• 제목/요약/키워드: All solid-state

검색결과 389건 처리시간 0.026초

박막전지용 LIPON 전해질 박막의 제조 및 특성 평가 (Fabrication and Characterization of LIPON Electrolyte Thin Film for All Solid State Thin Film Battery)

  • 손봉희;전은정;남상철;조원일;윤영수
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
    • /
    • pp.228-231
    • /
    • 1999
  • The preparation and electrical properties of LIPON electrolyte were investigated in order to fabricate all solid state thin film battery. The LIPON thin film was deposited by r.f. sputtering of Li$_3$PO$_4$ target in O$_2$-N$_2$ mixtures. The LIPON deposited at N$_2$+10% O$_2$ ratio had a conductivity at 25 $^{\circ}C$ of 1.8${\times}$10$\^$-6/S/cm. The ion conductivity of the LIPON films decreased as the O$_2$ content of the process gas increased.

  • PDF

Enhancement of Power System Transient Stability and Power Quality Using a Novel Solid-state Fault Current Limiter

  • Fereidouni, A.R.;Vahidi, B.;Mehr, T. Hoseini;Doiran, M. Garmroodi
    • Journal of Electrical Engineering and Technology
    • /
    • 제6권4호
    • /
    • pp.474-483
    • /
    • 2011
  • Solid-state fault current limiters (SSFCL) in power systems are alternative devices to limit prospective short circuit currents from reaching lower levels. Fault current limiters (FCL) can be classified into two categories: R-type (resistive) FCLs and L-type (inductive) FCLs. L-type FCL uses an inductor to limit fault level and is more efficient in suppressing voltage drop during a fault. In contrast, R-type FCL is constructed with a resistance and is more effective in consuming the acceleration energy of generators during a fault. Both functions enhance the transient stability of the power system. In the present paper, a novel SSFCL is proposed to enhance power system transient stability and power quality. The proposed SSFCL uses both functions of an L-type and R-type FCL. SSFCL consists of four diodes, one self-turn-off IGCT, a current-limiting by-pass inductor (L), and a variable resistance parallel with an inductor for improvement of power system stability and prevention of over-voltage across SSFCL. The main advantages of the proposed SSFCL are the simplicity of its structure and control, low steady-state impedance, fast response, and the existence of R-type and Ltype impedances during the fault, all of which improve power system stability and power quality. Simulations are accomplished in PSCAD/EMTDC.

On Electric Field Induced Processes in Ionic Compounds

  • Schmalzried, H.
    • 한국세라믹학회지
    • /
    • 제38권6호
    • /
    • pp.499-505
    • /
    • 2001
  • The behaviour of ionic compound crystals under combined chemical and externally applied electrical potential gradients is discussed. Firstly, a systematic overview is given. Then a formal analysis follows. The transport equations of the ions and the electric defects predict that even with reversible electrodes demixing, and in particular decomposition of the compound will occur if the applied d.c. current density is sufficiently high. These predictions are illustrated by appropriate experiments. With the help of the solid solution (Me, Fe)O, where Fe-ions are the dilute species, we investigate experimentally the behaviour of a ternary ionic crystal under a d.c. electric current load. All the compounds were placed in a galvanic cell, and the internal reactions which then could be observed were driven by the electric field in this cell. In addition, we discuss the influence of the electric field on the classical solid state reaction AX+BX=ABX$_2$, if again the reaction couple is placed in a galvanic cell.

