- KIST increases charge and discharge efficiency with magnesium metal chemical activation process - Expected to commercialize magnesium secondary batteries by utilizing non-corrosive general electrolyte A research team led by Dr. Minah Lee of the Energy Storage Research Center at the Korea Institute of Science and Technology(KIST) has developed a chemical activation strategy of magnesium metal that enables efficient operation of magnesium batteries in common electrolytes that are free of corrosive additives and can be mass-produced. While the demand for lithium-ion batteries is exploding due to the rapid growth of the electric vehicle and energy storage system(ESS) markets, the supply and demand of their raw materials such as lithium and cobalt are mostly dependent on specific countries, and thus there are great concerns about securing a stable supply chain. For this reason, research on next-generation secondary batteries have been actively conducted, and secondary batteries utilizing magnesium, which is abundant in the earth's crust, are gaining attention. [Figure 1] COMPARISON OF ELECTROCHEMICAL REVERSIBILITY OF MAGNESIUM METAL BEFORE AND AFTER CHEMICAL ACTIVATION Magnesium secondary batteries can be expected to have a high energy density because they utilize Mg2+, a divalent ion instead of monovalent alkali metal ions such as lithium. The highest energy density can be obtained by directly utilizing magnesium metal as a anode, of which volumetric capacity is about 1.9 times higher than lithium metal. [Figure 2] Cycling performance of activated magnesium metal Despite these advantages, the difficulty of efficiently charging and discharging magnesium metal due to its reactivity with electrolytes, has hindered its commercialization. KIST researchers have developed a technology to induce a highly efficient charge and discharge reaction of magnesium metal, opening the possibility of the commercialization of magnesium secondary batteries. In particular, unlike previous studies that utilized corrosive electrolytes to facilitate the charging and discharging of magnesium, the researchers utilized a common electrolyte with a similar composition to existing commercial electrolytes, enabling the use of high-voltage electrodes and minimizing corrosion of battery components. [Figure 3] (Left) Lithium metal, (middle) Magnesium metal with the equivalent capacity as the left lithium metal but smaller in size, (right) Magnesium anode immersed in chemical activation solution The team synthesized an artificial protective layer with a novel composition based on magnesium alkyl halide oligomers on the magnesium surface by a simple process of dipping the magnesium metal to be used as the anode into a reactive alkyl halide solution prior to cell assembly. They found that selecting a specific reaction solvent facilitated the formation of nanostructures on the magnesium surface, which in turn facilitated the dissolution and deposition of magnesium. Based on this, they suppressed unwanted reactions with electrolytes and maximized the reaction area through nanostructuring to induce highly efficient magnesium cycling. By applying the developed technology, the overpotential can be reduced from more than 2 V to less than 0.2 V when charging and discharging magnesium metal in a common electrolyte without corrosive additives, and the Coulombic efficiency can be increased from less than 10% to more than 99.5%. The team demonstrated stable charging and discharging of activated magnesium metal more than 990 cycles, confirming that magnesium rechargeable batteries can operate in conventional electrolytes that can be mass-produced. "This work provides a new direction for the existing magnesium secondary battery research, which has been using corrosive electrolytes that prevent the formation of interfacial layers on magnesium metal surfaces," said Dr. Minah Lee of KIST. "It will increase the possiblity of low-cost, high-energy-density magnesium secondary batteries based on common electrolytes suitable for energy storage systems (ESS).“ ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was funded by the Ministry of Science and ICT (MSIT) through the KIST Major Project and the National Research Foundation of Korea (NRF) Mid-Career Researchers Program, and the results were published in the latest issue of ACS Nano (IF:18.027, JCR top 5.652%), an international journal in the field of nanomaterials. Journal : ACS Nano Title : Reversible magnesium metal cycling in additive-free simple salt electrolytes enabled by spontaneous chemical activation Publication Date : 8-May-2023 DOI : https://doi.org/10.1021/acsnano.2c08672

