Battery Pack Venting With Stacked Porous Plates for Hot Gas Discharge
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Solution Overview
Problem
Existing battery packs face safety issues due to the vigorous ejection of high-temperature discharge gas from lithium-ion batteries, which can cause smoking and ignition when discharged through metal mesh vents, as the gas is not effectively attenuated before exiting the case.
Innovation Solution
A battery pack design featuring a porous resin plate with multiple through-holes arranged at non-facing positions, creating an expansion gap that allows the discharge gas to diffuse and adiabatically expand, reducing its temperature and energy before being discharged, thereby preventing adverse effects like smoking and ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a metal mesh member is provided in the vent hole to discharge gas quickly, then the discharge gas can be rapidly expelled from the case, but the high-temperature discharge gas (400°C or higher) causes adverse effects such as smoking and ignition when passing through the mesh member
Solution Approach 1:
The patent replaces the metal mesh member with a porous plate having numerous through-holes. The porous structure allows the discharge gas to pass through multiple small holes rather than a continuous mesh, creating numerous small flow paths that reduce gas velocity and allow for better heat dissipation, thereby preventing ignition and smoking while maintaining effective gas discharge
Solution Approach 2:
The patent changes the physical parameters of the discharge path by using a porous plate with specific pore size distribution and density. This modifies the flow characteristics of the discharge gas, reducing its temperature and velocity through the numerous small holes, which prevents the harmful effects of high-temperature gas ejection while maintaining adequate discharge capability
2Productivity
If the through-holes of stacked porous plates are arranged at facing positions, then the discharge path is shorter and gas discharge is more efficient, but the discharge gas retains high temperature and energy causing safety issues
Solution Approach 1:
The patent employs asymmetric arrangement of through-holes in stacked porous plates, where the through-holes in adjacent plates are positioned at non-facing locations. This asymmetric configuration creates a zigzag discharge path that lengthens the travel distance of the gas, increasing the time for heat dissipation and energy attenuation, thereby improving safety while maintaining discharge efficiency
Solution Approach 2:
The patent utilizes the stacking dimension of multiple porous plates to create a three-dimensional discharge path. By arranging through-holes at non-facing positions in stacked plates, the gas must traverse through multiple layers in the vertical dimension, effectively lengthening the discharge path and enhancing heat dissipation without significantly increasing the horizontal footprint
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 design enhances safety by dispersing and attenuating the discharge gas energy, preventing vigorous ejection and reducing the risk of ignition, ensuring safer discharge of high-temperature gases from the battery pack.
Implementation Method 1
the discharge gas passes through through-holes 5a provided in porous plates 5 and expansion gap 8 and is discharged to an outside of the case... the discharge gas passes through the through-holes of the porous plates, diffuses while being adiabatically expanded in the expansion gap
Data Source
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AI summary
Safety is ensured by suppressing adverse effects caused by a high-temperature discharge gas ejected from a discharge valve of a battery. A battery pack includes battery cell (1) having a discharge valve opened when an internal pressure exceeds a set pressure, and case (2) housing battery cell (1). Case (2) has opening (26), and opening (26) is blocked by porous plate (5) made of resin. Porous plate (5) has a plurality of through-holes (5a), an expansion gap of a discharge gas is formed by stacking a plurality of the porous plates (5), through-holes (5a) provided in each of porous plates (5) are arranged at non-facing positions not facing through-holes (5a) provided in adjacent another porous plate (5), and the discharge gas of the discharge valve passes through through-holes (5a) provided in porous plates (5) and the expansion gap and is discharged to an outside of the case.