The 100% owned Korean subsidiary of Sumitomo Chemical will stop a sapphire wafer ingot production and instead will focus on secondary battery separator business, as Korean battery makers are expanding their reaches across the world, supplying global top-tier EV car makers and ESS makers.

The company is already supplying its separators for Panasonic.

SSLM was established in 2011 under a 50%:50% joint-venture between Samsung Electronics and Sumitomo Chemical to address captive LED chip markets, as Samsung staked out LED chips as one its strategic business items for the future. Yet, the business got caught into doldrums, as the global market was flooded with a deluge of China makers, suffering from excessive capacity.

Samsung pulled put out of the business selling out its 50% stake to Sumitomo.

Separator is a key material in making a secondary rechargeable battery, acting as permeable membrane placed between a battery's anode and cathode. It is moistened with electrolyte and forms a catalyst that promotes the movement of ions from cathode to anode on charge and in reverse on discharge.

SSLM has jumped in to the separator market since 2015, as the secondary rechargeable battery market has started to rapidly grow with the growth of energy storage system or ESS and electric car market.