Battery Cap Assembly Mesh Venting for Active Material Containment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary batteries face issues with the discharge of heated active material during gas release, ignition, or explosion, which can lead to chain combustion and damage to surrounding batteries or devices.
Innovation Solution
A cap assembly with a safety vent and a screen member featuring stacked unit screens with different mesh forms and dome shapes, along with a current interrupt member, to prevent the discharge of active material during pressure increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a safety vent is provided to discharge gas when pressure increases, then battery safety is improved, but heated active material can be discharged to the outside causing chain combustion
Solution Approach 1:
A screen member is introduced as an intermediary component between the safety vent and the external environment. This screen member allows gas to pass through while blocking heated active material particles, thus mediating between the need for pressure relief and the need to prevent harmful material discharge that could cause chain combustion.
Solution Approach 2:
The screen member utilizes a porous structure with specific mesh sizes that permit gas molecules to pass through while physically blocking larger active material particles. This porous filtration approach enables selective passage based on particle size, allowing safe pressure relief without discharging harmful heated material.
2Object-generated harmful factors
If a screen member is added to block active material discharge, then chain combustion is prevented, but device complexity increases
Solution Approach 1:
The screen member is designed to serve multiple functions simultaneously: it acts as a filtration barrier to block active material, provides structural support within the cap assembly, and maintains the integrity of the safety vent system. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
3Ease of manufacture
If the cap assembly structure is simplified, then manufacturing ease is improved, but safety performance during ignition or explosion is reduced
Solution Approach 1:
The cap assembly is segmented into distinct functional components: the top cap, the safety vent, and the screen member. This segmentation allows each component to be optimized for its specific function while maintaining overall manufacturing efficiency. The screen member as a separate component can be mass-produced using standard mesh fabrication techniques and then integrated into the cap assembly.
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
The cap assembly effectively blocks or reduces the discharge of high-temperature active material, preventing chain ignitions and explosions in battery modules or packs.
Implementation Method 1
when ignition or the like occurs at the electrode assembly 30, the pressure inside the battery can 20 increases
Implementation Method 2
the pressure increase deforms the safety vent 12 so that the gas inside the battery can 20 is discharged to the outside
Implementation Method 3
it is possible to block or reduce that the active material is discharged to the outside of the battery can 200
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a cap assembly having an improved structure to block or reduce the discharge of heated active material in a situation such as gas release. The cap assembly is coupled to an open end of a battery can, and includes a top cap disposed on an uppermost portion of the cap assembly in a protrusive form to form a positive electrode terminal; a safety vent disposed below the top cap to deform a shape when an internal pressure of the battery can increases; a gasket configured to surround edges of the top cap and the safety vent; and a screen member interposed between the top cap and the safety vent and having an edge surrounded by the gasket, the screen member being at least partially configured in a mesh form.