  • PDF

Solid Lipid Nanoparticles as Drug Delivery System for Water-Insoluble Drugs

  • Li, Rihua;Lim, Soo-Jeong;Choi, Han-Gon;Lee, Mi-Kyung
    • Journal of Pharmaceutical Investigation
    • /
    • 제40권spc호
    • /
    • pp.63-73
    • /
    • 2010
  • Solid lipid nanoparticles (SLNs) have emerged to combine the advantages of polymeric nanoparticles and lipid emulsions in early 1990s. SLNs can present several desirable properties derived from the solid state core. When formulating SLNs, there should be careful considerations about the physical state of the inner solid lipid core and its polymorphism and supercooling behavior. In this review, SLNs were compared to lipid emulsion and emulsion of supercooled melt to understand the unusual behaviors compared to lipid emulsions and to have insights into stability and release mechanism. SLNs have been regarded as biocompatible system because lipids are usually well-tolerable ingredients than polymers. Several studies showed good tolerability of SLNs in terms of cytotoxicity and hemolysis. Similar to various other nanoparticulate drug delivery systems, SLNs can also change biodistribution of the incorporated drugs in a way to enhance therapeutic effect. Most of all, large scale production of SLNs was extablished wihtout using organic solvents. Although there is no SLN product in the market till date, several advantagious properties of SLNs and the progress we have seen so far would make commercial product of SLNs possible before long and encourage research community to apply SLN-based formulations for water-insoluble drugs.

SnO2 기반 고체상의 투과도 가변 소자 제조 (Fabrication of SnO2-based All-solid-state Transmittance Variation Devices)

  • 신동균;서유석;이진영;박종운
    • 반도체디스플레이기술학회지
    • /
    • 제19권3호
    • /
    • pp.23-29
    • /
    • 2020
  • Electrochromic (EC) device is an element whose transmittance is changed by electrical energy. Coloring and decoloring states can be easily controlled and thus used in buildings and automobiles for energy saving. There exist several types of EC devices; EC using electrolytes, polymer dispersed liquid crystal (PDLC), and suspended particle device (SPD) using polarized molecules. However, these devices involve solutions such as electrolytes and liquid crystals, limiting their applications in high temperature environments. In this study, we have studied all-solid-state EC device based on Tin(IV) oxide (SnO2). A coloring phase is achieved when electrons are accumulated in the ultraviolet (UV)-treated SnO2 layer, whereas a decoloring mode is obtained when electrons are empty there. The UV treatment of SnO2 layer brings in a number of localized states in the bandgap, which traps electrons near the conduction band. The SnO2-based EC device shows a transmittance of 70.7% in the decoloring mode and 41% in the coloring mode at a voltage of 2.5 V. We have achieved a transmittance change as large as 29.7% at the wavelength of 550 nm. It also exhibits fast and stable driving characteristics, which have been demonstrated by the cyclic experiments of coloration and decoloration. It has also showed the memory effects induced by the insulating layer of titanium dioxide (TiO2) and silicone (Si).

Pt/LiCoO2/LiPON/Cu와 Pt/LiCoO2/LiPON/LiCoO2/Cu 구조를 갖는 Li-free 박막전지 (Li-free Thin-Film Batteries with Structural Configuration of Pt/LiCoO2/LiPON/Cu and Pt/LiCoO2/LiPON/LiCoO2/Cu)

  • 신민선;김태연;이성만
    • 한국표면공학회지
    • /
    • 제51권4호
    • /
    • pp.243-248
    • /
    • 2018
  • All solid state thin film batteries with two types of cell structure, Pt / $LiCoO_2$ / LiPON / Cu and Pt / $LiCoO_2$ / LiPON / $LiCoO_2$ / Cu, are prepared and their electrochemical performances are investigated to evaluate the effect of $LiCoO_2$ interlayer at the interface of LiPON / Cu. The crystallinity of the deposited $LiCoO_2$ thin films is confirmed by XRD and Raman analysis. The crystalline $LiCoO_2$ cathode thin film is obtained and $LiCoO_2$ as the interlayer appears to be amorphous. The surface morphology of Cu current collector after cycling of the batteries is observed by AFM. The presence of a 10 nm-thick layer of $LiCoO_2$ at the interface of LiPON / Cu enhances the interfacial adhesion and reduces the interfacial resistance. As a result, Li plating / stripping at the interface of LiPON / Cu during charge/discharge reaction takes place more uniformly on Cu current collector, while without the interlayer of $LiCoO_2$ at the interface of LiPON / Cu, the Li plating / stripping is localized on current collector. The thin film batteries with the interlayer of $LiCoO_2$ at the interface of LiPON / Cu exhibits enhanced initial coulombic efficiency, reversible capacity and cycling stability. The thickness of the anode current collector Cu also appears to be crucial for electrochemical performances of all solid state thin film batteries.

