Electrode Assembly Non-Coated Ends Volume Reduction
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Solution Overview
Problem
Existing secondary battery electrode assemblies face challenges in reducing volume without compromising capacity, as they are heavily influenced by the properties and performance of the electrode materials, which are not efficiently optimized in current designs.
Innovation Solution
The electrode assembly design incorporates a non-coated portion on the roll-starting and roll-finishing ends of the electrodes, allowing for a reduced volume without affecting capacity, by minimizing the active material coating on specific surfaces and arranging the electrodes in a jelly-roll configuration with a separator for insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If active material is coated on the entire surface of electrodes including roll-starting and roll-finishing ends, then the capacity of the battery is increased, but the volume of the electrode assembly increases
Solution Approach 1:
The patent applies local quality by differentiating the coating strategy across different regions of the electrode. The active material is coated on the main active regions of the electrode but intentionally left uncoated on the roll-starting and roll-finishing end portions. This localized differentiation allows the electrode to maintain capacity in the active regions while reducing volume by eliminating unnecessary coating on the end portions that do not contribute to electrochemical performance.
2Quantity of substance
If active material is coated on roll-starting and roll-finishing ends, then more active material is utilized, but the coated active material does not contribute to capacity and increases volume
Solution Approach 1:
The patent extracts or removes the active material coating from the roll-starting and roll-finishing end portions of the electrode. By taking out the unnecessary coating from these specific regions, the invention eliminates the problem of wasted active material that does not contribute to capacity. The active material is retained only in the regions that actually participate in electrochemical reactions, thereby improving capacity efficiency.
3Ease of manufacture
If electrodes are wound with full coating, then manufacturing is simpler, but the battery volume is larger than necessary
Solution Approach 1:
The patent applies preliminary action by pre-defining the uncoated end portions during the electrode manufacturing process, before the winding step. The electrode is prepared with designated uncoated regions at the roll-starting and roll-finishing ends in advance, so that when the electrodes are wound into the jelly-roll configuration, the final battery assembly automatically achieves the desired compact volume without requiring post-processing or complex winding adjustments.
Data Source
AI summary
Disclosed are an electrode assembly, a method of manufacturing the same, and a secondary battery including the same. The electrode assembly includes a first electrode coated with a first active material, a second electrode coated with a second active material, and a separator between the first and second electrodes. The first and second electrodes and the separator are wound into a jelly-roll. At least one of the first and second electrodes includes a non-coated portion where an active material is not coated on a roll-starting end or a roll-finishing end of the at least one of the first and second electrodes, the non-coated portion is at a region of a side surface of the at least one electrode, and the region having the non-coated portion does not face an electrode having a different polarity from the at least one of the first and second electrodes with the separator therebetween.