Mind the Pad!

As mentioned in the introduction, battery systems for electrified rail and mass transportation face unique challenges due to the high vibration, extreme temperatures, and heavy loads that they are subjected to. These are also true for battery-electric heavy-duty industrial applications like in trucks, forklifts, agricultural or construction vehicles.

Based on comparable technologies used in electric car batteries, there are still differences in operation conditions, requirements and challenges batteries in mass transportation and heavy-duty machinery face.

These challenges can cause significant damage to the battery and reduce its performance, safety, and lifetime. For example, high vibration can cause internal damage to the battery cells, while extreme temperatures can lead to thermal runaway and even fire. There is a critical need for solutions that can address these challenges and ensure that battery systems in rail and mass transportation applications are safe, reliable, and long-lasting. And advanced silicone materials are currently the go-to material. Let us dive deeper into the how and why.

Silicone pads used in heavy-duty battery applications are typically made of high-quality silicone rubber material that is specifically designed to withstand the harsh and demanding conditions of these industries. Depending on the use in cell-to-cell or cell-to-pack, thermal interface or cushioning applications, the exact type of silicone pad used are adapted to the specific needs, operating conditions and the desired level of protection required.

• Cell-to-cell or cell-to-pack silicone compression pads: Depending on the battery pack design, these silicone materials are used to provide defined pressure on the cells allowing ideal cell performance and prolonged lifetime during expansion and compression. In addition, they help mitigate thermal runaway propagation in creating insulation barriers between adjacent cells.
• Thermal Interface silicone materials: In mass transportation and heavy industry battery applications, the enormous amount of power in short time can cause extreme temperatures in the battery and can put the entire system at risk. TIM (Thermal Interface Materials) made of silicone are ideal to dissipate heat away from the system.
• Vibration dampening and cushioning silicone materials: Due to specific densities, thicknesses and material design, silicone cushioning pads help reduce vibration, improve thermal management and enhance shock absorption in battery systems.

Overall, the unique combination of thermal properties, customizable densities and compression-force-deflection (CFD) properties as well as strong resistance against electrical, chemical, mechanical and environmental stresses, silicone pads are preferred choices for high-end battery applications in mass transportation and heavy industry.

Silicone pads offer improved battery performance and efficiency, enhanced safety and reliability as well as longer battery lifetime which make them very interesting for engineers designing high-end batteries with high power density. New technologies and material combinations i.e. with Mica or with adhesives make these materials often unseen champions that can make the difference.

Even though silicones offer premium functionality, there are other promising polyurethane-based solutions that also have amazing properties and advantages in specific applications. So how do you find exactly the most suitable solution?

With EV engineers across the globe working on innovative and ever more powerful battery designs, there is no one-size-fits-all solution for battery pads. This makes identifying the right solution a true challenge but there are some key factors to consider when selecting silicone pads for rail, marine, aircraft, agriculture, industrial and mass transportation battery applications, such as:

• Material composition
• Density
• Temperature range
• Vibration damping properties

There are numerous solutions out there and to make it even more complex, there are many ways to modify existing standard solutions or to customize and co-develop new application-specific products. No product guide, selector or well-developed tool can currently spit out the perfect solution at the touch of a button. Especially, as the pace of new developments and technologies is astonishing. The best approach might still be to talk to your expert, provide application details, must-haves and potential hurdles. This article can help you understand the importance of these materials, give certain directions and help start the discussion with your expert of choice.

With battery-electric mobility on the rise and new technologies opening new dimensions, silicone pads can be the turbocharger for batteries in EV, trains, airplanes, marine, mass transportation and industrial applications. Be sure you "Mind the (silicone) Pad" and talk to your tape expert as these innovative materials could be the key that turns challenges into battery-electric solutions.