- Substantially reducing the amount of platinum and iridium used in water electrolysis devices - Reducing iridium usage to one-tenth of current levels while maintaining high performance Green hydrogen, which produces hydrogen without the use of fossil fuels or the emission of carbon dioxide, has become increasingly important in recent years as part of efforts to realize a decarbonized economy. However, due to the high production cost of water electrolysis devices that produce green hydrogen, the economic feasibility of green hydrogen has not been very high. However, the development of a technology that drastically reduces the amount of rare metals such as iridium and platinum used in polymer electrolyte membrane water electrolysis devices is opening the way to lower production costs. [Figure 1] (A) CATALYST SHAPES MADE WITH CONVENTIONAL TECHNOLOGY (RED-IRIDIUM CATALYST/GREEN-PLATINUM) A research team led by Dr. Hyun S. Park and Sung Jong Yoo of the Hydrogen and Fuel Cell Research Center at the Korea Institute of Science and Technology (KIST) announced that they have developed a technology that can significantly reduce the amount of platinum and iridium, precious metals used in the electrode protection layer of polymer electrolyte membrane water electrolysis devices, and secure performance and durability on par with existing devices. In particular, unlike previous studies that focused on reducing the amount of iridium catalyst while maintaining the structure that uses a large amount of platinum and gold as the electrode protection layer, the researchers replaced the precious metal in the electrode protection layer with inexpensive iron nitride having large surface area and uniformly coated a small amount of iridium catalyst on top of it, greatly increasing the economic efficiency of the electrolysis device. The polymer electrolyte membrane water electrolysis device is a device that produces high-purity hydrogen and oxygen by decomposing water using electricity supplied by renewable energy such as solar power, and it plays a role in supplying hydrogen to various industries such as steelmaking and chemicals. In addition, it is advantageous for energy conversion to store renewable energy as hydrogen energy, so increasing the economic efficiency of this device is very important for the realization of the green hydrogen economy. In a typical electrolysis device, there are two electrodes that produce hydrogen and oxygen, and for the oxygen generating electrode, which operates in a highly corrosive environment, gold or platinum is coated on the surface of the electrode at 1 mg/cm2 as a protective layer to ensure durability and production efficiency, and 1-2 mg/cm2 of iridium catalyst is coated on top. The precious metals used in these electrolysis devices have very low reserves and production, which is a major factor hindering the widespread adoption of green hydrogen production devices. [Figure 2] Schematic of the electrode fabrication process for this development To improve the economics of water electrolysis, the team replaced the rare metals gold and platinum used as a protective layer for the oxygen electrode in polymer electrolyte membrane hydrogen production devices with inexpensive iron nitride (Fe2N). To do so, the team developed a composite process that first uniformly coats the electrode with iron oxide, which has low electrical conductivity, and then converts the iron oxide to iron nitride to increase its conductivity. The team also developed a process that uniformly coats an iridium catalyst about 25 nanometers (nm) thick on top of the iron nitride protective layer, reducing the amount of iridium catalyst to less than 0.1 mg/cm2, resulting in an electrode with high hydrogen production efficiency and durability. The developed electrode replaces the gold or platinum used as a protective layer for the oxygen generating electrode with non-precious metal nitrides while maintaining similar performance to existing commercial electrolysis units, and reduces the amount of iridium catalyst to 10% of the existing level. In addition, the electrolysis unit with the new components was operated for more than 100 hours to verify its initial stability. "Reducing the amount of iridium catalyst and developing alternative materials for the platinum protective layer are essential for the economical and widespread use of polymer electrolyte membrane green hydrogen production devices, and the use of inexpensive iron nitride instead of platinum is of great significance," said Dr. Hyun S. Park of KIST. "After further observing the performance and durability of the electrode, we will apply it to commercial devices in the near future." The research was supported by the Ministry of Trade, Industry and Energy (Minister Lee, Chang-Yang) and KIST Major Projects, and the results were published online in the latest issue of the international scientific journal Applied Catalysis B:Environmental (IF: 24.319, top 0.926% in JCR). ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was conducted through the KIST Major Projects supported by the Ministry of Science and ICT (Minister Lee Jong-ho), and the results were published online in the latest issue of the international scientific journal Applied Catalysis B:Environmental (IF: 24.319, top 0.926% in JCR). Journal : Applied Catalysis B:Environmental Title : High-performance water electrolyzer with minimum platinum group metal usage : Iron nitride-iridium oxide core-shell nanostructures for stable and efficient oxygen evolution reaction Publication Date : 9-March-2023 DOI : https://doi.org/10.1016/j.apcatb.2023.122596

