Cylindrical Battery Current Collector Layout for Lower Resistance Heat
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Solution Overview
Problem
Conventional cylindrical batteries face issues with high resistance and heat generation due to concentrated current flow, leading to potential ignition and internal short circuits, especially during rapid charging, and have limitations in energy density and space efficiency, which complicates their use in electric vehicles.
Innovation Solution
A cylindrical battery design with a current collecting plate structure that disperses impact and vibration, reducing the risk of damage to coupling portions, and incorporates a silicon-based negative electrode active material to enhance energy density and thermal stability, while using single particles or pseudo-single particles as positive electrode active material to minimize particle breakage and improve conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a strip-shaped electrode tab is used to connect the electrode assembly and electrode terminal, then the battery structure is simple, but the current collection efficiency is poor due to large resistance and large heat generation
Solution Approach 1:
The electrode tab is divided into multiple parallel strips instead of using a single strip-shaped tab. This segmentation increases the total cross-sectional area for current flow, reducing resistance and heat generation while maintaining structural simplicity
Solution Approach 2:
The electrode tab structure transitions from a single-dimensional strip to a multi-dimensional parallel arrangement, utilizing spatial distribution to increase current collection area without significantly increasing overall complexity
2Quantity of substance
If the cylindrical battery form factor is increased to apply to electric vehicles, then the energy density increases, but the battery may ignite due to heat generation around the electrode tab during rapid charging
Solution Approach 1:
The electrode tab is segmented into multiple parallel strips, distributing the current flow across multiple pathways. This reduces the current density and heat generation at any single location, preventing ignition during rapid charging while maintaining high energy density
Solution Approach 2:
The heat generation issue is converted into a benefit by using the heat dissipation capability of the parallel strip structure. The increased surface area of multiple strips enhances heat dissipation while the distributed current flow prevents localized overheating that could lead to ignition
3Reliability
If the uncoated portion of the positive electrode and negative electrode are positioned at the top and bottom of the jelly-roll type electrode assembly, then the current collection efficiency is improved, but the welding portion is vulnerable to damage from external impact and vibration
Solution Approach 1:
The electrode assembly is designed with the uncoated portions positioned at the top and bottom, which are naturally protected by the battery housing structure. This prior positioning arrangement cushions the welding portions from external impacts and vibrations that would otherwise damage them
Solution Approach 2:
The electrode tabs are positioned in the vertical dimension (top and bottom) rather than lateral positions, utilizing the protective enclosure of the battery housing in the vertical direction to shield the welding portions from mechanical damage while maintaining electrical efficiency
Data Source
AI summary
A cylindrical battery includes an electrode assembly; a battery housing configured to accommodate the electrode assembly through an open portion; a first current collecting plate having a support portion disposed on the electrode assembly, at least one first tab coupling portion extending from the support portion, and at least one first housing coupling portion extending from an end of the first tab coupling portion, the first current collecting plate being located within the battery housing; a second current collecting plate having a rim portion disposed on the electrode assembly, a second tab coupling portion extending inwardly from the rim portion, and a terminal coupling portion spaced apart from the second tab coupling portion; a cap plate configured to seal the open portion of the battery housing; and a battery terminal coupled with the terminal coupling portion.