Composite Current Collector With Thickened Tab Connection Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries with conventional metal current collectors face issues of high contact resistance and low connection qualified rate due to poor binding force between tabs and composite current collectors, leading to potential thermal runaway.
Innovation Solution
A current collector structure with stacked metal and polymer layers, where the metal layer is thickened in tab connection regions to improve welding strength and binding force, reducing contact impedance and increasing connection qualified rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer/metal composite current collector is used to improve safety performance, then thermal runaway risk is reduced, but contact impedance increases and connection qualified rate decreases
Solution Approach 1:
The patent applies local quality by creating a composite current collector with non-uniform metal layer distribution. The metal layer thickness varies across different regions: it is thicker in the tab connection region to ensure low contact impedance and high connection qualified rate, while thinner in non-tab regions to maintain safety benefits. This localized variation resolves the contradiction by optimizing each region for its specific function.
Solution Approach 2:
The patent uses composite materials by combining polymer substrate with metal coating layers. The polymer provides safety benefits (preventing thermal runaway) while the metal layers provide electrical conductivity. The composite structure allows simultaneous achievement of safety performance and electrical connection quality through proper material selection and layer design.
2Reliability
If a polymer/metal composite current collector is used to improve safety performance, then thermal runaway risk is reduced, but binding force between tab and current collector deteriorates
Solution Approach 1:
The patent applies local quality by concentrating the metal layer in the tab connection region where binding force is needed. The metal coating provides strong adhesion to the tab, while the polymer substrate maintains safety performance. This localized metal distribution resolves the contradiction between safety and binding strength.
Solution Approach 2:
The composite structure of polymer and metal layers works synergistically: the polymer provides safety benefits while the metal provides binding strength. The metal layer acts as an adhesive interface between the tab and polymer substrate, resolving the contradiction between safety and mechanical strength.
3Manufacturing precision
If metal layer thickness is increased in tab connection region to improve binding force, then contact impedance is reduced, but device complexity increases
Solution Approach 1:
The patent uses local quality to create a current collector with spatially varying metal layer thickness. The metal layer is thicker only in the tab connection region where low contact impedance is needed, while remaining thin in other areas. This localized approach reduces contact impedance without requiring a uniformly thick metal layer, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent applies parameter changes by varying the metal layer thickness parameter across different regions of the current collector. The thickness parameter is optimized for each region: thicker in tab connection areas for low impedance, thinner in non-tab areas for simplicity. This parameter variation resolves the contradiction between contact impedance and structural complexity.
Data Source
AI summary
The present disclosure provides a current collector and an application thereof. A first aspect of the present disclosure provides a current collector including M metal layers and N polymer layers. The metal layer and the polymer layer are stacked, where each of L metal layers includes a tab connection region and a non-tab connection region and a thickness of the tab connection region is greater than that of the non-tab connection region, and M≥1, N≥1, L≥1, and M≥L. The present disclosure provides a current collector, which effectively improves the welding strength of the tab by performing a thickening treatment on the tab connection region for connecting the tab in the metal layer, thereby improving the binding force between the tab and the current collector and reducing the contact impedance of the tab connection region, and improving the connection qualified rate between the tab and the metal layer.