Secondary Battery Connection Member Protrusion for Gas Discharge
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Solution Overview
Problem
Secondary batteries face issues with tab breakage due to vibration and shock, leading to gas discharge blockage, which affects energy density and cycle life, and poses safety hazards due to accumulated bubbles in the electrolyte.
Innovation Solution
The design includes a cap plate, electrode terminal, electrode assembly with a tab extending from the body, and a connection member with a support plate that protrudes to facilitate gas discharge, ensuring the bare height and body length ratio allows for efficient gas release, preventing overheating and improving ion transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tab and connection member are made larger to prevent breakage from vibration and shock, then reliability improves, but gas discharge is blocked affecting energy density and cycle life
Solution Approach 1:
The connection member is segmented into a support plate portion and a connection plate portion. The support plate provides structural reinforcement to prevent tab breakage, while the connection plate establishes electrical connection. This segmentation allows each part to optimize its function without compromising the other.
Solution Approach 2:
The support plate extends in the thickness direction of the battery to provide mechanical support, while the connection plate extends in the length direction to establish electrical connection. By utilizing different spatial dimensions, the design simultaneously achieves mechanical strength and electrical conductivity without interfering with gas discharge pathways.
2Strength
If the connection member size is increased to ensure mechanical strength, then tab breakage resistance improves, but gas discharge pathways are blocked
Solution Approach 1:
The connection member has different local qualities: the support plate portion has high mechanical strength to prevent tab breakage, while the connection plate portion has high electrical conductivity for current transmission. This local differentiation allows each region to optimize its property for its specific function.
Solution Approach 2:
The support plate acts as an intermediary between the tab and the connection plate, providing mechanical support to the tab while allowing the connection plate to establish electrical connection. This intermediary structure prevents tab breakage without blocking gas discharge pathways.
3Length of stationary object
If the support plate protrudes closer to the body to reduce battery height, then compactness improves, but gas discharge may be blocked
Solution Approach 1:
The support plate is designed with a specific protrusion distance that dynamically balances mechanical support requirements and gas discharge requirements. The protrusion distance is optimized to provide sufficient support while maintaining adequate clearance for gas discharge pathways.
Solution Approach 2:
The design optimizes the protrusion distance parameter of the support plate to achieve the desired balance between compactness and gas discharge efficiency. By carefully controlling this geometric parameter, the battery achieves reduced height without compromising gas discharge pathways.
Data Source
Figure 1~2
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AI summary
A secondary battery includes a cap plate (10), an electrode terminal (20), an electrode assembly (30), and a connection member (40), the connection member (40) includes a first connecting plate (41) connected to a tab, a second connecting plate (42), and a support plate (43), at least a part of the support plate (43) protrudes, relative to the first connecting plate (41), towards a side close to a body, and the protruding part of the support plate (43) is attached to the body; a minimum distance between the support plate (43) and a bottom surface of the electrode assembly (30) in a height direction of the secondary battery is a bare height H of the body on its side, a size of the body in a length direction of the secondary battery is a body length L, and the bare height H and the body length L satisfy the following relationship: 0.1 ≤ H/L ≤ 0.8. A vehicle is further disclosed. Such configuration of the secondary battery can avoid the first electrode plate or the second electrode plate from producing the black spot to a greatest extent, thereby increasing an energy density and a cycle life of the secondary battery and improving safety of the secondary battery.