Use Of Electrolytes Research Articles

Hydroxyapatite particles prepared by electrocrystallisation from aqueous electrolytes

Synthetic crystalline hydroxyapatite Ca 10(PO 4) 6(OH) 2 is an analog of bone apatite and in recent years has received considerable attention as a bioactive material for a wide variety of applications. A novel process for electrocrystallisation of pure hydroxyapatite particles from aqueous electrolytes for use in orthopaedic and orthopaedic reconstruction procedures is reported.

ChemInform Abstract: Structure and Properties of Sn(II)‐β′′‐Alumina.

AbstractSingle crystals of Sn(II)‐β''‐alumina are prepared by ion‐exchange of Na‐β''‐alumina using molten anhydrous SnCl2 (400 °C, inert atmosphere, 20 min).

Development of ion‐conducting polymer electrolytes for use in high‐energy lithium rechargeable batteries

AbstractPolymers based on poly(thylene oxide) (PEO) are a very promising new type of stable electrolytes for lithium rechargeable batteries. Their relatively low ionic conductivities can be more than compensated by the very small electrolyte thicknesses that can be used. Specific energies of 100 Wh/kg at sustained specific powers of 70 W/kg, have been obtained at Hydro‐Québec with 100 μm of PEO electrolyte at 100°C. In an electric vehicle, this would give a driving range of over 300 km at 80 km/h, more than three times as much as lead‐acid batteries. PEO‐related polymers have been developed for lower temperature applications such as computers or portable appliances. Advantages over competitive Ni‐Cd batteries are higher energy densities and absence of self‐discharge, with expected shell lifes of 10 years. Laboratory prototypes (3600 cm2, 10 Wh) demonstrate the absence of scale‐up effects and excellent cycling capability (over 300 charge‐discharge cycles).

Strength improvement in beta? alumina by incorporation of zirconia

Beta″ alumina ceramic electrolytes for use in Na/S batteries are inherently weaker than most engineering ceramics due to the presence of weakly-bonded conduction planes in the crystal structure and to difficulties in controlling grain growth during firing. Substantial improvement in microstructural control is obtained by incorporation of monoclinic zirconia (m-ZrO2) or partially stabilized zirconia (PSZ) resulting in increases in strength and fracture toughness to around 350 MPa and 4 MPam1/2, respectively. PSZ may adversely influence the electrical resistivity of the ceramic owing to the presence of impurities. With most zirconia powders a high level of retention of tetragonal zirconia (t-ZrO2) is obtained at levels of addition up to 15% by weight ZrO2. At these levels ZrO2/β″-Al2O3 ceramics show low resistivity and stable resistance in Na/S cells.

On-line electrolytic dissolution of alloys in flow injection analysis : Part 2: Spectrophotometric determination of molybdenum in steels

Electrolytic dissolution of steels is used for the determination of molybdenum by the flow injection spectrophotometric thiocyanate method. A direct current (200 mA) is applied for 8 s to the solid sample placed on a simple electrolytic chamber; the dissolved material serves as the injected sample zone. The best electrolyte for use as carrier stream is 1.0 M KCl/0.1 M HCl. No measurable baseline drift was observed during continous operation for 4 h. The sample throughput is 40 h −1. Calibration is done with reference steel standards and is linear in the range o.7–2.7% (w/w) molybdenum; for a content of 2.21%, the relative standard deviation is 2.3% ( n=10).

Study of an organic silver ion solid electrolyte for use as an oxygen probe

Doping a small amount of NH 4I in pure [(CH 3) 4N] 2Ag 13I 15 results in a kind of material with electric conductivity of 6.0×10 −2 ( ω cm) −1 at 25°C which is 0.5 to 1 time higher than that of the undoped electrolyte. An oxygen probe has been made by using this material as the electrolyte. Such a probe has higher stability and linear relationship between the output voltage and the oxygen content. The relations between the structure, the properties and the electric conduction have been discussed.

ChemInform Abstract: The High Aqueous Solubility of K2S and Its Effect on Bulk and Photoelectrochemical Characteristics of Cd(SeTe)/Sx2‐ Cells.

AbstractThe measured high aqueous solubility of KZS, compared to NazS, results in the preparation of a novel series of polysulfide electrolytes for use in CdX/Sä′ PEC′s. An increase in K28 concentration in electrolytes containing a fixed ratio of dissolved sulfur to alkali sulfide is shown to: l. modify the distribution of polysulfide species in solution, 2. increase the solution absorbance of light, 3. negatively shift the redox potential, 4. increase the calculated disproportionation‐limited lifetime of the solution, and 5. decrease K+ activity.

