Emf Data Research Articles

Experimental and theoretical studies on thermodynamic activities of binaries ferric and magnesium chlorides in aqueous solutions at various temperatures

The investigation of the thermodynamic properties of binary systems of ferric and magnesium chlorides in aqueous solutions was reported at various temperatures using both the hygrometric method and thermodynamic modeling. Water activities were measured over a molality range of 0.100 up to mmax(FeCl3)= 2.500 mol·kg−1 and to mmax(MgCl2)=(5.798, 6.090, 6.394, and 6.839) mol·kg−1at temperatures from 298.15 K to 353.15 K, respectively. From the new measurements, the osmotic coefficients of water were evaluated and compared with the existing literature data at ambient temperature. These coefficients were treated at various temperatures using established thermodynamic models of the Pitzer, Filippov–Charykov–Rumyantsev, extended ion interaction, and Clegg–Pitzer–Brimblecombe. The relevant properties of ferric and magnesium electrolyte solutions were determined in the temperature range. Indeed, the parameterizations of FeCl3(aq) and MgCl2(aq) were evaluated and employed for the computation of solute activity and osmotic coefficients. Based on literature emf data for MgCl2(aq) at a temperature of 298.15 K, the consistency of the activity coefficients was evaluated using an adequate model, and an excellent description of the prediction activity coefficients is obtained by the extended ion interaction model. Then, the recommended activity coefficients were given at various temperatures by extending this procedure. An experimental investigation was also carried out to evaluate the solubility equilibrium of MgCl2 in aqueous solutions at different temperatures. The solubility product and standard Gibbs energies of dissolution and formation were also calculated at different temperatures and compared with those existing in the literature.

Thermodynamic Study of the Activity of Cadmium Chloride in Aqueous Solutions at Various Temperatures

The thermodynamic properties of cadmium chloride in aqueous solutions were investigated by the hygrometric method and thermodynamic modeling at different temperatures. The water activities were measured in the molality range from 0.10 mol·kg–1 up to mmax = (6.60 to 7.65) mol·kg–1 at temperatures from 298.15 to 353.15 K, respectively. From the newly measured data, the osmotic coefficients of water were deduced. The cadmium chloride aqueous solutions contain some additional complexes such as CdCl2(aq), Cd2+(aq), CdCl+(aq), CdCl3–(aq), and CdCl42–(aq). Based on emf data of the literature for CdCl2(aq) at 298.15 K, the consistency of the activity coefficient was evaluated using an adequate model. The parametrizations were developed by the ion interaction models, and the Filippov–Charykov–Rumyantsev model is the only one that gives a better representation of the experimental results with excellent prediction of the activity coefficients. This procedure is extended to obtain the recommended activity coefficients at various temperatures. The water activities, activity coefficients, and molalities of the saturated points were used to calculate the solubility product and the Gibbs energy of dissolution at different temperatures. The calculated ΔGdiss° was compared with that existing in the literature at 298.15 K, and good agreement is obtained.

Comparison of thermodynamic data of the ternary Cu–Sn–Zn system, measured with the EMF and with the calorimetric method

Abstract The enthalpy of mixing of the ternary Cu –Sn–Zn system was measured using a Calvet-type calorimeter. The investigations were carried out along the three cross sections Cu : Sn = 1 : 2, 1 : 1, and 2 : 1. Zn was added in the concentration range between 0 and 50 at.%. The calorimetric results were compared with EMF data investigated in an earlier work by Peng and Mikula [1]. The results of the calorimetric measurements show very good agreement in the copper-rich region, compared with the EMF measurements, but in the Cu : Sn = 1 : 2 cross section the results do not fit perfectly. The difference between both measuring methods was at the most ΔH = 300 J/mol at the cross section Cu : Sn = 1 : 1 and ΔH = 150 J/mol at the Cu : Sn = 2 : 1 cross section.

