Electric vehicle battery packs can reach energy densities of 220-300 Wh/kg, creating significant thermal challenges during failure events. When thermal runaway occurs, cell temperatures can surge beyond 800°C, generating combustible gases at rates exceeding 2L/min per cell, and creating flame jets that reach 1100°C. Without proper containment, these thermal events can propagate through an entire pack in under 10 minutes.

The fundamental challenge lies in designing housing systems that can withstand extreme thermal conditions while simultaneously managing pressure buildup, directing gas flow, and maintaining structural integrity.

This page brings together solutions from recent research—including battery modules with integrated gas discharge pathways, housings with elastic sections for dynamic pressure compensation, multi-layer fire-resistant coatings, and degassing collectors with expandable thermal management systems. These and other approaches provide practical implementation strategies for vehicle manufacturers seeking to enhance battery safety without compromising energy density or performance.

1. Explosion-Proof Electric Vehicle Drive Structure with Outer Wall-Mounted Powertrain Containment System

BEIJING ZHONGZHONGYAN CONSTRUCTION MACHINERY MANUFACTURING CO LTD, 北京市政中燕工程机械制造有限公司, 2023

A novel explosion-proof drive structure for electric vehicles that prevents rear axle fires through a unique containment system. The structure features a fixed, outer wall mounting system for the electric powertrain, with the powertrain mounted to the outer wall rather than the vehicle's body. This design eliminates the rear axle as a potential ignition point and significantly improves the vehicle's explosion-proof capabilities.

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2. Rotating Electrical Machine System with Integrated Fireproof Boundary and Terminal Housing Configuration

HONDA MOTOR CO LTD, 2023

A rotating electrical machine system with integrated fire protection that eliminates the need for separate relay connectors. The system features a rotating electrical machine housing with a fireproof component that serves as a boundary between the electrical terminal area and the mechanical shaft. The terminal housing is positioned at one end of the housing, with the fireproof component covering the other end. A first insertion hole is created in the fireproof component, and the terminal housing closes this hole. This design achieves comprehensive protection while maintaining the conventional relay connector configuration.

3. Battery Module Housing with Integrated Pressure Protection, Thermal Management, and Controlled Gas Exhaust System

SIEMENS MOBILITY GMBH, 2023

Battery system framework for vehicle power management that integrates multiple lithium-ion battery cells into a single module. The framework employs a specially designed housing with integrated pressure protection, thermal management, and controlled gas exhaust system to prevent fire propagation through convective cooling. The housing is made of fire-resistant materials, with separate compartments for each battery cell, and features a hermetically sealed interface between modules. The system utilizes a controlled gas exhaust system to manage hot gases from cell failures, ensuring rapid cooling and preventing system damage.

4. Vehicle Body with Multi-Layer Ammonium Polyphosphate and Polyurethane Fire-Resistant Coating

AUDI AG, 2023

Vehicle design incorporating a fire-resistant coating on vehicle body components to protect occupants from thermal damage in the event of battery fire. The coating, comprising multiple layers of ammonium polyphosphate and polyurethane, expands significantly in temperature beyond its decomposition point to create a thermal barrier. This design enables effective fire protection while maintaining structural integrity, particularly in regions with fire-resistant coatings on the vehicle body.

5. Battery Module with Integrated Gas Discharge Pathway and Protective Region for Thermal and Mechanical Stress Mitigation

BMW AG, 2022

Protecting battery components in traction batteries from thermal and mechanical stress during cell failure by creating a localized gas discharge path. The assembly comprises a battery module with a cell complex formed from a plurality of battery cells, a single housing of the battery cells for the secondary battery cells, a degassing area where the body exhausts hot gases is located on the upper side of the monomer complex, and a protective region that guides and directs the hot gas flow through a guide structure. The protective region is positioned between the underside of the battery part and the upper side of the cell complex.

CN115244757A-patent-drawing

6. Modular Battery Housing with Elastic Section for Dynamic Pressure Compensation

VOLKSWAGEN AG, 2022

Modular battery with adaptive pressure compensation in its housing. The battery comprises multiple battery cells housed in a gas-tight receptacle within a flexible, elastic housing section. The housing section incorporates a stretchable material that dynamically adjusts its dimensions in response to temperature and pressure changes, ensuring optimal pressure balance. This adaptive material enables the battery to maintain reliable cell-to-cell contact while accommodating variations in internal pressure. The housing's elastic material also provides structural integrity during thermal expansion and contraction.

