A Solid-State Thin-Film Electrolyte, Lithium Silicon Oxynitride, Deposited by using RF Sputtering for Thin-Film Batteries

Dan Na,Byeongjun Lee,Baeksang Yoon,Inseok Seo 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.9

In this study, a new lithium-silicon-oxynitride (LiSiON) solid-state thin-film electrolyte was investigated for the first time. The LiSiON thin-film electrolyte was deposited by using the RF sputtering technique. In order to compare the LiSiON thin-film electrolyte to lithium phosphorous oxynitride (LiPON), a conventional thin-film electrolyte, were deposited LiPON thin-film electrolytes by using RF sputtering. Surface morphologies and cross-sectional views of the thin-film electrolytes were characterized by using field emission scanning electron microscopy (FE-SEM). The thin-films showed smooth surfaces without any cracks and pinholes. The smooth surfaces are thought to decrease the interfacial resistance between the electrolyte and the electrodes. In addition, surface morphologies were characterized by using atomic force microscopy (AFM). The sputtering rates were calculated using the thicknesses of the thin-films, as obtained from cross-sectional views. The structural properties of the thin-films were characterized using X-ray diffraction (XRD). All thin-films showed amorphous properties compared to the target material which is a crystalline material. The ionic conductivity of the LiSiON thin-film was 2.47 × 10-6 (S/cm), which is slightly higher than that of a common thin-film electrolyte LiPON.

Specific considerations for obtaining appropriate La_1−<i>x</i>Sr_<i>x</i>Ga_1−<i>y</i>Mg_<i>y</i>O_{3−<i>δ</i>} thin films using pulsed-laser deposition and its influence on th

Hwang, Jaeyeon,Lee, Heon,Lee, Jong-Ho,Yoon, Kyung Joong,Kim, Hyoungchul,Hong, Jongsup,Son, Ji-Won Elsevier 2015 Journal of Power Sources Vol.274 No.-

<P><B>Abstract</B></P> <P>To obtain La<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>Ga<SUB>1−<I>y</I> </SUB>Mg<SUB> <I>y</I> </SUB>O<SUB>3−<I>δ</I> </SUB> (LSGM) thin films with the appropriate properties, pulsed-laser deposition (PLD) is employed, and specific considerations regarding control of the deposition parameters is investigated. It is demonstrated that with a target of stoichiometric composition, appropriate LSGM thin films cannot be produced because of the deviation of the composition from the target to the thin film. Only after adjusting the target composition an LSGM thin film with an appropriate composition and phase can be obtained. The optimized LSGM thin film possesses an electrical conductivity close to that of the bulk LSGM. In contrast, non-optimized thin films do not yield any measurable electrical conductivity. The impact of the optimization of the LSGM thin-film electrolyte on the cell performance is quite significant, in that a solid-oxide fuel cell (SOFC) with an optimized LSGM thin-film electrolyte produces a maximum power density of 1.1 W cm<SUP>−2</SUP> at 600 °C, whereas an SOFC with a non-optimal LSGM thin-film electrolyte is not operable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Exact transfer of the composition of the LSGM target to the film is not possible. </LI> <LI> Target composition control and a high deposition temperature are necessary. </LI> <LI> An SOFC with an optimized LSGM thin-film electrolyte yielded 1.1 W cm<SUP>−2</SUP> at 600 °C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Highly conductive and mechanically robust nanocomposite polymer electrolytes for solid-state electrochemical thin-film devices

Lee, Seung Ju,Yang, Hae Min,Cho, Kyung Gook,Seol, Kyoung Hwan,Kim, Sangwon,Hong, Kihyon,Lee, Keun Hyung Elsevier 2019 Organic electronics Vol.65 No.-

<P><B>Abstract</B></P> <P>Ionic liquid-based polymer electrolyte composites (PECs) with high mechanical strength and ionic conductivity were fabricated by using a semicrystalline homopolymer network. Morphological, mechanical, and electrical properties of semicrystalline homopolymer-based PECs were investigated over the composition range of 10–50 polymer wt%. The PECs consisted of poly(vinylidene fluoride) (PVDF) and a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). The amorphous PVDF chains were solvated by the liquid electrolyte and interconnected the phase-separated PVDF crystalline-domains, acting as physical crosslinks. The ionic conductivity and specific capacitance of the homopolymer PECs were found to be very high, ranging from 0.4 to 4.9 mS/cm and from 2.6 to 9.1 μF/cm<SUP>2</SUP>, respectively. The elastic moduli of the PECs that range from 4 to 38 MPa were also greater than those of PECs prepared by using other polymeric networks. These PECs were successfully applied as electrolyte membranes in electrical double layer supercapacitors and as high-capacitance gate insulators in electrochemical thin-film transistors. These results provide detailed systematic data for fabricating high-performance solid polymer electrolytes for electrochemical thin-film devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polymer electrolyte composites with both high mechanical strength and ionic conductivity. </LI> <LI> Polymer electrolytes as a high-capacitance gate insulator in thin-film transistors. </LI> <LI> Low voltage operation (<1 V) of P3HT transistors at high polymer fraction. </LI> <LI> Polymer electrolytes as an electrolyte membrane in electric double layer supercapacitors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation and Electric Characterization of Single Phase La0.8Sr0.2Ga0.8Mg0.2O3 and La0.8Sr0.2Ga0.8Mg0.115Co0.085O3 Thin Films

