Dependence Of Heat Capacity Research Articles

Revisiting the Extension of SGTE Heat Capacity Data to Zero Kelvin: Combining Classical Fit Polynomials with Debye–Einstein Functions

AbstractIt is demonstrated in this work that a four parameter Debye–Einstein integral is an excellent fitting function for heat capacity values of pure elements from zero Kelvin to room temperature provided that there are no phase transformations in this temperature range. The standard errors of the four parameters of the Debye–Einstein approach are provided. As examples the temperature dependent molar heat capacities of Fe, Al, Ag and Au are calculated in the temperature range from 0 to 300 K. Standard molar entropies, enthalpies and values of a molar Gibbs energy related function are derived from the molar heat capacities and the values are compared to literature data. The next goal focuses on a seamless transition of these low temperature heat capacities to SGTE (Scientific Group Thermodata Europe) unary data. This can be achieved by penalyzing deviations in the heat capacity values and in their temperature derivatives at the transition point. Whereas the constrained heat capacities of Fe and Al mimic the experimental data, the calculated values deviate considerably in case of Ag and Au. As an alternative a smooth transition in the heat capacities and the temperature derivative is achieved by a switch function employed close to the transition region.

Refined prediction of thermal transport performance in amorphous silica

Thermal transport in amorphous silica (a-SiO2) and silica aerogel is critically important for thermal protection and microelectronics applications. However, notable disparities exist between the predicted and measured thermal conductivity of a-SiO2. Inspired by the dual-phonon theory proposed by Luo et al. [Nat. Commun. 2020, 11, 2554] for crystalline materials, this work introduces a dual-diffuson transport method for amorphous materials. The criterion based on the thermal diffusivity is employed to differentiate between normal diffusons and phonon-like diffusons. Herein, the thermal conductivity of a-SiO2 is investigated by combining a modified Allen-Feldman (AF) theory with the dual-diffuson transport method. The present method is validated well by the measurement using the transient plane source (TPS) method. In addition, the results indicate that normal diffusons primarily govern the thermal transport in a-SiO2, with only a minor contribution from phonon-like diffusons. The temperature dependence of specific heat capacity and mode linewidth contributes to the positive temperature-dependent thermal conductivity. The quantum effect of specific heat capacity is the primary influencing factor in the temperature range of 100–1000 K, while the mode linewidth becomes dominant at higher temperatures. Finally, a theoretical framework for predicting the solid thermal conductivity of silica aerogel is introduced by including the temperature effect on the inherent thermophysical properties of the backbone. This work uncovers the physical mechanisms underlying temperature-dependent thermal transport in a-SiO2 and silica aerogels.

Large reversible magnetocaloric effect in rare-earth molybdate RE2(MoO4)3 (RE: Gd and Tb) compounds

We report on the synthesis, structural, DC magnetic susceptibility studies on Gd2(MoO4)3 and Tb2(MoO4)3 polycrystals, prepared by conventional solid-state reaction method. Temperature and magnetic field (H) dependent magnetization and heat capacity measurements have been carried out to estimate the isothermal magnetic-entropy change (−ΔSm) and adiabatic temperature change (ΔTadi) in both rare-earth molybdates. No obvious long-range magnetic ordering can be found down to 2 K in both studied compounds. The estimated maximum value of –ΔSm at 3.5 K for 70 kOe is 31.1 J kg−1 K−1 and 16.7 J kg−1 K−1 in Gd2(MoO4)3 and Tb2(MoO4)3, respectively. Further, the calculated total-adiabatic temperature change for Gd2(MoO4)3 was 12.8 K, and Tb2(MoO4)3 has shown 9.8 K. The difference in the observed magnetocaloric and adiabatic temperature responses of Tb2(MoO4)3 compared to Gd2(MoO4)3 could be attributed to the presence of orbital angular moment of Tb3+ ions and relatively low-value of magnetization. Both the systems show a large magnetocaloric effect (MCE) (−ΔSm ∼ 12 J kg−1 K−1) even in low applied H (<20 kOe) attainable by a permanent magnet. Large magnetocaloric behaviour of Gd2(MoO4)3 and Tb2(MoO4)3 systems at a moderate field change along with very low electrical conductivity and the absence of thermal and magnetic field hysteresis in magnetization make them conducive to their use as promising magnetic refrigerants in the vicinity of liquid-helium temperatures.

