Oak-Mitsui Inc. is a New York incorporated, wholly owned subsidiary of Mitsui Kinzoku (of Japan), which is the world’s largest manufacturer of copper foils as well as other high-performance products for the electronics industry. The company has locations in Hoosick Falls, NY, Camden, SC (US Copper Foils headquarters) and Riverside, CA. It specializes in the development and production of world-class performance foils for the electronics and lithium ion battery markets. Oak-Mitsui Technologies (a subsidiary of Oak-Mitsui Inc.) is located in Hoosick Falls and supplies the FaradFlex® line of embedded capacitor materials that eliminate the need for discrete capacitors in high-performance electronic circuit boards.
Mitsui Kinzoku has a long history in the production of battery materials. The company was a supplier of materials for primary battery cells for decades and was instrumental in the development of the nickel metal hydride batteries used in the Toyota Prius. Mitsui Kinzoku currently supplies cathode materials for both NiMH and Li-ion batteries from its facility in Takehara, Japan. On the development side, the company is working on Si-based anodes for increased Li-ion battery performance. To support this kind of work, it maintains a full Li-ion cell pilot line for the production and testing of 18650 cells.
Focusing on the domestic operation, Oak-Mitsui is the only electro-deposited copper foil manufacturer in the Americas. This capability uniquely positions the company to support the growing Li-Ion battery market in North America. Electro-deposition of copper is not a new technology, but considerable expertise is required in order to obtain the ideal properties for the copper foil utilized in the anode current collectors in these batteries.
Oak-Mitsui offers four types of copper foil for the anode current collector in Li-ion batteries. These foils are available in widths from 150mm to 1346mm and in thicknesses from 9.5μ to 70μ. A patented treatment technology allows for the highest level of coating adhesion, which enables the use of reduced amounts of binder in the anode carbon coating. Oak-Mitsui has the ability to work with cell manufacturers to optimize foils for their particular application and typically can support lead-times of three weeks from order receipt. As a result of the company’s global footprint (it has factories in Japan, Taiwan and Malaysia, along with distribution into China), it can support companies in the US as well as their overseas affiliates.
“We feel that Oak-Mitsui is strategically positioned to serve the needs of the US energy storage market,” says John Andresakis, VP of Strategic Technologies at Oak-Mitsui Technologies. “As the only copper foil manufacturer in North America, we can provide the type of service that is difficult to achieve for foreign suppliers. Oak-Mitsui has a history of working with our customers to tailor our products to fit their needs and not try to make a ‘one size fits all’ material. We jumped at the chance to join NY-BEST (in fact we are one of the founding companies) so we could work with other companies, academia and government labs to further energy storage technology in the US. NY-BEST has lived up to our expectations.”
Oak-Mitsui Technologies was established in 2003 in Hoosick Falls in order to pursue growth opportunities in the United States. The FaradFlex Embedded Capacitor materials were the first products developed at OMT and generated several US and foreign patents. These materials utilize thin dielectric materials deposited between two layers of special copper foil in order to provide improved power distribution inside printed circuit boards and modules. FaradFlex is the leading material under 25 microns in thickness and is utilized by customers throughout North America and around the world. Oak-Mitsui continues to improve the capacitance density of these products as well as developing new applications.
Oak-Mitsui Technologies continues its role in seeking out new opportunities and partnerships of interest to its parent company, particularly in such areas as energy storage, fuel cell technology, photovoltaic technology, and advanced lighting technologies. Partnerships of interest may include other companies, academic institutions and government laboratories and agencies.
As a company vigorously pursuing a growing participation in New York’s energy storage value chain, Oak-Mitsui Technologies is an active and enthusiastic member of NY-BEST.