임윤택,손종역 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.2

La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) and La0.8Sr0.2Ga0.8Mg0.115Co0.085O3 (LSGMC) thin films were deposited on single crystalline (001) Al2O3 substrates using a pulsed laser deposition technique. The LSGM and LSGMC thin films exhibited only a single phase, which was verified through x-ray diffraction (XRD) experiments. Scanning electron microscopy (SEM) showed that the grain size of the LSGM film was smaller than that of the LSGMC films. Below 800 K, the ionic conductivity of both the thin films was higher than that of bulk sample. Furthermore,the LSGM thin film showed higher ionic conductivity than the LSGMC thin film at temperatures above 600 K.

유기용매 전해조를 이용한 리튬이차박막전지용 Sn 음극의 제조

김동훈,도칠훈,이정훈,이덕준,하경화,진봉수,김현수,문성인,황영기,Kim, Dong-Hun,Doh, Chil-Hoon,Lee, Jeong-Hoon,Lee, Duck-Jun,Ha, Kyeong-Hwa,Jin, Bong-Soo,Kim, Hyun-Soo,Moon, Seong-In,Hwang, Young-Ki 한국전기화학회 2008 한국전기화학회지 Vol.11 No.4

박막 리튬이차전지의 고용량 음극을 개발하기 위하여, Sn(II) 아세테이트를 포함한 유기전해조 도금법을 이용하여 Sn 박막전극을 제조하였다. $Li^+$와 $Sn^{2+}$를 포함한 전해조에 대한 순환전위전류시험 결과 3종류의 환원 반응이 나타났으며, $2.0{\sim}2.5\;V$ 영역이 Ni 집전체 표면에 대한 Sn의 석출 반응에 해당한다. 수계전해액에 대한 $Sn^{2+}$의 표준환원전위는 2.91 V vs. $Li^+/Li^{\circ}$ 인데 반해 유기전해조에서는 보다 낮은 전위에서 환원반응이 일어났다. 이는 유기전해질의 고저항과 $Sn^{2+}$의 낮은 농도에 기인한 과전위의 결과로 생각된다. 제조한 전극의 물리적 특성 및 전기화학적 특성을 연구하였다. 석출한 Sn 전극을 $150^{\circ}C$로 열처리하여 보다 높은 결정성을 얻을 수 있었고, 이를 Sn/Li 전지로 구성하여 전기화학적 실험을 한 결과 0.25 V와 0.75 V에서 각각 합금화-탈합금화 과정을 확인 할 수 있었다. 제조한 전극의 두께를 전기량을 통하여 계산한 바 $7.35{\mu}m$였으며, 가역용량은 $400{\mu}Ah/cm^2$을 얻었다. Sn-thin film as high capacitive anode for thin film lithium-ion battery was prepared by organic-electrolyte electroplating using Sn(II) acetate. Electrolytic solution including $Li^+$ and $Sn^{2+}$ had 3 reduction peaks at cyclic voltammogram. Current peak at $2.0{\sim}2.5\;V$ region correspond to the electroplating of Sn on Ni substrate. This potential value is lower than 2.91 V vs. $Li^+/Li^{\circ}$, of the standard reduction potential of $Sn^{2+}$ under aqueous media. It is the result of high overpotential caused by high resistive organic electrolytic solution and low $Sn^{2+}$ concentration. Physical and electrochemical properties were evaluated using by XRD, FE-SEM, cyclic voltammogram and galvanostatic charge-discharge test. Crystallinity of electroplated Sn-anode on a Ni substrate could be increased through heat treatment at $150^{\circ}C$ for 2 h. Cyclic voltammogram shows reversible electrochemical reaction of reduction(alloying) and oxidation(de-alloying) at 0.25 V and 0.75 V, respectively. Thickness of Sn-thin film, which was calculated based on electrochemical capacity, was $7.35{\mu}m$. And reversible capacity of this cell was $400{\mu}Ah/cm^2$.

