Pressure-Triggered Battery Venting and Internal Short-Circuit Structure
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Solution Overview
Problem
Secondary batteries, particularly lithium-ion batteries, are prone to safety issues such as ignition or explosion due to increased internal pressure from excessive heat, overcharging, foreign substance intrusion, or damage, which current safety measures have not adequately addressed.
Innovation Solution
A secondary battery design incorporating a cap plate with a first exhaust hole, an insulating member with a larger second exhaust hole, a current collecting member, a guide member, and a short-circuit member that moves to contact the cap plate under pressure, allowing for a short-circuit and gas release without additional components, enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional safety measures are used, then basic protection is provided, but the battery is still prone to ignition or explosion under excessive internal pressure
Solution Approach 1:
The short-circuit member is pre-positioned within the guide member and the exhaust hole is pre-configured with a larger diameter in the insulating member. When abnormal pressure occurs, these pre-arranged structures immediately activate to short-circuit the battery terminals and vent gas, preventing ignition or explosion before they can occur.
Solution Approach 2:
The harmful excessive internal pressure that could cause ignition or explosion is converted into a beneficial force that drives the short-circuit member upward. The pressure automatically triggers the safety mechanism by pushing the short-circuit member to contact the cap plate, creating a short-circuit and opening the exhaust hole to release the harmful pressure.
2Reliability
If additional safety components are added, then protection against internal pressure is improved, but the device complexity increases
Solution Approach 1:
The short-circuit member and exhaust hole function are merged into a single integrated safety mechanism. The short-circuit member simultaneously performs two functions: creating a short-circuit between terminals and opening the exhaust hole for gas release. The insulating member's larger diameter exhaust hole is integrated with the guide member structure, eliminating the need for separate safety components.
Solution Approach 2:
The short-circuit member serves multiple functions: it acts as a movable component that responds to pressure, creates an electrical short-circuit to stop current flow, and simultaneously opens the exhaust hole for gas venting. The exhaust hole structure in the insulating member serves both as an insulator and as the opening mechanism for pressure relief.
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 provides enhanced stability by automatically short-circuiting and releasing gas under abnormal conditions, preventing further pressure buildup and potential explosions, while simplifying the configuration by eliminating the need for extra components.
Implementation Method 1
the short-circuit member being configured to move upward to come into contact with the cap plate in response to pressure generated within the case
Implementation Method 2
an elastic member disposed in the guide member and configured to apply pressure to the short-circuit member from above
Data Source
AI summary
A secondary battery includes a case that accommodates an electrode assembly; a cap plate sealing an opening of the case and including a first exhaust hole, and having a first polarity; an insulating member disposed on a lower portion of the cap plate and including a second exhaust hole with a larger diameter than the first exhaust hole, and positioned to correspond to the first exhaust hole; a current collecting member disposed on a lower portion of the insulating member and electrically connected to the electrode assembly, and having a second polarity different from the first polarity; a guide member disposed in a lower portion of the second exhaust hole and electrically connected to the current collecting member; and a short-circuit member including a conductive material and disposed in the guide member to move to come into contact with the cap plate in response to pressure generated within the case.