Composite Current Collector With Thickened Tab Connection Region
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Solution Overview
Problem
Conventional lithium-ion battery current collectors with polymer/metal composites face issues of high contact resistance and low connection qualified rate due to poor binding force between the tab and the current collector, affecting the performance of the battery.
Innovation Solution
A current collector structure is designed with stacked metal and polymer layers, where the metal layer in the tab connection region is thickened to improve the welding strength and binding force, reducing contact impedance and increasing the 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 is prevented, but contact impedance increases and connection qualified rate decreases
Solution Approach 1:
The patent applies local quality by creating a thickened metal layer specifically in the tab connection region while maintaining a thinner metal layer in other regions. This localized thickening improves the binding force and reduces contact impedance at the connection point without unnecessarily increasing the overall material usage or affecting other regions of the current collector.
Solution Approach 2:
The patent changes the thickness parameter of the metal layer from uniform to non-uniform distribution. By controlling the metal layer thickness to be greater in the tab connection region compared to other regions, the patent optimizes both the electrical connection quality and the safety performance of the current collector.
2Reliability
If a polymer/metal composite current collector is used to prevent internal short circuit, then thermal runaway is avoided, but binding force between tab and current collector decreases
Solution Approach 1:
The patent applies local quality by concentrating the thickened metal layer specifically in the tab connection region. This localized approach strengthens the binding force where it is most needed (at the tab connection point) while maintaining the polymer/metal composite structure's short circuit prevention capabilities in other regions.
Solution Approach 2:
The patent utilizes composite materials by combining polymer and metal layers with non-uniform metal distribution. The polymer layer provides thermal insulation and short circuit prevention, while the locally thickened metal layer provides enhanced binding force and electrical conductivity at the connection region, creating a synergistic composite structure.
Data Source
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AI summary
The present invention provides a current collector and an application thereof. A first aspect of the present invention provides a current collector including M metal layers and N polymer layers. The metal layer and the polymer layer are stacked, where 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 invention 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, reducing the contact impedance of the tab connection region, and improving the connection qualified rate between the tab and the metal layer.