Preparation of Magnesium Thin Film by Non-Aqueous Electrolysis at Room Temperature

박제식,이철경 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

The synthesis of a magnesium thin film by simple electrolysis was investigated in three non-aqueous electrolytes. Linear sweep voltammograms of magnesium on the copper electrode showed the possibility of electrodepositing metallic magnesium at room-temperature. Morphology of the magnesium thin film could be controlled by controlling the applied current. The metallic magnesium thin film could be easily and uniformly deposited on a copper electrode under galvanostatic conditions in THF solution of EtMgBr. The magnesium film formation was confirmed by X-ray diffractometry and scanning electron microscopy with energy-dispersive spectroscopy.

Preparation of Magnesium Thin Film by Non-Aqueous Electrolysis at Room Temperature

Park, Jesik,Lee, Churl Kyoung 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.3

The synthesis of a magnesium thin film by simple electrolysis was investigated in three non-aqueous electrolytes. Linear sweep voltammograms of magnesium on the copper electrode showed the possibility of electrodepositing metallic magnesium at room-temperature. Morphology of the magnesium thin film could be controlled by controlling the applied current. The metallic magnesium thin film could be easily and uniformly deposited on a copper electrode under galvanostatic conditions in THF solution of EtMgBr. The magnesium film formation was confirmed by X-ray diffractometry and scanning electron microscopy with energy-dispersive spectroscopy.

Deposition of Electrolyte for Intermediate Temperature Solid Oxide Fuel Cells by Combined Thin Film Deposition Techniques

하승범(Ha, Seungbum),지상훈(Jee, Sanghoon),와카스 하산 탄비르(Tanveer, Waqas Hassan),이윤호(Lee, Yoonho),차석원(Cha, Suk Won) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

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.

ALD YSZ 연료극 중간층 박막 적용을 통한 고체 산화물 연료전지의 성능 향상

안지환,김형준,유진근,오성국,An, Jihwan,Kim, Hyong June,Yu, Jin Geun,Oh, Seongkook 한국마이크로전자및패키징학회 2016 마이크로전자 및 패키징학회지 Vol.23 No.3

본 논문은 원자층 증착법을 이용해 증착된 YSZ 박막을 산화 세륨계 전해질 기반 고체 산화물 연료전지의 연료극 중간층으로 적용한 결과를 보여준다. $500^{\circ}C$ 이상의 고온에서는 산화 세륨계 전해질의 전기전도도가 상승하여 이를 전해질로 사용한 고체 산화물 연료전지의 개회로 전압이 하강하고 성능이 저하된다. 원자층 증착법을 이용해 연료극 측 전해질 표면에 증착된 YSZ 박막은 얇은 두께(60 nm)에도 불구하고 산화 세륨계 전해질 표면을 완벽하게 도포함으로써, 전해질을 관통하는 전자의 흐름을 막아 개회로 전압을 최대 20%까지 상승시켰다. 이를 통해 $500^{\circ}C$에서의 최대 전력 밀도는 52%가 상승하였다. This paper demonstrates the successful application of yttria-stabilized zirconia thin films deposited by atomic layer deposition to the anode-side interlayer for cerium oxide electrolyte based solid oxide fuel cell. At the operating temperature over $500^{\circ}C$, the electrical conductivity of cerium oxide electrolyte is known to dramatically increase and, therefore, the open circuit voltage of the cell decreases leading to the decrease of the performance. Ultra-thin (60 nm) atomic layer deposited yttria-stabilized zirconia thin film in this study conformally coated the anode-side surface of the cerium oxide electrolyte and efficiently blocked the electrical conduction through the electrolyte. Accordingly, the open circuit voltage increased by up to 20%, and the maximum power density increased by 52% at $500^{\circ}C$

High-Performance Protonic Ceramic Fuel Cells with Thin-Film Yttrium-Doped Barium Cerate–Zirconate Electrolytes on Compositionally Gradient Anodes

Bae, Kiho,Lee, Sewook,Jang, Dong Young,Kim, Hyun Joong,Lee, Hunhyeong,Shin, Dongwook,Son, Ji-Won,Shim, Joon Hyung American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.14

<P>In this study, we used a compositionally gradient anode functional layer (AFL) consisting of Ni-BaCe0.5Zr0.35Y0.15O3-delta (BCZY) with increasing BCZY contents toward the electrolyte -anode interface for high-performance protonic ceramic fuel cells. It is identified that conventional homogeneous AFLs fail to stably accommodate a thin film of BCZY electrolyte. In contrast, a dense 2 mu m thick BCZY electrolyte was successfully deposited onto the proposed gradient AFL with improved adhesion. A fuel cell containing this thin electrolyte showed a promising maximum peak power density of 635 mW cm(-2) at 600 degrees C, with an open-circuit voltage of over 1 V. Impedance analysis confirmed that minimizing the electrolyte thickness is essential for achieving a high power output, suggesting that the anode structure is important in stably accommodating thin electrolytes.</P>