WO3/NiO 상호 보완적인 구조의 전고체 전기변색 필름 (All-Solid-State Electrochromic Film with WO3/NiO Complementary Structure)

  • 신민경;이선희;서인태;강형원;한승호
    • 한국전기전자재료학회논문지
    • /
    • 제35권3호
    • /
    • pp.275-280
    • /
    • 2022
  • An all-solid-state electrochromic film was fabricated by laminating tungsten oxide (WO3) and nickel oxide (NiO) thin films deposited by a reactive DC magnetron sputtering on flexible ITO films. The influence of oxygen partial pressure on the crystal structure, microstructure, optical properties, and electrochromic properties of WO3 and NiO thin films were investigated. WO3 and NiO films showed the best electrochromic properties under the flow of Ar:O2=80:20 and Ar:O2=90:10, respectively. The EC film fabricated with an optimized WO3 and NiO films showed a high coloration efficiency, a fast response time, and a stable optical modulation. It is expected that flexible EC window films will pave the way for the next-generation energy-saving windows.

Li3PO4 Coated Li[Ni0.75Co0.1Mn0.15]O2 Cathode for All-Solid-State Batteries Based on Sulfide Electrolyte

  • Lee, Joo Young;Park, Yong Joon
    • Journal of Electrochemical Science and Technology
    • /
    • 제13권3호
    • /
    • pp.407-415
    • /
    • 2022
  • Surface coating of cathodes is an essential process for all-solid-state batteries (ASSBs) based on sulfide electrolytes as it efficiently suppresses interfacial reactions between oxide cathodes and sulfide electrolytes. Based on computational calculations, Li3PO4 has been suggested as a promising coating material because of its higher stability with sulfides and its optimal ionic conductivity. However, it has hardly been applied to the coating of ASSBs due to the absence of a suitable coating process, including the selection of source material that is compatible with ASSBs. In this study, polyphosphoric acid (PPA) and (NH4)2HPO4 were used as source materials for preparing a Li3PO4 coating for ASSBs, and the properties of the coating layer and coated cathodes were compared. The Li3PO4 layer fabricated using the (NH4)2HPO4 source was rough and inhomogeneous, which is not suitable for the protection of the cathodes. Moreover, the water-based coating solution with the (NH4)2HPO4 source can deteriorate the electrochemical performance of high-Ni cathodes that are vulnerable to water. In contrast, when an alcohol-based solvent was used, the PPA source enabled the formation of a thin and homogeneous coating layer on the cathode surface. As a consequence, the ASSBs containing the Li3PO4-coated cathode prepared by the PPA source exhibited significantly enhanced discharge and rate capabilities compared to ASSBs containing a pristine cathode or Li3PO4-coated cathode prepared by the (NH4)2HPO4 source.

비점성 정체 유동 하에서의 응고와 열전달 (Heat Transfer and Solidification in the Inviscid Stagnation Flow)

  • 유주식;김용진
    • 한국전산유체공학회지
    • /
    • 제5권1호
    • /
    • pp.27-32
    • /
    • 2000
  • This study investigates the problem of phase change from liquid to solid in the inviscid stagnation flow. The instantaneous location of the solid-liquid interface is fixed for all times by a coordinate transformation. Finite difference method is used to obtain the solution of the unsteady problem, and the growth rate of solid and the transient heat transfer from the surfaces of solid are investigated. The transient solution is dependent on the three dimensionless parameters, but the final steady state is determined by only one parameter of temperature ratio/conductivity ratio. It is observed that the instantaneous heat flux at the surface of solid can be obtained with sufficient accuracy by measuring the thickness of the solid or vice versa.

  • PDF