- A KIST research team succeeds in the development of a simplified CO2 conversion process without a CO2 capture process - Outperforms conventional CO2 conversion technology in terms of economic feasibility and environmental impact The issue of achieving the target of net-zero CO2 emissions has emerged as a matter of future survival of mankind, with the impact of climate change causing a palpable sense of crisis in the everyday lives of people. The technology of Carbon dioxide Capture Utilization and Storage(CCUS), one of the methods for achieving net-zero CO2 emissions has drawn attention as an innovative technology for reducing CO2 emissions. CCUS is the very technology for which Elon Musk, the CEO of Tesla Inc., announced his funding of $100 million in prize money over four years starting in 2021. However, the high energy consumption required in the process of purification, pressurization, separation, and reuse of CO2 poses a challenge to the industrial application of these technologies in practice. The research team led by Drs. Ung Lee and Da Hye Won at the Clean Energy Research Center, Korea Institute of Science and Technology (KIST, President Seok Jin Yoon), announced that they succeeded in developing a process for producing high-value-added synthesis gas (syngas) by direct electrochemical conversion of CO2 captured using a liquid absorbent. The research achievement is expected to provide a cost-effective solution for CCUS technology, which has restricted wider applications of the technology. [Figure 1] Schematic diagram comparing the novel CO2 utilization technology(the proposed reaction swing absorption(RSA) pathway) with conventional CCU pathways The CO2 conversion process developed by the research team utilizes the CO2 captured in a liquid absorbent; in this way, the conventional CCU pathways with complex and energy-consuming processes of purification and pressurization of CO2 for pure gaseous CO2 production are no longer needed. For this reason, the proposed method outperforms the conventional CCUS technology, with superior cost-effectiveness and enhanced effect of reducing CO2 emissions. In addition, since unreacted CO2 is still captured in the liquid absorbent, there is no need for an additional separation process with syngas, a product from the pathway; another advantage is that the ratio of hydrogen to CO in the syngas can be more easily controlled. [Figure 2] Simplified CO2 conversion process Also, the research team was able to maximize the efficiency of the direct CO2 conversion in the liquid phase by conducting experiments for selecting the best absorbent, optimizing the catalyst, designing electrochemical reactor as well as testing long-term stability. In addition, simulation studies with numerical modeling of the industrial-scale process were also carried out to examine the feasibility of commercialization of the developed process. Furthermore, through techno-economic analysis and life cycle assessment, it is estimated that the newly developed CO2 conversion process will be able to reduce production costs by 27.0% and CO2 emissions by 75.7% compared to the conventional CCUS technology. [Figure 3] Schematic of the novel electrochemical CO2 reduction technology(RSA pathway) In addition, the proposed technology demonstrated an equivalent level of competitive price when compared to the current market price of chemicals dominated by fossil fuel-based technologies. In particular, in the case of syngas, the production cost was reduced by 27.02% compared to the conventional process (reduction of the production cost from $0.89/kg to $0.65/kg, and CO2 emissions from 1.13kg CO2/kg to 0.27kg CO2/kg. If the developed CO2 conversion process is applied to a major CO2 emission source such as a thermal power plant, the proposed technology is expected to be able to produce high-value chemicals such as ethylene at a low cost while reducing CO2. Dr. Da Hye Won, a senior research scientist at KIST, reported, “The significance of the proposed technology lies in that we have achieved technological progress in the efficient production of high-concentration syngas through the electrochemical process by utilizing captured CO2.” Dr. Ung Lee, the principal research scientist at KIST, commented, “We expect that the proposed technology will be applicable to a range of electrochemical conversion systems that utilize CO2, and we plan to move onto the next stage of continuous process demonstration and verification as well as technology transfer to business entities in the future.” ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was conducted as a part of the “Carbon to X project for the production of useful materials” with the support of the Ministry of Science and ICT (Minister Lee Jong-Ho), and the results were published in Nature Communications (IF 17.694, JCR 7.432%), a world-renowned scientific journal, on December 5, 2022. Journal : Nature Communications Title : Toward economical application of carbon capture and utilization technology with near-zero carbon emission Publication Date : 5-Dec-2022 DOI : https://doi.org/10.1038/s41467-022-35239-9