Machine-learning assistant DFT study of half-metallic full-Heusler alloy N2CaNa: Structural, electronic, mechanical, and thermodynamics properties

We studied the structural, electronic, mechanical, and thermodynamic properties of N2CaNa full Heusler alloys using density functional theory (DFT). Results for the structural analysis establish structural stability with a minimum formation energy of 29.9 eV. The compound is brittle and mechanically stable, having checked out with the Pugh criteria. The B/G ratio of bulk modulus B to shear modulus G for N2CaNa is 4.766, hence the material is ductile. N2CaNa alloy is ductile in nature. The Debye model correctly predicts the low-temperature dependence of heat capacity, which is proportional to Debye’s T3 law. Just like the Einstein model, it also recovers the Dulong–Petit law at high temperatures, suggesting the thermodynamic stability of the compounds at moderate temperatures. The results demonstrate potential N2CaNa for applications in spintronics, structural engineering, and other fields requiring materials with tailored properties.

Modeling the Size Dependence of Specific Heat Capacity and Thermal Expansion Coefficient of Metallic Nanocrystals

Modeling the Size Dependence of Specific Heat Capacity and Thermal Expansion Coefficient of Metallic Nanocrystals

Precise integration boundary element method for solving nonlinear transient heat conduction problems with temperature dependent thermal conductivity and heat capacity

The precise integration boundary element method (PIBEM) is used to solve nonlinear transient heat conduction problems with temperature dependent thermal conductivity and heat capacity in this article. At first, a boundary-domain integral equation can be obtained by using the fundamental solution for steady linear heat conduction problems. Secondly, the domain integrals are converted into boundary integrals by using the radial integration method to get a pure boundary integral equation, which can retain the advantage of dimension reduction of the boundary element method. Then, after discretization, a first-order nonlinear differential equation system in time is obtained, and the precise integration method with predictor-corrector technique is used to solve the system of nonlinear equations. In the end, several numerical examples are presented to verify the accuracy and stability of the presented method. The results obtained by the presented method are less affected by the time step size and satisfactory results can be obtained even for a large time step size.

CFD simulation of solid/liquid phase change in commercial PCMs using the slPCMlib library

Modelling the solidification and melting behavior of phase change materials (PCMs) can present several challenges, including non-isothermal phase change, multi-step transitions, complex enthalpy-temperature relations and convective heat transfer. To tackle these challenges, this study proposes a novel numerical method based on real experimental data for modelling complex phase change behavior of commercial PCMs in Ansys Fluent CFD software. The phase transition of PCMs is simulated with the apparent heat capacity (AHC) method, which is implemented as a User-Defined Function (UDF). Heat convection is simulated with the Boussinesq approximation. The method is validated by comparing to the Ansys Fluent built-in Solidification and Melting (S&M) model for the case of piecewise constant heat capacity. The results show that AHC method provides excellent agreement with S&M model for a piecewise constant heat capacity model. In addition, the AHC method solves convergence problems even for narrow phase change temperature ranges when a smooth heat capacity function is assumed. Finally, the AHC model is also tested on a set of commercial PCMs exhibiting complex phase change behavior. Temperature dependent specific heat capacities are determined from heat capacity data provided by PCM manufacturing companies and are imported as cubic Hermite spline functions from the solid-liquid phase change material library slPCMlib available at https://slpcmlib.ait.ac.at/. From the presented case study and tested PCMs it can be concluded that the AHC method is numerically robust when used with sufficiently smooth heat capacity functions, and it can be recommended for the analysis of heat transfer with PCMs showing a complex phase change behavior.

Fragility and Tendency to Crystallization for Structurally Related Compounds.

