Square Battery Tab Laser Welding for Lower Weight and Energy Loss
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Solution Overview
Problem
The existing connection method for square batteries, which uses auxiliary and connection sheets for welding, increases weight, occupies internal space, reduces mass specific energy, and leads to energy loss and thermal runaway due to inefficient energy transmission.
Innovation Solution
A square battery design with direct laser welding of tabs to the cover plate, eliminating the need for auxiliary and connection sheets, and employing ultrasonic pre-welding to improve the connection quality and reduce energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary welding sheet and connection sheet are used for welding core to cover plate, then welding connection is achieved, but weight increases and mass specific energy decreases
Solution Approach 1:
The patent removes the auxiliary welding sheet and connection sheet from the battery structure, achieving direct welding between the core tab and cover plate pole. This extraction of unnecessary components reduces battery weight while maintaining welding connection through direct metal-to-metal contact.
Solution Approach 2:
The patent merges the functions of the auxiliary welding sheet, connection sheet, and direct welding into a single direct welding process. By combining these separate components and operations into one integrated welding step, the structure is simplified and weight is reduced while preserving the essential welding connection function.
2Reliability
If auxiliary welding sheet and connection sheet are used, then welding connection is achieved, but internal space is occupied and space utilization rate decreases
Solution Approach 1:
The patent extracts and removes the auxiliary welding sheet and connection sheet from the battery internal structure. This elimination of intermediate components frees up internal space that was previously occupied by these sheets, improving space utilization rate while maintaining the welding connection through direct contact.
3Reliability
If auxiliary welding sheet and connection sheet are used for energy transmission, then connection is achieved, but energy loss occurs and temperature rises
Solution Approach 1:
The patent removes the auxiliary welding sheet and connection sheet that were causing energy loss during energy transmission. By extracting these intermediate components, a direct energy transmission path is established between the core and cover plate, reducing resistance and minimizing energy loss, thereby lowering temperature rise during battery operation.
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 enhances internal space utilization, mass specific energy, and reduces the risk of thermal runaway by providing a more efficient energy transmission path and improved welding firmness, while minimizing weight and energy loss.
Implementation Method 1
the tab is connected directly to the pole by laser welding
Implementation Method 2
performing ultrasonic pre-welding for a tab of a core according to a first solder printing area to form the ultrasonic pre-welded tab
Data Source
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AI summary
The present disclosure provides a square battery and a welding method. The square battery includes: a cover plate provided with a pole; and a core provided with a tab, where the tab is directly connected to the pole by laser welding, so that construction of an energy transmission path of the battery is realized, and a charging and discharging function of the core is realized. Additionally, since the tab of the core of the square battery is directly connected to the cover plate of the square battery, an auxiliary welding sheet and a connection sheet are removed, thereby improving the internal space utilization rate and the mass specific energy of the square battery.