Materials for rechargeable batteries

Asahi Kasei’s SunForce™ is a foam based on our XYRON™ modified polyphenlyene ethers. These products combine the unique advantages of foams—light weight and good thermal insulation—with flame retardance, dimensional stability, the ability to form products with thin walls, and other advantages far beyond the capabilities of conventional foams.

Although it is a foam, the molding material SunForce™ can be used in areas that require flame resistance, and has an extremely high level of flame resistance according to UL's Flame retardance standard for plastics and parts, UL-94. It is the first particle foam beads material in the world to receive the "V-0" certification.

SunForce™ is lightweight foam with the unique advantage of being intrinsically fire-retardant (UL94V-0); to date they have been adopted or evaluated for applications to peripheral components surrounding battery packs in electric vehicles. SunForce™ is also well-suited for forming the trays used in the manufacture and shipping of LIBs. In particular, trays made from SunForce™ foam offers the following advantages:

• The use of this extremely flame-retardant (UL-94 V-0) foam material will yield improved safety in the manufacture and shipping of LIB cells.​
• Lighter-weight trays: Trays made from SunForce™ foam can be lighter in weight than trays made from injection-molded resins. (Specific gravity of 10x foam grades: 0.1 kg/L).​

Please feel free to contact us for further information on SunForce™ foam, including dimensional tolerances and chemical-resistance data.

Asahi Kasei’s LEONA™ polyamide resin is an engineering plastics featuring high strength, high rigidity, high heat resistance, and outstanding chemical resistance. These materials may be further strengthened by reinforcing them with glass fibers or similar fillers, improving their strength, rigidity, durability, and dimensional stability.

Here we present specialized LEONA™ grades suitable for secondary processing steps such as laser welding or laser marking. These are ideal materials for system components such as battery casings, and components made from these materials can be smaller in size in lighter in weight than components made from other materials.

Laser welding is a secondary processing technique used to form strong junctions between components.
One scenario in which welding proves useful is the manufacture of batteries or other products containing high-energy-density components such as electronic substrates or battery packs that must be tightly enclosed inside a hermetically-sealed chassis. However, conventional welding techniques such as vibration welding or ultrasonic welding are not recommended for this purpose as they may damage the delicate system components inside the chassis. (Meanwhile, using screws or similar hardware to seal the chassis has the drawback of requiring extra space to accommodate boss regions.)

Instead, we use laser welding, which allows the formation of strong junctions with no risk of damage to internal components, thereby allowing the size and weight of manufactured products to be reduced.

Techniques for imprinting information onto products are important for ensuring product traceability and reliability.

One such technique is laser marking, in which laser irradiation of a product generates bubbles in surface resin layers, leaving behind indelible marks on the product surface.

Asahi Kasei’s LEONA™ SN11B polyamide resin is a high-strength, high-rigidity, UL94V-0 (0.75 mm)-certified flame-retardant material that is halogen- and red-phosphorus free and has a comparative tracking index (CTI) equal to or greater than 600V, PLC=0. In addition to these specifications, LEONA™ SN11B boasts excellent welding strength.

Moreover, LEONA™ SN11B is ideally suited for laser marking, producing clear, precise lettering—even for extremely small characters—and an outstanding takt time, thus helping to reduce the size and weight of final products.