Safety in E-Mobility: Managing Thermal Runaway and Thermal Propagation
Battery Safety Starts Between the Cells and Extends to the Battery Enclosure
A defect in a single battery cell can quickly become a hazard for the entire battery system and, in turn, pose a serious risk to vehicle occupants and emergency responders. This is why the thermal safety architecture of an HV battery pack plays a critical role in determining how a critical event develops.
The challenge: During a thermal runaway event, extreme temperatures, hot particles and gases are generated within a very short period of time. If this energy is transferred to neighboring cells, a single-cell event can escalate into a chain reaction known as thermal propagation.
This is why the solution cannot be limited to a single area within the battery pack.
With novaVOLT® and novaVOLT® AERO, Frenzelit offers high-performance insulation solutions for different protection functions within HV battery systems, ranging from insulation between individual battery cells to protection of the entire battery enclosure. The objective is always the same: to stop thermal events or at least delay them long enough to significantly reduce the associated risk.
Thin. Lightweight. High-temperature resistant. And adaptable to the specific battery design.
One Thermal Runaway Event. Two Levels of Protection.
01 | Between the Cells: Preventing or Delaying Thermal Propagation
novaVOLT® AERO
The most effective thermal safety architecture begins where a potential chain reaction starts: between the individual battery cells.
When a cell experiences thermal runaway, heat transfer to neighboring cells must be reduced as much as possible.
This is where novaVOLT® AERO comes into play.
This high-temperature-resistant, compressible insulation material containing aerogel can be integrated as a cell spacer or compression pad between battery cells.
This creates a highly effective thermal barrier exactly where it is needed.
The Advantage for Battery Development
- High thermal insulation performance with minimal material thickness
- Low additional weight
- Integration directly between the cells
- Combination of thermal insulation and compression
- Adaptable to cell geometry and battery architecture
- Suitable for applications with highly limited installation space
Enhanced safety does not automatically require more installation space or additional weight.
02 | At the Battery Enclosure: Protection During Thermal Runaway
novaVOLT®
Even if thermal runaway cannot be prevented entirely, the battery system must provide the highest possible level of protection for its surroundings and for vehicle occupants.
This is where novaVOLT® fulfills another critical protection function.
These mica-free inorganic paper solutions have been specifically developed for protection during thermal runaway events in EV battery systems.
Even at extremely high temperatures, novaVOLT® offers excellent resistance to impacting particles and can help delay burn-through of the battery cover during a thermal event.
As a result, novaVOLT® supports the thermal protection architecture wherever a critical event within the battery pack must be shielded from the outside environment.
A single cell may fail. The safety architecture must not.
From the Cell Gap to the Battery Cover
Thinking of Thermal Safety as a System
Between the Cells
- novaVOLT® AERO
- Thermal barrier
- Reduced heat transfer to neighboring cells
- Support against thermal propagation
Battery Enclosure / Battery Cover Area
- novaVOLT®
- High-temperature and particle protection
- Delays burn-through
- Protection against flame release
This creates a safety architecture specifically tailored to the respective risk scenario.
Maximum Protection. Minimal Impact on Battery Architecture.
When developing modern EV battery systems, protection performance is not the only factor that matters.
Every additional component affects:
Installation space. Weight. Assembly. Complexity. Cost.
This is exactly why Frenzelit does not develop its solutions independently of the battery pack.
Material, material thickness, geometry and positioning are all tailored to the specific application.
The Goal
As much protection as necessary. As little material as possible.
This enables thermal protection functions to be integrated quickly and efficiently into both existing and new battery platforms.
Battery Safety Is Becoming a Development Requirement.
Thermal propagation is receiving increasing attention in international safety requirements for electric vehicles.
Regulatory developments relating to UN R100 and UN GTR No. 20 clearly demonstrate that the behavior of a battery system following the thermal runaway of a single cell is becoming a key element in the safety assessment of HV batteries.
For OEMs and battery developers, this means:
Thermal propagation can no longer be considered only at the end of the development process.
The thermal safety architecture must be incorporated into battery pack design from the very beginning.
With novaVOLT® and novaVOLT® AERO, Frenzelit provides materials and customized components that can be specifically integrated into existing battery architectures.
Two Materials. Different Tasks. One Common Goal.
novaVOLT® AERO
Application: Between battery cells
Function: Thermal insulation and compression
Objective: Reduce heat transfer and prevent or delay thermal propagation
Particularly relevant for: Highly limited installation space and demanding weight and insulation requirements
novaVOLT®
Application: Within the battery system, particularly in the battery enclosure area
Function: High-temperature, particle and fire protection
Objective: Limit the effects of thermal runaway and delay burn-through of the battery enclosure
The Battery Pack Should Not Have to Adapt to the Material.
We Develop the Solution to Fit the Battery Pack.
Cell format, pack geometry, thermal loads, compression requirements, installation space and manufacturing processes vary from one vehicle platform to another.
That is why Frenzelit does not view novaVOLT® and novaVOLT® AERO as standard products.
Our material and application experts work with you to develop the right solution for your specific battery architecture.
From selecting the most suitable material and defining material thickness and geometry through to a ready-to-install component.
Your Battery Architecture. Your Safety Requirements. Our Material Expertise.
Thermal Runaway Cannot Simply Be Designed Away.
Its Effects Can.
The earlier thermal protection measures are integrated into the development of an HV battery pack, the more efficiently safety, installation space and weight can be balanced.
So let's not wait until the battery pack has already been fully designed before discussing fire protection.
Talk to our experts about your battery architecture.
Future World Electromobility
In addition to thermal runaway and thermal propagation, galvanic corrosion, sealing performance and thermal management are also essential considerations in the design of modern e-mobility applications.