Battery Cover Vent Assembly for Temperature-Triggered Pressure Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries in battery modules face safety risks due to inadequate pressure release during thermal runaway, leading to potential explosions, as existing explosion-proof valves fail to manage pressure effectively.
Innovation Solution
A cover assembly for secondary batteries featuring a blocker with a temperature-responsive fastener that deforms to unblock an air hole, allowing gas discharge and reducing pressure, while a sealing member enhances sealing performance to prevent electrolyte leakage and external vapor ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an explosion-proof valve based on air pressure control is used, then pressure release function is provided, but during thermal runaway the valve fails to release pressure in a timely manner leading to explosion risk
Solution Approach 1:
The patent changes the triggering parameter from air pressure to temperature. The fastener is designed with a specific melting point (80-200°C) that is lower than the thermal runaway temperature, enabling it to deform and trigger the explosion-proof valve at appropriate temperatures during thermal runaway, ensuring timely pressure release.
Solution Approach 2:
The patent replaces the air pressure control mechanism with a temperature-responsive mechanical system. The fastener's phase change or deformation at specific temperature automatically triggers the mechanical movement of the blocker, eliminating the need for complex pressure sensing and control mechanisms.
2Reliability
If the air hole is blocked to prevent gas leakage during normal operation, then sealing performance is improved, but during thermal runaway pressure cannot be released
Solution Approach 1:
The patent makes the blocking state dynamic rather than static. The blocker is connected to the fastener, which changes state based on temperature. During normal operation, the fastener maintains the blocker in a sealed position. During thermal runaway, the fastener deforms and releases the blocker, enabling automatic adaptation to different operational conditions.
Solution Approach 2:
The system uses the temperature rise during thermal runaway as the triggering signal itself. The fastener's temperature-responsive deformation automatically initiates the pressure release mechanism without external intervention, making the system self-regulating and adaptive to emergency conditions.
3Speed
If a fastener with melting point between 80°C to 200°C is used, then timely response to thermal runaway is achieved, but the fastener deforms at relatively low temperature
Solution Approach 1:
The patent carefully selects and controls the melting point parameter of the fastener material to be between 80-200°C. This parameter range ensures the fastener deforms early enough during thermal runaway to allow timely pressure release, while remaining above normal operating temperatures to maintain sealing during regular use.
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 solution effectively prevents explosions by releasing pressure and heat, slows down thermal runaway, and improves safety and service life by ensuring secure blocking of the air hole without additional fastening objects, thus enhancing energy density and safety performance.
Implementation Method 1
the fastener is configured to deform in response to a temperature rise, so that the blocker stops blocking the air hole
Implementation Method 2
a sealing member disposed between the blocker and the cover plate, surrounding the air hole, and configured to seal a gap between the blocker and the cover plate
Data Source
AI summary
This application relates to a cover assembly of a secondary battery. The cover assembly includes a cover plate with an air hole; a blocker inserted into and blocking the air hole; a sealing member disposed between the blocker and the cover plate configured to seal a gap between the blocker and the cover plate; and a fastener disposed inside the air hole. The fastener is connected to the cover plate, the blocker is connected to the cover plate through the fastener. The fastener is configured to deform in response to a temperature rise, so that the blocker stops blocking the air hole. The blocker stops blocking the air hole as a temperature inside a housing rises, to discharge gas from the housing through the air hole. In this way, the secondary battery can be prevented from an explosion, while partial heat is taken away through gas discharge.