- Revealed the principle that gaseous materials cause densification of proton ceramic electrolytes - One step closer to commercializing protonic ceramic electrolysis cells for green hydrogen production Green hydrogen production technology is absolutely necessary to finally realize the hydrogen economy because unlike gray hydrogen, green hydrogen does not generate large amounts of carbon dioxide in the production process. Green hydrogen production technology based on solid oxide electrolysis cells (SOEC), which produce hydrogen from water using renewable energy, has recently attracted attention because it does not generate pollutants. Among these technologies, high-temperature SOECs have the advantage of excellent efficiency and production speed. The protonic ceramic cell is a high-temperature SOEC technology that utilizes a proton ceramic electrolyte to transfer hydrogen ions within material. These cells also use a technology that can reduce operating temperatures from 700 ℃ or more to 500 ℃ or less, thereby reducing system size and price and improving long-term operation reliability by delaying deterioration. However, it has been difficult to enter the commercialization stage because the key mechanism responsible for sintering protonic ceramic electrolytes at relatively low temperatures during the cell manufacturing process has not been specifically identified. Dr. Ho-Il Ji, Dr. Jong-Ho Lee, and Dr. Hyungmook Kang's research team at the Energy Materials Research Center, Korea Institute of Science and Technology (KIST, President Yoon Seok Jin), announced that they have increased the possibility of commercialization by identifying this electrolyte sintering mechanism: a next-generation high-efficiency ceramic cell that had not previously been identified. The research team designed and conducted various model experiments based on the fact that the transient phase generated on the electrode during the electrolyte-electrode sintering process affects the densification of the electrolyte. They discovered for the first time that supplying the electrolyte with a small amount of gaseous sintering aid material from the transient phase promotes sintering of the electrolyte. Gaseous sintering aids are extremely rare and technically difficult to observe; therefore, the hypothesis that the densification of the electrolyte in proton ceramic cells is caused by vaporized sintering aids has never been proposed. The research team verified the gaseous sintering aid using computational science and confirmed that the reaction did not impair the unique electrical properties of the electrolyte. Thus, the design of the core manufacturing process of proton ceramic cells is expected to be possible. Dr. Ji of KIST said, "Through this research, we have come one step closer to developing the core manufacturing process for protonic ceramic cells. We plan to conduct research on the manufacturing process of large-area, high-efficiency proton ceramic cells in the future." He also mentioned that, "If large-area technology is successfully developed, it will be possible to produce pink hydrogen in connection with next-generation nuclear technology as well as green hydrogen in connection with renewable energy, which will lead to the commercialization of ceramic cells and accelerate the realization of the hydrogen economy." This research was conducted under major KIST projects, the New Renewable Energy Technology Development Project by the National Research Foundation of Korea, supported by the Ministry of Science and ICT (Minister Jong-ho Lee), and the New Renewable Energy Technology Development Project by the Korea Institute of Energy Technology Evaluation and Planning, which is supported by the Ministry of Trade, Industry, and Energy (Minister Chang-yang Lee). The research results were published in the latest issue of ACS Energy Letters (IF: 23.991, top 3.211% in the JCR field), an international journal in the field of energy. Journal: ACS Energy Letters Title: An Unprecedented Vapor-Phase Sintering Activator for Highly Refractory Proton-Conducting Oxides Publication Date: 21-Oct-2022 DIO: https://doi.org/10.1021/acsenergylett.2c02059 The principle of accelerating electrolyte densification in the proton ceramic cell manufacturing process

- Complete replacement of existing petrochemical-based solvents with environmentally friendly solvents - Production of economically secured and environmentally friendly biofuels and renewable chemicals in a ‘one-pot process’ Biomass refers to biological organisms, including plants, that synthesize organic matter utilizing solar energy and animals that use these plants as food. Biomass also includes resources that can be converted into chemical energy. To achieve carbon neutrality by 2050, substantial efforts have been made worldwide to develop biorefinery technology that can replace fossil fuels with biofuels. However, the conventional biofuel production process involves the use of highly toxic solvents, which are mainly derived from petroleum causing environmental and economic concerns. Dr. Kwang Ho Kim’s research team at the Clean Energy Research Center of Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) developed a green solvent that can completely replace conventional petrochemical-based solvents while maximizing the efficiency of biofuel production. The researchers announced that it is now possible to produce sustainable and economically secured biofuels. After screening various solvent candidates, the KIST research team synthesized a green deep eutectic solvent that is also biocompatible with microorganisms during the fermentation process. The synthesized eutectic solvents were systematically analyzed by advanced nuclear magnetic resonance spectroscopy and computational analysis. The ‘one-pot process’ based on the newly developed solvent maximized the