Secondary Battery Tab Bending for Misalignment Reduction
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Solution Overview
Problem
Conventional secondary batteries face issues with tab misalignment and short-circuits due to tab thickness and length, leading to potential accidents during assembly and operation.
Innovation Solution
The secondary battery design features a tab with a connecting portion, an extending portion, and a bending portion, where the tab is bent in the height direction and only provided on one side of the main body, with a supporting piece to alleviate misalignment and reduce redundancy, enhancing safety by minimizing the risk of short-circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tab is made thicker to ensure connection strength, then the connection reliability is improved, but the misalignment degree between tabs increases
Solution Approach 1:
The patent introduces a new spatial dimension by bending the tab in the thickness direction of the electrode assembly. This dimensional change allows the tab to reach the connecting piece while reducing the required tab length in the planar direction, thereby minimizing misalignment between innermost and outermost tabs while maintaining adequate thickness for connection reliability.
Solution Approach 2:
The tab is divided into distinct functional segments: a connecting portion for main body, an extending portion, and a bending portion. This segmentation allows each part to perform its specific function optimally - the connecting portion maintains thickness for reliability, while the bending portion manages the spatial transition to reduce misalignment.
2Ease of operation
If the tab is made longer to reach the connecting piece, then the connection accessibility is improved, but the redundancy of the tab increases causing potential short-circuits
Solution Approach 1:
By utilizing the thickness direction (Z-axis) for tab extension through bending, the patent achieves connection accessibility without proportionally increasing the tab's planar length. This dimensional approach reduces redundant tab material that could cause short-circuits while ensuring the outermost tab reaches the connecting piece.
Solution Approach 2:
The tab configuration is made asymmetric by providing tabs at only one side of the main body rather than both sides. This asymmetric design optimizes the tab length and bending geometry to achieve precise alignment with the connecting piece while minimizing redundancy and short-circuit risks.
3Stability of the object's composition
If tabs are provided at both sides of the main body, then the structural symmetry is improved, but the tab thickness and misalignment increase
Solution Approach 1:
The patent deliberately adopts an asymmetric configuration by providing tabs at only one side of the main body. This design choice prioritizes tab alignment precision and reduces misalignment issues over structural symmetry, as the single-sided tab arrangement allows for optimized bending geometry and reduced thickness accumulation.
4Volume of moving object
If the tab is bent more to fit the connecting piece, then the space utilization is improved, but the misalignment degree increases
Solution Approach 1:
The patent optimizes space utilization by bending the tab in the thickness direction rather than increasing planar curvature. This dimensional approach achieves compact fitting within the battery structure while maintaining better alignment precision, as the bending occurs perpendicular to the plane of tab stacking rather than within the stacking plane.
Data Source
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AI summary
The present disclosure relates to technical field of energy storage devices, and in particular, to a secondary battery and a vehicle. The secondary battery includes a top cover plate, electrode terminals disposed on the top cover plate, at least one electrode assembly including a main body and a plurality of conductive portions extending from the main body. The plurality of conductive portions is stacked and forms a tab, and the main body is formed by winding a first electrode plate, a second electrode plate and a separator disposed between the first electrode plate and the second electrode plate. The secondary battery also includes connecting pieces for connecting the tab to the electrode terminal. The tabs extend from one side of the main body viewed in thickness direction and are bent with respect to height direction and is connected to the connecting piece.