Electrode Assembly Manufacturing via Contact Lug Bonding
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Solution Overview
Problem
Existing methods for producing electrode units for battery cells face challenges in maintaining homogeneous force distribution and preventing delamination due to electrode expansion and aging, which can lead to loss of contact between electrodes and separators, especially in wound configurations.
Innovation Solution
A method involving the cohesive connection, specifically gluing, of plate-shaped segments of an electrode to a band-shaped separator layer, with contact lugs free of active material, allowing for precise positioning and assembly through Z-folding, winding, or stacking, using adhesive films to secure the segments without direct contact with active material, and ensuring mechanical fixation and protection from foreign particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is applied directly to active material of electrodes, then bonding strength between electrode and separator is improved, but electrochemical performance deteriorates due to adhesive interference with active material
Solution Approach 1:
The patent introduces contact lugs as an intermediary element between the electrode and separator. The contact lugs are made of adhesive-free current collector material and are bonded to the separator, while the electrode is bonded to the contact lugs. This intermediary structure allows the adhesive to be applied only to the contact lugs and separator, not directly to the active material, thereby maintaining both bonding strength and electrochemical performance.
2Device complexity
If electrodes are fixed to separator at edge regions only, then manufacturing complexity is reduced, but reliability deteriorates due to potential delamination and loss of contact during electrode expansion
Solution Approach 1:
The patent divides the electrode structure into segments with contact lugs at regular intervals along the length of the electrode. These contact lugs are bonded to the separator at multiple discrete locations rather than continuously along the entire edge. This segmentation provides distributed mechanical anchoring points that prevent delamination while maintaining manufacturing simplicity.
3Volume of moving object
If wound electrode assembly configuration is used, then space utilization is improved, but stability deteriorates due to heterogeneous force distribution and delamination at curves during aging
Solution Approach 1:
The patent applies adhesive to the separator and contact lugs before assembly, creating pre-bonded connection points that are established prior to winding. This preliminary bonding ensures that the electrodes are securely attached to the separator at critical locations before the winding process begins, preventing delamination and maintaining homogeneous force distribution even when the assembly is wound into a compact configuration.
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 method enables precise electrode positioning, high manufacturing speed, low tolerances, improved electrochemical performance, reduced internal resistance, and enhanced mechanical stability and safety by avoiding adhesive interference with active materials and preventing separator shrinkage under thermal stress.
Implementation Method 1
contact tabs of several plate-shaped segments of a first electrode are bonded, in particular glued, to a ribbon-shaped first separator layer
Data Source
Figure 1
Figure 2a~2c
Figure 3a~3c
AI summary
The invention relates to a method for producing an electrode unit for a battery cell comprising the following steps: substance-to-substance bonding of contact lugs (35, 36) of a plurality of plate-shaped segments of a first electrode (21, 22) to a strip-shaped first separator layer (18), substance-to-substance bonding of a strip-shaped second separator layer (19) to the contact lugs (35, 36) of the segments of the first electrode (21, 22) or to the first separator layer (18) such that a strip-shaped composite element (50) is produced, wherein an active material (41, 42) of the segments of the first electrode (21, 22) is surrounded by the first separator layer (18) and by the second separator layer (19), and arranging a plurality of plate-shaped segments of a second electrode (21, 22) on the composite element (50). The invention further relates to an electrode unit for a battery cell, produced by the method according to the invention.