[NEWS IN FOCUS] Korean companies rush to incorporate silicon into EV battery anodes

Silicon is emerging as the next holy grail in the global EV race for its potential to sharply cut the charging time for electric vehicles — possibly to less than five minutes.

A Tesla car sits at a Tesla Supercharger station on Feb. 15 in Sausalito, California. [AFP/YONHAP]

Silicon is emerging as the next holy grail in the global EV race for its potential to sharply cut the charging time for electric vehicles — possibly to less than five minutes.

Touted as the next “game changer,” major Korean companies are rushing investments to develop state-of-the-art technology to add silicon to their anodes, one of the four key materials in making EV batteries that determines the charging speed.

SKC, 41 percent owned by SK Inc., in July formed a subsidiary dedicated to developing silicon-based anodes. It acquired 22 percent of Britain’s Nexeon, the company that is scheduled to construct a 1,000-ton silicon anode factory in Gunsan, North Jeolla.

SK Materials in 2021 formed a 75:25 joint venture with Washington-based Group14 Technologies to together invest 25 billion won ($18.7 million) over six years to build a facility in Sangju, North Gyeongsang. The plant is slated to start operation in 2027.

Posco Future M's factory for manufacturing anode materials made of artificial graphite [YONHAP]

Posco is also investing 300 billion won to build a 5,000-ton silicon-based anode materials factory in Pohang, North Gyeongsang.

Lotte Energy Materials, previously known as Iljin Materials, invested 7.9 billion won in French startup Enwires, which runs a 2.5-ton pilot plant.

Silicon is an alternative to graphite, the current main ingredient in making anodes. The traditional graphite-based anodes can fully charge EVs anywhere from as quickly as 20 minutes to as long as 10 hours, depending on the charger.

Silicon is known to have 10 times more energy density than graphite. Higher energy density in battery materials translates into faster charging times and longer driving ranges for electric vehicles.

Theoretically, by applying some 5 to 10 percent of silicon to the anodes, the charging time can be reduced to five minutes.

Hana Securities estimated that the size of the global silicon-based anode market, which is valued at $400 million this year, will jump to $28.7 billion in 2032.

“The usage of high-nickel cathodes to increase energy density has already reached its limit,” Kim Hyun-soo, a researcher at Hana Securities, said. “As global names like Tesla and LG Energy Solution consider silicon-based anodes for their future batteries, the market will boom in earnest starting in 2024.”

Tesla has reportedly been considering applying silicon-based anodes in its “4680” cylindrical batteries, which are batteries with a diameter of 46 millimeters and a height of 80 millimeters. They have a higher energy density than existing batteries, reducing battery costs by 50 percent.

Porsche is already using batteries made with silicon-based anodes, supplied by Daejoo Electronic Materials, in its Taycan EVs.

Posco Future M's anode materials [YONHAP]

So far, Daejoo Electronic is the only Korean company that manufactures anode materials with around 5 percent silicon content. It also applies the materials to Audi, for its E-tron GT EV.

The silicon amount will grow to 8 percent next year, Daejoo said. The company is set to supply the materials to five more global automakers next year.

The “game-changing” materials, however, still have some hurdles left to jump over.

When the batteries are being charged, lithium ions move from the cathodes to the anodes, causing the volume of some raw materials in the anodes to expand. This expansion may reduce the battery's life expectancy.

The expansion of silicon-based anodes is about four times larger than anodes made of graphite.

“Energy density compared to volume is a significant measure in developing silicon-based anodes,” said Jeong Hun-ki, a researcher at the Korea Institute of Science and Technology, during a conference in January. “EVs should be designed with more consideration given to the energy density per volume, not the weight themselves.”

BY SARAH CHEA, KO SUK-HYUN [chea.sarah@joongang.co.kr]