Welded Cap Plate Structure for Higher-Capacity Secondary Batteries
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Solution Overview
Problem
Conventional secondary batteries have limitations in capacity and cost due to the need for a beading part and crimping part that occupy space within the battery, which can be optimized for increased capacity and reduced production time and cost.
Innovation Solution
A secondary battery design that eliminates the beading part and crimping part by welding the cap plate directly to the electrode assembly, allowing for a more compact electrode assembly and reduced manufacturing time and cost, featuring a concavely recessed welding portion, radial extension, and a safety vent notch on the cap plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a beading part and crimping part are used to fix the cap assembly, then the structural integrity is ensured, but the battery capacity is reduced due to occupied space
Solution Approach 1:
The patent removes the beading part and crimping part from the battery structure, extracting these components that were occupying valuable internal space. The cap assembly is instead directly welded to the can body, eliminating the need for separate fixing mechanisms and thereby increasing the space available for the electrode assembly and electrolyte, which directly improves battery capacity.
2Reliability
If a beading part and crimping part are used to fix the cap assembly, then the structural integrity is ensured, but the manufacturing time and cost are increased
Solution Approach 1:
The patent merges the cap assembly fixation process into a single welding operation that directly joins the cap assembly to the can body. This eliminates the sequential operations of forming a beading part and then performing crimping, reducing the number of manufacturing steps, decreasing production time, and lowering manufacturing costs while maintaining structural integrity through the weld joint.
3Ease of manufacture
If the cap plate is welded directly to the electrode assembly, then the manufacturing process is simplified, but the welding precision requirement is increased
Solution Approach 1:
The patent applies local quality by providing a welding portion on the cap plate with specific geometric features (concave recess or protrusion) that localize the welding interaction to a precise area. This design feature guides the welding process, ensuring accurate alignment between the cap plate and electrode assembly, and reduces the tolerance requirements for the overall assembly while maintaining manufacturing simplicity.
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 battery capacity by utilizing the previously occupied space for the electrode assembly, reduces production time, and lowers costs by eliminating the need for the beading and crimping processes.
Implementation Method 1
a welding portion welded in contact with an upper end of the electrode assembly
Data Source
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AI summary
A secondary battery includes: an electrode assembly; a can having an open upper end and accommodating the electrode assembly; and a cap plate coupled to the upper end of the can and having a welding portion welded in contact with an upper end of the electrode assembly.