Separator Sheet Adhesion for Folding-Free Electrode Stacking
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Solution Overview
Problem
Existing technologies fail to effectively prevent the folding of separator surplus portions in lithium secondary batteries, which can lead to internal short circuits and safety issues due to exposed electrodes.
Innovation Solution
A separator adhesion apparatus that includes a transfer unit, sensor, and adhesion unit with elastic tips or rolls to press and adhere spacing portions between separator sheets, ensuring they are synchronized with the electrode stack's movement to prevent folding and secure adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If separator sheets are stacked with electrodes overlapping to form unit cells, then battery capacity and energy density are improved, but separator surplus portions become unfixed and may fold or tear during transfer
Solution Approach 1:
The patent applies preliminary action by fixing the separator surplus portions to the electrode assembly before transfer operations. The fixing process includes positioning the surplus portions and securing them with adhesive or thermal bonding, preventing folding or tearing during subsequent handling and transfer of the unit cells.
2Reliability
If separator surplus portions are extended beyond electrode peripheries to ensure coverage, then electrode protection is improved, but folding risk during transfer increases
Solution Approach 1:
The patent positions and fixes the separator surplus portions in advance before transfer operations. By securing the surplus portions to the electrode assembly through adhesive application or thermal bonding during the assembly stage, the handling complexity during transfer is reduced while maintaining electrode protection.
3Strength
If lamination process is applied to adhere electrodes and separator sheets, then adhesion strength is improved, but technology for fixing separator surplus portions perpendicular to transfer direction is not provided
Solution Approach 1:
The patent segments the fixing process into two distinct operations: (1) lamination for adhering electrodes and separator sheets during the stacking process, and (2) a separate fixing process for securing separator surplus portions perpendicular to the transfer direction. This segmentation allows each process to be optimized independently, with the fixing process using adhesive application or thermal bonding specifically targeted at the surplus portions.
Solution Approach 2:
The patent applies preliminary action by positioning and fixing the separator surplus portions before transfer operations. The fixing process includes applying adhesive to the surplus portions or using thermal bonding to secure them to the electrode assembly, ensuring they remain fixed during subsequent handling perpendicular to the transfer direction.
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
Prevents folding of separator surplus portions, thereby preventing short circuits and enhancing the safety of lithium secondary batteries by ensuring secure adhesion between adjacent separators.
Implementation Method 1
the adhesion unit includes a tip 221 configured to press the spacing portion 115, the tip 221 being made of the elastic material
Data Source
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AI summary
The present invention relates to a separator adhesion apparatus configured to press and adhere a spacing portion between first electrodes and a spacing portion between second electrodes to each other in an electrode stack including a first separator sheet having the first electrodes disposed thereon so as to be spaced apart from each other by a predetermined distance and a second separator sheet having the second electrodes disposed thereon so as to be spaced apart from each other by a predetermined distance, the separator adhesion apparatus including an adhesion unit located above the electrode stack, the adhesion unit being configured to press the spacing portion between the first electrodes and the spacing portion between the second electrodes, and a support roll located under the electrode stack, the support roll being configured to support the electrode stack, wherein an elastic material is added to at least a part of an outer surface of the adhesion unit, whereby adjacent separator sheets are adhered to each other at the spacing portion.