[Bojo, Battery] "Find the Second Ecopro" Value Chain in the All-Solid-State Era

Samsung SDI Decides H1 Mass Production Scale and Composition
'Dream Battery' Production in Sight... Mass Production by 2027
Sulfide-Based Trend... Emerging as a New Value Chain

Editor's Note'Bojo, Battery' is a series that takes a closer look at the battery industry, which has emerged as the center of next-generation advanced industries. It examines the agile movements, strategies, and conflicts among governments and companies worldwide vying to dominate the battery manufacturing ecosystem. We will also cover the technological competition to create safer and longer-lasting batteries. Our goal is to provide a 'support' function that enhances and assists readers' and investors' understanding of the battery industry. We will share battery stories that are easy to approach.

All-solid-state batteries refer to batteries composed entirely of solid materials.

The era of all-solid-state batteries is rapidly approaching. Mass production is expected in three years. Known as the 'dream battery' for its superior safety and energy density compared to existing batteries, this battery is attracting attention. With Samsung SDI finalizing the scale and configuration of its all-solid-state mass production line in the first half of this year, interest is also growing in the changes to the value chain of the all-solid-state battery era.

According to the battery industry on the 12th, LG Energy Solution and Samsung SDI plan to mass-produce sulfide-based all-solid-state batteries by 2027. SK On aims to establish a sulfide-based solid battery pilot line by next year and begin commercial mass production from 2029. Among them, Samsung SDI is showing 'quick steps toward commercialization.' At the InterBattery 2024 event, which closed on the 8th, Juyoung Ko, Vice President and Head of Samsung SDI's Medium and Large Product Planning Team, said, "We submitted all-solid-state battery samples to three OEMs (automobile manufacturers) last December and are currently evaluating them," adding, "We need to decide on the scale and construction of the mass production line investment in the first half of this year." Samsung SDI established a pilot line for producing sample all-solid-state batteries last year at its research center in Suwon, Gyeonggi Province, and began production.

All-solid-state batteries refer to batteries composed entirely of solid materials. They replace the liquid electrolyte that transfers ions between the cathode and anode with a solid electrolyte. Solid electrolytes are more resistant to shocks and damage compared to liquids and also serve as a partition, allowing the separator to be minimized or eliminated. This enables the battery to be lighter or to increase energy density by adding more cathode active material in the freed-up space.

All-solid-state batteries are broadly classified into three types: sulfide-based, oxide-based, and polymer-based. Among these, the technology gaining dominance, with participation from Korea's top three battery companies as well as Japan's Toyota and Panasonic in development and mass production, is the sulfide-based all-solid-state battery. The sulfide-based type boasts the highest ionic conductivity and can achieve a high energy density of over 900 Wh per liter.

However, sulfide-based all-solid-state batteries generate hydrogen sulfide gas, which is harmful to humans, when reacting with moisture. Therefore, it is necessary to develop materials with low reactivity to moisture, and since existing electrode production processes (wet processes) are difficult to use, dry processes must be developed. The cell manufacturing process and operation require very high pressure. It is necessary to develop a pressurization structure at the module and pack levels to implement this or to develop materials that can operate under low-pressure conditions.

Cathode active material with single-crystal structure is essential... Anode materials evolving with lithium metal and anode-free types

The cathode active material, which accounts for 40% of battery costs, does not undergo significant changes in all-solid-state batteries. To facilitate ion movement within the solid-state battery, electrodes must be formed uniformly. Solid powders need to be pressed into films under higher temperatures and pressures. In this process, the existing polycrystalline cathode active materials, which are fragile and prone to breaking, are unsuitable. Single-crystal (single-particle) cathode active materials, which have a solid single-particle structure, are expected to gain more attention in the all-solid-state battery era.

Korean cathode material companies such as LG Chem, POSCO Future M, and EcoPro are already producing or supplying single-crystal cathode materials to customers. Although their prices are higher than those of polycrystalline cathode materials, they are focusing on improving mass production efficiency in preparation for growing demand. L&F is developing single-crystal cathode materials with a goal of mass production in the third quarter of this year.

All-solid-state batteries can be configured with lithium metal anodes or anode-free cells without anode active materials. Lithium metal anode materials are made by coating copper foil with lithium metal foil tens of nanometers thick. Lithium metal itself is lightweight and much thinner than graphite, allowing the battery size and volume to be significantly reduced compared to conventional graphite or silicon anodes. This improves energy density, enabling electric vehicles to travel longer distances with the same battery size as existing batteries.

In Korea, Hyundai Motor Company began technical development cooperation early in 2021 with the U.S. company SolidEnergy Systems (SES) to secure lithium metal battery technology for electric vehicles. In April 2022, Lotte Chemical signed a business agreement with the U.S. startup SolidElect to develop lithium metal anode materials and is considering investing $200 million by 2025 to establish lithium metal anode material production facilities in the U.S. In May last year, POSCO Group partnered with SKC to jointly develop next-generation anode materials, including lithium metal anode materials.

Existing batteries use liquid electrolytes composed of organic materials, but all-solid-state batteries use solid electrolytes. Solid electrolytes also serve as separators that prevent direct contact between the cathode and anode. There is no risk of leakage due to temperature changes or external shocks. Using solid electrolytes does not directly increase energy density, but it allows the removal or reduction of separators, battery casing, and cooling water from the battery structure, enhancing safety.

Several domestic companies are entering the solid electrolyte industry. The value chain is centered around Samsung SDI, including EcoPro BM and Lotte Energy Materials. POSCO Holdings is developing both sulfide- and oxide-based solid electrolytes simultaneously through its joint venture with Jungkwan, POSCO JK Solid Solutions. SK IT plans to pursue the solid electrolyte business as a new venture. Representative overseas companies include Solid Power and Idemitsu Kosan. Demand for solid electrolytes is expected to grow from 2,000 tons in 2027, when mass production of all-solid-state batteries begins, to 43,000 tons in 2030, a 2050% increase.

The growth potential of lithium sulfide, a key raw material for solid electrolytes, is also significant. Lithium sulfide is used in solid electrolytes for all-solid-state batteries and also replaces lithium hydroxide used in existing NCM (nickel-cobalt-manganese) cathode materials. In Korea, Lake Materials, Isu Specialty Chemicals, and Jungseok Chemical produce lithium sulfide. According to estimates by Hanwha Investment & Securities, the combined production capacity of these companies is about 200 tons, while demand is expected to exceed 15,000 tons by 2030.