Tab-Less Cylindrical Electrode Assembly With Cut Uncoated Ends
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Solution Overview
Problem
Conventional cylindrical battery cells face issues with high resistance and heat generation due to the design of electrode tabs, leading to reduced current collection efficiency and increased risk of ignition, especially in large-capacity batteries.
Innovation Solution
A tab-less cylindrical battery cell design where the uncoated portions of the electrodes are positioned at the top and bottom of the jelly-roll type electrode assembly, with a current collecting plate welded to these portions to increase the welding cross-sectional area, and a cutting device is used to form cut surfaces and forming portions that enhance current path area without deforming the boundary between the forming portion and the cut surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electrode tabs are designed as strips coupled to uncoated portions of electrodes, then the battery cell structure is simple and easy to manufacture, but resistance is high and heat generation is excessive
Solution Approach 1:
The patent removes the traditional strip-shaped electrode tabs from the battery structure. Instead of having separate tabs coupled to uncoated portions, the invention extracts this problematic component entirely and replaces it with a tab-less design where current collection is achieved through the electrode structure itself, eliminating the source of high resistance and heat generation
Solution Approach 2:
The patent transitions from a one-dimensional strip-shaped tab to a two-dimensional current collecting plate that contacts the uncoated portions at multiple points. This dimensional change increases the effective contact area and current path, reducing resistance and heat generation while maintaining manufacturing simplicity
2Ease of manufacture
If electrode tabs are designed as strips coupled to uncoated portions, then the battery cell structure is simple, but current collection efficiency is poor
Solution Approach 1:
The patent removes the traditional strip-shaped electrode tabs that cause poor current collection efficiency. By extracting this problematic component and implementing a tab-less design with current collecting plates, the invention achieves both manufacturing simplicity and improved current collection efficiency through increased contact area and optimized current paths
Solution Approach 2:
The patent employs a composite structure combining the electrode body with integrated current collecting plates made of conductive materials. This composite design enhances current collection efficiency by creating multiple parallel current paths while maintaining the simplicity of the overall battery structure
3Loss of energy
If uncoated portions are positioned at top and bottom of jelly-roll electrode assembly with current collecting plate welded to them, then welding cross-sectional area is increased and resistance is reduced, but the boundary between forming portion and cut surface may deform or tear
Solution Approach 1:
The patent applies preliminary actions by first forming the uncoated portions at the top and bottom ends of the electrode assembly, then precisely cutting them to create flat surfaces, and finally welding the current collecting plates. This sequence of preliminary actions ensures proper positioning and prevents boundary deformation during welding
Solution Approach 2:
The patent changes physical parameters by controlling the thickness, position, and surface flatness of the uncoated portions. By optimizing these parameters, the invention achieves adequate welding cross-sectional area while preventing deformation and tearing at the boundaries between forming portions and cut surfaces
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 reduces electrical resistance, suppresses heat generation, and decreases the likelihood of ignition by increasing the current path area and preventing deformation or tearing, thereby enhancing the safety and performance of large-capacity battery cells.
Implementation Method 1
a cutter is used to cut a uncoated portion of an electrode assembly in an axial direction of the electrode assembly to form a forming portion
Implementation Method 2
a press is used to press the forming-scheduled portion in a radial direction of the electrode assembly to form the forming portion
Implementation Method 3
welding a current collecting plate to the uncoated portions
Data Source
AI summary
A cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and a vehicle comprising same, and a method for manufacturing the battery cell are provided. The cutting device includes a first cutter portion which forms a first cutting line in an axial direction on an uncoated portion while moving in the axial direction of the electrode assembly, and separates a scheduled cutting portion and a scheduled forming portion on the basis of the first cutting line; and a second cutter portion which forms a second cutting line in the circumferential direction with respect to the uncoated portion while moving in the radial direction of the electrode assembly, and forms a cut surface portion in the uncoated portion of the electrode assembly.