Samsung announced on March 14 that it has broken ground on a 6,500-square-meter all-solid-state battery test line at the site of its research facility in Yeongtong-gu, Suwon-si, Gyeonggi-do. The company named it “S-Line,” where S stands for “Solid,” “Sole,” and “Samsung SDI.”

Samsung SDI plans to introduce pure battery electrode plates, solid electrolyte processing equipment and battery assembly equipment at the S-Line. So far, the company has made one or two prototypes in the lab. When the S-Line is completed, large-scale pilot production will be possible.

All-solid-state batteries contain solid electrolytes, so there is little risk of fire. While they have a high energy density, solid-state batteries are also believed to be a game changer.

Samsung SDI is developing a solid-state battery with a sulfide-based electrolyte. Compared with polymer oxide-based electrolytes, this electrolyte has advantages in terms of scale-up of production and charging speed. Samsung SDI has obtained the design and patent of the sulfide electrolyte material and has entered the technology verification stage.

“The construction of the test line means that Samsung SDI has overcome the technical difficulties of mass production of all-solid-state batteries to a certain extent,” an industry source said.

The biggest remaining hurdle now is the technology to ensure faster charging at room and low temperatures. The ionic conductivity of solid electrolytes is lower than that of liquid electrolytes, so the charge-discharge rate of all-solid-state batteries is lower than that of conventional batteries.

The pilot line will bring Samsung SDI closer to mass production of all-solid-state batteries than its competitors. LG Energy Solution and SK On are developing all-solid-state battery technology with the goal of starting mass production around 2030.

Among battery startups, Volkswagen-backed QuantumScape plans to start mass production of all-solid-state batteries as early as 2024. Solid Power, which has BMW and Ford as major shareholders, also announced that it will release electric vehicles with solid-state batteries in 2025. SES, backed by Hyundai Motor Co and General Motors (GM), also hopes to commercialize lithium metal batteries by 2025.

Meanwhile, Samsung SDI liquidated its Wuxi-based battery pack company SWBS in late 2021, according to battery industry sources. Samsung SDI previously completed the liquidation of another battery pack company, SCPB, based in Changchun, China, in early 2021. As a result, Samsung SDI has completely withdrawn from the battery pack business in China.

Samsung SDI is planning to focus on operating battery cell factories in Tianjin and Xi’an by closing all of its battery pack factories in China.