Curved End Plate Current Interrupt Device for Secondary Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current secondary batteries fail to effectively prevent explosions and exhibit dispersion in operating pressure due to inadequate current interruption mechanisms, particularly at the connection portion between the negative current collecting plate and the case.
Innovation Solution
A secondary battery design featuring a curved end plate connected to the negative current collecting plate through an insulator, with notches that allow for controlled disconnection under predetermined pressures, creating a current interrupt device that disconnects before explosion, thereby reducing pressure dispersion and maintaining a stable disconnected state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vent plate and sub-plate are connected by welding to form a current interrupt device, then current can be interrupted when internal pressure rises, but the connection portion is easily broken and disconnected, and current is only interrupted after explosion occurs
Solution Approach 1:
The connection portion is divided into multiple separate connection points between the vent plate and sub-plate. This segmentation distributes the mechanical stress and allows the connection to maintain integrity while still enabling current interruption when the vent separates under high pressure.
Solution Approach 2:
The connection portion is designed with pre-formed connection structures that enable current interruption to occur before explosion. The vent plate and sub-plate are configured to separate at a controlled pressure threshold, interrupting current proactively rather than reactively after explosion begins.
2Device complexity
If the sub-plate is formed in a plate shape to form a connection portion with the vent, then the structure is simple, but there is large dispersion in the operating pressure at which disconnection occurs
Solution Approach 1:
The sub-plate incorporates localized connection structures with specific geometric features at the connection points with the vent plate. These local structural modifications create consistent mechanical properties and stress distribution, reducing dispersion in disconnection pressure while maintaining overall structural simplicity.
3Reliability
If the connection portion disconnects under high internal pressure to interrupt current, then current interruption is achieved, but the bottom of the case breaks outwardly and the disconnected state cannot be maintained when pressure decreases
Solution Approach 1:
The connection portion is designed with features that prevent the bottom of the case from breaking outward when pressure increases. The reinforced connection structure and optimized geometry counteract the outward force, allowing current interruption while maintaining the structural integrity of the case bottom and preserving the disconnected state.
Data Source
AI summary
A secondary battery having a current interrupt device (CID) between a negative current collecting plate and a case of the secondary battery. The secondary battery includes: an electrode assembly including a positive electrode, a separator, and a negative electrode; a case housing the electrode assembly; a cap assembly coupled to the case for sealing the case; a positive current collecting plate connected to the positive electrode and the cap assembly; an insulator in the case adjacent an end plate of the case; and a negative current collecting plate connected to the negative electrode and the end plate of the case, the end plate being curved convexly toward an inner cavity of the case.