Battery Can-Collector Welding Structure for Low-Heat Laser Joining
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Solution Overview
Problem
The existing manufacturing process of battery cells involves multiple labor-intensive welding processes, leading to reduced production efficiency and increased costs, and poses risks of assembly errors, heat damage to internal components, and laser penetration due to component tolerances.
Innovation Solution
A welding structure for a battery can, current collector plate, and cap that allows for easy assembly with accurate alignment and close contact, minimizing heat impact on internal components, and integrating welding processes to reduce assembly errors and laser penetration risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple individual welding processes are used to connect the current collector plate to the cap/side wall member and the cap to the side wall member, then reliable electrical connection and sealing are achieved, but production efficiency decreases and labor costs increase
Solution Approach 1:
The patent combines multiple separate welding processes into a single integrated welding operation. The current collector plate, cap, and side wall member are positioned to abut each other, allowing simultaneous welding of all connections in one process step, thereby eliminating sequential operations and improving productivity while maintaining reliable welds.
Solution Approach 2:
The patent employs preliminary positioning structures including abutting surfaces and positioning protrusions that pre-align the current collector plate, cap, and side wall member before welding. This preliminary action ensures accurate alignment and stable positioning, enabling the subsequent single-step welding process to achieve reliable connections without requiring multiple adjustment and welding cycles.
2Ease of manufacture
If the side wall member, cap, and current collector plate are simply assembled without firm fixation, then assembly is easy, but assembly accuracy decreases and laser welding becomes unreliable due to gaps from tolerances
Solution Approach 1:
The patent divides the positioning function into separate modular elements: abutting surfaces for alignment, positioning protrusions for location, and clamping structures for fixation. This segmentation allows each component to perform its specific positioning function independently, achieving high assembly accuracy while maintaining ease of assembly through modular design.
Solution Approach 2:
The patent introduces intermediary positioning structures such as positioning protrusions and abutting surfaces that mediate between the components. These intermediaries ensure accurate relative positioning of the current collector plate, cap, and side wall member, eliminating gaps caused by tolerances while keeping the assembly process simple and straightforward.
3Speed
If laser welding is performed on simply assembled parts with gaps, then welding speed is high, but the laser may penetrate directly into the can and damage the electrode assembly
Solution Approach 1:
The patent performs preliminary positioning and firm fixation of the components before laser welding. The abutting surfaces and positioning structures ensure that the current collector plate, cap, and side wall member are tightly aligned with no gaps, preventing laser penetration into the can while maintaining high welding speed through the stability of the pre-positioned assembly.
Solution Approach 2:
The patent implements preliminary anti-action by using clamping and positioning structures to prevent the harmful effect of component movement and gap formation during welding. This preliminary constraint ensures that the laser energy is confined to the weld zone and cannot penetrate into the can, protecting the electrode assembly from damage while maintaining high welding speed.
4Strength
If the can, cap, and current collector plate are heated to high temperature for welding, then welding is achieved, but heat affects the electrode assembly and causes deterioration
Solution Approach 1:
The patent segments the heating zone by concentrating the laser energy precisely at the weld interface between the current collector plate, cap, and side wall member. This localized heating achieves the necessary weld strength while minimizing heat exposure to the electrode assembly, preventing thermal deterioration of the battery components.
Solution Approach 2:
The patent uses the abutting structure and positioning protrusions as intermediaries that establish precise geometric relationships between components. This precise positioning ensures that laser energy is focused exactly where needed for welding, creating a controlled heat zone that achieves strong welds while protecting the electrode assembly from excessive heat through accurate spatial separation.
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
Enhances production efficiency, increases energy density, and lowers production costs by ensuring stable and durable welds while preventing laser penetration and heat damage to the electrode assembly.
Implementation Method 1
this welding may be performed by a laser
Implementation Method 2
the laser beam 100 is directed to weld the side wall member 11, the cap 16, and the current collector plate 32
Implementation Method 3
the can, the cap, and the current collector plate are made of metals with high thermal conductivity. For this reason, the heat generated to weld the can and the cap may affect the electrode assembly accommodated inside the can
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present disclosure provides a welding structure of a battery can, a current collector plate and a cap, a battery cell utilizing the same, and a manufacturing method thereof. The current collector plate of the battery cell includes a body portion connected to an electrode tab of the electrode assembly, a can connection portion that is disposed radially further outward than the body portion and is connected to at least one of the side wall member and the cap, and a bridge whose radial inner side is connected to the body portion and whose radial outer side is connected to the can connection portion, and which extends radially. The bridge includes a first bending portion bent so that an extension direction of the bridge portion extending radially outward is directed to an axial outer side, a second bending portion bent so that an extension direction of the bridge portion extending axially outward is directed to a radial outer side, and an offset bridge portion whose radial inner side is connected to the first bending portion and whose radial outer side is connected to the second bending portion. Accordingly, the impact of the welding heat of the can and the cap on the electrode assembly through the current collector plate may be minimized.