Lithium Battery Cover Plate Layout for More Cell Space
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Solution Overview
Problem
Traditional lithium battery cover plate structures fail to meet high-rate overcurrent requirements due to limited internal space, which restricts battery capacity and energy density improvements.
Innovation Solution
A lithium battery design featuring a housing with a positive electrode cover plate component, a negative electrode cover plate, and connecting sheets that allow for direct welding and increased structural stability, along with a sealing mechanism that enhances sealing performance and eliminates space limitations within the battery cell, thereby increasing capacity and energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If a traditional cover plate structure is used, then the structural integrity is maintained, but the internal space of the cell is limited which restricts battery capacity and energy density
Solution Approach 1:
The cover plate is divided into a first cover plate and a second cover plate that are separately positioned at opposite ends of the housing. This segmentation allows each cover plate to be independently optimized for its specific function while collectively providing structural support, thereby increasing the internal space without compromising overall structural integrity.
Solution Approach 2:
The patent transitions from a single integrated cover plate design to a distributed multi-plate configuration along the length of the housing. This dimensional redistribution of structural support functions allows maximization of the internal cell space while maintaining necessary mechanical strength through strategically positioned multiple support points.
2Power
If slot rolling is performed on housing to meet high-rate overcurrent requirement, then overcurrent capacity is improved, but internal space is reduced which is not conducive to increasing battery capacity
Solution Approach 1:
Instead of performing slot rolling on the entire housing which would consume significant internal space, the patent segments the current collection function across multiple cover plates with connecting sheets. This distributed architecture achieves the required overcurrent capacity through multiple parallel current paths without requiring extensive modification of the housing structure, thereby preserving internal space.
Solution Approach 2:
The patent introduces connecting sheets as intermediary components between the electrode groups and cover plates. These connecting sheets provide efficient electrical connection for high-rate current transfer without requiring the housing itself to be modified through space-consuming slot rolling operations, thus mediating between the conflicting requirements of overcurrent capacity and internal space.
3Reliability
If multiple connection relations are implemented in structural parts, then sealing performance and overcurrent performance are improved, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into the cover plate assembly: the first and second cover plates provide both structural support and sealing functions, while the connecting sheets simultaneously establish electrical connections and mechanical attachments. This functional integration achieves improved sealing and overcurrent performance without proportionally increasing device complexity, as the same components serve multiple purposes.
Data Source
AI summary
The present application relates to the technical field of batteries, and provides a lithium battery and a method for preparing a lithium battery. The method for preparing a lithium battery described in the present application includes the following steps: S1, connecting, after insulating connection of a positive electrode connecting sheet and a positive electrode cover plate component, a side of the positive electrode connecting sheet facing back to the positive electrode cover plate component with a positive electrode end of a cell electrode group, to form a cell electrode group component: S2, placing the cell electrode group component into a housing from a negative electrode end of the housing, and clamping the positive electrode cover plate component into a positive electrode end of the housing, to enable a periphery of the positive electrode cover plate component to be connected with the housing; S3, connecting a negative electrode connecting sheet with a negative electrode end of the cell electrode group, connecting a protruding side of a first connecting portion of the negative electrode cover plate with the negative electrode connecting sheet, and connecting a second connecting portion of the negative electrode cover plate with the negative electrode end of the housing; and S4, connecting a sealing sheet with an end opening of a liquid injection hole away from the positive electrode connecting sheet. The lithium battery obtained through the method for preparing a lithium battery of the present application can increase an internal space of a cell and improve a battery capacity and an energy density.