Samsung SDI Co., Ltd. () is a battery and electronic materials manufacturer headquartered in Yongin, Gyeonggi-do, South Korea. Samsung SDI operates its business with Energy Solutions and Electronic Materials segment. The Energy Solution segment manufactures rechargeable batteries used for IT device, automotive, and Energy Storage System (ESS) applications, and the Electronic Materials segment produces materials for semiconductors and displays. In the first half of 2022, Samsung SDI is ranked sixth in the world with a market share of 5 percent according to SNE research.
Samsung SDI was founded as Samsung-NEC Inc. in 1970, producing vacuum tubes. It expanded into cathode ray tubes by 1975. In 1984, the company name was changed to Samsung Electron Device Inc. and expanded into LCDs two years later. By 1998, the company had developed a cylindrical lithium-ion battery. In 1999, the company's name became Samsung SDI Co., Ltd. Samsung SDI started producing AMOLEDs in 2007.
In 2012, Samsung SDI and several other major companies were fined by the European Commission for price fixing of TV cathode-ray tubes. Samsung SDI merged with Cheil Industries in 2014. In 2015, the company acquired Magna International's battery pack business. In 2022, Samsung SDI started to build a pilot line for solid-state batteries in the South Korean city of Suwon and began its first production from the very line in 2023.
In February 2026, the Hungarian news outlet Telex reported that carcinogenic substances had been detected at more than 500 times the permitted level at the company's battery plant in Göd, and alleged that the company failed to address or disclose the issue. According to Agence France-Presse (AFP), the allegations became public following the leak of a government surveillance report involving the monitoring of Samsung's local executives. Critics cited by Telex and AFP argued that the Hungarian government was reluctant to take measures such as temporarily closing the plant due to potential economic and political consequences. On the 11th, the Supreme Court of Hungary overturned a lower court's revocation of the plant's environmental certification.
As of 30 June 2023.
As of October 2023, the company operates two battery cell plants in South Korea and four overseas battery cell plants in the United States, China, Hungary and Malaysia.
Samsung SDI's rugby union team played in the Korea Rugby League, the top division in Korea, from its formation in 2003 to 2014. It won the championship 4 times.