production efficiency of high-purity biofuels and biochemicals by integrating three to four complex existing processes into one consolidated process. It was also announced that the one-pot process that uses environmentally friendly solvents is sustainable, does not emit pollutants, does not require washing water, and allows for the reuse of solvents. Dr. Kim of KIST said, “By overcoming the uneconomical problems currently being faced by the biorefinery industry via the development of green solvents and maximization of biofuel production process efficiency, Korea will be able to take the lead in the ‘Race to Zero’ by developing this sustainable technology.” This research was supported by by the KIST and the National Research Foundation of Korea (Minister Jong Ho Lee). This collaborative research was conducted between the University of British Columbia, State University of New York, National Institute of Forest Science of Korea and Korea Military Academy. The research results were published in the latest issue of Green Chemistry (Impact Factor: 11.034), an international journal in the energy and environment field and were selected as the back cover. One-pot process for producing biofuels and biochemicals from biomass using environmentally friendly eutectic solvents Title: One-pot conversion of engineered poplar into biochemicals and biofuels using biocompatible deep eutectic solvents Journal: Green Chemistry DOI: https://doi.org/10.1039/D2GC02774G

- Revealed cause of the reduced lifespan of manganese-based cathode materials, and expensive nickel is expected to be replaced - Battery strategy with improved lifespan by 62% with electrode-electrolyte interface stabilization technology Currently, most cathode materials used in batteries for electric vehicles are layered oxides composed of nickel for over 60% of the transition metals. Using nickel-rich layered oxide is advantageous in securing the mileage of an electric vehicle due to its high energy density, but its usage is limited by instability in the supply and demand of nickel raw materials. As an alternative, researchers focused on spinel cathode materials that use manganese as the main element, considering manganese is traded at a price of about 1/17 of nickel in the international spot market; however, the rapid decline in lifespan was an obstacle to commercialization. The Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) announced that Dr. Jihyun Hong's research team at the Energy Materials Research Center identified the cause of the rapid decline in life span-a chronic problem of high-capacity manganese-based spinel cathode materials. This team worked on significantly increasing the possibility of commercializing lithium batteries with manganese cathode materials as next-generation electric vehicle batteries. Manganese-based spinel cathode materials can theoretically store energy with a high density comparable to nickel-based commercial cathode materials. Considering the price of metal raw materials, the energy density per price for manganese-based spinel cathode could reach 2.8 times that of nickel-based cathodes. However, when using the battery at full capacity, a rapid decrease in lifespan is observed; as a result, practically only approximately 75% of the theoretical value could be stored. It has been established that the trivalent manganese (Mn3+) formed during the charging and discharging process of manganese-based spinel cathode materials distorts the crystal structure of the material, leading to the elution of manganese into the electrolyte and eventually causing a reduction in the lifespan of the cathode material. As a result, most research has focused on suppressing the formation of trivalent manganese. Contrary to mainstream academic theories, Dr. Hong's team at KIST (first author: student researcher Gukhyun Lim) recently discovered that cathode materials exhibit excellent lifespan characteristics even when trivalent manganese is formed if the operating voltage range of the battery is adjusted. The research team utilized advanced material characterization techniques, including synchrotron radiation techniques, to interpret the phenomena that existing theories cannot explain. Through the thorough analyses, for the first time, it was identified that the side reaction at the interface between the cathode material and electrolyte during the repeated charging and discharging process is the cause of lifespan reduction. The research team further presented a key strategy to dramatically improve the lifespan of manganese-based materials by stabilizing the cathode-electrolyte interface. As an example of this strategy, introducing an EC-free electrolyte resulted in a 62% improvement in lifespan compared to commercial electrolytes. This improvement results in the highest capacity retention and rate capability among the performances of manganese-based spinel cathode materials simultaneously using nickel and manganese redox reactions reported so far. Dr. Hong of KIST said, "Through this research, KIST presented a new methodology for commercializing manganese-based high-energy cathode materials, which will be a catalyst for the expansion of electric vehicles." He also mentioned, "If academia and industry focus on applying the interface stabilization technology of nickel-based cathode