폭발·화재 위험 없는 전고체전지 상용화에 한 걸음 다가선 한국전기연구원(KERI)의 획기적인 연구결과가 국제 저명 학술지의 논문으로 게재됐다. KERI 차세대전지연구센터 소속의 박준우 박사와 성정환 연구원(UST KERI 캠퍼스 학생 연구원)이 공정 과정과 비용은 절반 이하로 줄이고, 결과물의 품질은 2배 이상 높인 ‘고체전해질(황화물계) 입도 제어 및 습식 합성 공정’ 기술을 개발했다.
▲KERI's Dr. Park Jun-woo (center) team poses with a solid electrolyte manufactured through a wet synthesis process and a prototype of an all-solid-state battery utilizing the solid electrolyte.
Dr. Park Jun-woo's team develops 'solid electrolyte wet synthesis process'
The groundbreaking research results of the Korea Electrotechnology Research Institute (KERI), which brought us one step closer to commercializing all-solid-state batteries without the risk of explosion or fire, were published as a paper in an internationally renowned academic journal.
Dr. Park Jun-woo and researcher Seong Jeong-hwan (student researcher at UST KERI Campus) from KERI Next-Generation Battery Research Center developed a 'solid electrolyte (sulfide system) particle size control and wet synthesis process' technology that reduces the process and cost by more than half and increases the quality of the result by more than double.
All-solid-state batteries replace the 'electrolyte' that transfers ions between the positive (+) and negative (-) electrodes with a solid, which has a low risk of fire or explosion, rather than a liquid.
On the other hand, in order for solid electrolytes to be used in all-solid-state batteries (especially the positive electrode (+)), the particle size must be very small, on the order of several micrometers, which is equivalent to one-hundredth of the thickness of a human hair.
KERI's achievement is the development of a technology to mass-produce fine, high-ionic conductivity solid electrolytes using a simple process.
The solid electrolytes that many researchers at home and abroad have manufactured using various methods have large particles, requiring separate processes such as mechanical crushing. In this process, not only was time and physical cost consumed, but the deterioration of the solid electrolyte performance due to pulverization was a major obstacle to commercialization.
Accordingly, Dr. Park Jun-woo's team introduced fine raw materials (such as lithium sulfide) and used a method to significantly reduce the particle size of the final product by controlling the 'nucleation' speed that each substance generates through a chemical reaction. It became possible to manufacture a fine solid electrolyte with only a simple wet synthesis process without a complex process.
With this successful chemical composition control, the ionic conductivity of the resulting product was about twice (2 mS/cm -> 4.98 mS/cm) higher than that of the conventional solid electrolyte process (‘dry synthesis’ and pulverization via high-energy ball milling). This is a great achievement for the KERI research team, which has found the optimal combination through experiments on many materials and various analyses over the years.
The results of the related research were recognized for their excellence and published in the March issue of 'Energy Storage Materials,' a renowned international academic journal in the energy field. The 'JCR Impact Factor', which evaluates the influence of academic journals, is 20.4, which puts it in the top 5.2% in its field.
KERI's Dr. Park Jun-woo said, "With the appropriate selection of raw materials and reliable control of chemical reactions, we were able to skip the complicated and expensive process that had been performed to refine the solid electrolyte through our unique 'simple process'." He added, "Even with the greatly simplified process, the quality of the solid electrolyte is much superior, securing both 'corporate accessibility' and 'efficiency' for mass production and commercialization."
KERI, which has completed a number of patent applications for its achievements, expects the related technology to receive much attention from the solid-state battery industry and plans to promote technology transfer by discovering companies in demand.
In addition, the goal is to lead the specialized technology market for manufacturing high-quality solid electrolytes inexpensively and in large quantities by linking this achievement with the existing 'special wet synthesis method (technology for mass producing solid electrolytes using inexpensive raw materials (starting materials) at 1/10 the cost using patented special additives)' that has been developed and owned.
Meanwhile, KERI is a government-funded research institute under the National Research Council of Science and Technology of the Ministry of Science and ICT. This research was conducted as a basic project of KERI and the 'Nano-Fusion Innovation Product Technology Development Support Project' of the Ministry of Trade, Industry and Energy.
