The use and storage of renewable energies is also finding increasing application in private and commercial environments: stationary home battery storage systems based on Li-ion battery technology are a market with a great future. BMZ GmbH, a leading system supplier for lithium-ion batteries, develops such battery home storage devices, which are also marketed under its own name as the EES 7.0, EES 9.0 and ESS X storage series. This means that the regenerative solar power generated in photovoltaic systems can be used in private and commercial applications more independently of the time of day and the position of the sun.

Covestro supports the various BMZ battery projects with material selection, during plastic-compatible component design and with CAE-based component simulations to meet the requirements of the UN Transport Test for Batteries (UN 38.3). Further services include moldflow analyses and technical injection molding support.

“Every battery project is technically demanding, which is why I am all the more pleased that plastics from Covestro can make an important contribution here,” explains Jens Ufermann from Covestro, who looks after BMZ GmbH locally, adding: “Together with customers like BMZ, we are working on sustainable product and application developments to master the challenges of future battery technologies.”

High requirements for stationary and mobile applications
Similar to battery systems for mobile applications such as cars, buses, scooters and pedelecs, energy density and safety are important aspects in the development of battery products for stationary use, as is the case with BMZ GmbH’s energy storage systems.

“Our in-depth understanding of the diverse applications of battery systems and our many years of experience in materials for battery applications enable us to provide our customers with both technical expertise and suitable products,” says Dr. Julian Marschewski, Market Development Manager in Electric Vehicle Battery Packaging.

Polycarbonate blends with tailored properties
Bayblend (PC+ABS) blends from Covestro play an important role in both mobile and stationary battery applications, for example in placing individual cylindrical battery cells in 18650 or 21700 format in a cell holder. To achieve this, the material must have excellent mechanical properties, above all high impact strength, but also high flowability in order to achieve the thinnest possible walls between the individual battery cells when manufacturing the cell holders through injection molding.

Additional safety in later use is provided by the incorporation of flame retardant grades that meet the high flame retardancy standards of Underwriters Laboratories according to category UL 94 V-0.

Broad range of products
The Covestro portfolio for battery applications continues to evolve. For cell holders for holding cylindrical battery cells, pouch cell frames, battery housings and similar applications the focus is on both unfilled (Bayblend FR3010, Bayblend FR3040) and mineral-filled (Bayblend FR3020, Bayblend FR3021) along with glass-fiber-reinforced (Bayblend FR3060 EV) flame retardant Bayblend products. Covestro also offers thermally conductive polycarbonate grades of the Makrolon TC product family that can contribute to battery thermal management.