German chemical companies Henkel and Covestro have collaborated to develop a solution that enables cylindrical lithium-ion battery cells to be fixed inside a plastic cell holder.
The solution is based on Henkel’s Loctite AA 3963 battery assembly adhesives and Covestro’s UV-transparent polycarbonate blend Bayblend®.
Once all cells are placed into the adhesive and secured in the holder, curing is activated with ultra-violet (UV) light and takes place in less than five seconds.
The solution was developed for compatibility with high-volume automated dispensing techniques. The acrylic adhesive was formulated for use with the cell holder, which is constructed of flame-retardant plastic.
It provides strong adhesion to the substrate material and offers production adaptability through long open times and short cure cycles.
Frank Kerstan, head of e-Mobility Europe at Henkel, said: “The Loctite OEM-approved adhesive designed to secure cylindrical lithium-ion cells into a carrier is a one-part, cure-on-demand formulation.
“After high-speed dispensing, the material’s long open time inherently builds adaptability into the process by allowing for any unexpected production interruption.”
The cell holders are manufactured from Covestro’s PC+ABS blend Bayblend® FR3040 EV. With a thickness of a millimeter, the plastic meets category V-0 of the Underwriters Laboratories’ UL94 flammability rating but shows good permeability for UV radiation in the wavelength range above 380 nanometers.
Steven Daelemans, market development manager E-Mobility in the Polycarbonates segment at Covestro, said: “The material allows us to construct dimensionally stable parts that are necessary for automated mass assembly.
“Together with the fast-curing capability of the Loctite adhesives, this material combination delivers an innovative approach to large-scale cylindrical lithium-ion battery module production.”
Image: Battery modules with cylindrical cells are constructed with Covestro’s Bayblend® material and efficiently assembled with Henkel’s Loctite adhesive. (Photo: Henkel, PR082)