The present study was designed to investigate the physical stability of three organic materials with similar chemical structures. The examined compounds revealed completely different crystallization tendencies in their supercooled liquid states and were classified into three distinct classes based on their tendency to crystallize. (S)-4-Benzyl-2-oxazolidinone easily crystallizes during cooling from the melt; (S)-4-Benzylthiazolidine-2-thione does not crystallize during cooling from the melt, but crystallizes easily during subsequent reheating above Tg; and (S)-4-Benzyloxazolidine-2-thione does not crystallize either during cooling from the melt or during reheating. Such different tendencies to crystallize are observed despite the very similar chemical structures of the compounds, which only differ in oxide or sulfur atoms in one of their rings. We also studied the isothermal crystallization kinetics of the materials that were shown to transform into a crystalline state. Molecular dynamics and thermal properties were thoroughly investigated using broadband dielectric spectroscopy, as well as conventional and temperature-modulated differential scanning calorimetry in the wide temperature range. It was found that all three glass formers have the same dynamic fragility (m = 93), calculated directly from dielectric structural relaxation times. This result verifies that dynamic fragility is not related to the tendency to crystallize. In addition, thermodynamic fragility predictions were also made using calorimetric data. It was found that the thermodynamic fragility evaluated based on the width of the glass transition, observed in the temperature dependence of heat capacity, correlates best with the tendency to crystallize.

Influence of lithium on the temperature dependence of heat capacity and thermodynamic functions changes in AK1 alloy based on high-purity aluminum

The heat capacity of the AK1 alloy based on high-purity aluminum with lithium was determined in the cooling mode using the known heat capacity of the reference aluminum sample. By means of mathematical processing of cooling rate curves of samples from AK1 alloy with lithium and the reference sample, polynomials describing their cooling rates were obtained. Further, the polynomials of the temperature dependence of the heat capacity of alloys, described by a four-member equation, were established using the experimentally found values of the cooling rates of samples from alloys and the standard, taking into account their mass. Using integrals from specific heat capacity, models of temperature dependence of enthalpy, entropy and Gibbs energy changes were established. It was found that the heat capacity of the alloys increases with rising temperature. The addition of lithium when the temperature is up to 600 K significantly increases the heat capacity, and at temperatures above 600 K lithium in amounts of 0.5 wt. % reduces the heat capacity of the initial alloy AK1. It is shown that lithium addition increases the enthalpy and entropy of the initial AK1 alloy and decreases the Gibbs energy value.

Thermophysical properties of the biofuel components: A mini-guide to the critical properties, heat capacities, and thermal conductivities

Experimental data on the critical temperature, critical pressure, heat capacity, and thermal conductivity of the compounds involved in the production of biofuels have been compiled and critically evaluated. The compilation contains the critical temperature and critical pressure of 56 compounds, the heat capacity of 63 compounds, and the thermal conductivity of 35 compounds and covers the period from 1886 to September 2023. The recommended values of the critical temperatures and pressures have been determined. The parameters of correlating polynomials for the temperature dependence of heat capacities and thermal conductivities have been obtained. The compounds under consideration are the components of biofuels or platform chemicals. Some methyl and ethyl esters of saturated and unsaturated acids, furanic compounds, levulinic acid and alkyl levulinates, gamma-valerolactone, alpha-angelica lactone, triglycerides, and several alkyl pentanoates are among the compounds studied.

Heat Capacity of Indium or Gallium Sesqui-Chalcogenides.

The chalcogenides of p-block elements constitute a significant category of materials with substantial potential for advancing the field of electronic and optoelectronic devices. This is attributed to their exceptional characteristics, including elevated carrier mobility and the ability to fine-tune band gaps through solid solution formation. These compounds exhibit diverse structures, encompassing both three-dimensional and two-dimensional configurations, the latter exemplified by the compound In2Se3. Sesqui-chalcogenides were synthesized through the direct reaction of highly pure elements within a quartz ampoule. Their single-phase composition was confirmed using X-ray diffraction, and the morphology and chemical composition were characterized using scanning electron microscopy. The compositions of all six materials were also confirmed using X-ray photoelectron spectroscopy and Raman spectroscopy. This investigation delves into the thermodynamic properties of indium and gallium sesqui-chalcogenides. It involves low-temperature heat capacity measurements to evaluate standard entropies and Tian-Calvet calorimetry to elucidate the temperature dependence of heat capacity beyond the reference temperature of 298.15 K, as well as the enthalpy of formation assessed from DFT calculations.

