Battery Pack Venting Barrier for Pressure Relief and Flame Containment
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Solution Overview
Problem
Battery packs face issues with thermal runaway and ignition due to external events like overcharging and shocks, leading to the decomposition of internal materials and discharge of flammable substances, which can cause damage and secondary fires.
Innovation Solution
A battery pack design featuring a pack housing with a venting passage and a blocking unit comprising a first blocking member and a second blocking member with a mesh structure, which blocks substances from entering the venting passage at lower pressures while allowing venting gas to escape, preventing the propagation of flames and ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a venting passage is provided to release pressure from battery cells, then pressure relief function is improved, but flammable substances and flames can escape to the outside causing fire propagation
Solution Approach 1:
A blocking unit is introduced as an intermediary component between the accommodation space and venting passage. This blocking unit includes a first blocking member and a second blocking member with mesh structure that work together to filter and block flammable substances while allowing venting gas to pass through, thus mediating between pressure relief needs and fire prevention requirements
Solution Approach 2:
The second blocking member employs a mesh structure with specific pore size (24 or more eyes per 1 in²) that allows small gas molecules to pass through while blocking larger flammable particles and dust. This porous structure enables selective permeability based on particle size, achieving both venting and filtration functions
2Reliability
If a blocking unit is added to prevent flammable material discharge, then fire safety is improved, but device complexity increases
Solution Approach 1:
The blocking unit is segmented into two distinct blocking members with different functions: the first blocking member provides primary blocking and structural support, while the second blocking member with mesh structure provides fine filtration. This segmentation allows each component to be optimized for its specific function while maintaining overall simplicity
Solution Approach 2:
The blocking unit utilizes parameter changes in material properties and structural configuration. The first blocking member is designed to break at specific pressure thresholds (higher than or equal to reference pressure), while the second blocking member maintains a specific mesh density (24 or more eyes per 1 in²). These parameter specifications enable predictable behavior under different pressure conditions without requiring complex control systems
3Stress or pressure
If the first blocking member is designed to break at high pressure to relieve pressure, then pressure relief function is improved, but structural strength is reduced
Solution Approach 1:
The first blocking member is pre-designed with specific mechanical properties that cause it to break at predetermined pressure thresholds (higher than or equal to reference pressure). This preliminary design of failure characteristics ensures that when excessive pressure occurs, the blocking member will automatically break to relieve pressure, transforming a potential weakness into a safety feature
Solution Approach 2:
The system incorporates a dual-blocking structure where the second blocking member with mesh structure provides continuous protection even after the first blocking member breaks. This beforehand cushioning ensures that while the first member sacrifices its strength to relieve pressure, the second member remains intact to continue blocking flammable substances, providing layered safety
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 solution effectively minimizes thermal runaway and ignition within the battery pack, improves safety by preventing the discharge of flammable materials and flames, and reduces the risk of fire propagation, enhancing overall safety and reliability.
Implementation Method 1
a second blocking member disposed within the first blocking member, the second blocking member having a mesh structure
Implementation Method 2
the blocking unit blocking a substance generated in the pack unit from entering the venting passage
Data Source
AI summary
A battery pack may include a pack housing including an accommodation space and a venting passage connecting the accommodation space to outside, a partition wall member partitioning the accommodation space, a plurality of pack units including battery cells, the plurality of pack units disposed in the accommodation space, and a blocking unit provided between the accommodation space and the venting passage, the blocking unit blocking a substance generated in the pack unit from entering the venting passage.