Wound Lithium-Ion Battery Electrode Plate Tab Design
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Solution Overview
Problem
The existing wound lithium-ion battery production methods face issues with misalignment and burrs due to double die-cutting, leading to self-discharge and safety hazards, and require additional ceramic coating, which increases cost and reduces energy density.
Innovation Solution
An electrode plate design with fixed tab intervals and varying tab widths, allowing single die-cutting, ensuring precise alignment and eliminating the need for secondary cutting, thus avoiding burrs and reducing self-discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If double die-cutting is used to form tabs and intervals, then the interval between tabs can be increased with the number of turns, but misalignment and burrs occur leading to self-discharge and safety hazards
Solution Approach 1:
The electrode plate is divided into multiple tabs segmented along the winding direction, with each tab having a specific width and position. The segmentation allows for precise control of tab locations without requiring multiple die-cutting operations, thereby avoiding misalignment and burr formation that compromise safety.
Solution Approach 2:
The tab widths and positions are predetermined in the electrode plate design before winding. By pre-calculating the optimal tab dimensions based on the winding geometry and electrode plate dimensions, the design ensures proper alignment after winding without requiring post-winding adjustments or multiple cutting steps.
2Manufacturing precision
If double die-cutting is used to form tabs and intervals, then the interval between tabs can be increased with the number of turns, but production efficiency decreases due to additional cutting steps
Solution Approach 1:
The design combines the functions of tab formation and interval creation into a single die-cutting operation. By integrating the tab width and spacing requirements into one cutting step, the process eliminates the need for sequential cutting operations, thereby maintaining high production efficiency while achieving precise tab intervals.
Solution Approach 2:
The tab width is designed as a variable parameter that changes according to its position along the winding direction. This parameter variation allows the single die-cutting operation to accommodate the increasing interval requirements as the number of turns increases, maintaining accuracy without additional cutting steps.
3Reliability
If ceramic material is coated on the edge of the electrode plate for insulation, then self-discharge is eliminated, but cost increases and energy density decreases
Solution Approach 1:
The design extracts and eliminates the need for ceramic coating by optimizing the electrode plate structure itself. Through precise tab positioning and sizing, the design prevents self-discharge mechanisms without requiring additional insulating material layers, thereby maintaining high energy density while ensuring reliability.
4Reliability
If ceramic coating is applied to eliminate self-discharge effects, then safety is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The design converts the potential harm of self-discharge into a benefit by using the tab geometry and positioning themselves as the protective feature. The precise tab design naturally prevents self-discharge without requiring additional coating processes, thereby simplifying the manufacturing process while maintaining safety.
Data Source
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AI summary
Provided are an electrode plate and a battery cell of a wound lithium-ion battery and a method for manufacturing same. The electrode plate comprises an electrode plate body and at least two groups of tabs arranged on the electrode plate body, with each group of tabs including multiple tabs, wherein the multiple tabs have equal intervals therebetween, and the widths of the multiple tabs are successively increased by 2πΔt, with Δt being the sum of the thicknesses of a positive electrode plate, a negative electrode plate and two layers of a separation film of the battery cell of the lithium-ion battery. The present invention can avoid the problem in the prior art of burrs on an electrode plate due to secondary die-cutting, and can reduce the possibility of self-discharge of the battery. Since the body of each tab is completely coated with an electrode material, the energy density is high, thereby improving the safety of the battery. By means of slightly adjusting the widths of the tabs, continuous production is realized.