Оценка термодинамических свойств химических соединений в системах Me-Si-O, Fe-Si-B, Fe-Cr-B и в некоторых системах, используемых для получения покрытий

A comparative analysis was performed for evaluating thermodynamic properties of a number of condensed and gas-phase compounds formed in the Me-Si-O, (Me = Al, Ba, Pb, Fe, Cr, Fe, Ni, Mn, Mo), Fe-Cr-B and Fe-Si-B systems, including those with impurities of oxygen, manganese, nickel, molybdenum and aluminium, and in some systems used for coatings production. The data on the enthalpies of the formation and on the coefficients of 1 ÷ 7 equations for the calculation of the temperature dependences of isobaric-isothermal potential, entropy and heat capacity for 84 compounds were obtained. The results of the comparative correlation analysis of thermodynamic properties for a number of condensed and gas-phase compounds formed in the Me-Si-O, (Me = Al, Ba, Pb, Fe, Cr, Fe, Ni, Mn, Mo) and Fe-Cr-B, Fe-Si-B systems, including those with impurities of oxygen, manganese, nickel, molybdenum and aluminium, and in some systems used for coatings were obtained. The correlation dependences of thermodynamic properties had a multiple correlation coefficient – R = 0.98 and standard deviations for heat capacity σ ~ 4.8 % (for gas-phase compounds σ ~ 0.6 %), entropy σ ~ 5.8 %, the enthalpy of formation σ &lt; 8 %, oxide systems σ ~ 3 % and silicates σ ~ 2 %. As a result, the enthalpies of formation and 1 ÷ 7 – coefficients of the equations for calculating the temperature dependences of isobaricisothermal potential, entropy and heat capacity for 84 condensed and gas-phase substances were estimated. The obtained thermodynamic data were tested in the thermodynamic analyses of the formation of compounds in various systems and showed satisfactory agreement with experimental results.

УРАВНЕНИЯ СОСТОЯНИЯ ДЛЯ РАСЧЕТА ТЕМПЕРАТУР УДАРНО-ВОЛНОВОГО СЖАТИЯ МОЛЕКУЛЯРНЫХ КРИСТАЛЛОВ

The paper analyzes the equations of state of energy-related materials, which are molecular crystals, to define the optimal equation of state for determining the shock wave compression temperatures of these materials. The analysis of the cold pressure component showed that its form allows reproducing the known experimental data for triaminotrinitrobenzene (TATB) and pentaerythritol tetranitrate (PETN) with high accuracy. No shock adiabat can be constructed in a wide range of pressures because detonation is initiated for energy-related materials during shock wave compression. The paper tests an algorithm for constructing shock adiabats using experimental data on TATB and PETN isothermal compression. A comparison of experimental and calculated shock adiabats for PETN showed their alignment with the accuracy of the experimental error. The paper uses the example of TATB and PETN to propose an approach for determining the shock wave compression temperatures of energy-related materials by calculating the propagation of a steady shock wave in them. The proposed approach allows constructing shock adiabats of energy-related materials and analyzing the influence of various expressions to describe the dependence of heat capacity at constant volume on temperature by the value of the shock wave compression temperature of energy-related materials.

A theoretical study of Lifshitz transition for 2H-TaS2.

