Battery Venting Structure for Controlled Fracture Under Pressure
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Solution Overview
Problem
Conventional batteries face issues with unintended fracture locations when the temperature of the electrode assembly increases, compromising reliability.
Innovation Solution
The battery design incorporates a gas-discharge valve at a specific surface and eccentrically located joining portions on the case, ensuring controlled gas release and minimizing unintended fractures by concentrating stress on thicker sealing plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gas-discharge valve is provided at the upper surface (sealing plate) of the battery, then gas discharge function is achieved, but unintended fracture may occur at other locations when temperature increases
Solution Approach 1:
The joining portions are positioned asymmetrically relative to the case structure, with specific offset distances from the case ends. This asymmetric positioning creates intentional stress concentration zones at the joining portions rather than at the case ends, preventing unintended fracture at locations other than the gas-discharge valve.
Solution Approach 2:
The case is designed with varying thickness characteristics - thicker at the joining portions and thinner at the gas-discharge valve location. This local quality differentiation ensures that stress concentrates at the thicker joining portions during temperature increase, protecting the case from unintended fracture while allowing controlled fracture at the valve.
2Stability of the object's composition
If joining portions are located at the center of the case, then structural symmetry is achieved, but stress distribution becomes uniform causing unintended fracture at case ends
Solution Approach 1:
The joining portions are deliberately positioned asymmetrically with respect to the case ends, with offset distances that create non-uniform stress distribution. This breaks the symmetry that would otherwise cause stress to concentrate at the case ends, redirecting stress concentration to the joining portions instead.
Solution Approach 2:
The case thickness is varied locally to be thicker at the joining portions compared to other areas. This local quality change ensures that even with asymmetric positioning, the joining portions can withstand higher stress concentrations without fracturing, while the thinner case ends are protected from stress concentration.
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 battery reliability by securely fracturing the gas-discharge valve while preventing unintended fractures, effectively managing internal pressure and maintaining structural integrity.
Implementation Method 1
a gas-discharge valve, the outer surface including a first surface and a second surface, the first surface extending in a direction of a plane including a first direction, the second surface being connected to one end portion of the first surface in the first direction, the second surface being substantially orthogonal to the first surface, the gas-discharge valve being provided at the second surface
Implementation Method 2
at least one of the first joining portion and the second joining portion is eccentrically located on the second surface side in the first direction
Data Source
AI summary
In a battery, a case has an outer surface and a gas-discharge valve, the outer surface including a first surface and a second surface, the first surface extending in a direction of a plane including a first direction, the second surface being connected to one end portion of the first surface in the first direction, the second surface being substantially orthogonal to the first surface, the gas-discharge valve being provided at the second surface. The electrode assembly and a current collector are joined at a first joining portion, the current collector and an electrode terminal are joined at a second joining portion, and at least one of the first joining portion and the second joining portion is eccentrically located on the second surface side in the first direction.