Cylindrical Battery Cell Connection Structure for Weld-Free Series Linking
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Solution Overview
Problem
Existing technologies require separate tools or additional processes like welding for electrical connection between cylindrical battery cells, leading to instability and increased weight, and lack flexibility in design due to standardized sizes.
Innovation Solution
A cylindrical battery cell design with an inwardly concave recessed portion in the battery case and a connection member featuring a coupling portion and pressure contact portion, allowing for screw-fastened series connection without additional members, using elastic members for stable contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate tool (wrench) is used to rotate the screw head for connecting battery cells, then the battery cells can be connected in series, but additional tools are required and the operation becomes more complex
Solution Approach 1:
The connection member is designed with a self-aligning structure where the protrusion automatically engages with the recess when the battery cells are brought together. The elastic member provides self-adjusting contact pressure, eliminating the need for external tools to tighten or secure the connection.
Solution Approach 2:
The connection member integrates both the electrical contact function and the mechanical fastening function into a single component. The protrusion structure combines the electrical contact point with the mechanical engagement feature, eliminating the need for separate fastening operations.
2Reliability
If welding is used for electrical connection between battery cells, then electrical connection is achieved, but additional processes and equipment are required
Solution Approach 1:
The patent replaces the welding process (thermal/chemical joining) with a mechanical insertion system. The protrusion is simply inserted into the recess, and the elastic member provides continuous contact pressure, achieving reliable electrical connection without welding equipment or processes.
Solution Approach 2:
The elastic member automatically maintains optimal contact pressure between the connection member and the battery terminal through its inherent elasticity, eliminating the need for external adjustment or securing processes that would be required with welding.
3Power
If additional members (battery pack case, electrical connection member) are added to increase capacity and voltage, then battery pack functionality is achieved, but weight increases
Solution Approach 1:
The connection member merges the electrical connection function with the mechanical support function. By integrating these functions into a single lightweight component rather than using separate heavy-duty connectors and mounting brackets, the overall weight increase is minimized while achieving the required power scaling.
4Manufacturing precision
If standardized sizes are used for cylindrical secondary batteries, then manufacturing consistency is maintained, but design freedom in devices is reduced
Solution Approach 1:
The connection member is designed as a modular, standardized component that can be applied to various battery cell configurations. The universal protrusion-recess interface allows the same connection design to work with different battery arrangements (series, parallel, combinations), providing design flexibility while maintaining manufacturing standardization.
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
Enables stable electrical connection between battery cells without separate tools or processes, maintaining connection integrity while minimizing length increase and design flexibility.
Implementation Method 1
an elastic member configured to apply an elastic force in a pressing direction toward the other cylindrical battery cell when the connection member is inserted into the recessed portion
Data Source
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AI summary
The present invention relates to a cylindrical battery cell including an electrode assembly having a structure in which a positive electrode sheet and a negative electrode sheet are wound in the state in which a separator is interposed between the positive electrode sheet and the negative electrode sheet, a battery case configured to receive the electrode assembly, and a cap assembly loaded on an upper end of the battery case, wherein a connection member for series connection between cylindrical battery cells is mounted to an upper part of the cap assembly, and an inwardly concave recessed portion is formed in a bottom of the battery case, whereby it is possible to achieve electrical connection between a plurality of cylindrical battery cells using a simple method.