■ Eunyoung Choi / Ph.D., Korea Atomic Energy Research Institute [Anchor] Lithium-ion batteries, commonly used in electric vehicles and mobile phones, are convenient to use, but they have the disadvantage of being explosive. All-solid batteries, also known as dream batteries, are also under development, but their development speed is slowing down due to poor performance and economic feasibility. However, a domestic research team has developed a technology to mass-produce semi-solid batteries, which have the advantages of both batteries, using radiation technology. Today on 'Science Master', we will learn more about this. Eunyoung Choi, a senior researcher at the Advanced Nuclear Cycle Technology Development Department of the Korea Atomic Energy Research Institute, has arrived. Hello? [Interview] Hello. [Anchor] Before introducing the technology you developed, please explain what all-solid batteries and semi-solid batteries are. [Interview] Yes. First, I think it would be quicker to understand what all-solid and semi-solid batteries are by looking at a diagram. The batteries we use most in our daily lives are lithium-ion batteries, which are composed of a cathode, anode, a separator between them, and an electrolyte. The liquid electrolyte is a flammable substance, which poses a risk of fire or explosion. On the other hand, solid-state batteries eliminate the separator and liquid electrolyte and use solid electrolytes instead, so there is almost no risk of fire, making them very safe. However, they are not yet commercialized due to poor performance caused by interfacial resistance issues and side reactions of solid electrolytes. Semi-solid batteries have semi-solid electrolytes, which are in gel form, so their ion conductivity is higher than solid electrolytes and their stability is higher than liquid electrolytes, so they can be said to have the advantages of both liquid and solid batteries. [Anchor] So, you developed the 'one-pot' technology, which allows for mass production of these semi-solid batteries using radiation technology. Please introduce this technology. [Interview] The 'one-pot' process refers to a process in chemistry where reactants react continuously in a single reactor to create products. This time, our research team developed a semi-solid battery one-pot production technology using electron beams. By irradiating the battery with an electron beam, multiple finished products can be produced at the same time, so it can be called the 'one-pot' technology. An electron beam is a type of radiation that can change the structure and properties of a substance, so when an electron beam is irradiated on a liquid electrolyte, the liquid can change into a semi-solid form. A method has been proposed to produce a finished product by irradiating an electron beam on a pouch-type battery that contains a liquid electrolyte and other battery materials and then changing it into a semi-solid electrolyte. In this study, we experimentally confirmed that a semi-solid battery that surpasses the performance of existing liquid electrolyte batteries can be produced simultaneously by stacking multiple units at once using a one-pot process. Since electron beam irradiation is possible while vertically stacked in a trailer manner, it can be said that productivity has greatly improved. [Anchor] You said that you are irradiating a liquid electrolyte with an electron beam to make a semi-solid battery in the shape of a gallon. You said that mass production is possible. Then how many batteries can you produce in one minute? [Interview] Since an electron beam has high energy, it has a strong property of penetrating materials. By utilizing this characteristic, even when multiple batteries are stacked vertically like a book, it can penetrate without much change in intensity to some extent. The battery used in this study was confirmed to be able to transmit up to 7 electron beams while maintaining the intensity in a vertically stacked state. If a set of vertically stacked batteries is continuously supplied on a trailer, a large quantity can be produced in a short period of time. Based on 1 minute, more than 20 commercialized batteries can be produced. [Anchor] But how did you find out how and how much to irradiate the electron beam to create the best battery performance instead of just irradiating it? [Interview] Since various materials are used inside a battery, the effect of the electron beam is slightly different for each material. If exposed to a high-intensity electron beam, the materials can be damaged. First, we analyzed the effect on each individual material inside the battery, such as the positive electrode, negative electrode electrolyte, separator, and binder, when irradiating the electron beam. In particular, in the case of the electrolyte, impurities are generated by the high-intensity electron beam, which can result in a rapid deterioration in the battery performance. Therefore, we found the optimal irradiation dose that does not damage the materials and then verified the battery performance. [Anchor] I think the secret is the intensity and time of the electron beam. What do you think is the difference compared to the existing semi-solid battery production method? [Interview] In order to make a semi-solid electrolyte in the existing technology, an initiator must be used to initiate a chain reaction, and then ultraviolet irradiation and heat treatment are required. If an excessive amount of initiator is used, a side reaction occurs, and a large amount of cross-linking agent must be used, which can worsen battery performance. Using an electron beam eliminates the need for an initiator, and a small amount of cross-linking agent can be used, making it the optimal method for improving battery performance. [Anchor] This is a technology that does not require an initiator. That is what you are saying. Then, how much more economical is the production process you have developed compared to the existing process? [Interview] There were many evaluations that the expansion of production volume was limited when using an electron beam, and the high price of the electron beam equipment was insufficient for economical efficiency. The newly developed process is highly productive because multiple batteries are stacked on a conveyor belt and irradiated with an electron beam at once, so it can be said to be highly economical. Although it is somewhat more expensive than existing liquid electrolyte batteries, it can actually be said to be more economical because safety has been greatly improved. [Anchor] However, as shown in the picture, there is a concern that the electron beam will not reach the battery at the bottom well when stacking several batteries and irradiating them with electron beams. [Interview] As you mentioned, when stacking a large number of batteries, we confirmed that the electron beams on the bottom batteries were weak and could not form a semi-solid. When irradiating the electron beams at a level that did not damage the materials inside the batteries, the number of semi-solids that could be formed was 7. If the electron beam irradiation conditions are changed according to the thickness of the battery, it is judged that there will be no problem in applying it to a large number of batteries at the same time. [Anchor] What is currently needed for commercialization of this technology? [Interview] In the future, we plan to apply this technology to the production of batteries with higher capacities than those used in this study and conduct optimization experiments necessary for commercialization. If we apply it to batteries with different capacities, we will select the appropriate electron beam conditions and automate mass production. We will also conduct process optimization to accelerate commercialization. [Anchor] Batteries are always considered a key area for the next-generation technology hegemony competition. I think the technology you explained today will play a big role in the future. We were with Dr. Eunyoung Choi of the Advanced Nuclear Cycle Technology Development Department of the Korea Atomic Energy Research Institute. Thank you. YTN Science Kim Ki-bong ([email protected]) #ElectronBeam #MassBatteryProduction #Battery #News #Information [YTN Science Original Article] https://science.ytn.co.kr/program/vie... [Program Production Inquiry] [email protected]