Mitsubishi expanded production to meet rising demand, with almost ¥2.5 billion (US$31.75 million) having been invested in the project. The SEPALENT produced at the new plant will undergo quality testing to be certified by each lithium-ion secondary battery manufacturer. The new plant is expected to launch its commercial production in 2013.

The separator is a porous film that allows the proper amount of lithium ions to pass through but prevents electrical shorts caused by the cathode coming into contact with the anode. The film also has a shutdown function as a safety switch in case of thermal runaway by closing the pores of the separator.

By making use of our material design and film-forming technologies, Mitsubishi Plastics has developed a highly-functional, cost effective separator with a long cycle-life and excellent output rate at low temperatures. The production of the separator was launched in August 2009 at the Nagahama Plant (12 million m²/year). Since then, the separator has been adopted for use in lithium batteries for mobile phones, power tools and laptop computers. The Company also developed a high heat-resistant separator for hybrid and electric vehicles, for which demand is expected to grow significantly over the coming years. Mitsubishi Plastics decided to construct a new plant and install the second production line last year.

Mitsubishi Plastics will promote the sale of SEPALENT by strengthening collaboration with Mitsubishi Chemical Corporation which sells four materials related to lithium-ion secondary batteries, and at the same time, is constantly developing highly functional separators that can meet the needs of its customers. In this way, the Company continues its efforts to further expand the lithium-ion battery materials business of the Mitsubishi Chemical Holdings Group.