Battery Case Scoring for Sealed Pressure Relief
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Solution Overview
Problem
Existing battery explosion-proof structures, such as pressure-relief through holes with bursting discs and scored cases, suffer from sealing issues, inconsistent score depths leading to potential liquid leakage or inadequate pressure relief.
Innovation Solution
A battery design featuring a case with a first and second shell, where an explosion-proof score is provided on either shell, allowing for gas exhausting and pressure relief without the need for a through hole, thereby improving sealing and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure-relief through hole with a bursting disc is provided in the case, then the battery can exhaust gas and relieve pressure, but a gap exists between the bursting disc and the pressure-relief through hole which affects the sealing of the battery
Solution Approach 1:
The invention removes the pressure-relief through hole and bursting disc assembly from the case structure. Instead, it scores the case directly to create an explosion-proof score that serves as the pressure relief mechanism, eliminating the sealing gap issue entirely while maintaining pressure relief functionality
Solution Approach 2:
The invention combines the pressure relief function and the case structure into a single integrated component. The explosion-proof score is formed directly in the case wall, merging the relief mechanism with the case itself, thereby eliminating separate components and potential sealing gaps
2Ease of manufacture
If the explosion-proof score is scored according to operators' experience, then the manufacturing process is simple, but the score depth is inconsistent which may cause liquid leakage or inadequate pressure relief
Solution Approach 1:
The invention specifies precise parameter ranges for the explosion-proof score depth (0.05-0.15 times the case wall thickness) and provides calculation formulas relating score depth to case dimensions and material properties. This transforms the subjective experience-based process into an objective parameter-controlled process, ensuring consistent and reliable results
Solution Approach 2:
The invention establishes a feedback mechanism where the score depth is determined by calculated parameters based on case wall thickness and material tensile strength. This creates a controlled process where the outcome can be predicted and adjusted based on measured case properties, ensuring consistent quality
3Reliability
If the explosion-proof score depth is too large, then the pressure relief capability is improved, but an extremely thin portion of the case is resulted which is easily cracked to cause liquid leakage
Solution Approach 1:
The invention defines the optimal score depth parameter as 0.05-0.15 times the case wall thickness, which is sufficient to create pressure relief capability while maintaining adequate remaining wall thickness to prevent structural failure and liquid leakage during normal operation
4Strength
If the explosion-proof score depth is insufficient, then the case structural integrity is maintained, but the pressure cannot reach the burst pressure of the explosion-proof score so gas cannot exhaust
Solution Approach 1:
The invention sets the minimum score depth at 0.05 times the case wall thickness, which is sufficient to create an effective pressure relief path while maintaining structural integrity. This parameter ensures that the score creates a weak point that will fail at the designed burst pressure, enabling reliable gas exhaust
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 battery achieves enhanced safety and sealing by utilizing an explosion-proof score that effectively relieves pressure without compromising the battery's integrity, ensuring reliable gas exhausting and preventing explosions.
Implementation Method 1
the explosion-proof score is provided in the first shell and/or the second shell... may be used for gas exhausting and pressure relief when the pressure inside the case is too high
Implementation Method 2
a burst pressure of the explosion-proof score is P... the explosion-proof score is equivalent to a locally thinned portion provided on the case and may be used for gas exhausting and pressure relief
Data Source
AI summary
A battery includes a jelly roll and a case. The case includes a first shell and a second shell; the first shell has an accommodation cavity therein, the first shell is provided with an opening communicated with the accommodation cavity, the jelly roll is disposed in the accommodation cavity, and the second shell blocks the opening. An explosion-proof score is provided in the first shell and/or the second shell. A burst pressure of the explosion-proof score is P, a tensile strength of a material of the case is σb, a diameter of the first shell (2) is D, a wall thickness of the case is H, and a depth of the explosion-proof score (211) is h. In a case where the explosion-proof score is linear,P=(H-h) σbD-0.6(H-h);or in a case where the explosion-proof score is curved,P=2(H-h) σbD-1.2(H-h).