Thermodynamic study of the thallium-thulium tellurides by EMF method

In this study the phase equilibria in the Tl2Te–Tl2Te3–TlTmTe2compositions area of the Tl–Tm–Te ternary system were studied by powder X-ray diffraction (PXRD) analysis. Based on PXRD data, the solid-phase equi-libria diagram was plotted. The thermodynamic functions of the Tl9TmTe6and TlTmTe2ternary compounds were calculated by the electromotive forces method. The electrochemical cells of the following type (−) TmТе (s.) | glycerol + KCl + TmCl3 | (Tm in alloys of Tl–Tm–Te system) (s.) (+) were assembled and their EMF were measured in the 300-450 Ktemperature range. Based on obtained EMF data for the Tl2Te3–TlTe–TlTmTe2and TlTe–TlTmTe2–Tl9TmTe6three-phase regions, the relative partial thermodynamic functions of TmTe in alloys were calculated. The combination of these functions with the partial molar functions of thulium in TmTe allowed calculating the corresponding partial functions of thulium in the above phase regions. The potential-forming reactions responsible for the indicated partial molar values were obtained based on con-structed solid-phase equilibria diagram. Using indicated potential-forming reactions, for the first time, the standard thermodynamic functions of formation and standard entropies of the Tl9TmTe6and TlTmTe2 compounds were calculated.

Assessment of MgHf4P6O24 Solid-State Electrolyte in High-Temperature Electrochemical Mg-Sensors

The chemical synthesis of MgHf4P6O24 solid-state electrolyte was achieved using a modified sol-gel method by directly substituting the B-site in MgZr4P6O24 solid-state electrolyte [1], resulting in a considerably low activation energy of Ea = 0.74 ± 0.04 eV and a promising ionic conductivity of 4.52 x 10-4 Scm-1 at 747 oC. Using TGA-DSC measurement data, the synthesised xerogel powders were calcined at relatively low temperature of 800-900 oC, while the calcined nanopowders were pressed into pellets of 13 mm diameter (Ø) and 3.8 mm thickness with a uniaxial steel die at 5 kN compressive pressure, and later sintered at 1000 ≤ T oC ≤ 1550. However, 1300 oC was adapted as the sintering temperature in this study because the optimum samples density and composition stability were achieved at 1300 oC. X-ray diffraction reveals a good crystallinity of the calcined nanopowders phase having an average crystallite size of 20±2 nm and 42±2 nm at 800 oC and 900 oC, respectively, indicating that crystallite size increases as a function of calcination temperature, which is consistent with the TGA-DSC profiles and confirmed using HRTEM.The sintered MgHf4P6O24 solid-state electrolyte was subsequently characterised for their electrical and thermodynamic properties, identifying reliable ionic and transport data of the solid-state electrolyte. Furthermore, the average transport number of Mg2+-cations in the MgHf4P6O24 solid-state electrolyte measured as a function of Mg concentration in liquid Al is 0.84 ± 0.03. The ionic conductivity and emf data of the novel solid-state electrolyte in this study was compared with those of MgZr4P6O24 electrolyte [2-4], showing similar trend which defines the similarity in both chemical and structural properties of the B-site elements on the periodic table.Relying on the structural, chemical stability and ionic conductivity data characterised in this study, the electrochemical Mg-sensor was fabricated. The high-temperature electrochemical Mg-sensor was fabricated using the highly conducting Mg2+-cation solid-state electrolyte characterised in this study and a biphasic powder mixture of MgCr2O4 + Cr2O3 + O2 reference electrode in air, and testing in liquid Al alloys at 700 ± 5 oC after successful variation of Mg concentration using electrochemical method was achieved and the test rig is presented in Fig.1 [1-3]. The testing outcome shows a linear dependence of sensor voltage on the logarithm of Mg concentration. MgHf4P6O24 solid-state electrolyte has been identified in this study to have useful applications during refining, virgin metals alloying and scrap metal recycling for the benefit of our environment and depleting climate. Figure 1. Schematic of high-temperature electrochemical Mg-sensor test rig [1-3].

