• 전기화학회지
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• 제24권4호
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• pp.100-105
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• 2021

최근 리튬이차전지의 안전성을 향상시킨 전고체 전지가 많은 관심의 대상이 되고 있으나 전도성 세라믹 또는 고체 고분자 전해질을 적용한 고체전지는 높은 계면 저항, 부반응 등과 같은 문제점을 지니고 있어 전기화학적 특성이 낮다. 기존 전고체 전지의 이러한 문제점을 해결하기 위하여 복합고체 전해질이 제안되었으며 본 연구에서는 나시콘 구조의 나노 입자 Li_1.5Al_0.5Ti_1.5P₃O₁₂ (LATP) 전도성 세라믹, PVdF-HFP, 카보네이티 기반 액체전해질을 복합화 하여 유사고체 전해질을 제작하였다. 이 복합고체 전해질은 5.6 V의 높은 전압 안전성을 가지며 리튬이온의 탈리-착리 테스트에서 리튬 금속전극의 덴드라이트 성장 억제 효과가 있음을 보여준다. 또한 복합고체 전해질을 적용한 LiNi_0.83Co_0.11Mn_0.06O₂ (NCM811)기반 전지에서 4.8 V의 높은 충전 종지 전압에도 241.5 mAh/g의 높은 방전 용량을 나타내며 안정적인 전기화학 반응이 일어난다. NCM811 기반 전지의 90도 충전-방전 중에도 전지의 단락이나 폭발 없이 139.4 mAh/g 방전 용량을 보인다. 따라서 LATP기반 복합고체 전해질은 리튬이차전지의 안전성과 전기화학적 특성을 향상 시킬 수 있는 효과적인 방법임을 알 수 있다.

• Corrosion Science and Technology
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• 제22권4호
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• pp.287-296
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• 2023

Li-ion batteries have been gaining increasing importance, driven by the growing utilization of renewable energy and the expansion of electric vehicles. To meet market demands, it is essential to ensure high energy density and battery safety. All-solid-state batteries (ASSBs) have attracted significant attention as a potential solution. Among the advantages, they operate with an ion-conductive solid electrolyte instead of a liquid electrolyte therefore significantly reducing the risk of fire. In addition, by using high-capacity alternative electrode materials, ASSBs offer a promising opportunity to enhance energy density, making them highly desirable in the automotive and secondary battery industries. In ASSBs, Li metal can be used as the anode, providing a high theoretical capacity (3860 mAh/g). However, challenges related to the high interfacial resistance between Li metal and solid electrolytes and those concerning material degradation during charge-discharge cycles need to be addressed for the successful commercialization of ASSBs. This review introduces and discusses the interfacial reactions between Li metal and solid electrolytes, along with research cases aiming to improve these interactions. Additionally, future development directions in this field are explored.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1591-1596
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• 2020

고분자를 기반으로 하는 고체전해질은 용이한 가공성, 재료의 유연성뿐만 아니라 배터리, 슈퍼커패시터를 포함하는 이차전지 등 다양한 전기화학 소자에 응용이 가능한 소재로서, 기존 전해질의 낮은 이온전도도 및 전기화학적 안정성을 향상시키기 위하여 다양한 이온성 액체 기반의 고체 전해질에 관한 연구가 활발히 진행 중에 있다. 이온성 액체의 높은 이온전도성, 넓은 전기화학 안정성, 열적 안정성을 활용한 고분자 전해질은 다양한 전자소자에 활용되고 있다. 따라서 본 연구에서는 이온성 액체의 종류와 비율의 최적화를 통하여 고분자 기반의 고체 전해질을 제조하고 전기화학적 성능을 분석하여 이차전지를 포함한 다양한 전자 소자에 응용이 가능한 이온성 액체 기반의 전해질을 개발하고자 하였다. 이온성 액체의 비율을 최적화를 통하여 제조된 고분자 기반 고체 전해질의 이온 전도도는 1.46-2 S/cm로 확인되었다. 이온전도도가 향상된 이온성 액체와 고분자 기반의 고체 전해질은 다양한 이차전지에 활용될 수 있을 것으로 사료된다.

• Transactions on Electrical and Electronic Materials
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• 제8권2호
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• pp.73-78
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• 2007

The crystallization temperature in GeTe solid electrolyte films was improved by in situ-nitrogen doping by rf magnetron co-sputtering technique at room temperature. The crystallization temperature of $250\;^{\circ}C$ in electrolyte films without nitrogen doping increased by approximately $300\;^{\circ}C$, $350\;^{\circ}C$, and above $400\;^{\circ}C$ in films deposited with nitrogen/argon flow ratios of 10, 20, and 30 %, respectively. A PMC memory device with $Ge_{45}Te_{55}$ solid electrolytes deposited with nitrogen/argon flow ratios of 20 % shows reproducible memory switching characteristics based on resistive switching at threshold voltage of 1.2 V with high $R_{off}/R_{on}$ ratios. Nitrogen doping into the silver saturated GeTe electrolyte films improves the crystallization temperature of electrolyte films and does not appear to have a negative impact on the switching characteristics of PMC memory devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.174-175
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• 2007