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7. Electric Vehicle Battery System with Integrated Fire-Resistant Thermal Isolation and Protection Components

Dongfeng Motor Corporation Ltd., DONGFENG MOTOR COMPANY LTD, 2022

Electric vehicle power battery system with enhanced thermal management through integrated fire protection. The system comprises a battery support, battery modules arranged on the support, each with thermal isolation structures, and a fire-resistant cover that wraps the support and modules. The cover incorporates a fire-resistant material in its longitudinal direction adjacent to the modules, ensuring comprehensive protection against thermal runaway. The system also features a wire harness wrapped with fire-resistant cloth to prevent electrical arcing during thermal events.

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8. Degassing Collector with Heat-Resistant Thermal Insulation and Expandable Space for Traction Batteries

BAYERISCHE MOTOREN WERKE AG, 2022

A degassing collector for traction batteries in electric vehicles that enables reliable emergency cooling of hot gases without direct environmental discharge. The collector integrates heat-resistant thermal insulation into the degassing space, which is expanded by the hot gas to capture and dissipate thermal energy. The collector's design allows for controlled expansion of the degassing space, enabling precise temperature management while preventing ignition. The collector's thermal insulation and expansion capabilities enable efficient cooling of hot gases generated during cell faults, ensuring safe operation of the traction battery system.

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9. Fire-Resistant Enclosure for Vehicle Inverters with Bottom-Mounted Heat Dissipation and Flame Retardant Particle System

DATONG BAISHENG ELECTRONIC ELECTRICAL CO LTD, Datong Baisheng Electronics and Electrical Co., Ltd., 2022

A fire-resistant enclosure for motor vehicle inverters that incorporates a unique heat management system. The enclosure features a bottom-mounted heat dissipation system with strategically positioned holes that contain flame retardant particles. When the enclosure is damaged, these particles fall to the bottom, blocking heat dissipation pathways and preventing fire spread. The enclosure's design ensures stable operation during vehicle acceleration and deceleration, with the top-mounted support system maintaining the inverter's position. The bottom-mounted heat management system provides comprehensive protection against fire propagation.

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10. Lithium Battery Safety Structure with Integrated Pressure Relief Ports and Airbag Collection Systems

SHAANXI AOLIN BOSI ELECTRIC POWER ENERGY CO LTD, 2021

A safety structure for lithium batteries designed to prevent thermal runaway and secondary damage. The structure integrates pressure relief ports and airbag collection systems to manage the thermal runaway process. By preventing the rapid ejection of flammable materials from the battery, the structure enables controlled release of heat and pressure, reducing the risk of catastrophic explosions and secondary damage.

11. Electric Vehicle Battery Enclosure with Fire Protection Layer and Targeted Gas Evacuation Passage

VOLKSWAGEN AG, 2021

Electric vehicle with a high-voltage battery that prevents thermal runaway during accidents. The vehicle features a specially designed battery enclosure with a fire protection layer that includes a targeted passage opening above the battery cell outlets. This passage enables controlled evacuation of hot exhaust gases from the battery system, preventing thermal runaway and ensuring safe egress of occupants during battery failure or fire events.

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12. Battery Housing with Three-Layer Structure and Integrated Gas Ducts for Thermal Management

VOLKSWAGEN AG, 2021

Battery housing for electric vehicles with enhanced thermal protection and evacuation capability. The housing features a three-layer structure with an inner sheet metal part, an outer sheet metal part, and a fire protection insulation layer. The insulation layer is designed to absorb thermal energy and prevent gas from escaping the housing during thermal events. The housing cover has a metallic top and bottom plate, with gas ducts connecting these plates to emergency degassing valves. The cover's design prevents gas from escaping the housing while maintaining occupant safety.

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13. Battery Module with Selectively Severable Frame for Controlled Cell Decompression

BAYERISCHE MOTOREN WERKE AG, 2021

Battery module for electric vehicles that prevents thermal runaway by automatically disassembling when a cell experiences internal fault or thermal event. The module comprises a cell assembly with multiple cells, each containing a degassing element for releasing hot gas. The module has a frame that can be selectively severed by hot gas when cell faults occur, releasing cell compression and preventing thermal propagation through the module. This design enables rapid and controlled cell failure detection and decompression through the module frame, preventing thermal runaway and ensuring safe operation of the battery system.

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14. Motor with Integrated Fire-Resistant Protective Cover and Heat Insulation Board

QINGDAO TIANYI GROUP HONGQI MOTOR CO LTD, Qingdao Tianyi Group Hongqi Electric Co., Ltd., 2020

Fire-resistant motor for high-temperature environments, featuring a protective cover comprising a fire prevention board and a heat insulation board. The board integrates the protective cover components, providing comprehensive protection against high-temperature conditions while maintaining electrical functionality. The board is arranged on the outer side of the motor main body, with the heat insulation board positioned on the inner layer. This integrated design ensures both fire protection and electrical integrity.