materials, which has accumulated a lot of capabilities, to manganese-based next-generation cathode materials, we expect that Korean companies in the automobile industry could maintain a higher level of competitiveness in the future." This research was conducted under major KIST projects and Individual Research program (excellent young researcher, mid-career researcher) of the National Research Foundation of Korea with the support of the Ministry of Science and ICT (Minister Jong-ho Lee), with the research results selected as the full front cover page paper of 'Advanced Energy Materials' (IF: 29.698, top 2.464% in the JCR field), a world-renowned journal in the field of energy materials. [Figure 1] Selected image for the full front cover page paper [Figure 2] Changes in the price of cathode materials over the past three years (left), performance comparison of manganese-based cathode materials compared to other cathode materials (right). The square indicates the manganese-based cathode material studied with this achievement. [Figure 3] Newly identified maganese-based spinel cathode-electrolyte interface side reation mechanism Title: Regulating Dynamic Electrochemical Interface of LiNi0.5Mn1.5O4 Spinel Cathode for Realizing Simultaneous Mn and Ni Redox in Rechargeable Lithium Batteries Journal: Advanced Energy Materials DOI: https://doi.org/10.1002/aenm.202202049

Due to unusual weather conditions caused by global warming, countries around the world have been suffering from disasters such as extreme heat waves, droughts, and floods in recent years, raising a sense of crisis. Meanwhile, Korean researchers have developed a new catalyst material to realize the resourceization of carbon dioxide, one of the causes of greenhouse gases that cause global warming. Korea Institute of Science and Technology (KIST, President Yoon Seokjin) announced that the team of Dr. Hyung-Suk Oh and Dr. Woong Hee Lee at the Clean Energy Research Center developed a nickel sulfide catalyst used to convert carbon dioxide, the main culprit of greenhouse gases, into carbon monoxide, which is used as a raw material for industries. When the catalyst was applied to the actual conversion systerm, the carbon dioxide conversion performance was three times or more than that of the existing nickel single atom catalyst. Carbon dioxide accounts for most of the substances that cause global warming and has the greatest impact on the greenhouse effect. Through an electrochemical reduction reaction, carbon dioxide can be converted into useful compounds such as carbon monoxide, ethylene, antacid, and methanol. Therefore, research to collect, utilize, and store carbon dioxide is being actively carried out. In particular, carbon monoxide (CO) is a very important basic raw material in the industry. Since carbon monoxide is very chemically unstable, it is mainly used as a reducing agent in the chemical, metal and electronic industries. It also has the highest economic value among chemical materials that can be made of carbon dioxide because of its high production compared to energy input. Research on converting carbon dioxide into carbon monoxide has been based on presioud metal catalysts such as expensive silver and gold. For full-scale commercialization, the development of inexpensive catalyst materials is the key. A nickel(Ni)-based single atom catalyst has been developed as an alternative to a precious metal catalyst, but there is a limit to the conversion rate of carbon dioxide, that is, the maximum current amount, being low. The KIST research team proposed a relatively inexpensive nickel sulfide catalyst and applied it to an actual system to confirm that its performance was high. It was known that only nickel in a single atomic state can be used for carbon dioxide conversion, and nickel catalysts in other metalic states are not possible. However, the research team confirmed though operando analysis that the nickel sulfide catalyst exhibits high electrochemical carbon dioxide conversion activity by simulating the electroninc structure of the single atomic nickel catalyst during the reaction. In addition, it has been confirmed that power efficiency (Faradaic efficiency 3) is also improved by more than three times (70%) compared to the existing nickel monatomic catalyst (22%) Dr. Oh of KIST said, "The nickel sulfide catalyst material, which was simulated by analyzing the reaction and behavior of the nickel single atom catalyst in real time, was born through an original catalyst research and development method called electronic structure imitation. The significance of the study is that it presented new possibilities for developing various low-cos catalysts." He also said, "We plan to make efforts to quickly commercialize nickel sulfide catalysts through follow-up studies such as long-term durability in the future." With the support of the Ministry of Science and ICT (Minister Lee Jong-ho), this study was conducted as a KIST institutional program, 'Carbon to X Project', and a 'Creative Convergence Research Project' by the National Science and Technology Research Association (Chairman Kim Bok-cheol). It was also published in the latest issue of Advanced Energy Materials, an international journal in the field of energy and environment (IF: 29.698, the top 2.464% in the field of JCR).

