Rechargeable Battery Tab Coupling Uncoated Regions
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Solution Overview
Problem
Rechargeable batteries face issues with deformation and reduced design margin due to thickness variations at the electrode tab locations, affecting the flatness and capacity of the electrode assembly and cell.
Innovation Solution
The solution involves coupling electrode tabs to uncoated regions of the electrodes while maintaining a tab gap, with the second electrode's internal side end uncoated region facing the first electrode tab, and using an insulating tape to manage thickness and prevent short-circuiting, thereby reducing thickness deviations and enhancing flatness and design margin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electrode tab is coupled to an electrode at a location with larger thickness, then the electrode tab can be securely connected, but the flatness of the electrode assembly deteriorates and the design margin of thickness is reduced
Solution Approach 1:
The patent applies local quality by creating uncoated regions at specific locations on the electrodes where electrode tabs will be coupled. These uncoated regions have different properties (no active material coating) compared to the coated regions, allowing the electrode tabs to be coupled at locations with appropriate thickness characteristics while maintaining overall electrode functionality. This resolves the contradiction by enabling secure tab coupling without compromising flatness in the coated active regions.
Solution Approach 2:
The electrode is segmented into coated regions (with active material) and uncoated regions (without active material). This segmentation allows different functional zones: the coated regions maintain electrode performance and flatness, while the uncoated regions provide suitable thickness characteristics for reliable electrode tab coupling. The separation of these functions into distinct zones resolves the contradiction between connection reliability and flatness.
2Reliability
If an electrode tab is coupled to an electrode, then electrical connection is achieved, but deformation occurs at the electrode tab location reducing design margin
Solution Approach 1:
By creating localized uncoated regions at specific positions on the electrodes, the patent enables electrode tab coupling at locations with controlled thickness characteristics. The uncoated regions provide appropriate thickness for reliable mechanical and electrical connection, while the surrounding coated regions maintain uniform thickness and flatness, thus resolving the contradiction between electrical connection reliability and thickness uniformity.
Solution Approach 2:
The uncoated regions are prepared in advance during electrode manufacturing, before electrode tab coupling occurs. This preliminary preparation ensures that the electrode has pre-defined coupling locations with appropriate thickness characteristics, preventing deformation and thickness non-uniformity that would occur if tabs were coupled to coated regions. This advance preparation resolves the contradiction between achieving electrical connection and maintaining manufacturing precision.
Data Source
AI summary
A rechargeable battery includes: an electrode assembly including a separator between a first electrode and a second electrode each having uncoated regions and coated regions, and in which the separator, the first electrode, and the second electrode are spirally wound; a case that houses the electrode assembly; and a first electrode tab and a second electrode tab to be drawn outside of the case that are respectively coupled to the uncoated regions of the first electrode and the second electrode while maintaining a tab gap between the first electrode tab and the second electrode tab, where the first electrode tab is coupled to a gap uncoated region between the coated regions of the first electrode, and where in a thickness direction of the electrode assembly, in an area facing the first electrode tab, an internal side end uncoated region of the second electrode is located.