Thermodynamic investigation of Cr2TeO6 and Cr2Te4O11

Knowledge on thermodynamic stability of the compounds formed by the interaction of volatile fission products with the components of structural materials during reactor operation is important to predict life time of the nuclear fuel pin inside a nuclear reactor. In the present study, thermodynamic properties of two compounds viz., Cr2TeO6(cr) and Cr2Te4O11(cr) in Cr-Te-O system are reported. The standard molar Gibbs energy of formation of Cr2TeO6(cr) and Cr2Te4O11(cr) have been determined by EMF measurement technique employing galvanic cells: (-) Pt, C, Cr2O3(cr), Te(cr or l), Cr2TeO6(cr)│CSZ│O2(g) (pO2 = 0.21 atm), Pt (+) and (-) Pt, C, Cr2TeO6(cr), TeO2(cr), Cr2Te4O11(cr)│CSZ│O2(g) (pO2 = 0.21 atm), Pt (+), in the temperature range 685 ≤ T/K≤877 and 705 ≤ T/K≤843, respectively. The standard Gibbs energy of formation of Cr2TeO6(cr) and Cr2Te4O11(cr) derived from the measured EMF data could be expressed as: ΔfGº (Cr2TeO6, cr) (±5.6 kJ.mol−1) = -1644.2 + 0.5606 T (725 ≤ T/K≤877) and ΔfGº (Cr2Te4O11, cr) (±6.3 kJ.mol−1) = -2458.2 + 1.013 T (705 ≤ T/K≤843), respectively. The values of ‘third-law’ enthalpy of formation ΔHf,298Ko of Cr2TeO6(cr) and Cr2Te4O11(cr) are found to be -1632.2 ± 0.8 kJ mol-1 and -2432.4 ± 0.5 kJ mol−1, respectively.

Thermodynamıc Propertıes of the BiTe and Bi8Te9 Compounds

Two-phase alloys Bi8Te9+Bi4Te5 and BiTe+Bi8Te9 were studied by the electromotive forces method (EMF) in the temperature range 300-450 K. From the EMF data, the relative partial molar functions of bismuth in the alloys were calculated. The potential-forming reactions responsible for these partial functions were compiled, the values of the standard thermodynamic functions of formation, and the standard entropies of Bi8Te9 and BiTe compounds were calculated. A comparative analysis of the data for BiTe with the literature data was carried out; for Bi8Te9, the thermodynamic functions were obtained for the first time.

Thermodynamic Properties of Sr–Sn Alloys via Emf Measurements and Thermal Analysis

The thermochemical properties of Sr-Sn alloys were determined by electromotive force (emf) measurements to evaluate liquid tin as an interacting electrode material for separating alkaline-earth elements from molten salt solutions. A Sr(s)∣CaF2-SrF2∣Sr(in Sn) cell was used to measure emf values for twelve Sr-Sn alloys at mole fractions xSr = 0.02‒0.43, allowing the determination of thermochemical properties such as activity and partial molar quantities of Gibbs energy, entropy, and enthalpy of Sr at 730‒1110 K. Activity values of Sr in liquid Sn were as low as 6.9 × 10‒12 at 800 K and xSr = 0.02 indicating highly non-ideal solution behavior between Sr and Sn. Phase transitions were also determined from the emf data and were validated via differential scanning calorimetry (DSC). Through the combination of emf measurements for thermochemical properties, X-ray diffraction (XRD) for phase constituents, and DSC measurements for phase transitions, this work established more complete thermodynamic properties of the Sr-Sn binary system.

Assessment of thermodynamic data for CuCrO2 delafossite from calorimetric measurements

A detailed investigation of the thermodynamic properties of delafossite CuCrO2 was carried out by experimental methods on synthetic CuCrO2 delafossite samples (differential scanning calorimetry from ambient to 871 K and drop calorimetry from 823 to 1123 K) and theoretical methods (density functional theory). Based on these data and available literature (low temperature heat capacity measurements and calculations, high temperature emf data), we propose, for the first time, a full set of thermodynamic data for the phase CuCrO2. Our selection comes to: ΔfH°298(CuCrO2) = −670.8 ± 1.3 kJ mol−1, S°298(CuCrO2) = 88.9 J K−1, and cp°(T)=1.02564.102-2.87159.107 T-3-1.28542.105 T-1.5 (298 < T < 1300 K).

