Battery Module Senseline Tab Resistance Welding
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Solution Overview
Problem
Existing battery module connections face challenges in maintaining reliable electrical contact and durability due to geometric variations in bus bar projections and senseline tabs, which can affect weld quality and longevity.
Innovation Solution
The use of a projection resistance welding process to join senseline tabs on a multi-layered cell sense flex circuit with bus bars, where the projections penetrate into the tabs to ensure good electrical contact, and the application of adhesive material to reinforce the joints, providing variable geometry and orientation to optimize contact areas and joint strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If projection resistance welding is used to join senseline tabs to bus bars, then electrical contact reliability is improved, but manufacturing complexity increases due to geometric variation requirements
Solution Approach 1:
The bus bar projections are designed with specific geometric variations (different heights, widths, and penetration depths) to create optimal local contact conditions at each weld interface. This local quality variation ensures reliable electrical contact while managing the complexity through controlled geometric parameters rather than uniform design.
Solution Approach 2:
The invention utilizes parameter changes in the projection geometry (height, width, penetration depth) to optimize welding quality. By varying these parameters across different projections, the system achieves consistent electrical contact reliability while the parameters themselves provide a framework for managing manufacturing complexity through standardized variation patterns.
2Manufacturing precision
If projections penetrate deeply into senseline tabs, then weld quality is improved, but risk of full penetration and exposure of bus bar material increases
Solution Approach 1:
Different projections are designed with different penetration depths to achieve optimal weld quality at each location without unnecessary full penetration. This localized optimization ensures that each projection penetrates only as deep as needed to create reliable electrical contact, minimizing exposed bus bar material while maintaining weld quality.
Solution Approach 2:
The invention employs partial penetration rather than full penetration in most cases, applying just enough welding action to achieve reliable electrical contact. This partial action approach prevents over-penetration and exposure of bus bar material while still achieving the required weld quality for electrical connectivity.
3Strength
If adhesive material is applied to reinforce welded joints, then joint strength is improved, but manufacturing steps increase
Solution Approach 1:
The joint design combines welding and adhesive bonding to create a composite connection system. The welding provides strong electrical and mechanical bonding, while the adhesive material adds reinforcement and environmental protection. This composite approach improves joint strength while using standardized materials and processes to manage manufacturing complexity.
Solution Approach 2:
The adhesive material serves as a protective layer applied after welding to cushion the joint against environmental factors and mechanical stresses. This beforehand protection reinforces the welded joint and extends its service life, while the adhesive application is a simple post-welding step that does not significantly increase manufacturing complexity.
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 method enhances the robustness of battery module connections by ensuring consistent and durable electrical contact, improving weld quality, and providing enhanced corrosion protection and vibration dampening, thus supporting the reliability and performance of battery packs in various applications.
Implementation Method 1
The bus bar has at least one projection and is projection resistance welded to the senseline tab such that the at least one projection penetrates into the senseline tab at least as far as the senseline contained therein
Data Source
AI summary
A battery module includes a battery cell, a bus bar, and a multilayered cell sense flex circuit having a senseline tab containing a portion of a senseline. The flex circuit determines a battery cell voltage. The bus bar has surface projections, possibly with a variable height and/or width, such that the bus bar penetrates into the tab at least as far as the senseline. Adhesive material may be used on the welded joint. A method of manufacturing the battery module includes forming, in the bus bar, one or more surface projections, e.g., multiple projections having the variable height and/or width, positioning a senseline tab of the flex circuit adjacent to such projections, and joining the tab to the surface projections such that the projections penetrate at least partially into the flex circuit at least as far as the senseline.