Tab-Less Cylindrical Battery Current Collector for Heat Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cylindrical batteries face issues with heat generation and internal shorts during rapid charging, leading to safety concerns and reduced energy density due to concentrated current flow at electrode tabs, and inefficient electrical wiring in battery packs for electric vehicles.
Innovation Solution
A tab-less cylindrical battery design with improved current collection efficiency, where the positive and negative electrode uncoated regions are positioned on the top and bottom of the jelly-roll assembly, and a current collector is welded to these regions, along with a current interruption mechanism integrated into the current collector to manage overcurrent situations without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrode tabs are provided on conventional cylindrical batteries for current collection, then current collection efficiency is improved, but concentrated current flow causes heat generation and safety issues during rapid charging
Solution Approach 1:
The patent divides the single electrode tab into multiple electrode tabs (first electrode tab and second electrode tab) positioned at different locations on the electrode assembly. This segmentation distributes the current collection points, reducing current density at each tab and thereby reducing heat generation during rapid charging while maintaining efficient current collection
2Productivity
If electrode tabs are used for electrical connection, then current collection is improved, but the welded portion becomes vulnerable to damage from external impacts and vibrations
Solution Approach 1:
The patent positions electrode tabs at specific locations on the electrode assembly (first electrode tab at one end, second electrode tab at the other end) to optimize both current collection and mechanical durability. This local optimization ensures that welded portions are distributed away from concentrated stress points, reducing vulnerability to impact and vibration damage while maintaining effective current collection
3Reliability
If additional current interruption components are added to manage overcurrent, then safety is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent integrates the current interruption function directly into the electrode tab structure itself. The electrode tabs are designed with inherent mechanical properties that allow them to deform or break under excessive current conditions, eliminating the need for separate current interruption components. This merging of functions maintains safety while reducing device complexity and manufacturing cost
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 design disperses external impacts, reduces heat generation, ensures safety by rapid current interruption, and enhances energy density and assembly efficiency by minimizing resistance and optimizing electrical connections.
Implementation Method 1
a current collector coupled onto the electrode assembly... maximizing the contact area of the electrode tabs and the current collectors, and minimizing the resistance at the connected portion between components
Implementation Method 2
a current collector may be coupled onto each of the two surfaces of the jelly roll... a current collector is welded to these regions
Implementation Method 3
an internal short may occur due to excessive heat induced by the increased resistance
Data Source
AI summary
A battery includes an electrode assembly including a first electrode, second electrode, and a separator between the first electrode and the second electrode, the first electrode including a first region coated with an active material and a second region at a first side and adjacent to the first region, the second region being exposed beyond the separator, and at least part of the second region is an electrode tab; a housing including a first end with a first opening, the housing accommodating the electrode assembly; a first current collector including an edge portion on the electrode assembly, a second region coupling portion extending from the edge portion and coupled with the second region, and a terminal coupling portion spaced apart from the second region coupling portion; and a terminal coupled with the terminal coupling portion.