Nanostructured Magnetic Sorbents for Selective Recovery of Uranium(VI) from Aqueous Solutions

Direct sol-gel, novel template, and additional high-temperature reduction procedures for preparing iron oxides and their composites, showing promise for selective sorption of dissolved U(VI) from aqueous media of various acidities, are described. The sorption activity of the materials was studied, the kinetic curves of the sorption were obtained, and the efficiency of the selective recovery of U(VI) from aqueous solutions with different pH values using the new sorbents was compared. The probable mechanism of the U(VI) sorption onto the sorbents studied was suggested on the basis of SEM, XPS, emf, and BET data. The quantitative sorption of U(VI) is determined to a greater extent by the composition of the sorbent solid phase, rather then by the specific surface area of the sorbents, which ranges from 0.1 to 47.3 m2 g−1 depending on the synthesis procedure. The crystalline Fe0 phase in the sorbents prepared using additional high-temperature reduction plays the key role in the U(VI) sorption by the reducing deposition mechanism. The saturation magnetization for this type of sorbents can reach 133–140 emu g−1, which is an additional advantage allowing magnetic separation of the spent sorbents from the treated solutions.

Phase Equilibria in the Cu2Se–Cu3AsSe4–Se System and Thermodynamic Properties of Cu3AsSe4

The Cu2Se–Cu3AsSe4–Se system has been studied using differential thermal analysis, X-ray diffraction, and emf measurements on concentration cells using Cu4RbCl3I2 as a solid electrolyte. We have constructed a number of vertical sections through the phase diagram, the room-temperature solid-state phase compatibility diagram, and a projection of the liquidus surface. The primary crystallization fields of the phases present and the types and coordinates of in- and univariant equilibria in the system have been identified. The system has been shown to contain a broad liquid–liquid immiscibility region. Using emf data, we evaluated the standard thermodynamic functions of formation and standard entropy of the Cu3AsSe4 compound.

Determination of Thermodynamic Properties of Alkaline Earth-liquid Metal Alloys Using the Electromotive Force Technique

A novel electrochemical cell based on a CaF2 solid-state electrolyte has been developed to measure the electromotive force (emf) of binary alkaline earth-liquid metal alloys as functions of both composition and temperature in order to acquire thermodynamic data. The cell consists of a chemically stable solid-state CaF2-AF2 electrolyte (where A is the alkaline-earth element such as Ca, Sr, or Ba), with binary A-B alloy (where B is the liquid metal such as Bi or Sb) working electrodes, and a pure A metal reference electrode. Emf data are collected over a temperature range of 723 K to 1,123 K in 25 K increments for multiple alloy compositions per experiment and the results are analyzed to yield activity values, phase transition temperatures, and partial molar entropies/enthalpies for each composition.

Determination of Thermodynamic Properties of Alkaline Earth-liquid Metal Alloys Using the Electromotive Force Technique.

A novel electrochemical cell based on a CaF2 solid-state electrolyte has been developed to measure the electromotive force (emf) of binary alkaline earth-liquid metal alloys as functions of both composition and temperature in order to acquire thermodynamic data. The cell consists of a chemically stable solid-state CaF2-AF2 electrolyte (where A is the alkaline-earth element such as Ca, Sr, or Ba), with binary A-B alloy (where B is the liquid metal such as Bi or Sb) working electrodes, and a pure A metal reference electrode. Emf data are collected over a temperature range of 723 K to 1,123 K in 25 K increments for multiple alloy compositions per experiment and the results are analyzed to yield activity values, phase transition temperatures, and partial molar entropies/enthalpies for each composition.

