EV Battery Tab Geometry for Short Circuit Prevention
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Solution Overview
Problem
Battery cells in electric vehicles face a risk of short circuits due to mechanical loads causing separators to be punctured by sharp edges and weld burrs on electrode tabs, leading to potential electrical failures.
Innovation Solution
The design includes electrode tabs with an electrode interface surface, a flat surface opposite the interface, and intermediate surfaces forming an acute angle, which reduces sharp edges and allows for laser ablation of weld burrs to prevent puncture of the separator, thereby minimizing the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electrode tabs with sharp edges are used, then manufacturing is simpler, but the separator is punctured causing short circuits
Solution Approach 1:
The tab is pre-formed with rounded edges and intermediate surfaces before welding occurs. This preliminary shaping prevents sharp edges from forming during the welding process, eliminating the need for post-welding processing while maintaining reliability.
Solution Approach 2:
The patent replaces traditional mechanical welding processes that create sharp edges and burrs with a combination of specialized tab geometry and laser ablation technology. The rounded tab edges work synergistically with controlled laser ablation to remove material cleanly without creating harmful sharp features.
2Productivity
If weld burrs are present on electrode tabs, then welding process is faster, but electrical failures occur due to separator puncture
Solution Approach 1:
The patent introduces an intermediate surface geometry on the tab that acts as a mediator between the welding process and the separator. This specialized surface geometry controls how weld material deposits and redirects burrs away from the separator, preventing punctures while maintaining high welding speeds.
Solution Approach 2:
The patent changes the physical parameters of the tab surface by creating intermediate surfaces with specific angles and curvatures. These geometric parameter changes alter the flow and deposition characteristics of weld material, preventing burr formation that would puncture the separator.
3Reliability
If laser ablation is used to remove weld burrs, then short circuit risk is reduced, but manufacturing complexity increases
Solution Approach 1:
The tab geometry is pre-designed with intermediate surfaces that anticipate and prevent burr formation in critical areas. This preliminary design reduces the amount of post-welding laser ablation needed, simplifying the overall manufacturing process while maintaining separator protection.
Solution Approach 2:
The patent uses the tab's intermediate surfaces as a template or copy of the desired final geometry. By pre-forming these surfaces, the welding process naturally produces the correct shape without requiring extensive post-processing, reducing 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 design effectively reduces the risk of short circuits and electrical failures by eliminating sharp edges and weld burrs, enhancing the reliability and safety of battery cells in electric vehicles.
Implementation Method 1
the separator having pores through which ions are exchanged between the first polarity electrode plate and the second polarity electrode plate
Implementation Method 2
ultrasonically welding the first polarity tab to the first polarity electrode plate by positioning an ultrasonic welding tool on the flat surface of the first polarity tab
Implementation Method 3
laser ablating weld burrs on the flat surface of the first polarity tab
Data Source
AI summary
Provided herein are systems, apparatuses, and methods of providing electrical energy for electric vehicles. A battery pack can be disposed in an electric vehicle to power the electric vehicle. A battery cell can be arranged in the battery pack. The battery cell can have a housing. The housing can define a cavity within the housing. The battery cell can have an electrode structure arranged within the cavity. The electrode structure can include a first polarity electrode plate, a second polarity electrode plate, and at least one separator. First and second polarity tabs are coupled with the first and second polarity electrode plates, respectively. The tabs include a flat surface, an electrode interface surface and at least one intermediate surface that extends therebetween. The at least one intermediate surface forms an acute angle with the electrode interface surface.