Battery Separator Meshing Structure for Drop Impact Resistance
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Solution Overview
Problem
Secondary batteries used in portable devices and electric vehicles face safety issues due to separator shrinkage and potential short circuits when dropped, with existing solutions like hot-pressing being unsuitable for ceramic-coated separators and risking thermal effects.
Innovation Solution
A cell design featuring a meshing structure between separators that prevents shrinkage by forming a bonding force between multilayers when the cell is dropped, using protrusions and receiving spaces to maintain separator integrity and prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hot-pressing is used to bond separators, then bonding force between separators is improved, but thermal effects may cause safety issues and it is unsuitable for ceramic-coated separators
Solution Approach 1:
The patent replaces the thermal bonding system (hot-pressing) with a mechanical bonding system. The meshing structure consists of protrusions on one separator that mechanically interlock with corresponding recesses on the adjacent separator, creating a mechanical bond without thermal effects. This substitution eliminates the harmful thermal effects while maintaining or improving the bonding force between separators.
2Reliability
If separator thickness is increased to prevent shrinkage, then dropping performance is improved, but cell volume and energy density are reduced
Solution Approach 1:
The patent segments the separator into multiple thin layers with alternating meshing structures (protrusions and recesses) rather than using a single thick separator. This segmentation allows the separators to bond mechanically through the meshing structures, providing shrinkage resistance during dropping while keeping each individual separator layer thin, thus avoiding excessive cell volume increase.
3Strength
If meshing structure is added to separators, then bonding force and shrinkage resistance are improved, but device complexity increases
Solution Approach 1:
The meshing structure on the separator utilizes a porous or reticulated pattern of protrusions and recesses that can be integrated into the separator manufacturing process. This structure provides mechanical interlocking for bonding while maintaining the porous characteristics necessary for electrolyte penetration and ion transport, thus adding bonding functionality without significantly complicating the separator structure or manufacturing.
Data Source
AI summary
The present application discloses a cell and a battery, the cell comprising a first electrode, a second electrode, and a first separator and a second separator that are disposed between the first electrode and second electrode, wherein the first separator includes a first meshing structure beyond the first electrode and the second electrode, the second separator includes a second meshing structure beyond the first electrode and the second electrode, and the first meshing structure is meshed with the second meshing structure along a thickness direction of the cell. The cell provided by the present application can improve the dropping performance of the cell and enhance the safe use of cell.