Battery Case Venting Layout to Prevent Unintended Fracture
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Solution Overview
Problem
Conventional batteries face issues with unintended fractures at high temperatures due to inadequate gas discharge mechanisms, compromising reliability.
Innovation Solution
The battery design incorporates a gas-discharge valve at a specific location on the case surface, with eccentrically located joining portions for the electrode assembly and current collector, ensuring controlled gas release and minimizing unintended fractures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gas-discharge valve is provided on the case, then gas discharge function is improved, but unintended fracture occurs at high temperature
Solution Approach 1:
The case is designed with non-uniform thickness where the first plate-shaped portion (at the gas discharge location) has a thickness larger than three times that of the second plate-shaped portion. This creates localized structural differences that direct fracture to occur only at the gas-discharge valve location when internal pressure increases, preventing unintended fracture at other locations while maintaining reliable gas discharge function.
Solution Approach 2:
The case structure is pre-designed with differentiated thickness regions before any thermal or pressure events occur. The thicker first plate-shaped portion is intentionally positioned to withstand higher stresses and prevent fracture, while the thinner second plate-shaped portion allows controlled fracture at the gas-discharge valve location, thereby preemptively preventing harmful unintended fractures.
2Ease of manufacture
If joining portions are located at the center, then manufacturing is simplified, but temperature distribution becomes uneven causing unintended fracture
Solution Approach 1:
The joining portions are positioned asymmetrically on the second surface of the case rather than at the center. This asymmetric arrangement creates a deliberate temperature distribution pattern where the region near the joining portions has different thermal characteristics, preventing uniform temperature rise and avoiding unintended fracture while maintaining manufacturability through controlled asymmetric design.
3Ease of manufacture
If the case thickness is uniform, then manufacturing is easier, but fracture occurs at unintended locations
Solution Approach 1:
The case is designed with non-uniform thickness where the first plate-shaped portion (at the gas discharge location) has a thickness larger than three times that of the second plate-shaped portion. This creates localized structural differences that direct fracture to occur only at the gas-discharge valve location when internal pressure increases, preventing unintended fracture at other locations while maintaining reliable gas discharge function.
Solution Approach 2:
The case is divided into distinct plate-shaped portions with different thickness characteristics. The first plate-shaped portion and second plate-shaped portion are segmented with clearly defined thickness differences, allowing each region to serve its specific function: the thicker first portion prevents unintended fracture while the thinner second portion accommodates the gas-discharge valve.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
In a battery (1), a case (100) has an outer surface and a gas-discharge valve (150), the outer surface including a first surface (120, 130) and a second surface (112A), the first surface (120, 130) extending in a direction of a plane including a first direction, the second surface (112A) being connected to one end portion of the first surface (120, 130) in the first direction, the second surface (112A) being substantially orthogonal to the first surface (120, 130), the gas-discharge valve (150) being provided at the second surface (112A). The electrode assembly (200) and a current collector (400) are joined at a first joining portion (411, 421), the current collector (400) and an electrode terminal (300) are joined at a second joining portion (431, 441), and at least one of the first joining portion (411, 421) and the second joining portion (431, 441) is eccentrically located on the second surface (112A) side in the first direction.