ChemInform Abstract: Electrochemical Kinetics of Sulfur Dioxide Reactions in Molten Bisulfates.

AbstractAlkali‐metal bisulfates are candidate electrolytes for use in electrochemical flue‐gas desulfurization.

The viscosity and structure of solutions. Part 2.—Measurement of the B coefficient of viscosity for alkali-metal chlorides in propan-1-ol–water mixtures at 25 and 35 °C

Measurements of the B coefficients of viscosity in the Jones–Dole equation ηr= 1 +Ac½+Bc are reported for the alkali-metal chlorides in the propan-1-ol–water system at 25 and 35 °C; they extend to 85%(w/w) propanol for Cs+Cl– to 70%(w/w) propanol for Na+Cl– and K+Cl– and 30%(w/w) propanol for Li+Cl–. Photoelectric timing and high-precision density measurements were used in determining the relative viscosities, ηr, of the solutions. Conductivity measurements of intermediate precision gave values of the limiting equivalent conductivities of the electrolytes for use in the calculation of A, above. To 50% alcohol, the equivalent conductances of the ions could be established accurately using transport numbers from another investigation. To 30% alcohol the Jones–Dole equation was obeyed by all the electrolytes except Li+Cl–, where an additional term Dc2, with small positive values of D, was required. For mixtures containing 50%(w/w) alcohol or more, the Jones–Dole equation was of the correct form to represent the ηr, but the values of A required were larger than the theoretical ones; the conductivity measurements indicated that the electrolytes were associated in these mixtures. The values of the ion-pair dissociation constants, determined from the conductivity measurements, were about those expected from Bjerrum theory; they were used to calculate the degree of dissociation α of the ion pairs. Values of Bi, referring to the free ions, were obtained by fitting the ηr to the equation ηr= 1 +A(αc)½+Biαc+Bp(1 –α)c in which Bp is the corresponding coefficient for the ion pairs. Values of the partial molal volumes of the electrolytes at infinite dilution in the various solvent mixtures were obtained from the density measurements. The densities and viscosities of the mixtures are recorded.

The electrochemical kinetics of sulfur dioxide reactions in molten bisulfates

Alkali-metal bisulfates are candidate electrolytes for use in electrochemical flue-gas desulfurization. The kinetics are explored of the electrochemical reactions of gases containing sulfur dioxide and oxygen on gold electrodes in alkali bisulfate at 205°C. The cathodic reaction is found to be strongly dependent upon gaseous sulfur dioxide content, but nearly independent of oxygen, within the range of the experiment. All evidence points to a scheme whereby dissolved sulfur dioxide reacts with an oxide layer on the electrode to form pyrosulfate. The anodic reaction also appears strongly dependent on sulfur dioxide concentration; however, the pathway remains unclear.

Na +-ion conducting glasses

Na +-ion conduction in glass is discussed with the aim of selecting suitable electrolytes for use in Na/S cells operating around 350°C. From an extensive survey of many glass systems including silicates, borates, etc., it is found that the conductivity increases with increasing optical basicity (Λ), while the activation energy falls toward an apparent limiting value of ca. 50 kJ mol −1. The use of special additives such as NaCl does not lead to any further improvement. Several “optimised ionic conductors” have been identified, where σ ⪢ 10 −2 S cm −1 at T g. These are the best materials for use in battery applications provided they are stable in the cell environment.

The applicability of a nitrate melt as a cell electrolyte in a flue gas desulphurization cell

This paper presents equilibrium and kinetic studies of the O 2 and O 2/SO 2 electrodes in molten NaNO 3-KNO 3 eutectic at 380°C. For the O 2 electrode the overall reaction is given by the equation: 1 2 O 2 + 2 e − = O 2−. The exchange currents for this reaction are higher with platinum than with gold and are 1–2 orders of magnitude higher than those previously measured in molten sulphates. The overall reaction of the O 2/SO 2 electrode is: SO 2 + O 2 + 2 e − = SO 2− 4. Gold is a better catalyst than platinum for this reaction, quite similar to the case in molten sulphates. Molten NaNO 3-KNO 3 seems to be an appropriate electrolyte for use in a new electrochemical flue gas desulphurization process in the temperature range of 350–450°C.

Thermal-shock behavior of zirconia-based solid electrolyte for use in steelmaking processes.

The thermal-shock behavior of ZrO2-CaO and ZrO2-MgO pellets was investigated by immersing these pellets into liquid iron without preheating temperature or with preheating temperature. The moduli of rupture before and after the thermal-shock were measured by a three point bending technique. A good thermal-shock resistance was realized for partially stabilized zirconia containing 5 to 7mol% of stabilizer. The relationship between the thermal-shock resistance and the transport rate of gases through the cracks created during thermal-shock is discussed.

