Wound Battery Cell Tab Stack Layout for Short-Circuit-Safe Welding
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Solution Overview
Problem
Existing battery technologies face issues with welding quality and safety due to the risk of short circuits and false welding during the connection of tabs in electrode assemblies, which can lead to overheating and potential chemical substance degradation.
Innovation Solution
A battery cell design with a tab stack structure that includes multiple layers and specific welding areas, optimized ratios and distances, and conductive members to enhance welding quality and reduce the risk of short circuits and overcurrent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs are welded directly to conductive members in conventional battery designs, then the welding process is simple and fast, but the risk of short circuits and false welding increases due to burns on separator film or tabs during welding
Solution Approach 1:
The tab stack structure is divided into multiple layers with different functions: outer layers provide protective coverage and inner layers enable electrical connection. This segmentation allows the welding area to be protected from burns while maintaining welding quality, resolving the contradiction between reliability and structural complexity.
Solution Approach 2:
The multi-layer tab stack structure is pre-assembled before the welding process. The outer layers are positioned to cover and protect the inner welding areas beforehand, preventing burns on separator film or tabs during welding. This preliminary protective action ensures welding quality without requiring complex real-time control during welding.
2Reliability
If the tab stack structure has more layers and higher thickness to prevent welding through, then welding quality improves and short circuit risk reduces, but the manufacturing complexity increases
Solution Approach 1:
Multiple tabs are stacked and combined into a single integrated tab stack structure that functions as one welding unit. The outer layers are merged to form a protective envelope around the inner layers, reducing the number of separate welding operations needed while maintaining reliability and reducing short circuit risk.
Solution Approach 2:
The outer layers of the tab stack structure automatically provide protective coverage for the inner welding areas during the welding process. The structure is self-protecting, where the arrangement of tabs themselves creates the protective barrier without requiring additional external protective components or complex assembly procedures.
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 design improves welding quality, reduces the risk of short circuits and overcurrent, and enhances the overall safety and performance of the battery cell.
Implementation Method 1
The conductive members are welded to the tab stack structure and electrically connected to the electrode terminal
Data Source
AI summary
A battery cell includes an electrode assembly housed in a shell. The electrode assembly comprises a plurality of electrode sheets of opposite polarities and separators interposed therebetween. The electrode sheets and separators are wound along a winding direction to form a wound structure. At least one electrode sheet includes a current collector substrate and a plurality of tabs. The tabs are connected to a side edge of the substrate extending in the winding direction and are spaced apart along that direction. At least some of the tabs are bent toward the winding axis, forming a tab stack at an end of the wound structure. The battery cell further includes conductive members welded to the tab stack and electrically connected to an electrode terminal located on a wall of the shell. Also disclosed are a battery including the battery cell and an electrical device incorporating the battery.