Zigzag-Folded Separator Electrode Assembly for Thin Li-Ion Cells
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Solution Overview
Problem
The challenge is to enhance the energy density of lithium secondary batteries while maintaining a thin thickness and preventing short circuits, which requires precise adjustment of component dimensions and spacings in the battery assembly.
Innovation Solution
The electrode assembly features a zigzag-folded separator with anode and cathode plates alternately stacked between folded portions, and an anode plate at the uppermost and lowermost positions, allowing for a thin design without increasing thickness and minimizing the risk of short circuits through strategic gap adjustments and adhesive fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of secondary batteries is reduced to increase energy density, then volumetric energy density is improved, but the risk of short circuit between electrodes increases and product quality becomes harder to ensure
Solution Approach 1:
The separator is folded into a zigzag shape with multiple folded portions, segmenting the space between electrodes into distinct regions. This segmentation maintains adequate spacing between anode and cathode plates while reducing the overall battery thickness, thereby preventing short circuits while improving energy density
Solution Approach 2:
Instead of reducing thickness in one dimension, the invention uses the folding pattern to create a three-dimensional zigzag structure. This allows the separator to occupy space efficiently in multiple dimensions, maintaining electrode spacing without increasing overall battery thickness
2Reliability
If the dimensions and spacings of individual components are adjusted to prevent short circuit, then reliability is improved, but the alignment precision and manufacturing complexity increase
Solution Approach 1:
The zigzag-folded separator structure automatically maintains proper spacing between electrodes through its geometric configuration. The folded portions act as self-aligning features that guide electrode plate positioning, reducing the need for high-precision external alignment during manufacturing
Solution Approach 2:
The folded portions of the separator serve as intermediary structures between adjacent electrode plates. These folded sections provide physical guidance and spacing maintenance, facilitating easier alignment of components during assembly while ensuring reliable short circuit prevention
Data Source
AI summary
An electrode assembly for secondary battery according to an Example of the present application may comprise a plurality of anode plates; a plurality of cathode plates; and a separator disposed between the plurality of cathode plates and the plurality of anode plates, wherein the separator may be folded in a zigzag shape, and the plurality of anode plates and the plurality of cathode plates may be alternately stacked in a section between folded portions of the separator to form a stack, and an anode plate may be disposed on an uppermost portion and a lowermost portion of the stack.