- Expected to replace lithium-based energy storage systems that have a high risk of explosions with aqueous zinc batteries. Successful growth and optimization of zinc metal anodes through low-cos and ecofriendly electroplate processes. Most energy storage systems (ESSs) have recently adopted lithium-ion batteries (LIBs), with the highest technology maturity among secondary batteries. However, these are argued to be unsuitable for ESSs, which store substantial amounts of electricity, owing to fire risks. The instability of the international supply of raw materials to construct LIBs has also emerged as a crucial concern. By contrast, aqueous zinc-ion batteries (AZIBs) use water as the electrolyte, which fundamentally prevents battery ignition. Furthermore, the price of zinc, the raw material, is only one-sixteenth of that of lithium. The research team led by Dr. Minah Lee at the Energy Storage Research Center in the Korea Institute of Science and Technology (KIST; President Seok-Jin Yoon) announced that they had succeeded in developing a technology for manufacturing “high-density zinc metal anodes,” which is key to commercializing AZIBs. This manufacturing technology is expected to act as a catalyst for the mass production of AZIBs because zinc metal anodes with high energy density and long lifespan can be produced through a simple electroplating process by using low-cost and ecofriendly solutions. In theory, because AZIBs utilize two electrons per ion, they are advantageous in terms of volumetric energy density relative to alkali metal-ion batteries. If the capacity of the zinc metal used as the anode for making the battery does not exceed twice that of the cathode, it is possible to realize an energy density comparable to that of the LIBs commercialized today. Furthermore, even if the capacity of the zinc metal reaches five times that of the cathode, it is still competitive in that it is similar to that of sodium-ion batteries, which are attracting attention as the next generation of batteries owing to their low cost and material abundance. However, zinc metal anodes restrict the energy density and lifespan of AZIBs because of the irregular growth of nanoparticles during battery operation. A low zinc metal particle density and a large surface area in the anode accelerate corrosion with the electrolyte, thus depleting the active zinc metal and the electrolyte. Existing studies have typically used zinc metals that were 20 times thicker than what was required to counteract the lifespan limitations; paradoxically, this led to an inevitable decline in energy density and cost competitiveness, the biggest strengths of AZIBs. Thus, the team led by Dr. Minah Lee at the KIST controlled the microstructure of zinc metal anodes to reduce the prevalence of the side reactions that induce the decline in energy density and lifespan of AZIBs. The team adopted a deep eutectic solvent (DES) solution, which can be easily synthesized at room temperature, was to construct the compact zinc anodes. This DES solution is composed of choline chloride and urea mixed at a mole ratio of 1:2; the mixture becomes a liquid complex with a melting point of 12 °C. The researchers confirmed that a zincophilic copper–zinc alloy layer spontaneously forms between the zinc and copper current collectors within the DES, enabling high-density zinc particles to grow. The researchers succeeded in using this discovery to develop an electroplating process that allows zinc metals to grow densely and evenly in the low-cost and ecofriendly DES solution. Application of the manufactured zinc metal anode to an aqueous zinc battery system showed that the corrosion reactions are effectively suppressed, and the capacity is maintained at more than 70% after more than 7000 repeated charges and discharges. This result is exceptional relative to those of similar existing studies that utilized thin zinc, and the values far exceed the charging and discharging lifespans (1000–2000 times) of commercial LIBs. Dr. Minah Lee of the KIST stated, “We were able to develop a core technology for commercializing AZIBs that can solve the fire safety issue of ESSs, which is the biggest obstacle to the provision and expansion of renewable energy.” She added, “We expect that this compact zinc anode manufacturing technology will open the way for the mass production of AZIBs by combining a particularly economical and ecofriendly DES solution with an electroplating process already widely used throughout the industry.” - Image Unlike zinc particles, which are irregularly formed in a conventional aqueous electrolyte and induce corrosion, zinc grown in a DES solution is tight and uniform and maintains a stable structure even after charging and discharging in an aqueous electrolyte

- Enhancement four times the conventional production rate, 100 times the durability compared to conventional commercial electrodes. - High potential use for LOHC hydrogen reservoir. "Carbon dioxide as a resource" and "hydrogen energy utilization" are considered to be the most practical measures to realize carbon neutrality. However, technological innovation is essential for them to be feasible both environmentally and economically. To this end, a Korean research team developed a proprietary technology that harnesses the synergy of both fields: "carbon dioxide as a resource" and "hydrogen energy utilization." The Korea Institute of Science and Technology (KIST; President: Seok-Jin Yoon) reported that the research group of Dr. Hyung-Suk Oh at the Clean Energy Research Center has developed a technology that stably converts carbon dioxide into useful liquid compounds (formate) by performing high-volume synthesis with fluorine-doped tin oxide catalysts. Also called methanoic acid, formate is a basic chemical raw material used in various industries such as food processing, preservatives, dyeing agents, plasticizers, snow removal agents, and cure retardants owing to its distinctive sour taste, anti-bacterial properties, and its ability to control pH. In recent years, it has also been in the spotlight as a raw material