Lithium ion batteries take centre stage in development of alternative drives

Jon Lawson

Alexander Usselmann explains how his company assists this development with a safety-relevant solution

Lithium-ion batteries play an essential role in the vision of electromobility. They offer impressive benefits such as emission-free drives, high efficiency and low self-discharge. But their design also requires special fire protection measures during their use.

Thermal runaway

Lithium-ion batteries are chemical energy storage systems that release the stored charge through a chemical reaction. When a certain operating temperature is reached, there is a so-called thermal runaway in the battery, which means that it heats up on its own to the point of destruction. The reason is that lithium-ion batteries, unlike lead or nickel versions, must rely on flammable components.

An electronic malfunction or mechanical damage can cause the lithium ions to withdraw the oxygen stored in the cathode, which may result in oxidation of the electrolyte. This creates gases and vapours. The pressure and temperature increase. At temperatures between 120 and 300°C, the separator melts and the electrolyte stars to burn. This causes a short circuit and thermal decomposition of the cathode. The oxygen released in this process, combined with the thermal energy, ignites the other battery components and produces temperatures of over 1,000°C.

Danger from the outside

Lithium-ion batteries are classified as dangerous goods in transport or storage. They respond to their environment with great sensitivity. In any event, the energy sources should never be directly or permanently exposed to higher temperatures.

Thanks to Thermamax’s extensive experience with high-temperature insulations, it can contribute to the operational safety of battery systems. The Tmax-Battery Housing protects the environment against the effects of thermal runaway and the battery against the risks of high ambient temperatures.

To protect lithium-ion batteries against fire, it is not enough to just develop high-temperature insulation. Instead the temperature must be monitored permanently. This is why the Tmax-Battery Housing has thermal management with high-performance cooling.

The insulated housing reliably protects the battery from external influences, such as water, extreme temperatures, dust or vibrations. If there is a strong increase in pressure, the burst valve opens and thus prevents a possible explosion. The valve automatically closes when the pressure drops.

Its features include a modular and scalable design and an easy to maintain assembly. It is pressured balanced and resistant to high temperature. It also offers protection against water spray as well as being highly resistant to stone impact.

The key benefits the solution delivers are: maximum safety in case of accident; entended battery range and longer lifecycle; and greater operational safety.

For more information visit Thermamax


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