Prismatic Battery Welding Window for Short-Circuit Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing prismatic batteries face issues with internal short-circuits due to sputtered fine particles infiltrating during laser welding of exposed substrates, and struggle to firmly weld substrates with varying lengths, leading to potential disconnection and reduced battery performance under vibration and impact.
Innovation Solution
A prismatic battery design featuring a pressing plate with opposing surfaces and a slit along its folded back section, allowing exposed substrate sections to be welded by a high energy beam from a transverse direction, dispersing particles and ensuring secure welding without enlarging substrate margins, and incorporating an inverted L-shaped current collecting body for enhanced fixing strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If laser welding is performed on exposed substrate sections, then welding strength is improved, but sputtered fine particles infiltrate the electrode causing internal short-circuits
Solution Approach 1:
A shielding plate is introduced as an intermediary component between the laser welding zone and the electrode. The shielding plate blocks sputtered fine particles from infiltrating the electrode while allowing the laser beam to weld the substrate sections to the current collecting body, thus preventing internal short-circuits without compromising welding strength
Solution Approach 2:
The harmful effect of sputtered particles is extracted and isolated from the electrode by using the shielding plate to redirect particles away from the electrode, separating the welding process from the particle infiltration path
2Reliability
If substrate margins are enlarged to accommodate welding, then welding stability is improved, but battery capacity is reduced
Solution Approach 1:
The mechanical approach of enlarging substrate margins is replaced with a laser-based welding system that uses high energy density to achieve strong welds on smaller substrate areas. The laser beam concentrates energy precisely on the welding zone, enabling stable welding without requiring additional substrate area, thus preserving battery capacity
3Productivity
If high energy beam welding is used, then welding speed is improved, but particle sputtering increases causing internal short-circuits
Solution Approach 1:
The shielding plate serves as a mediator that allows high energy beam welding to proceed at high speed while simultaneously blocking the harmful sputtered particles from reaching the electrode, thus maintaining both welding speed and preventing internal short-circuits
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 significantly reduces the likelihood of internal short-circuits, ensures stable welding, and allows for the production of batteries capable of high current output without increasing the battery's size or reducing capacity, while maintaining reliability under mechanical stress.
Implementation Method 1
the plurality of exposed sections and the pressing plate are welded by a high energy beam from a transverse direction through the slit
Implementation Method 2
sputtered fine particles infiltrating during laser welding
Data Source
AI summary
A prismatic battery according to one embodiment of the present invention includes a flat electrode group 10 stacked or rolled by mutually positive and negative electrodes with a separator therebetween, a pressing plate 13A, a current collecting body 18A or 18B and a plurality of exposed sections 16, at least one end of the positive and negative electrodes substrates in a width direction being uncoated with a positive or negative electrode mixture. The pressing plate 13A is welded to the exposed sections 16. The pressing plate 13A includes opposing surfaces with a space therebetween provided by folding back a metal plate, and includes a slit 15 along a folded back section at least to one of the opposing surface's side. The exposed sections 16 are inserted into a gap of the pressing plate 13A, and the exposed sections 16 and the pressing plate 13A are welded by a high energy beam from a transverse direction through the slit 15. This provides a prismatic battery for large current application in electric vehicles and hybrid electric vehicles.