for eco-friendly biodegradable plastic. Because most formate is currently produced via the thermo-chemical reaction of fossil fuels, carbon dioxide emissions are inevitable during the manufacturing process. While it can be manufactured in an eco-friendly manner if carbon dioxide is directly converted into formate via an electro-chemical reaction, it would be necessary to increase electrode material performance responsible for converting the gas to a liquid phase, and to ensure durability, which allows electrodes to function stably for a long time. The KIST research team focused on the fact that fluorine-doped tin oxide has a lower tendency than regular tin oxide to metalize and maintain the carbon dioxide conversion activity of catalysts. By using a relatively simple method of doping fluorine during the synthesis of Tin oxide, the researchers developed an electrode that maintains high formate conversion activity in a stable manner. The fluorine-doped tin oxide electrode manufactured by the proposed method was shown to have a formate production rate that is four times that of an existing commercial tin oxide electrode, and its durability improved by at least 100 times, so its performance is maintained even during a long-term reaction time of over a week. Alternatively, formate is one of the most promising candidates as a liquid organic hydrogen carrier (LOHC), which is a hydrogen storage material that bonds hydrogen with a third substance to enable storage and transportation without the need to rely on expensive heavy-duty specialized containers. The core of LOHC technology is to secure liquefied compounds with high storage capacity for hydrogen and safety, even when exposed to external factors; formate has this characteristic. With the application of the technology developed by the researchers, as the environmental and economic concerns (which were previously considered weaknesses) will be resolved simultaneously, a reevaluation of its competitiveness is expected against other candidate materials such as ammonia. According to Dr. Hyung-Suk Oh, "By developing highly efficient electrodes, we can build a continuous system mass-producing formate from carbon dioxide." "Not only is this a direction for Carbon Capture, Utilization and Storage (CCUS), but also it is a "killing two birds in one stone" kind of technology that provides large amount of formate ideal for hydrogen storage. We expect it to contribute greatly to carbon neutrality in the future as the renewable energy supply increases and the hydrogen-based society advances, making the system economically feasible." - Image Production and utilization of formate with fluorine-doped tin oxide catalyst for CO2 conversion

- Development of polymer additives to solve the performance degradation of large-area solar cells based on the solution process. - Future expectations regarding solar cell technology commercialization that can be applied in printing technology Solar cell technology is a prominent clean energy source. In particular, organic solar cells, part of the third generation of solar cells, are gaining attention as a core technology for urban solar ray energy generation as they can be printed and applied to exterior walls or glass windows of buildings. However, the photoactive area that absorbs sunlight and converts it to electricity remains significantly smaller than 0.1 cm². Additionally, commercialization is obstructed by performance and reproducibility problems that occur when expanding the cell area to several m2 where practical energy supply levels are available. A research team led by Dr. Hae Jung Son of the Advanced Photovoltaics Research Center at the Korea Institute of Science and Technology (KIST; President: Seok-Jin Yoon) discovered the factors causing performance degradation in large-area organic solar cells and announced the development of a new polymer additive material for large-area, organic solar cell technology development. The research team focused on the photoactive layer’s compositional form in organic solar cells and the solution process, which is a part of the organic solar cell manufacturing process. The spin coating method, a solution process mainly used in the laboratory research stage, creates a uniform photoactive layer mixture as the solvent evaporates rapidly while the substrate rotates at a high speed. However, the large-area, continuous solution process designed for industrial use caused solar cell performance deterioration because the solar cell material solution’s solvent evaporation rate was too slow. Consequently, unwanted aggregation between the photoactive materials can be formed. The research team developed a polymer additive that can prevent this phenomenon by interacting with materials prone to aggregate. As a result, ternary photoactive layers containing polymer additives were fabricated to prevent aggregation in photoactive layers. Additionally, owing to possible nano-level structure control, solar cell performance improvements and stability security are acquired against light-induced temperature increases during solar cell operation. A 14.7% module efficiency was achieved, resulting in a 23.5% performance increase compared to that of the conventional binary system. Efficiency and stability were simultaneously demonstrated by maintaining over 84% initial efficiency for 1,000 hours, even in an 85℃ heated environment. KIST’s Dr. Son stated, “We have gotten closer to organic solar cell commercialization by proposing the core principle of a solar cell material capable of high-quality, large-area solution processing,” further expressing that “commercialization through follow-up research will make eco-friendly self-sufficient energy generation possible that is easily applicable to exterior building walls and automobiles and also utilized as an energy source for mobile and IoT devices.” - Image (left) high-efficiency, high-stability, organic solar module incorporating ternary photoactive layers. (right) Performance of the high-efficiency, high-stability, organic solar module incorporating ternary photoactive layers