Solid State Ionics Vol 1

(An interdisciplinary journal devoted to experimental and theoretical research involving properties related to ionic transport phenomena in solids) M Stanley Whittingham (ed) 1980 Amsterdam: North-Holland xiv + 161 pp price $74.75 (for 6 issues during 1980) This new journal deals with the physics, chemistry and materials science of ion transport phenomena in solids. It is timely and welcome since this is a fast growing field, particularly as there is very considerable interest in the practical development of solid electrolytes for use in high energy density batteries.

A convenient, non-hydrating electrolyte medium for the measurement of electrodermal activity.

ABSTRACTTwo experiments with 12 subjects each compared electrodermal recordings taken simultaneously with four different electrolyte media. These were polyethylene glycol, Unibase/glycol, Unibase, and hydrated agar (i.e., a site recorded with agar electrolyte after presoaking it with water). The primary purpose was to compare the electrolyte containing a mixture of Unibase/glycol with the other electrolytes. The glycol and the hydrated agar were assumed to reflect low and high levels of epidermal hydration, respectively, while Unibase provided a comparison with Unibase alone. These comparisons were made for positive SPRs and rapid recovery SCRs (and their associated prestimulus levels), which are believed to reflect the endosomatic and exosomatic manifestations of the epidermal membrane response.Unibase/glycol was quite similar to glycol alone; thus it offers a more convenient electrolyte for use when minimal hydration is required. The results were interpreted as indicating that Unibase/glycol is preferable for skin potential recordings, while Unibase is to be preferred for skin conductance recordings.

Search for new silver-ion solid electrolytes for use in batteries.

THE α-phase of AgI, which is stable above 146 °C, has a silver-ion conductivity of 1 Ω−1 cm−1 at 150 °C (ref. 1), which would make it a suitable solid electrolyte for high temperature batteries. The room-temperature conductivity of the stable phase of AgI is disappointingly low (10−6−6 Ω−1 cm−1) and although samples with conductivities approaching 3 × 10−4 Ω−1 cm−1 can be prepared2, such values are insufficient to make it of use as an electrolyte in solid state batteries at room temperature. There is, however, considerable interest in producing solid electrolytes, based on AgI combined with organic cation iodides to give high silver-ion conductivity at room temperature4–9. We report here on the conductivities of representatives of three hitherto unexamined classes of compounds, AgI–selenonium iodide, AgI–telluronium iodide and AgI–bis-sulphonium diiodide.

Discussion of “Activities and phase boundaries in the Cr−Ni system using a solid electrolyte technique”

Pugtiese and Fitterer a~ have recently reported an exhaustive study of the activities and phase boundaries in the Cr-Ni system using galvanic cell technique. In their experiments, calcia-stabilized zirconia served as the solid electrolyte and a~r as the reference electrode. In the initial experiments, Cr + Cr.~Oa served as the "other" electrode and allowed the determination of the free energy of formation of CreOa from the cell electromotive force. In the following experiments, they used Cr-Ni alloy + Cr2Oa as the working electrode and calculated the activity of chromium in the alloy from the cell electromotive force and the free energy of formation of Cr203. Pugliese and FRterer have correctly pointed out that in studies of this type precaution must be taken to select an electrolyte for use within its limitations as an ionic conductor. They have mentioned that according to Tretjakow and Schmalzried a* the equilibrium oxygeu pressure for Cr-CraOa is within the range of ionic conduction for catcia-stabitize d zirconia. Unfortunately the authors failed to mention that a few other investigators a2'aa do not agree with Tretjakow and Schmatzried. The conclusions of Tretjakow and 8chmalzried are based only on galvanic cell experiments involving calcia-stabilize d zirconia as the electrolyte. A more conclusive study should involve comparison of the electromotive force of two independent gatvanic cells

Sound absorption in some liquid metals: Gitis, M.B., Mikhailov, I.G., Niyazov, S. Soviet Physics-Acoustics, Vol 14, No 1 (July-September 1968) pp 42–45

Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca–Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500–700 °C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm−2, the calcium–bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca–Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode–electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca–Bi intermetallic formation thereby improving the discharge capacity.

Base Electrolytes for Use in Polarographic Determinations

IN the course of recent research on the application of the polarographic method to the routine analysis of magnetic materials of the 'Permalloy' type, we have found several new base electrolytes which offer considerable advantages for quantitative polarography. They are characterized by the very satisfactory shape of the 'waves', in general free from disturbing maxima, which they yield with a number of metal ions.

Electrolyte for Use in Electro-Metallurgy

Electrolyte for Use in Electro-Metallurgy