Yi Sik Choi CEO of S-Materials

-World-First Innovation, Developed the world’s only growth method for hexahedral-shaped sapphire single crystals

-Economic Breakthrough, Dramatically reducing investment costs and production overhead for the mass production of silicon-based anode materials

[CEOs of Incubated Companies at KATECH Chungnam Cheonan–Asan InnoTown] S-Materials, A Leader in Defense·Optical Sapphire and Next-Generation Anode Materials
S-Materials is a specialized developer of sapphire for military and optical applications, as well as anode materials for secondary batteries. The company was founded in June 2019 by CEO Yi Sik Choi (56).

S-Materials successfully developed South Korea's first military-grade sapphire window. Currently, its proprietary sapphire windows are utilized in the infrared (IR) seekers of long-range missiles and are supplied to the nation’s largest defense contractors. Expanding its horizons, the company is also spearheading the commercialization of silicon-based anode technology for secondary batteries, a technology transferred from Kongju National University (Cheonan campus).

The company stands as the only entity globally to have developed a hexahedral-shaped sapphire single crystal growth method. Furthermore, S-Materials has a proven track record as the third in the world to successfully develop and mass-produce sapphire single crystals for LEDs. Notably, it was the first in Korea to apply sapphire windows to the IR seeker of the Long-range Surface-to-Air Missile (L-SAM). This achievement is the result of over a decade of joint R&D with the Agency for Defense Development (ADD) and Hanwha Aerospace, and the technology is expected to be expanded across next-generation missile system development projects.

“Currently, only three companies worldwide have successfully achieved mass production of silicon-based anode materials”, said CEO Choi.

“While competitors rely on Gas Phase Evaporation, which requires high energy costs, or wet milling, which is time-consuming and expensive, S-Materials utilizes the world’s only dry milling process. This allows us to develop silicon-based anodes for lithium secondary batteries that excel in quality, productivity, and cost-competitiveness.”

In addition, S-Materials has internally developed the High-Energy Milling Machine used for manufacturing nano-silicon powder. This internal capability allows the company to drastically reduce CAPEX and production costs during future mass production. Beyond cost, it ensures manufacturing competitiveness through ease of maintenance and overall operational efficiency.

Regarding future plans, CEO Choi stated, “It has been about four years since we began the full-scale development of silicon-based anode mass-production technology. During this time, we secured R&D funding through government programs like TIPS, Scale-up TIPS, and Post-TIPS, as well as investments from four institutions, including Daekyo Investment. In 2024, our growth potential was publicly recognized when we were selected as a Cheonan Future Unicorn (C-STAR) company.” He added, “While we have focused on proving the potential of our technology until now, we will now concentrate on delivering tangible results from our years of preparation.”

Foundation: June 2019
Core Business: Sapphire for defense and optics; Anode materials for secondary batteries.
Achievements: 2022–2024, Secured 450M KRW in R&D funding via the Ministry of Science and ICT’s Original Technology Development Project, Mar 2023 Selected for the TIPS program, Jun 2023 Completed the IBK Changgong (Daejeon) program, Jun 2024 Selected as a Cheonan Future Unicorn (C-STAR) company, Sep 2024 Selected for Scale-up TIPS, Dec 2024 Won the Grand Prize at the Deep-tech Scale-up IR Competition, Oct 2025 Selected for the Post-TIPS program, Investment Secured Series A funding (3.5B KRW) from Daekyo Investment, KDB Capital, Innopolis Partners, and IBK

reporter jinho lee
jinho2323@hankyung.com