Battery Safety Vent Structure for Stable Venting Pressure
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Solution Overview
Problem
Existing secondary batteries face interference issues with the top cap during venting pressure measurement, leading to delayed venting and potential safety hazards due to improper venting pressure distribution.
Innovation Solution
The secondary battery design incorporates a safety vent with a rupture notch portion and a bending notch portion on its bottom surface, which are recessed and positioned to prevent interference with the top cap, ensuring stable venting at preset pressures by allowing the bending notch to absorb pressure and maintain a secure distance from the top cap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a safety vent with a simple rupture portion is used, then the structure is simple and easy to manufacture, but the top cap interferes with the safety vent during venting pressure measurement causing delayed venting
Solution Approach 1:
The safety vent is divided into multiple functional portions: a rupture portion for pressure relief, a rupture notch portion that defines the boundary, and a bending notch portion spaced apart from the rupture notch. This segmentation allows each portion to perform its specific function independently, preventing interference with the top cap while maintaining structural simplicity.
Solution Approach 2:
The bending notch portion is positioned in a different spatial location (spaced apart from the rupture notch toward the center of the rupture portion) to create dimensional separation. This spatial arrangement ensures that when the rupture portion ruptures, the bending notch does not interfere with the top cap, solving the interference problem through dimensional positioning.
2Device complexity
If the bending notch portion is positioned closer to the rupture notch, then the structure is simpler, but interference with the top cap occurs during venting
Solution Approach 1:
Different portions of the safety vent are given different functional qualities: the rupture notch portion is positioned to allow rupture at the predetermined pressure, while the bending notch portion is positioned at a specific distance toward the center to provide structural support and prevent top cap interference. Each portion has its optimized local position for its specific function.
3Quantity of substance
If the rupture portion is made larger, then more gas can be vented, but the bending notch portion becomes more difficult to position to avoid top cap interference
Solution Approach 1:
The bending notch portion is pre-positioned at a predetermined distance from the rupture notch toward the center of the rupture portion. This preliminary positioning ensures that when the rupture occurs and gas venting begins, the bending notch is already in the correct position to prevent top cap interference, allowing the rupture portion to be sized for maximum gas venting capacity without positioning conflicts.
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
This design enhances venting pressure distribution by preventing top cap interference, ensuring the rupture notch portion vents gas safely at the predetermined pressure, thereby improving safety and preventing explosions or ignition.
Implementation Method 1
a bending notch portion which is disposed at a position spaced apart from the rupture notch portion toward a center of the rupture portion on a bottom surface of the rupture portion facing the inside of the can member, wherein the bending notch portion is bent when the internal pressure within the can member increases
Data Source
AI summary
The present invention relates to a secondary battery capable of improving venting pressure distribution. A secondary battery including an electrode assembly, a can member that accommodates the electrode assembly, and a top cap assembly that covers an opening of the can member. The top cap assembly includes a top cap positioned at the uppermost portion and a safety vent part positioned below the top cap. The safety vent part includes a rupture portion that is ruptured when an internal pressure within the can member equals or exceeds a predetermined pressure, a rupture notch portion that defines a boundary of the rupture portion, and a bending notch portion which is spaced apart from the rupture notch portion toward a center of the rupture portion on a bottom surface of the rupture portion, and the bending notch portion is bent when the internal pressure within the can member increases.