Cylindrical Battery Cell Cap-Collector Welding Without Internal Jig
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Solution Overview
Problem
The manufacturing process of cylindrical battery cells is inefficient due to the need for separate welding of the current collector plate to the cap or sidewall member and the cap to the sidewall member, which reduces energy density, increases production costs, and wastes internal volume by requiring a separate welding jig or mask.
Innovation Solution
A welding structure where the current collector plate, cap, and can function as both a mask and jig, allowing for a single welding process that integrates the connection of the current collector plate to the can and the cap to the sidewall member, enhancing energy density, production efficiency, and weld stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate welding jig or mask is used to maintain the current collector plate in close contact with the cap or sidewall member during welding, then welding stability is improved, but the internal volume of the can is wasted and energy density is reduced
Solution Approach 1:
The cap is designed to serve multiple functions: it seals the can opening and simultaneously acts as a welding jig to maintain the current collector plate in close contact with the sidewall member during welding. This eliminates the need for a separate welding jig or mask, preventing waste of internal volume while ensuring welding stability.
2Reliability
If separate welding processes are used for connecting the current collector plate to the cap/sidewall member and for connecting the cap to the sidewall member, then welding quality is ensured, but production time increases and productivity decreases
Solution Approach 1:
The welding process is integrated so that the current collector plate, sidewall member, and cap are welded together in a single operation. The cap serves as a welding jig that maintains proper positioning of the current collector plate against the sidewall member during welding, allowing both the plate-to-sidewall and cap-to-sidewall connections to be established simultaneously, thereby improving productivity while ensuring welding quality.
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 approach increases energy density by utilizing the internal volume of the can without waste, reduces production costs, and improves the durability and effectiveness of welds, thereby enhancing the overall efficiency and stability of the battery cell assembly process.
Implementation Method 1
The radially inner surface of the sidewall, a radially outer surface of the cap, and the peripheral portion of the current collector plate are welded to one another
Data Source
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AI summary
A battery cell includes: a can with an electrode assembly received therein, in which the can has a bottom member, a sidewall member connected to the bottom member and extending upwardly therefrom in an axial direction, and a cap covering an open end of the can at an axial end opposite to the bottom member. A current collector plate is connected to an electrode tab of the electrode assembly proximate the open end. The current collector plate includes: a central portion electrically connected to the electrode tab and a peripheral portion in electrical contact with a radially inner surface of the sidewall of the can. The peripheral portion is also in contact with an underside of the cap. The radially inner surface of the sidewall member, a radially outer surface of the cap, and the peripheral portion of the current collector plate are all welded to one another.