Battery Current Collector Layout to Block Foreign-Object Shorts
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Solution Overview
Problem
Existing batteries face issues with internal short circuits caused by metal foreign objects during assembly, which are not effectively addressed by current methods that reduce battery capacity.
Innovation Solution
A battery design that includes a current collector with a specific configuration and covering members to prevent foreign objects from entering the electrode body, using a sealing plate and insulation members to protect the welding areas of the tabs, thereby reducing the risk of internal short circuits without compromising battery capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bag-shaped porous body is used to protect the electrode body, then foreign objects are reduced, but the active material amount and battery capacity are reduced
Solution Approach 1:
The invention uses a thin film-shaped covering member (resin film) to cover the welding area on the current collector instead of a bag-shaped porous body. This thin film structure provides foreign object protection while occupying minimal space, thereby preserving the active material amount and battery capacity that would otherwise be reduced by a bulky porous body structure.
2Reliability
If metal foreign objects are removed by air blowing, suction, magnetic force adsorption, or wiping, then foreign objects are reduced, but the assembly complexity and time increase
Solution Approach 1:
The covering member is attached to the current collector before the electrode body is assembled into the battery. This preliminary action protects the welding area from foreign objects during assembly, eliminating the need for complex post-assembly foreign object removal processes such as air blowing, suction, magnetic force adsorption, or wiping with polishing tapes.
Solution Approach 2:
The covering member acts as an intermediary barrier between foreign objects and the welding area on the current collector. This simple physical barrier provides effective foreign object protection without requiring complex removal mechanisms or multiple processing steps.
3Reliability
If the welding area is exposed, then electrical connection is maintained, but foreign objects can enter and cause internal short circuits
Solution Approach 1:
The covering member is designed to cover only the specific welding area on the current collector where tabs are welded, rather than covering the entire current collector or electrode body. This localized coverage maintains electrical connection functionality while providing targeted protection against foreign object entry at the vulnerable welding points.
Data Source
AI summary
A battery includes: an electrode body obtained by stacking a positive electrode plate and a negative electrode plate with a separator interposed therebetween, the positive electrode plate including a first positive electrode tab group; an exterior body having an opening and housing the electrode body; a sealing plate sealing the opening: a positive electrode terminal attached to the sealing plate; and a substantially plate-shaped positive electrode current collector arranged substantially parallel to the sealing plate between the electrode body and the sealing plate and electrically connected to the positive electrode terminal. A positive electrode tab group of the electrode body is welded to a surface of the positive electrode current collector facing the electrode body, and a second tape covers an area corresponding to the back of a welding area of the positive electrode tab group on the surface of the positive electrode current collector facing the sealing plate.