15. Power Battery Pack Safety Monitoring System with Multi-Parameter Sensing

WUHU QIDA POWER BATTERY SYSTEM CO LTD, 2020

A safety monitoring system for power battery packs in electric vehicles that provides improved safety by continuously monitoring multiple parameters inside the battery pack. The system uses sensors to detect internal temperature, smoke concentration, coolant level, and cooling in/out temperatures. This allows comprehensive monitoring of battery pack conditions beyond just internal temperature. It enables detecting issues like overheating, smoke, coolant leaks, and cooling performance.

16. Networked Fire Suppression System with Fault Detection and Pre-Extinguishing Modules for Electric Vehicles

UNIV HANGZHOU DIANZI, 2020

An intelligent monitoring fire extinguishing system for electric vehicles that enhances safety through real-time detection and pre-extinguishing capabilities. The system comprises a fire extinguisher mounted on the vehicle chassis, a networked fire suppression system with multiple jet extinguishing modules, and a fault detection circuit that monitors vehicle electrical systems for circuit faults. When a fault is detected, the circuit triggers an alarm and initiates pre-extinguishing operations before the fire can spread. This integrated approach enables enhanced fire safety in electric vehicles by addressing both fire detection and suppression through a single, networked system.

17. Electric Vehicle with Heat-Insulating Groove and Spring-Loaded Thermal Protection in Battery Compartment

HANGZHOU CHOUXUAN TECH CO LTD, 2020

Electric vehicle with enhanced fire prevention through intelligent battery management. The vehicle features a battery compartment with a fixed bottom connection and a heat-insulating groove at the battery's bottom. The groove has a movable cover plate that can be positioned to optimize thermal management. The vehicle's battery compartment is also connected to a spring-loaded heat-insulating system, which provides additional thermal protection. The vehicle's control system monitors battery temperature and triggers an alarm when it exceeds a predetermined threshold. A dry battery compartment ensures continuous power supply. The vehicle's body has a fixed connection point for the battery slot, preventing battery movement during operation.

18. Modular Battery with Elastic Housing for Dynamic Pressure Compensation

VOLKSWAGEN AG, 2020

A modular battery design that enables flexible pressure compensation through elastic housing sections. The battery comprises multiple battery cells housed in a gas-tight enclosure with a lockable receptacle. The housing contains an elastic section that dynamically adapts to temperature and pressure changes, maintaining optimal cell-to-cell pressure balance. This passive compression mechanism enables reliable operation across varying environmental conditions without the need for separate pressure-compensation components. The elastic section is integrated into the housing design, eliminating the need for separate components and simplifying battery assembly.

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19. Battery Housing with Integrated Exhaust Duct and Flexible End-Cap for Thermal Runaway Management

WEBASTO SE, 2020

Battery housing for electric vehicles that integrates a controlled exhaust system to manage thermal runaway risks. The housing features an integrated exhaust duct with multiple internal openings that direct gas streams from battery modules to a dedicated collection chamber. This controlled gas flow pathway prevents uncontrolled releases of hot gases and combustion products into the environment, while capturing any sparks that may form during thermal events. The housing design incorporates a flexible, end-cap section that accommodates battery modules while maintaining structural integrity during thermal stress.

20. Energy Storage Device with Fire-Resistant Coating and Mineral Wool Content for Housing Protection

BAYERISCHE MOTOREN WERKE AG, 2019

Energy storage device for motor vehicles with enhanced fire protection. The device comprises a plurality of memory cells, each containing electrical energy, and a housing with a receiving area and an opening on one side. The device features a fire-resistant coating applied to the side of the housing, which protects the energy cells from thermal events. The coating is made from a non-combustible material with mineral wool content, ensuring fire resistance while maintaining structural integrity. The device is designed with the opening facing the interior of the vehicle, providing a safe installation position.

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21. Fire Extinguishing Device with Spring-Loaded Piston and Electric Push Rod Mechanism for Confined Spaces

22. High-Voltage Battery with Solid-State Cell Modules and Integrated Mechanical Support Framework

23. Battery Pack Casing Deformation Monitoring System with Real-Time Control Signal Generation for Pressure Regulation

24. Battery Pack Thermal Runaway Detection System with Multi-Parameter Monitoring

25. Lithium Iron Phosphate Battery with Nano-Particle Size Adjustment and Spring-Loaded Securement System

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