Sumitomo Chemical is making two moves to increase its presence in battery materials. The company says it will boost capacity to make aramid-polyolefin separators for lithium-ion batteries at its plant in Daegu, South Korea. The first phase of the fourfold expansion is set to be complete in August 2017. Separately, Sumitomo will raise its stake in Tanaka Chemical, a Japanese supplier of battery materials, from less than 15.0% to 50.1%. The two companies have cooperated since 2013 on cathode materials for car batteries.