Phase equilibria in the Ag2Se–GeSe2–SnSe2 system and thermodynamic properties of Ag8Ge1–x Sn x Se6 solid solutions

The Ag2Se–GeSe2–SnSe2 system has been studied in the temperature range 290–430 K using differential thermal analysis, X-ray diffraction, and emf measurements concerning silver concentration cells with Ag4RbI5 as a solid electrolyte. We have constructed a number of vertical sections; the 300-, 800-, and 900-K isothermal sections of the phase diagram; and a projections of the liquidus surface. It has been shown that the only pseudobinary join, Ag8GeSe6–Ag8SnSe6, contains a continuous series of solid solutions between the two crystalline phases of the constituent selenides and divides the system into two independent subsystems. Ag2Se–Ag8GeSe6–Ag8SnSe6 is a univariant, eutectic subsystem, and GeSe2–Ag8GeSe6–Ag8SnSe6–SnSe2 is an invariant eutectic subsystem. Experimental emf data were used to evaluate partial thermodynamic functions of the silver in the high-temperature and low-temperature Ag8Ge1–x Sn x Se6 solid solutions.

The Tl–I phase diagram revisited and the thermodynamic properties of thallium iodides

The Tl–I system has been studied using differential thermal analysis, X-ray diffraction, and emf measurements on TlI concentration cells. A more accurate Tl–I phase diagram is presented, according to which the compounds existing in the Tl–I system are TlI, Tl2I3, and TlI3. Thallium monoiodide melts congruently at 715 K and undergoes a polymorphic transformation at 440 K. The other iodides melt peritectically at 535 and 404 K, respectively. In contrast to what was reported previously, no compound of composition Tl3I4 has been obtained. Using experimental emf data, we evaluated relative partial molar thermodynamic functions of the TlI in alloys of the TlI–I system and the standard Gibbs free energy, enthalpy of formation, and standard entropies of TlI3 (−ΔG 298 0 = 142.79 ± 0.73 kJ/mol, −ΔH 298 0 = 135.37 ± 2.85 kJ/mol, and S 298 0 = 263.3 ± 7.4 J/(mol K)) and Tl2I3 (271.39 ± 1.47, 262.40 ± 5.34, and 322.8 ± 13.2).

Thermodynamic Investigations and Modeling of Co3O4-Based Conversion Anode Materials

