Lithium-ion batteries are getting economic development money in addition to a lot of attention, but there are other key parts of the electric car — many of them using plastics — vying to be part of a new auto supply chain.
Wiring harnesses, cables and connectors that were considered a low priority just a few years ago are now getting increased attention as the auto industry determines the best way to move electricity from the batteries to the wheels.
Packaging concerns are causing the industry to look at new ways to house lithium-ion cells, and even some old-school molders are looking at where they could fit in with high-technology electric cars while trying to bridge the gap between today's cars and those of the future.
“We're taking mainstream manufacturing processes to the electric vehicle market,” said Rick Schmidt, automotive sales engineer for Tasus Corp., a Bloomington, Ind.-based injection molder.
“We, as a community of automotive professionals, have got to work with these new companies,” he said at the Society of Automotive Engineers 2009 World Congress, held April 20-23 in Detroit.
Some production is already under way on hybrid vehicles and a few all-electric vehicles. EnerDel Inc. makes lithium-ion batteries for Norway's plastic-bodied Think car, and plans to supply batteries from its production site in Indianapolis if Think Global succeeds in expanding production to the U.S.
The battery uses some resin in its storage cells, including a polymer separator, but also uses proprietary plastics throughout the packaging in frames, end plates and structural rings, said quality manager John Corbett. One module of 24 individual cells contains about 50 different pieces of plastic.
EnerDel has an outside supplier molding those parts for its production in Indianapolis, where EnerDel also is based.
As more cars turn to electric drive, wire and cable suppliers are adjusting their products, and finding insulating plastics that will stand up to higher heat and higher voltage.
About 60 percent of the electrical wiring in cars today is insulated with PVC, said Daniel Winkler, product engineer for Leoni Cable Inc. of Rochester Mich., part of Leoni Kabel GmbH of Roth, Germany. But PVC insulation is rated to 221° F, while electric and hybrid vehicles must have cables rated to 257° F or higher.
Leoni and other cable suppliers like Champlain Cable Corp. of Colchester, Vt., are turning to cross-linked polyesters, polyurethane and other resins that can take the heat, with Leoni introducing its Hivocar line of cables using cross-linked PE insulation and PU specifically for hybrid, electric and fuel-cell vehicles.
“These are new applications in the car,” Winkler said.
Those applications also have increased the focus on wiring companies. In the past few years, wiring was ignored in favor of the electronic gadgets they powered, but now carmakers are asking new questions about temperatures and voltage, along with packaging and weight, trying to find the right combination of aluminum or copper wires and resin housings to minimize the weight of all those wires, while also fitting them into small areas.
Wiring harness makers are now at the center of those discussions.
“And there are battery companies coming to us and asking how to run the cable from one large battery pack, or if they split the batteries into two packs, how they should they connect them?” Winkler said.
The final wiring package is likely to include a blend of materials, with each cable and its insulation engineered for its specific use, he said, adding that injection molded connectors also must be adapted to cope with the higher voltage and temperatures.
The new supply chain will extend beyond just the electronics.
Tasus, the U.S. subsidiary of Tsuchiya Co. Ltd. of Nagoya, Japan, has been working on future development projects with Tesla Motors Inc. in Torrance, Calif., which makes the all-electric Tesla Roadster and recently announced plans to produce a sedan.
The Roadster is a low-volume, high-priced car: About 1,500 are produced annually at a cost of more than $100,000. To bring down the price and bring up the production, the company needs to simplify manufacturing.
Some of that work is simply helping Tesla's engineers adapt their designs to accommodate standard production, Schmidt said, such as adjusting parts for vibration welding. Tasus is also working to alter its parts, looking at cooling systems designed for internal combustion engines and instead using them to cool battery packs.
“It's really intriguing working with these people,” Schmidt said. “We're only a $28 million, Tier 2 supplier, but we're plugged in — no pun intended.”