A silicon-graphene composite anode material technology for lithium-ion batteries, capable of increasing electric vehicle (EV) driving range by over 20%, has been transferred from a government-funded research institute to a domestic company and is now on the verge of mass production. This technology, which enables the large-scale production of thousands of tons of high-quality graphene, is expected to contribute to the competitiveness of the national energy industry, including energy storage systems (ESS).
The Korea Electrotechnology Research Institute (KERI) announced on the 1st that the mass production of a lithium-ion battery anode material, for which the technology was transferred to the domestic electrical and electronic materials and components company JNC Materials, is progressing smoothly.
Silicon has 10 times the energy density of graphite, the conventional anode material, and also boasts faster charging and discharging speeds. However, the challenge has been to overcome its drawbacks: it expands up to three times in volume during charging and discharging, and it has low electrical conductivity.
The KERI research team utilized graphene, a 2D carbon nanomaterial. Graphene is highly conductive and electrochemically stable. It forms a mechanically strong, net-like coating layer that significantly mitigates the performance degradation caused by silicon's volume expansion.
The research team developed a specialized oxidation-reduction method to produce high-quality, high-conductivity graphene in various viscosities. This is an 'aqueous dispersion technology' applicable to the lithium-ion battery anode manufacturing process. They also succeeded in mass-producing a composite anode material with a 'core-shell' structure, where graphene envelops and protects the silicon like a shell.
Using the developed technology, the team has stably manufactured a high-capacity, high-quality anode by increasing the silicon content from less than 5% in conventional lithium-ion battery anodes to 20%—a more than four-fold increase. This performance can extend the driving range of an EV by over 20%. The team has also fabricated pouch-type cells to evaluate their electrochemical properties and has completed the registration of original patents both domestically and internationally.
JNC Materials, which acquired the technology in 2021 for a technology transfer fee of 1.1 billion KRW, has established its production environment after moving into the 'National Advanced Strategic Industry Special Complex for Secondary Batteries' in Jecheon, Chungcheongbuk-do. By scaling up KERI's original technology, the company built the first large-scale graphene mass production facility in Korea last year.
The anode material produced by creating composites with the graphene from this facility can be applied to batteries for approximately 60,000 EVs or hundreds of millions of smartphone batteries.
KERI stated, "The technology will be utilized in applications requiring high-capacity, high-performance lithium-ion batteries, such as ESS, high-performance artificial intelligence (AI) semiconductors, and servers, thereby greatly contributing to strengthening the competitiveness of the national energy and AI industries."
Jung Seung-yeol, head of KERI's Nano Convergence Research Center, explained, "The transferred technology is a commercialization-ready technology based on high-functional nanomaterials that can simultaneously achieve high capacity and stability in secondary batteries."
He added, "Even after the technology transfer, our researchers continued to collaborate closely with the company to lay the groundwork for mass-producing the composite anode material. This case, which seamlessly connects original technology development to commercialization, will be regarded as a successful model for the commercialization of technology from government-funded research institutes."
Lee Chang-keun, CEO of JNC Materials, said, "Based on KERI's innovative original technology and close mutual cooperation, we have achieved the significant milestone of mass-producing graphene."
