Secondary Battery Tab Lead-Out Device for Stable Connection
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Solution Overview
Problem
The existing connection between tabs and the cover plate in lithium-ion secondary batteries is prone to inaccuracy and instability, leading to potential overheating and reduced cycle life, especially under heavy current discharge in vehicles, due to inadequate welding control and increased internal resistance.
Innovation Solution
A tab lead-out device with an integrated insulating and conductive layer, featuring sector-shaped pores for precise tab alignment and connection, combined with a second pad and bolt connector for stable fixation, and laser ablation welding for enhanced conductivity, ensures reliable and efficient electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs are welded to the pole of the cover plate, then electrical connection is established, but welding position control accuracy deteriorates and connection stability worsens under heavy current
Solution Approach 1:
The patent introduces a tab lead-out device as an intermediary component between the tabs and the cover plate pole. This device includes a conductive layer that provides a standardized welding surface, and an insulating layer that electrically isolates the conductive layer from the cover plate. The intermediary structure enables precise positioning of multiple tabs while maintaining stable electrical connection under heavy current conditions.
Solution Approach 2:
The connection structure is segmented into distinct functional layers: the tab lead-out device is divided into a conductive layer for electrical connection and an insulating layer for electrical isolation. This segmentation allows independent optimization of welding position accuracy and connection stability, with the conductive layer providing precise welding surfaces and the insulating layer ensuring electrical safety.
2Power
If multiple tabs are connected to the pole, then current carrying capacity increases, but connection reliability deteriorates due to inadequate welding control
Solution Approach 1:
The tab lead-out device serves as a mediator that accommodates multiple tabs with standardized welding surfaces. The conductive layer provides consistent welding geometry for each tab, ensuring reliable connections even when multiple tabs are connected in parallel to increase current carrying capacity.
Solution Approach 2:
The patent transitions from direct radial connection of tabs to the pole to a planar connection structure where tabs connect to the conductive layer of the tab lead-out device. This dimensional change from three-dimensional radial arrangement to two-dimensional planar arrangement enables better control of welding positions and more consistent electrical connections.
3Reliability
If welding connection is used between tabs and pole, then electrical connection is established, but internal resistance increases and heat production increases
Solution Approach 1:
The patent changes the welding parameters by providing standardized welding surfaces on the conductive layer with optimized geometry and material properties. This enables consistent welding parameters across multiple tabs, reducing welding resistance and consequently reducing internal resistance and heat production in the overall battery structure.
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 solution provides stable and accurate connections, reduces internal resistance, decreases heat production, and improves battery cycle life by ensuring precise welding positions and increased contact area, making it suitable for high-performance applications like hybrid and electrical vehicles.
Implementation Method 1
said tabs are electrically connected to the conductive layer, and said conductive layer is electrically connected to the cover plate
Implementation Method 2
said insulating layer adjacent to the end of the core and a conductive layer away from the end of the core
Implementation Method 3
laser ablation welding for enhanced conductivity
Implementation Method 4
The connection between said tabs and the conductive layer of the tab lead-out device is a welding connection
Data Source
AI summary
Provided is a secondary battery comprising a core (7), tabs (4) protruding from an end of the core (7), a tab lead-out device placed at the end of the core (7), and a cover plate (1). The tab lead-out device includes an insulating layer (6) adjacent to the end of the core (7) and a conductive layer (5) distant from the end of the core (7). The tabs (4) are electrically connected to the conductive layer (5). The conductive layer (5) is electrically connected to the cover plate (1). The secondary battery further comprises a connector and a pad (3) stacked between the conductive layer (5) of the tab lead-out device and the cover plate (1). The tabs (4) are compacted between the pad (3) and the conductive layer (5) of the tab lead-out device by the connector.