Japan’s Toray Industries is buying out the 50% interest held by ExxonMobil’s Japanese affiliate, TonenGeneral, in the battery separator joint venture Toray Tonen Specialty Separator. Toray will pay TonenGeneral about $700 million. The companies formed the joint venture in early 2010 using ExxonMobil-developed technology for multilayered porous polyethylene membranes for lithium-ion batteries. The partnership has plants in Nasu, Japan, and Gumi, South Korea. Toray says it needs to take over the joint venture so it can better fend off competition in a fast-paced market. ExxonMobil recently acknowledged that it is in discussions with TonenGeneral about possibly restructuring its operations in Japan.