Cap Assembly Venting for Secondary Battery Activation Gas Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cylindrical secondary batteries face challenges in discharging gas generated during the activation process, which can affect initial capacity, SEI formation, and safety evaluations due to their airtight design.
Innovation Solution
A secondary battery design with a cap assembly featuring a safety vent exposed to the outside and a discharge hole, where the block is filled in the discharge hole by ball welding, allowing for complete gas discharge during pre-activation or activation processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery is designed to be airtight, then safety and sealing are improved, but gas discharge capability deteriorates
Solution Approach 1:
A discharge hole is formed in the cap assembly before battery assembly, and a block is pre-filled in the discharge hole. This preliminary preparation allows gas to be discharged during activation without requiring additional components or complex mechanisms, thus maintaining safety while enabling gas discharge.
Solution Approach 2:
The block filled in the discharge hole acts as an intermediary element. It is positioned to allow gas to pass through during activation but can be removed or melted later to seal the discharge hole, thus mediating between the need for gas discharge and the need for airtight sealing.
2Object-generated harmful factors
If a discharge hole is formed in the cap assembly, then gas discharge capability is improved, but sealing performance deteriorates
Solution Approach 1:
The block serves as a temporary intermediary that maintains the discharge hole open during activation but can be removed or melted to seal the hole afterward, thus achieving both gas discharge capability and sealing performance at different stages.
Solution Approach 2:
The discharge hole is designed to be dynamic rather than static. The block can be removed or melted based on the activation state, allowing the hole to transition from open (for gas discharge) to closed (for sealing), thus adapting to different operational requirements.
3Reliability
If the block is filled in the discharge hole by ball welding, then sealing reliability is improved, but manufacturing complexity increases
Solution Approach 1:
Ball welding replaces traditional mechanical sealing methods (such as threads, clips, or adhesives) with a thermal fusion process. This substitution achieves more reliable sealing while simplifying the overall manufacturing process by eliminating the need for additional sealing components or complex assembly steps.
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 enables effective gas discharge, preventing internal pressure buildup and electrode assembly expansion, while allowing for easy sealing post-discharge, thus enhancing battery performance and safety.
Implementation Method 1
the block is filled in the discharge hole by ball welding
Data Source
AI summary
A secondary battery includes an electrode assembly; a battery case in which the electrode assembly is housed, the battery case having an opened upper part; and a cap assembly coupled to the opened upper part of the battery case, wherein the cap assembly comprises a safety vent exposed to an outside. The safety vent includes a discharge hole, and a block is filled into the discharge hole.