A programmable metallization cell (PMC) memory structure with copper-saturated GeTe solid electrolyte films doped by nitrogen was prepared on a TiW bottom electrode by a co-sputtering technique at room temperature. The $Ge_{45}Te_{55}$ solid electrolyte films deposited with various $N_2$/Ar flow ratios showed an increase of crystallization temperature and especially, the electrolyte films deposited at $N_2$/Ar ratios above 30% showed a crystallization temperature above $400^{\circ}C$, resulting in surviving in a back-end process in semiconductor memory devices. The device with a 200 nm thick $Cu_{1-x}(Ge_{45}Te_{55})_x$ electrolyte switches at 1 V from an "off " state resistance, $R_{off}$, close to $10^5$ to an "on" resistance state, Ron, more than 20rders of magnitude lower for this programming current.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.84.1-84.1
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• 2011

Typical solid oxide fuel cells (SOFCs) have limited applications because they operate at high temperature due to low ionic conductivity of electrolyte. Thin film solid oxide fuel cell with yttria stabilized zirconia (YSZ) electrolyte is developed to decrease operating temperature. Pt/YSZ/Pt thin film SOFC was fabricated on anodic aluminum oxide (AAO). The crystalline structure of YSZ electrolyte by sputter is heavily depends on the roughness of porous Pt layer, which results in pinholes. To deposit YSZ electrolyte without pinholes and electrical shortage, it is necessary to deposit smoother and denser layer between Pt anode layer and YSZ layer by sputter. Atomic Layer Deposition (ALD) technique is used to deposit pre-YSZ layer, and it improved electrolyte quality. 300nm thick Bi-layered YSZ electrolyte was successfully deposited without electrical shortage.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권3호
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• pp.125-133
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• 2002

In order to fabricate stable conductive polymer actuators which can be operated in air, conductivity and solidity of polymer electrolyte materials have been studied. It was found that Nafion+LiCl is appropriate material to be used for conductive polymer actuator. Using the Nafion+LiCl solid polymer electrolyte, single layer PPy actuators have been fabricated and their deflection was measured. Double layer PPy actuators make up for shortcoming of single layer PPy actuator and displacement and frequency response can be improved by fabrication of double layer PPy actuator. This kind of all-solid-polymer actuator can be used for practical applications.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.114-118
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• 2022

The stabilized all-solid-state battery structure indicate a fundamental alternative to the development of next-generation energy storage devices. Existing liquid electrolyte structures severely limit battery stability, creating safety concerns due to the growth of Li dendrites during rapid charge/discharge cycles. In this study, a low-dimensional graphene quantum dot layer structure was applied to demonstrate stable operating characteristics based on Li+ ion conductivity and excellent electrochemical performance. Transmission electron microscopy analysis was performed to elucidate the microstructure at the interface. The low-dimensional structure of GQD-based solid electrolytes has provided an important strategy for stable scalable solid-state lithium battery applications at room temperature. This study indicates that the low-dimensional carbon structure of Li-GQDs can be an effective approach for the stabilization of solid-state Li matrix architectures.

• 전기화학회지
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• 제2권1호
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• pp.1-4
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• 1999

리튬이차전지는 충방전의 반복 동안의 액체전해질과 리튬음극과의 반응으로 수지상결정의 성장으로 리튬이 차전지에 있어서 안전성의 문제를 일으킨다. 고분자 전해질은 수지상 결정 형성을 억제하며 전해질에 성능을 향상시키는 연구가 활발히 진행중이다. 본 연구에서는 겔 전해질에 $Al_2O_3$를 첨가하여 전해질의 표면구조와 임피던스 특성을 조사하였다. 리튬이온의 수율은 $10wt\%\;PAN-Al_2O_3$ 전해질에 5mV의 전압을 인가했을 때 0.29였고 전해질의 이온전도도는 상온에서$2.3\times10^{-4} S/cm$였다. 무기 충진제가 고분자 전해질에 첨가되었을 때 이온전도도 및 이온수율은 무기 충진제가 첨가되지 않은 것보다 높게 나타났다.

• 한국표면공학회지
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• 제57권2호
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• pp.115-124
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• 2024

In advancing Li-ion battery (LIB) technology, the solid electrolyte interface (SEI) layer is critical for enhancing battery longevity and performance. Formed during the charging process, the SEI layer is essential for controlling ion transport and maintaining electrode stability. This research provides a detailed analysis of how vinylene carbonate (VC) influences SEI layer formation. The integration of VC into the electrolyte markedly improved SEI properties. Moreover, correlation analysis revealed a connection between electrolyte decomposition and battery degradation, linked to the EMC esterification and dicarboxylate formation processes. VC facilitated the formation of a more uniform and chemically stable SEI layer enriched with poly(VC), thereby enhancing mechanical resilience and electrochemical stability. These findings deepen our understanding of the role of electrolyte additives in SEI formation, offering a promising strategy to improve the efficiency and lifespan of LIBs.