The all-solid-state battery with vanadate glass-ceramic cathode

The Ga-Ag-Li|Li₇La₃Zr_1.89Al_0.15O₁₂|(Li₂O–B₂O₃–V₂O₅ + Fe) all-solid-state electrochemical cell has been designed with a simple sintering process. The Li₇La₃Zr_1.89Al_0.15O₁₂ solid electrolyte was prepared by sol-gel method. The lithium borovanadate glass was obtained by a convenient melt quenching technique. Cycliс voltammetry has shown that the current densities of the cell at 300 °C can reach several hundreds of μA cm^?2. At this temperature, the single cell voltage is about 3.2 and 0.8 V in the charged and discharged state, correspondingly. This cell produces a current enough to make a single LED of white color working. The cell surface discharge capacity exceeds 230 μAh cm^?2.     

Effect of Chromium Oxide Additions on the Stability of Glass Ceramic Sealants for Solid Oxide Fuel Cells

Russian Journal of Applied Chemistry - The development of electrochemical generators based on solid oxide fuel cells requires the development of sealant materials that would ensure gastight...     

Electric Conductivity of Glasses in the MgO–V2O5–P2O5 System

Russian Journal of Electrochemistry - Amorphous glasses of the composition xMgO–yP2O5– (100 – x – y)V2O5 with x = 1–5 and y = 5, 10, and 15 mol % are obtained by the...     

Influence of cerium oxide on properties of glass–ceramic sealants for solid oxide fuel cells

The influence of the cerium oxide concentration on the properties of glasses and glass ceramics of the SiO₂–Al₂O₃–CaO–Na₂O–MgO–K₂O–B₂O₃–CeO₂ system as potential adhesive and sealing materials for solid oxide fuel cells was studied. According to the data of differential scanning calorimetry, variation of the CeO₂ concentration does not appreciably influence the glass transition and crystallization temperatures of glasses. As the cerium oxide concentration is increased, the linear thermal expansion coefficient increases for the glasses but decreases for the partially crystalline samples. The gluing temperature of the glass sealants prepared allows their use for joining YSZ solid electrolytes with interconnectors of Crofer22APU type in solid oxide fuel cells..     

Conductivity and spectroscopic studies of Li<Subscript>2</Subscript>O-V<Subscript>2</Subscript>O<Subscript>5</Subscript>-B<Subscript>2</Subscript>O<Subscript>3</Subscript> glasses

Lithium vanadium-borate glasses with the composition of 0.3Li₂O–(0.7-x)B₂O₃–xV₂O₅ (x?=?0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, and 0.475) were prepared by melt-quenching method. According to differential scanning calorimetry data, vanadium oxide acts as both glass former and glass modifier, since the thermal stability of glasses decreases with an increase in V₂O₅ concentration. Fourier transform infrared spectroscopy data show that the vibrations of [VO₄] structural units occur at V₂O₅ concentration of 45 mol%. It is established that the concentration of V⁴⁺ ions increases exponentially with the growth of vanadium oxide concentration. Direct and alternative current measurements are carried out to estimate the contribution both electronic and ionic conductivities to the value of total conductivity. It is shown that the electronic conductivity is predominant in the total one. The glass having the composition of 0.3Li₂O-0.275B₂O₃-0.475V₂O₅ shows the highest electrical conductivity that has the value of 7.4?×?10^?5 S cm^?1 at room temperature.     

Thermal Properties of Na2O-MgO-TiO2-Al2O3-B2O3-SiO2 Glasses and Prospects for Their Use for Sealing Solid Oxide Fuel Cells

A series of Na₂O-MgO-TiO₂-Al₂O₃-B₂O₃-SiO₂ glasses promising as sealants for solid oxide fuel cells are prepared. The glassy state is confirmed by X-ray diffraction analysis, and the elemental composition is determined by inductively coupled plasma atomic emission spectroscopy. The coefficient of thermal expansion (CTE) is calculated from the dilatometric data; it varies within (69–77) × 10^?7 K^?1 and increases with the MgO to Al₂O₃ concentration ratio. The CTE calculation by the Appen method gives the results that are underestimated by 5–8% relative to the experimental data. The temperature dependences of the heat capacity of the glasses are determined by differential scanning calorimetry and calculated using the Kopp-Neumann rule. Comparison of the calculated values with the experimental data shows that the Kopp-Neumann rule is observed for the systems under consideration with relatively high accuracy. The sensitivity of different methods in determination of the glass transition point has been evaluated.