Battery Foil Clamping Fixture for Zero-Gap Laser Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser welding of stacked battery foils to battery tabs faces challenges in maintaining a consistent zero gap condition, leading to uneven heat distribution and potential burn-through or insufficient bonding as the number of foils increases, due to difficulties in clamping and maintaining the gap between sheets.
Innovation Solution
A clamping fixture and method that uses a first and second clamp member with a protrusion and weld slot configuration to deflect and plastically deform the battery foil-tab assembly, ensuring a consistent overlap and alignment for laser welding, thereby eliminating gaps and ensuring strong bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If laser welding is used to join stacked battery foils to battery tabs, then strong joints are formed, but as the number of sheets increases, uneven heat distribution occurs leading to potential burn-through or insufficient bonding
Solution Approach 1:
The clamp members are configured to pre-compress the stacked battery foils against the battery tab before laser welding begins. This preliminary compression action maintains consistent contact and eliminates gaps between foils, ensuring uniform heat distribution during the subsequent laser welding process and preventing both burn-through and insufficient bonding
Solution Approach 2:
The clamp members apply controlled mechanical pressure to the foil stack, changing the physical state from uncompressed to compressed. This parameter change in compression force ensures consistent foil-to-tab contact throughout the welding area, distributing laser heat uniformly across all foils regardless of stack height
2Quantity of substance
If the number of sheets of foil increases, then more electrical energy can be stored, but maintaining a zero gap condition between sheets becomes increasingly difficult
Solution Approach 1:
The clamp members are designed with specific local features including compression surfaces that contact the foils and tab, and positioning features that maintain alignment. These localized structural qualities enable the clamps to effectively compress and position even large stacks of thin foils, maintaining zero gap conditions despite the increased number of sheets
Solution Approach 2:
Before welding, the clamp members perform preliminary positioning and compression of the foil stack, ensuring all sheets are in intimate contact with each other and the tab. This preliminary action addresses gap control proactively, making the process scalable to larger numbers of foils without compromising precision
3Object-affected harmful factors
If gaps exist between sheets of foil during welding, then heat accumulation increases leading to potential burn-through, but eliminating gaps requires complex clamping mechanisms
Solution Approach 1:
The clamp members combine multiple functions into a single integrated component: compression of the foil stack, positioning against the tab, and maintenance of alignment during welding. This merging of functions achieves effective gap elimination without requiring complex multi-component clamping mechanisms, reducing device complexity while preventing heat accumulation from gaps
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
The solution effectively eliminates gaps between foils and the tab, ensuring a structurally strong and efficient laser weld by applying a clamping force to deform the foil-tab assembly out of plane, allowing for precise laser welding and minimizing heat accumulation issues.
Implementation Method 1
The protrusion surrounding the weld slot of the second clamp member is configured to cooperate with the opening of the first clamp member to plastically deform the portion of the battery foil-tab assembly
Implementation Method 2
Laser welding has been used for joining a stack of thin sheets of foil to a battery tab with some success. Laser welding forms strong joints
Data Source
AI summary
A method and fixture for welding a battery foil-tab assembly is disclosed. The fixture includes a first clamp member having a first clamping surface defining an opening extending into the first clamp member and a second clamp member having a protrusion surrounding a weld slot. The opening of the first clamp member is configured to receive a portion of the protrusion with the battery foil-tab assembly disposed therebetween. The second clamp member is moveable toward the first clamp member to align the weld slot of the second clamp member with the opening of the first clamp member, thereby causing the protrusion to cooperate with the opening of the first clamp to deflect a portion of the battery foil-tab assembly out of a plane parallel with the battery foil-tab assembly. A laser beam is directed at the out of plane portion to laser weld the battery foil-tab assembly.