SK IE Technology, a wholly owned electric vehicle battery material subsidiary under SK Innovation, began the operation of a separator factory recently completed in Changzhou, China, the company said Tuesday.

Equipped with an annual production capacity of 340 million square meters, the new plant will ramp up SKIET’s total capacity to 870 million square meters. When additional plants are completed in Poland and China, the figure will spike to 1.87 billion square meters by 2023.

Separators are one of the four key components of EV batteries along with cathodes, anodes and electrolytes. They are basically thin walls with tiny holes that divide cathodes from anodes. When batteries are charged and discharged, ions go back and forth between cathodes and anodes through these tiny holes.

Separators prevent cathodes and anodes from reacting with each other and triggering short circuits, which cause the flammable electrolytes to catch fire. In short, separators are what prevent batteries from exploding.

“The Changzhou plant, which is SKIET’s first overseas production base, will allow the company to react more swiftly to growing demand for separators in China, which accounts for half of the global EV market,” a company official said.

By Kim Byung-wook (kbw@heraldcorp.com)