Cylindrical Battery Tab Fixing via Insulative Vent Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cylindrical secondary batteries face challenges in increasing capacity while maintaining a stable structure, as the overall height of the cap assembly is reduced, making it difficult to specify the point of short circuit occurrence and hindered gas discharge due to insufficient venting member deformation space.
Innovation Solution
A cylindrical secondary battery design that omits the current interrupt device and gasket from the cap assembly, with a positive electrode tab directly coupled to a concave venting member and an insulative fixing member to securely attach the tab, allowing for easy separation during increased internal pressure, thus enhancing gas discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the overall height of the cap assembly is reduced to increase battery capacity, then the battery capacity increases, but the venting member deformation space becomes insufficient making it difficult to specify short circuit occurrence point and hindering gas discharge
Solution Approach 1:
The invention divides the cap assembly into distinct functional segments: the venting member for gas discharge, the current interrupt device for safety, and the insulating plate for electrical isolation. This segmentation allows each component to perform its function independently without interfering with others, enabling the venting member to deform adequately even in a compact cap assembly with reduced overall height.
2Quantity of substance
If the cap assembly height is reduced to increase battery capacity, then the battery capacity increases, but it becomes difficult to specify the point in time when short circuit occurs due to insufficient venting member deformation
Solution Approach 1:
The insulating plate serves as an intermediary component between the venting member and the current interrupt device. It provides a stable reference surface that allows the venting member to deform visibly and measurably when internal pressure increases, enabling precise detection of the short circuit occurrence point even in a compact design with reduced cap assembly height.
3Device complexity
If the current interrupt device and gasket are omitted from the cap assembly to simplify structure and reduce height, then the cap assembly structure is simplified and height is reduced, but the positive electrode tab requires secure attachment to ensure stable short circuit occurrence
Solution Approach 1:
The invention merges the functions of the positive electrode tab attachment, insulation, and venting into a single integrated insulating plate structure. This consolidation simplifies the cap assembly by eliminating separate gaskets and current interrupt devices, while the insulating plate itself provides secure attachment for the positive electrode tab through its structured design, ensuring reliable short circuit occurrence.
4Device complexity
If the positive electrode tab is directly coupled to the venting member with a fixing member to simplify structure, then the structure is simplified, but the fixing member must securely hold the tab while allowing easy separation during increased internal pressure
Solution Approach 1:
The fixing member is designed with dynamic characteristics that allow it to maintain a secure hold on the positive electrode tab under normal conditions, but to easily separate when internal pressure increases. This is achieved through a structure that can deform or release under pressure, enabling the system to adapt from a fixed state to a separated state based on operating conditions.
Data Source
AI summary
A cylindrical secondary battery includes a cylindrical can receiving an electrode assembly therein and having a cap assembly mounted to an open upper end thereof. The electrode assembly comprises a positive electrode sheet and a negative electrode sheet wound with a separator interposed therebetween. The cap assembly includes a top cap located at an upper portion thereof and protruding upwardly therefrom, a concave venting member located at the lower portion of the top cap and wrapping around an outer circumferential edge of the top cap, and a gasket configured to hermetically seal the cylindrical can. A positive electrode tab of the electrode assembly is directly coupled to a lower surface of the venting member, and the cylindrical secondary battery further comprises an insulative fixing member configured to fix the position of the positive electrode tab.