Conversion-type electrodes based on transition metal oxides are promising anode materials for the next-generation lithium-ion batteries (LIB) due to their high theoretic specific capacities, compared to the commercially used graphite anodes (372 mAh/g). Cobalt oxide based anodes exhibit theoretic specific capacities of up to 890 mAh/g (Co3O4). However, conversion materials need to overcome several drawbacks, including significant capacity losses after the first discharge, relatively low cycling stabilities, and a large potential hysteresis between charge and discharge. According to Larcher et al.[1], the charge / discharge reactions at very low current densities can be written as: 10 Li+ + Co3O4 + 10 e- ⇌ Li2O + 3 CoO + 8 Li+ + 8 e- ⇌ 3 Co + 4 Li2O. (1) For higher discharge current densities, the formation of the LixCo3O4 metastable intermediate phase, was reported[1]. x Li+ + Co3O4 + x e- → LixCo3O4. (2) Since the intermediate reactions taking place during the conversion mechanism are only partially understood, a combined experimental, modelling and simulation approach can be used to clarify the thermodynamics of the first discharge of Co3O4-based conversion anodes. Phase formation and open circuit voltages during lithiation / delithiation can be calculated using CALPHAD-based models and simulations of the multi-component systems. However, reliable thermodynamic and phase diagram data are essential pre-requisites to be able to model the Gibbs free energies of the phases for generation of self-consistent thermodynamic descriptions. Therefore, key thermochemical and phase diagram investigations were performed in this work to clarify inconsistencies in the existing literature data. Further, electrochemical tests were conducted to validate the results of the simulations as well as to generate new data for the thermodynamic modelling. First, the enthalpy of reduction of Co3O4 to CoO was determined using high-temperature oxide melt and transposed temperature drop calorimetry. This reaction is of particular importance because it is an intermediate step in the conversion reaction (see equation (1)). Secondly, since reliable heat capacity data are needed to extrapolate the thermodynamic descriptions to temperatures relevant for battery applications, the heat capacity of Co3O4 was measured in the temperature range of 200 to 1150 K using differential scanning calorimetry. The experimental data were then compared to calculations performed using an existing thermodynamic description of the Co-O system[2] to assess its reliability for extrapolations to higher order systems. A thermodynamic dataset of the Li-Co-O material system was developed. The results obtained from the simulation of the titration of LiCoO2 and CoO versus Li using the thermodynamic description were checked with EMF and phase diagram data at 673 K available in literature[3]. Furthermore, electrochemical cycling tests, galvanostatic intermittent titration technique (GITT) experiments and entropy measurements using coin cells were performed in our lab to verify extrapolations of the thermodynamic calculations to room temperature. In order to reproduce the experimentally measured quasi-open circuit voltage profiles, a thermodynamic description of the metastable LixCo3O4 phase (see equation 2) was included into the thermodynamic Li-Co-O dataset. [1] D. Larcher, G. Sudant, J.-B. Leriche, Y. Chabre, J.-M. Tarascon, J. Electrochem. Soc. 2002, 149, A234. [2] M. Chen, B. Hallstedt, L. J. Gauckler, J. Phase Equilib. 2003, 24, 212. [3] N. A. Godshall, I. D. Raistrick, R. A. Huggins, Mat. Res. Bull. 1980, 15, 561.

Thermodynamic properties of the SnSb2Te4 compound

The SnTe–Sb2Te3–Te system has been studied in the temperature range 300–430 K using emf measurements on reversible concentration cells of the type (–)SnTe(s) | liquid electrolyte, Sn2+ |(Sn–Sb–Te)(s)(+). The system has been shown to consist of two three-phase regions, separated by the SnSb2Te4–Te tie line. The best fit equation for the temperature-dependent emf data has been used to evaluate the partial thermodynamic functions of the SnTe and Sn in the alloys. Using these data, subsolidus phase diagram data for the SnTe–Sb2Te3–Te system, and relevant thermodynamic functions for SnTe and Sb2Te3, we calculated the standard Gibbs energy of formation, standard enthalpy of formation, and standard entropy of the SnSb2Te4 compound.

WITHDRAWN: Electrochemical properties of CaZrO 3 -α-based solid electrolyte

Abstract In this study, yttrium-doped calcium zirconate powders were synthesized by the conventional solid-state reaction method. The improved emf apparatus has been applied to measure the electrochemical values in the Y-doped CaZrO 3 system. The electromotive force of CaZr 0.96 Y 0.04 O 3− α has been measured by electrochemical cells of the type. ( − , ref. ) , Pt , gas mixture ( p ′ O 2 , p ″ H 2 ) | CaZr 0.96 Y 0.04 O 3 − α | gas mixture ( p ″ O 2 , p ″ H 2 ) , Pt , ( meas , + . ) The electromotive force (emf) was measured for various oxygen and hydrogen chemical potential gradients. The measurements were performed in a hydrogen-rich atmosphere for the temperature range from 973 to 1473 K. For almost all the conditions in the experiment, the measured emfs were well explained by regarding that the substantial predominant charge carrier is the proton. Under the hydrogen-rich atmosphere investigated, it was found that the emf generated only with the hydrogen activity gradient. The detailed analysis of the obtained emf data showed that the transport number of proton in CaZr 0.96 Y 0.04 O 3− α is almost unity for the hydrogen-rich atmosphere and its proton conduction domain is a little wider than that of the In-doped CaZrO 3 system.

