser cannot reach the upper plastic member when being irradiated, thereby improving reliability of the whole end cover assembly.