Battery Module Safety Wall Section for Flame Energy Dissipation
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Solution Overview
Problem
Electric vehicle battery modules face safety risks due to the potential for chain reactions of battery cell malfunctions, particularly with high-energy-density lithium-ion batteries, where a damaged cell can cause fires and explosions, and existing steel housings are heavy, expensive, and insufficiently protective.
Innovation Solution
A battery module housing with a safety wall section that burns through quickly in a needle flame test, creating an opening to escape the energy of a flame, reducing the risk of spreading heat and damage to neighboring cells, and using a polycarbonate material with specific composition for flame retardancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thick steel housings are used to protect battery cells from crash damage, then the protection level improves, but the weight and cost increase significantly
Solution Approach 1:
The housing is segmented into different functional zones: a rigid base structure for overall protection and a specific safety wall section with controlled burnout properties for flame management. This segmentation allows each part to be optimized for its specific function rather than making the entire housing uniformly thick and heavy.
Solution Approach 2:
The safety wall section has different material properties (controlled burnout time of 5-45 seconds) compared to the rest of the housing. This local quality difference allows the housing to provide both mechanical protection and controlled flame escape, avoiding the need for uniformly thick steel construction throughout.
2Reliability
If thick steel housings are used to protect battery cells from crash damage, then the protection level improves, but the manufacturing cost increases significantly
Solution Approach 1:
The material parameters of the safety wall section are specifically changed to achieve controlled burnout (5-45 seconds), creating a functional differentiation that reduces the need for excessive material thickness elsewhere. This parameter optimization allows cost-effective manufacturing while maintaining protection levels.
Solution Approach 2:
The housing uses composite construction combining rigid materials for structural protection with flame-reactive materials for the safety wall section. This composite approach provides both crash protection and flame management capabilities without requiring uniformly thick steel construction, reducing overall material costs.
3Quantity of substance
If battery cells are densely packed to maximize energy storage, then the energy density improves, but the risk of chain reaction from flame spread increases
Solution Approach 1:
The safety wall section converts the harmful flame energy into a beneficial controlled escape path. By designing the wall to burnout in 5-45 seconds, the flame is directed through a controlled opening rather than spreading uncontrollably to adjacent cells, transforming a potential chain reaction into a contained event.
Solution Approach 2:
The safety wall section acts as an intermediary element between adjacent battery cell receptacles. It provides a controlled interface that manages flame propagation, allowing energy release while preventing direct flame contact with neighboring cells through its specific burnout characteristics.
4Reliability
If rigid robust housings are used to prevent battery cell damage in crashes, then the protection level improves, but the ability to dissipate flame energy decreases
Solution Approach 1:
The housing structure is segmented to separate mechanical protection functions from flame energy dissipation functions. The rigid base provides crash protection while the dedicated safety wall section with controlled burnout properties handles flame energy release, allowing both functions to coexist effectively.
Solution Approach 2:
The safety wall section has locally optimized material properties (5-45 second burnout time) that differ from the rigid housing structure. This local quality differentiation enables the housing to simultaneously provide mechanical strength for crash protection and controlled combustibility for flame energy dissipation.
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 dissipates the energy of a defective battery cell's flame, preventing chain reactions and maintaining protection of the battery cells during normal operation while reducing the weight and cost of the housing.
Implementation Method 1
the material properties and thickness of which are such that the safety wall section in the needle flame test according to DIN EN ISO 11925-2 shows a burnout after a maximum of 45 s
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a battery module (8) having a battery module housing (10), wherein the battery module housing (10) encloses a battery module interior (12), wherein the battery module housing (10) has receptacles (14) for a specified number of battery cells (16) on the battery-module-interior side and wherein the battery module housing (10) comprises a safety wall section (20) in the region of at least one receptacle (14), the material properties and the thickness of which safety wall section are such that the safety wall section (20) is burned through after at most 45s, preferably at most 20s, further preferably at most 10s, in particular at most 5s, in the needle-flame test according to DIN EN ISO 11925-2. The invention further relates to a battery pack (2) having a battery pack housing (4), wherein the battery pack housing (4) encloses a battery pack interior (6), wherein the battery pack housing (4) has at least one receptacle for a battery module (8) on the battery-pack-interior side and wherein the battery pack (2) has a battery module (8) according to the invention accommodated in the receptacle. Finally, the invention further relates to an electric vehicle (42), wherein the electric vehicle (42) has a battery module (8) according to the invention and/or a battery pack (2) according to the invention.