Kuraray, the parent company of Kuraray Chemicals, will invest in Kureha Battery Materials Japan (KBMJ), a joint venture of Kureha and Itochu for producing materials for manufacturing batteries, thereby making a move into the materials business for lithium ion secondary batteries (LiB). In accordance with this, Kuraray Chemicals will establish a new production plant in conjunction with KBMJ and supply nitrogen PSA to this plant.

The reason that Kuraray is getting into this business involves hard carbon which is the negative electrode material of the LiB. The LiB is composed of a positive electrode which is made of lithium oxide and a negative electrode made of carbon. There is constant charging and discharging, due to lithium ions moving between these two electrodes. Because the negative electrode handle the charging of the batteries, it must have a good capacity for this charging of the batteries as well as being very durable.

In the past Kureha created a business for the pitch type hard carbon and has been supplying this in the field of the large type LiBs for industrial use and for use on cars. From now on, however, the main strategic fields for LiB electrode material will be the hybrid car and electric car fields. Development of new materials has become a topic of interest. Kuraray was aiming at getting into the LiB materials business, utilizing the knowledge related to carbon which it had cultivated in its activated carbon business.

Due to all of this, both companies are now cooperating in the development of a new hard carbon, which is based on plant material. Last year the time framework for commercialization was established for this. At the end of last year, Kuraray made an investment in KBMJ and agreement was reached for creating a joint business within this company.

The fact is that KBMJ and Kuraray Chemicals will establish a new joint venture to produce the product. During the course of next year the company will create a production setup capable of producing on the order of 1,000 tons a year. Regarding the ratio of the investment to be made, according to the Public Relations department of Kuraray, “Our investment in KBMJ is now under discussion.”

In the production process for hard carbon, a nitrogen needs to be created of under 200-300 ppm of the amount of oxygen in the reaction chamber to suppress reaction with the oxygen. Purging in the reaction chamber based on nitrogen PSA has become the general practice and here Kuraray Chemicals will supply the nitrogen PSA. Looked at from the point of view of the scale of carbon production, the PSA production capacity, based on a Gas Review estimate, is anticipated to be around 500 m3 an hour.