Stacked Secondary Battery Sub-Tab Design
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Solution Overview
Problem
Secondary batteries face limitations in capacity due to squandering of cell space and potential electrical shorts from tab portions penetrating into the electrode assembly during assembly.
Innovation Solution
A stacked electrode assembly with protruding uncoated portions connected to current collectors via ductile sub-tabs, which are bent and welded to prevent penetration and shorts, increasing capacity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a jelly-rolled electrode assembly is used, then the battery can be assembled, but cell space is squandered which limits battery capacity increase
Solution Approach 1:
The electrode assembly is segmented into multiple stacked electrode plates rather than a single rolled structure. This segmentation allows for more efficient space utilization within the battery cell, increasing the quantity of active material that can be packed into the available volume, thereby improving battery capacity without proportionally increasing cell volume.
Solution Approach 2:
The invention transitions from a two-dimensional rolled structure to a three-dimensional stacked configuration. By stacking electrode plates in multiple layers with alternating positive and negative electrodes, the design充分利用s the available cell volume in all three dimensions, eliminating the space wastage inherent in flat rolled structures and significantly increasing battery capacity.
2Reliability
If tab portions are connected to current collectors during assembly, then electrical connection is established, but tab portions may penetrate into the electrode assembly which degrades battery stability
Solution Approach 1:
A dedicated current collector structure serves as an intermediary component between the electrode plates and external terminals. The current collector is specifically designed with tabs that are strategically positioned and connected to prevent penetration into the electrode assembly while maintaining reliable electrical connection. This intermediary structure resolves the conflict between assembly ease and battery stability by providing a controlled interface for electrical connections.
Solution Approach 2:
The current collector tabs are pre-configured and positioned before final assembly to prevent potential penetration into the electrode assembly. By anticipating and counteracting the penetration issue in advance through proper tab design and positioning, the invention maintains battery stability without complicating the assembly process.
Data Source
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AI summary
A secondary battery (100) capable of achieving a higher capacity than a related art jelly-rolled electrode assembly is provided, the secondary battery (100) including an electrode assembly (110) including a first electrode plate (111) and a second electrode plate (112), each having an uncoated portion (114, 115) protruding from a respective one of laterally opposite sides of the electrode assembly (110); a current collector (150, 160) at a region corresponding to the uncoated portion (114, 115) of the electrode assembly (110); and a ductile sub-tab (157, 167) electrically connecting the uncoated portion (114, 115) of the electrode assembly (110) to the current collector (150, 160), wherein the uncoated portion (114, 115) and the sub-tab (157, 167) are connected to each other and bent together in the same direction.