Secondary Battery Electrode Tab Thickness Variation
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Solution Overview
Problem
Secondary batteries face challenges in achieving a balance between thin electrode assemblies for reduced thickness and high capacity while maintaining the stiffness of the electrode tab, which is crucial for both portable devices and larger applications like electric vehicles.
Innovation Solution
The design incorporates an electrode tab with different thicknesses inside and outside the electrode assembly, featuring a single layer inside and multiple layers outside, with a clad structure and specific thickness ratios to minimize overall thickness and maximize capacity while maintaining stiffness, using materials like aluminum and nickel for the main and auxiliary tab portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the electrode tab is made thinner to reduce the overall battery thickness, then the battery thickness is reduced, but the stiffness of the electrode tab deteriorates
Solution Approach 1:
The electrode tab is designed with non-uniform thickness: a first thickness in the region inside the electrode assembly and a second thickness in the region outside the electrode assembly, where the second thickness is greater than the first. This local variation in thickness allows the tab to be thin where space is constrained (inside the assembly) while maintaining sufficient stiffness where structural integrity is needed (outside the assembly).
Solution Approach 2:
The electrode tab is divided into two distinct regions with different thickness characteristics: an internal region (first tab region) with smaller thickness for space efficiency, and an external region (second tab region) with larger thickness for mechanical strength. This segmentation allows each region to be optimized for its specific functional requirements.
2Length of moving object
If the electrode assembly is made thinner to reduce battery thickness, then the battery thickness is reduced, but the capacity of the battery decreases
Solution Approach 1:
By making the electrode tab thinner only in the region inside the electrode assembly (first tab region) while maintaining adequate thickness outside, the design optimizes space utilization within the assembly without compromising the overall capacity. The active material volume is maximized in the regions that contribute to capacity while minimizing the space consumed by the tab structure.
Data Source
AI summary
A secondary battery includes: an electrode assembly, a case accommodating the electrode assembly, and an electrode tab electrically connected to the electrode assembly and extending from inside of the electrode assembly to outside of the case. The electrode tab has different thicknesses at the inside of the electrode assembly and the outside of the electrode assembly.