Sealed Battery Shield Geometry for Laser Weld Insulator Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-energy-density batteries face issues with insulator degradation and reduced airtightness during laser welding due to the close proximity of the laser-welded region and insulating member, leading to direct laser application and subsequent searing of the insulator.
Innovation Solution
A sealed battery design featuring a shield with an inclined portion on the closing plate's outer surface, positioned between the insulator and the fitted portion, which redirects laser light away from the insulator, preventing direct exposure and searing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rectangular cross-section shield is used between the insulating member and fitted portion, then the shield structure is simple and easy to manufacture, but laser light may be directly applied to the shield and leak to the insulator, causing searing and degradation
Solution Approach 1:
The shield cross-section is changed from a symmetric rectangular shape to an asymmetric shape with a tapered side. One side of the shield has a tapered surface that slopes away from the laser welding area, while the other side remains vertical or has a different angle. This asymmetric geometry prevents laser light reflection toward the insulator while maintaining manufacturing feasibility through standard forming processes.
Solution Approach 2:
The shield incorporates a tapered or curved surface instead of a flat rectangular face. The tapered surface gradually changes angle from the base to the top, creating a smooth transition that redirects laser light away from the insulator. This curved geometry effectively blocks laser light leakage while being formable through conventional metal forming techniques.
2Quantity of substance
If the distance between collector terminal and fitted portion is reduced to achieve high energy density, then battery energy density is improved, but the laser-welded region and insulator are located closer, causing laser light to directly apply to the insulator when incident angle deviates
Solution Approach 1:
The shield serves as an intermediary component positioned between the laser welding area and the insulator. This intermediate structure intercepts and redirects laser light before it can reach the insulator, providing a protective buffer zone. The shield absorbs or reflects laser energy away from sensitive components, enabling close spacing without compromising insulator integrity.
Solution Approach 2:
The shield is positioned in advance to prevent laser light from reaching the insulator before any harmful exposure can occur. By placing the shield between the fitted portion and insulator, the design proactively blocks potential laser leakage paths, preventing insulator degradation before it can happen during the welding process.
3Strength
If laser welding is performed on the fitted portion between battery case and closing plate, then the battery assembly is securely joined, but the insulator is seared and degraded due to laser light leakage
Solution Approach 1:
The shield divides the space between the laser welding area and the insulator into separate zones. By creating this physical segmentation, the shield isolates the insulator from the high-temperature laser welding environment. The shield acts as a thermal and optical barrier, allowing the welding process to proceed at full intensity without transferring excessive heat to the insulator.
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 insulator degradation and maintains the insulating capacity and airtightness of the battery by ensuring the laser light is applied to the shield rather than the insulator, even when the laser beam is slightly deviated during welding.
Implementation Method 1
the shield being interposed between the insulator and the fitted portion... redirects laser light away from the insulator, preventing direct exposure and searing
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A sealed battery (100) includes: a battery case (11) including an opening (12); a closing plate (15) closing the opening (12); a collector terminal (30) including an external connector (34) exposed at an outer surface (17) of the closing plate (15); a resin insulator (40) insulating the closing plate (15) and the external connector (34) from each other; a laser-welded region (14W) formed on a fitted portion (14) between the battery case (11) and the closing plate (15); and a shield (19) disposed on the outer surface (17) of the closing plate (15). The shield (19) is interposed between the insulator (40) and the fitted portion (14). The shield (19) includes an inclined portion (19a) inclined toward the fitted portion (14). The inclined portion (19a) defines a side face of the shield (19) adjacent to the fitted portion (14).