Tab-Less Cylindrical Battery Current Collector for Impact-Safe Welding
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Solution Overview
Problem
Cylindrical batteries face issues with heat generation and safety due to concentrated forces on welded portions during external impacts or vibrations, leading to potential damage and thermal runaway, especially during rapid charging, and require improved current collection efficiency and space optimization for electric vehicle applications.
Innovation Solution
A tab-less cylindrical battery design with a current collector structure that includes uncoated regions on the electrode assembly, where the current collector is welded to the uncoated regions, and a terminal coupling portion is spaced apart from the uncoated region coupling portion to disperse forces and enhance current interruption capabilities, allowing for efficient electrical connection and reduced resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current collector is welded directly to the uncoated region of the electrode, then electrical connection is achieved, but the welded portion concentrates external forces leading to damage during impacts or vibrations
Solution Approach 1:
The current collector is divided into distinct functional portions: a first current collector portion that contacts the uncoated region for electrical connection, and a second current collector portion that serves as a force-receiving structure. This segmentation separates the electrical connection function from the mechanical strength function, allowing each portion to be optimized for its specific purpose while preventing force concentration at the welded joint.
2Productivity
If electrode tabs are provided on two surfaces of the jelly roll to increase current collection efficiency, then contact area increases, but the coupled portion becomes more vulnerable to damage from external impacts and vibrations
Solution Approach 1:
The current collector structure is segmented into multiple portions with distinct functions. The first portion maintains contact with the uncoated region for current collection, while the second portion provides mechanical support and force distribution. This segmentation allows the battery to achieve high current collection efficiency through extended contact area while the force-receiving structure protects the coupled portions from impact damage.
3Manufacturing precision
If the current collector is designed to maximize contact area with electrode tabs, then resistance is minimized, but space for other components is reduced
Solution Approach 1:
The current collector extends in the radial direction of the battery to maximize contact area with the uncoated region, rather than only in the axial direction. This dimensional approach allows the first current collector portion to achieve extended contact area for low resistance while the force-receiving structure utilizes the axial space, thereby optimizing both electrical performance and space utilization in different spatial dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively disperses external impacts, minimizes heat generation, ensures safety by rapid current interruption, and optimizes space for higher energy density and efficient electrical wiring in battery packs for electric vehicles.
Implementation Method 1
a first current collector including an edge portion arranged on the electrode assembly, a first uncoated region coupling portion extending inward from the edge portion and coupled with the first uncoated region
Data Source
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AI summary
A battery according to an embodiment of the present disclosure includes an electrode assembly formed by winding a first electrode, a second electrode and a separator interposed between the first electrode and the second electrode around a winding axis, wherein the first electrode includes a first uncoated region free of an active material layer, the first uncoated region being disposed adjacent to an edge of the first electrode extending along a winding direction of the electrode assembly, wherein the first uncoated region is exposed from the separator and at least a part of the first uncoated region itself is used as an electrode tab; a housing in which the electrode assembly is arranged; a first current collector including an edge portion arranged on the electrode assembly, a first uncoated region coupling portion extending inward from the edge portion towards the winding axis and coupled with the first uncoated region, and a terminal coupling portion spaced apart from the first uncoated region coupling portion; and a terminal which is coupled with the terminal coupling portion.