As electric vehicle manufacturers aim for lighter-weight materials, crash resistance and battery pack protection, they are looking to structural adhesives to help bring all of those objectives together.
Companies such as 3M, Henkel Corp., Lord Corp. and DuPont know all about creating strong bonds between materials, and now they are applying their expertise to the EV battery realm.
Adhesives reduce or replace heavy mechanical fasteners in EV battery design. They provide a thinner and lighter bond — which can improve EV range — for a variety of battery components, and can bond dissimilar materials more quickly and with more flexibility and strength than traditional nuts and bolts.
Adhesives are designed with more accurate gap control in mind and bond parts such as battery cells, battery module side panels, cooling plates and more.
3M uses two-part epoxy and acrylic structural adhesives, which bond to a broad range of materials for different levels of strength, and urethane epoxy adhesives, which are best for modules or individual cells and have cooling applications.
Henkel, a German industry and consumer goods supplier, has structural adhesive products for EVs under a few different brands.
Henkel offers Loctite brand structural adhesives that aid assembly of battery cells, battery modules and battery packs. Loctite sealing technologies protect the battery from external fluids.
Henkel also offers Bergquist silicone- free materials, which are liquid gap fillers that manage the thermal load generated from the battery pack.
"There was no thermal material needed for batteries in a conventional car in the past," Frank Kerstan, Henkel business development manager, said. "Of course, it's a completely different game when you talk about thousands of battery cells."
Adhesive supplier Lord Corp. created thermally conductive structural adhesives for EV battery packs in place of an ordinary gap filler or thermal pad. The adhesives are lightweight and provide thermal management between battery cells. Lord also offers adhesives for structural bonding within a battery pack.
Materials supplier DuPont offers a suite of adhesives, such as its Betaseal brand. "Our structural adhesives were originally for crash safety related matters," said Christophe Van Herreweghe, DuPont's global strategic market manager for adhesives assembly and the Accelerating Hybrid Electric and Autonomous Driving, or AHEAD, initiative.
"They also give a huge benefit in terms of fatigue and driveability comfort of the vehicle," he said.
As automakers set goals for longer range, faster charging, lower cost and more, adhesives stick as one of the best answers.
"There is a need to constantly innovate and bring in new lightweight materials," Prasanna Srinivasan, manager of business development and marketing at Lord, said. "Adhesives in general actually add a lot of value to EVs."