Cylindrical Cell Housing Edge for Weld-Safe Seal Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium-ion energy storage cells face challenges in achieving high energy density and efficient integration into cell arrays, particularly due to difficulties in electrical connection methods that can damage seals during welding, especially in cylindrical round cells with radially inwardly bent housing cups.
Innovation Solution
The design includes a cylindrical energy storage cell with a radially inwardly bent opening edge of the housing cup having a greater wall thickness than the central section, allowing for safe welding of conductor rails without damaging the seal, and an annular seal that electrically insulates the housing cup and lid assembly, ensuring airtight and liquid-tight conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If welding is performed on the housing cup to connect conductor rails, then electrical connection is achieved, but the seal is damaged
Solution Approach 1:
The housing cup is segmented into two distinct wall thickness regions: a first wall thickness in the sealing area and a second, greater wall thickness in the welding area. This segmentation allows the seal to be protected from welding heat while providing a robust welding surface where needed.
Solution Approach 2:
The housing cup exhibits local quality variation through different wall thicknesses in different regions. The welding area has increased wall thickness to withstand welding thermal stress, while the sealing area maintains original wall thickness to preserve seal integrity. This localized property differentiation resolves the contradiction between welding capability and seal protection.
2Strength
If the housing cup wall thickness is increased to withstand welding, then welding durability is improved, but the seal area requires thinner walls to accommodate the seal
Solution Approach 1:
The housing cup wall is divided into separate thickness zones: a thicker welding zone for durability and a thinner sealing zone for seal accommodation. This spatial segmentation resolves the conflicting requirements of strength and seal compatibility.
Solution Approach 2:
Different wall thickness properties are assigned to different functional areas of the housing cup. The welding area has increased thickness for mechanical strength, while the seal area has reduced thickness for seal integration, achieving both requirements simultaneously.
3Ease of operation
If the opening edge is bent radially inwards to positively fix the lid assembly, then mechanical fixation is improved, but the wall thickness must be increased to withstand welding
Solution Approach 1:
The housing cup exhibits local quality variation with increased wall thickness specifically at the radially inwardly bent opening edge where welding is performed, while other areas maintain standard thickness. This localized thickening accommodates both the mechanical fixation function and the welding durability requirement.
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 the energy storage cell's ability to withstand high currents and heat dissipation, while maintaining seal integrity, enabling higher energy density and improved safety for integration into cell arrays.
Implementation Method 1
an annular seal which encloses a circular edge of the lid assembly and electrically insulates the housing cup and the lid assembly from each other
Implementation Method 2
The radially inwardly bent opening edge is formed from a housing cup wall and has a greater wall thickness than the housing cup in the central section
Implementation Method 3
Electrochemical energy storage elements can convert stored chemical energy into electrical energy through virtue of a redox-reaction
Implementation Method 4
They are based on the use of lithium, which can migrate back and forth between the electrodes of the cell in the form of ions
Data Source
AI summary
An energy storage cell includes an electrode-separator assembly winding with a first terminal end face, a second terminal end face, and a winding shell located therebetween. The energy storage cell further includes an airtight and liquid-tight housing that includes a metallic housing cup with a terminal circular opening, a lid assembly with a circular edge, and an annular seal that encloses the circular edge and electrically insulates the housing cup and the lid assembly from one another. The metallic housing cup includes a central section and a closure section. In the closure section, the annular seal is in press contact with the lid assembly and the metallic housing cup has an opening edge that is bent radially inwards over the circular edge of the lid assembly. A wall thickness of the radially inwardly bent opening edge is greater than a wall thickness of the central section.