Lifshitz transition was proposed to explain a change of the topology structure in a Fermi surface induced by continuous lattice deformation without symmetry breaking since 1960. It is well known that the anomalies of the kinetic coefficients (the coefficient of heat conduction and electrical conductivity, viscosity, sound absorption, etc.) are usually closely connected with the Lifshitz transition behavior. 2H-TaS2 is a typical representative to study its anomalies of temperature dependence of heat capacity, resistivity, Hall effect, and magnetic susceptibility. Its geometrical structure of the charge density wave (CDW) phase and layer number dependence of carrier-sign alternation upon cooling in the Hall measurements have not been well understood. The geometrical structure (T-Ts) of the CDW phase was predicted through first principles calculations for bulk and mono-layer 2H-TaS2. Driven by electron-lattice coupling, Ta atoms contract to form a partially gapped CDW phase. The CDW phase has a larger average interlayer separation of S-S atoms in the adjacent two layers compared with the metal phase, which results in a weaker chemical bonding among S-S atoms in the adjacent two layers and then a narrower bandwidth of the energy band. The narrower bandwidth of the energy band leads to a larger density of states (DOS) in the out-of-plane direction above the Fermi level for the CDW phase. As the Fermi level continually drops from the DOS region with a negative slope to that with a positive slope on cooling, the reversal of the p → n type carrier and the pocket-vanishing-type Lifshitz transition occur in the bulk 2H-TaS2. However, the Fermi level slightly drops by 6 meV and happens to be at the positions of pseudo band gaps, so the reduction of in-plane DOS and total DOS is responsible for the always p-type carrier in the mono-layer samples. Our CDW vector of the k-space separation between two saddle points is QSP ≈ 0.62 GK and can provide a theoretical support for the "saddle-point" CDW mechanism proposed by Rice and Scott. Our theoretical explanation gives a new understanding of both Lifshitz transition for symmetry breaking and reversal for the p-n carrier sign in the Hall measurements in various two-dimensional transition metal disulfides.

Complete thermodynamic characterization of second-order phase transition magnetocaloric materials exclusively through magnetometry

To fully assess and improve the performance of near room-temperature magnetic refrigerants, it is crucial to measure and compare their three most relevant thermodynamic properties, and their dependence on temperature (T) and applied magnetic field (H): the isothermal entropy change, ∆Siso(T,H); the adiabatic temperature change, ∆Tad(T,H); and the heat capacity, Cp(T,H). Typically, each thermodynamic property requires its own specialized measurements, which are very time-demanding and can be challenging to setup. In this work, we report a complete thermomagnetic characterization of a benchmark magnetocaloric material, gadolinium, using a single and commercially available SQUID magnetometer. By improving a recently reported method with incremental field ramping steps for measuring temperature through magnetization, we obtained a ∆Tad(T) curve under a 1 T field change with its peak amplitude and maximizing temperature respectively within 2 % and 0.8 % of previously reported values for gadolinium. We were also able to estimate the temperature dependent heat capacity, Cp(T,μ0H=0.85T), using the ∆Tad(T) measurements from magnetometry combined with magnetization versus temperature curves at different field values. This estimate of Cp around the transition temperature of gadolinium is within a relative error of 11 % of the experimental and reported values. The reported methodology allows the complete characterization of a second-order magnetocaloric material (∆Siso(T,H), ∆Tad(T,H), Cp(T,H)) around its Curie temperature using a single and widely available device, which can accelerate studies of different magnetocaloric materials’ performance, and approximate their implementation in magnetic refrigeration and/or waste heat energy harvesting industries.

Detailed Approach to Calculate the Heat Generation of Lithium-Ion Cells during Heat-Wait-Seek Tests in Accelerating Rate Calorimetry