Thermodynamic Investigation of Cobalt-Oxide Based Material Systems for Lithium Ion Batteries

Conversion-type electrode materials based on transition metal oxides are promising anode materials for next-generation lithium-ion batteries (LIB) because of their high theoretic specific capacities. However, conversion materials generally suffer from relatively low cycling-stabilities due to the loss of inter-particle contacts which occurs as a result of the conversion reaction. Co3O4 is an interesting conversion material since it exhibits a much higher theoretical specific capacity (890 mAh/g) compared to extensively used graphite (372 mAh/g). In addition, mixtures of Co3O4 with CuO have been shown to lead to further improvements in cycling stability and specific capacity[1]. Since the conversion reaction mechanism is still not well understood, the aim of this work is to use experimental thermodynamics combined with modeling and simulation to better understand the electrochemistry of the conversion reaction for Co3O4. During electrochemical cycling of LIBs, compositional changes and phase transformations of the electrodes take place when lithium ions are added or removed according to the equation: 10 Li+ + Co3O4 + 10 e- ⇌ Li2O + 3 CoO + 8 Li+ + 8 e- ⇌ 3 Co + 4 Li2O. (1) The equilibrium phases and coulometric titration curves during lithiation/delithiation can be calculated using CALPHAD-based thermodynamic descriptions of the multi-component material systems. However, the development of CALPHAD-based thermodynamic descriptions requires reliable thermodynamic and phase diagram data. Thus, in the first step of this work, key thermochemical experiments and phase diagram investigations were performed to clarify inconsistencies in the existing literature data. The enthalpy of reduction of Co3O4 to CoO was determined using high temperature oxide melt and transposed temperature drop calorimetry. This reaction is of particular importance for conversion electrodes because it is an intermediate step in the conversion reaction (see equation (1)). Additionally, since reliable heat capacity data are needed to extrapolate the thermodynamic descriptions to temperatures relevant for battery applications, the heat capacity of Co3O4 in the temperature range of 240 to 1150 K was measured using differential scanning calorimetry. The experimental data were then compared to calculations performed using an existing thermodynamic description of the Co-O system[2] to assess its reliability for extrapolations to higher order systems. Since phase diagram data in the Li-Co system are limited, several intermetallic samples were prepared, heat treated at different temperatures and quenched to room temperature. The samples were subsequently investigated using SEM, powder XRD and ICP-OES. A thermodynamic description of the Li-Co sub-system was developed based on these results and used for a preliminary thermodynamic description of the multi-component Li-Co-O material system. Calculations using the preliminary thermodynamic description were compared to experimentally determined emf and phase diagram data at 673 K from Godshall et al.[3]. Finally, results of electrochemical cycling tests performed in this work using half cells with coin cell geometry were discussed in comparison to calculations from the thermodynamic description of the Li-Co-O material system. [1] D. Wadewitz, W. Gruner, M. Herklotz, M. Klose, L. Giebeler, A. Voss, J. Thomas, T. Gemming, J. Eckert, H. Ehrenberg, J. Electrochem. Soc. 2013, 160, A1333-A1339. [2] M. Chen, B. Hallstedt, L. J. Gauckler, J. Phase Equilib. 2003, 24, 212. [3] N. A. Godshall, I. D. Raistrick, R. A. Huggins, Mat. Res. Bull. 1980, 15, 561.

Environmental Metabolic Footprinting: A novel application to study the impact of a natural and a synthetic β-triketone herbicide in soil

This study presents a novel approach for assessing the risk of agrochemicals in soil microcosms through the use of non-targeted metabolomics. The metabolome of treated soils was extracted and tested through LCMS profiling in order to generate an "Environmental Metabolic Footprint" (EMF). A dynamic characterization of pollution biomarkers was obtained through a multivariate statistical analysis of EMF data, where our results show the possible evolution towards a state of resilience. The EMF methodology was applied to two β-triketone herbicides in soil microcosms: one natural, leptospermone, and one synthetic, sulcotrione. In spite of a four-fold higher application dose, leptospermone exhibited a lower resilience time than did sulcotrione (ca. 30 days vs ca. 45 days respectively).