Battery Cell Vent Assembly for Smooth Venting and Chain Ignition Prevention
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Solution Overview
Problem
Existing battery cells are prone to chain ignition and do not ensure smooth venting performance during thermal runaway events.
Innovation Solution
A battery cell design featuring a vent member with a blocking member and a guide member that includes a guide body with increasing thickness from one end to another, ensuring controlled venting and preventing chain ignition by guiding the blocking member to open when internal pressure increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vent hole is provided in the cell case to enable pressure release, then venting performance is improved, but the risk of chain ignition between adjacent battery cells increases
Solution Approach 1:
The vent hole is segmented into multiple functional zones: a vent member for pressure release, a blocking member to prevent flame propagation, and a guide member to control blocking member movement. This segmentation allows the vent hole to simultaneously provide venting performance and prevent chain ignition by separating the venting function from the blocking function.
Solution Approach 2:
The blocking member acts as an intermediary element installed in the vent hole to prevent direct flame and gas propagation between adjacent battery cells. It is positioned to block the vent hole during normal operation and only opens when the vent member is activated, serving as a mediator between the internal pressure release need and the external flame propagation prevention need.
2Object-affected harmful factors
If a blocking member is installed in the vent hole to prevent chain ignition, then chain ignition prevention is improved, but venting performance deteriorates due to blocked gas discharge path
Solution Approach 1:
The blocking member is designed to be dynamic rather than static, capable of moving between a blocked position (preventing chain ignition) and an opened position (allowing venting). The guide member enables this dynamic movement by guiding the blocking member to open when the vent member is activated by internal pressure, thus resolving the contradiction between blocking and venting functions.
Solution Approach 2:
The blocking member is designed to automatically open when the vent member is activated by internal pressure increase, without requiring external intervention. The guide member ensures the blocking member moves smoothly to the opened position, allowing the system to self-manage the transition from blocked to vented state based on internal conditions.
3Reliability
If the vent member is designed to open easily for smooth venting, then venting performance is improved, but control over the opening timing and manner is reduced
Solution Approach 1:
The vent member and blocking member form a feedback-controlled system where internal pressure increase triggers the vent member to open, which in turn triggers the blocking member to open through the guide member. This feedback mechanism ensures that the blocking member opens at the appropriate timing (when internal pressure is high) and in a controlled manner (guided by the guide member), resolving the contradiction between easy opening and controlled opening.
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 design effectively prevents chain ignition and ensures smooth venting of gases, reducing the risk of multiple cells igniting due to thermal events.
Implementation Method 1
a vent member sealing the vent hole and to be opened if an internal pressure of the cell case increases
Data Source
AI summary
The present disclosure provides a battery cell including an electrode assembly, a cell case accommodating the electrode assembly and having a vent hole, a vent member sealing the vent hole and to be opened if (e.g., when) an internal pressure of the cell case increases, a blocking member installed in the vent hole and covering the vent member, and a guide member installed in the vent hole and to guide the blocking member in opening if (e.g., when) the vent member is opened.