Cylindrical Battery Cap-Collector Structure for Higher Energy Density
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Solution Overview
Problem
Cylindrical battery cells face reduced energy density and increased manufacturing costs due to the need for a second current collector plate and the space it occupies within the battery can, which also adds weight and complexity.
Innovation Solution
A battery cell design that omits the second current collector plate by using a cap with electrode connecting portions that directly contact and connect to the second electrode, allowing for electrical contact and reducing the number of parts and manufacturing steps, thereby increasing energy density and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a second current collector plate is used to connect the second electrode to the can, then reliable electrical connection is achieved, but the volume available for active materials is reduced and manufacturing complexity increases
Solution Approach 1:
The invention merges the cap and the second current collector plate into a single integrated component. The cap includes a body portion that closes the can opening and a current collector plate portion that extends into the can interior to contact the second electrode. This integration eliminates the need for a separate current collector plate while maintaining reliable electrical connection and maximizing volume for active materials.
Solution Approach 2:
The cap is designed to perform multiple functions simultaneously: it serves as both the closure for the can opening and as the current collector plate for electrical connection. The integrated structure includes both a body portion for sealing and a current collector plate portion for electrical contact, allowing one component to fulfill roles that traditionally required separate parts.
2Reliability
If a second current collector plate is used, then electrical connection is ensured, but the number of parts and manufacturing steps increases
Solution Approach 1:
The invention merges the cap and the second current collector plate into a single integrated component. The cap includes a body portion that closes the can opening and a current collector plate portion that extends into the can interior to contact the second electrode. This integration eliminates the need for a separate current collector plate while maintaining reliable electrical connection and maximizing volume for active materials.
3Reliability
If the cap extends deeply into the can to ensure electrical contact, then connection reliability improves, but the volume for active materials is reduced
Solution Approach 1:
The current collector plate portion extends in the radial direction from the body portion, rather than only in the axial direction. This dimensional change allows the current collector plate to reach the second electrode effectively while minimizing the axial extension into the can, thereby preserving maximum volume for active materials while ensuring reliable electrical contact.
Data Source
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AI summary
A cylindrical battery cell includes a battery can accommodating a jelly-roll type electrode assembly therein, and a cap covers and closes an open end of the battery can. The cap is bonded to a tab of an electrode of the electrode assembly. The cap includes two or more electrode connecting portions, each of which protrudes into the interior of the battery can along the axial direction. The electrode connecting portions are spaced apart from one another in a circumferential direction about a center of the cap, and at least two of the electrode connecting portions are positioned on opposing sides of the center of the cap. The cap functions as both a current collector plate and the cap, thus increasing energy density. Manufacturing methods are also disclosed, as is a battery pack including the battery cell and a vehicle equipped with the battery pack.