Cylindrical Battery Cell, and Battery Pack and Vehicle Including the Same
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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 resulting space constraints within the battery can, which also increases the weight of metal cans.
Innovation Solution
A battery cell design that omits the second current collector plate by using a cap with electrode connecting portions that directly contact the second electrode, allowing for electrical connection and reducing the number of parts and manufacturing steps, thereby enhancing 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 for electrode assembly is reduced and manufacturing cost increases
Solution Approach 1:
The cap is merged with the second current collector plate, integrating two previously separate components into one unified structure. The cap simultaneously serves as the closure for the battery can and as the current collector plate that electrically connects to the second electrode, eliminating the need for a separate second current collector plate and maximizing the internal volume for the electrode assembly.
Solution Approach 2:
The cap is designed to perform multiple functions: it closes the open end of the battery can, provides electrical connection to the second electrode through integrated current collector plates, and serves as a structural support element. This multi-functionality eliminates the need for separate components and reduces overall device complexity.
2Reliability
If a second current collector plate is used to connect the second electrode to the can, then electrical connection is established, but manufacturing cost and complexity increase
Solution Approach 1:
The cap is merged with the second current collector plate, integrating two previously separate components into one unified structure. The cap simultaneously serves as the closure for the battery can and as the current collector plate that electrically connects to the second electrode, eliminating the need for a separate second current collector plate and maximizing the internal volume for the electrode assembly.
Solution Approach 2:
The cap is designed to perform multiple functions: it closes the open end of the battery can, provides electrical connection to the second electrode through integrated current collector plates, and serves as a structural support element. This multi-functionality eliminates the need for separate components and reduces overall device complexity.
3Quantity of substance
If the cap includes electrode connecting portions that directly contact the second electrode, then energy density increases, but manufacturing precision requirements increase
Solution Approach 1:
The electrode connecting portions are pre-formed on the cap during cap manufacturing, with predetermined positions and shapes designed to match the electrode tabs. This preliminary preparation ensures proper alignment and reduces the precision requirements during the final assembly process, as the connecting portions are already configured to receive and contact the electrode tabs.
Solution Approach 2:
The electrode connecting portions act as intermediaries between the cap and the electrode tabs, providing a standardized interface that facilitates reliable electrical connection. These connecting portions can include contact surfaces, welding areas, or mechanical attachment features that mediate the connection process and ensure consistent electrical contact.
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
This design increases energy density, reduces internal resistance, and lowers manufacturing costs by eliminating the need for additional components, while improving the structural integrity and assembly efficiency of the battery cell.
Implementation Method 1
The cap includes a plurality of electrode connecting portions protruding into the interior of the battery can along the axial direction so as to make direct electrical contact with at least one tab of the second electrode
Data Source
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.