Battery Cell Venting Cover for Internal Gas Release and Flame Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face issues where flames or gas generated inside the case can flow into the exterior, and external flames or gas can flow into the interior, posing risks and instability.
Innovation Solution
A battery cell design featuring a venting cover with a venting sheet and support portion that opens under internal pressure to discharge internal flames or gas while preventing external gases from entering, using a venting line and cap structure to manage pressure differentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a vent is provided to connect the inside of the case and the outside of the case for communication therebetween, then gas generated inside the case can be released to the outside of the case when thermal runaway has occurred, but flames or gas flowing from the exterior of the case through the vent can also flow into the interior of the case
Solution Approach 1:
The venting cover is designed to dynamically open and close based on pressure differential. When internal pressure exceeds external pressure (thermal runaway), the venting cover opens to discharge internal gas. When external pressure exceeds internal pressure (external fire), the venting cover closes to prevent external gas infiltration. This dynamic response resolves the contradiction between allowing internal gas discharge and preventing external gas infiltration.
Solution Approach 2:
The venting cover acts as an intermediary element between the internal and external environments. It selectively mediates gas flow based on pressure conditions, allowing internal gas to pass through while blocking external gas. The support portion structure further mediates the mechanical force transmission to achieve selective opening/closing, resolving the contradiction by introducing a controlling intermediary mechanism.
2Object-generated harmful factors
If a venting cover is provided to be opened by pressure acting from the accommodating space to the outside of the case, then internal flames or gas can be discharged to the exterior, but external flames or gas can still flow into the interior when external pressure is higher
Solution Approach 1:
The support portion is pre-configured to provide preliminary anti-action against external pressure. When external pressure increases (external fire), the support portion's geometric structure resists deformation, maintaining the venting cover's closed state and preventing external flame/gas infiltration. This preliminary structural resistance ensures protection reliability while allowing internal discharge when needed.
Solution Approach 2:
The support portion features curved or rounded geometric structures that distribute external pressure more evenly, preventing localized deformation that could force the venting cover open. This curvature design enhances the structural integrity and reliability of preventing external flame/gas infiltration while maintaining the ability to open under internal pressure.
3Ease of operation
If the venting sheet is made flexible to open under pressure, then gas can be discharged, but the venting sheet may deform or fail under excessive external pressure
Solution Approach 1:
The venting sheet is designed as a flexible thin film that can open under internal pressure for gas discharge. The flexibility enables easy operation and gas flow. However, this flexibility creates vulnerability to external pressure deformation.
Solution Approach 2:
The support portion serves as an intermediary structural element between the flexible venting sheet and the rigid case. It provides mechanical reinforcement to the venting sheet, preventing excessive deformation under external pressure while maintaining the sheet's flexibility for opening under internal pressure. This intermediary support resolves the contradiction between flexibility and durability.
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
Effectively discharges internal flames or gas to the exterior while preventing external gases from entering, enhancing safety and stability of the battery cell and module.
Implementation Method 1
a venting cover disposed to cover the vent, and provided to be opened by pressure acting from the accommodating space to the outside of the case
Implementation Method 2
a venting cap having a support portion supporting the first surface of the venting sheet
Data Source
AI summary
A battery cell includes: a case accommodating an electrode assembly in an accommodating space; a cap plate coupled to at least one side of the case; a vent provided in the case or the cap plate; and a venting cover disposed to cover the vent, and provided to be opened by pressure acting from the accommodating space to the outside of the case, wherein the venting cover includes a venting sheet provided to be opened by a predetermined amount of pressure, and including a first surface facing the vent and a second surface opposite to the first surface; and a venting cap having a support portion supporting the first surface of the venting sheet.