Battery Electrode Lead Groove for Pressure-Triggered Current Blocking
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Solution Overview
Problem
Secondary batteries face safety risks due to swelling and potential ignition or explosion from internal pressure increases during overcharging or short circuits, necessitating a solution to block current flow and enhance safety.
Innovation Solution
The electrode lead in the secondary battery features a separation groove that breaks under high pressure, ensuring rapid disconnection of the current path by forming a groove in specific regions not covered by the lead film, allowing the lead to rupture and block electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode lead is made continuous and strong to ensure reliable current conduction, then the electrical connection reliability is improved, but the ability to rapidly break and block current under high pressure deteriorates
Solution Approach 1:
The separation groove is pre-formed in the electrode lead at a specific position before the battery operates. This preliminary structural preparation ensures that when high pressure occurs during overcharging or short circuit, the electrode lead can rapidly break at the groove to block current flow, converting the continuous strong connection into a controlled breakable structure that provides both reliability under normal conditions and safety under abnormal conditions.
2Ease of manufacture
If the electrode lead structure is made simple without separation groove, then the manufacturing complexity is reduced, but the safety response to internal pressure increase deteriorates
Solution Approach 1:
The electrode lead is segmented by forming a separation groove that divides it into two regions. This segmentation creates a predetermined weak point that allows the lead to break easily under high pressure, providing a simple yet effective safety mechanism. The groove can be formed through simple processes like laser drilling or mechanical punching, maintaining ease of manufacture while dramatically improving the safety response to internal pressure increase.
3Speed
If the separation groove is formed deep in the electrode lead to ensure rapid breaking, then the current blocking speed is improved, but the structural strength of the electrode lead deteriorates
Solution Approach 1:
The separation groove creates a localized region of reduced strength at a specific position in the electrode lead, while the rest of the lead maintains its full structural strength. This local quality change ensures that the groove can break rapidly under high pressure to block current, while the overall electrode lead remains strong enough for normal operation and assembly. The groove depth is optimized to provide sufficient breaking capability without compromising the overall structural integrity.
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 separation groove effectively prevents further current flow, enhancing safety by forcibly releasing the electrical connection and preventing extreme situations such as fire or explosion.
Implementation Method 1
When the temperature inside the battery rises due to overcharging exceeding the permitted current or voltage, internal short circuit, or the like in such a secondary battery, the internal pressure increases due to vaporization of the electrolyte, and as a result, so-called swelling phenomenon in which the battery swells occurs. When the swelling phenomenon occurs, a short circuit may occur locally as the battery is deformed, and the battery may be ignited or explode in extreme situation.
Data Source
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AI summary
The present disclosure relates to a secondary battery that may secure safety by realizing a current blocking function according to an increase in internal pressure. A secondary battery according to an embodiment of the present disclosure includes an electrode assembly to which an electrode lead is attached; a case accommodating the electrode assembly therein so that a portion of the electrode lead is exposed to an outside of the case; a sealing portion formed in the case to seal the electrode assembly; and a lead film covering a portion of an outer surface of the electrode lead and interposed between the electrode lead and the sealing portion, wherein the electrode lead includes a first region not corresponding to the lead film and exposed to the outside of the case, a second region corresponding to the lead film, and a third region not corresponding to the lead film and not exposed to the outside of the case, wherein a separation groove may be located in the third region.