By means of the Heat-Wait-Seek test in Accelerating Rate Calorimeters (ARC) the safety performance of Lithium-ion cells can be estimated. The most interesting measured parameters that can be extracted from these tests are the critical temperatures, such as the onset of self-heating, the venting or thermal runaway temperature. Another essential safety factor is the generated heat during cell failure. In general, the generated heat is calculated by an average heat capacity of the cell and the temperature difference in the experiment, which is not accurate enough especially when facing the challenges in specific volumetric energy density and safety of battery packs.In this study a more accurate way to calculate the generated heat is proposed, which consists of using temperature dependent heat capacity of the cell, based on its individual components. This leads to a significant difference in the calculated generated heat, for instance the specific heat capacity of NMC as a cathode material increases in the temperature range from 298 K to 398 K from 0.83 to 0.96 J/g·K, which is an increase of about 16 %. This leads to a difference in the calculated generated heat in this small range of 7 J/g (or 8 %), if a static specific heat capacity of 0.83 J/g·K and on the other hand a temperature dependent specific heat capacity is used. Moreover, the influence of additional heating steps, venting of the cell, melting of the separator and the overall accuracy of the measurement will be discussed. The investigation of these effects is in the focus of the project AnaLiBa (Analytics of Lithium-ion-Batteries), funded by the German Federal Ministry of Education and Research (BMBF) in the framework of the competence cluster Analytics/quality assurance (AQua). In this project the approach is applied to commercial type 21700 cells. The 21700 type cells are extensively used in battery packs, for instance in electric cars, due to their 20 % higher energy density with respect to the former used type 18650 cells. The cells were measured in an ES-ARC from Thermal Hazard Technologies, UK, using the Heat-Wait-Seek test. The generated heat was compared for either fresh cells and cells after cyclic aging. The cyclic aging was performed at 0 °C and 20 °C with a charging rate of 0.3C for 0 °C and 0.7C for 20 °C and a discharging rate of 2C for 20 °C and 0.5C for 0 °C until the state of health was at 80 % ±2 %. The two different temperatures studied in the cyclic aging were chosen as 0 °C to cause lithium plating and as 20 °C to cause a higher internal resistance due to a thicker solid-electrolyte-interface, which has a high influence on the measured properties in the Heat-Wait-Seek test and therefore on the generated heat.With this approach the generated heat in abuse tests can be calculated more accurately to simulate the propagation of heat during a single cell failure in a pack or to calculate the necessary thickness of a heat barrier for safer battery packs. This helps manufacturers to improve their battery pack design with respect to the specific volumetric energy density and safety.

Transport Properties of Equiatomic CoCrFeNi High-Entropy Alloy with a Single-Phase Face-Centered Cubic Structure

The key thermophysical properties necessary for the successful design and use of CoCrFeNi alloy in thermophysical applications have been measured experimentally, and the results have been compared with literature values and results previously obtained for commercial Ni-Cr alloys and equiatomic CoCrFeNi alloy. In particular, the thermal diffusivity, coefficient of thermal expansion (CTE), and specific heat capacity were measured for the as-cast and homogenized equiatomic CoCrFeNi alloy over a temperature range allowing the thermal conductivity to be calculated up to 1173 K. The thermal conductivity and thermal diffusivity of the equiatomic CoCrFeNi alloy were found to deviate from monotonic behavior in the temperature range from 773 to 1100 K. Such a deviation was previously observed in the behavior of the temperature dependence of CTE and specific heat capacity of the equiatomic CoCrFeNi alloy. The non-linear behavior is primarily the result of order/disorder phenomena for the as-cast and homogenized sample, as well as non-equilibrium solidification under arc melting conditions for the as-cast sample. The measured data of thermophysical properties are provided for thermally differently treated samples, and it is shown that there is a difference in the behavior of the temperature dependences of CTE, thermal diffusivity, and heat capacity.

Phase transitions, structure and properties of solid solutions V&lt;sub&gt;2 – Δ&lt;/sub&gt;ME&lt;sub&gt;0,02&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;

Subject of research: the article presents studies of the properties of solid solutions V2Me0,02O3 in the metaldielectric phase transition region.&#x0D; Purpose of research: to obtain temperature dependences of physical parameters (heat capacity, electrical resistance, magnetic susceptibility) of samples of the composition V2Me0,02O3 in the range of 60-400 K; to determine the effect of vanadium concentration and the type of alloying element on the parameters of the phase transition and the parameters of the energy spectrum of the crystal lattice.&#x0D; Methods and objects of research: the objects of research were solid solutions based on vanadium oxide V2O3, alloyed with aluminum, iron, chromium. Doping was used to regulate and stabilize the parameters of the V2O3 phase transition. The temperature of the phase transition was determined by measuring the temperature dependences of heat capacity, electrical resistance and magnetic susceptibility.&#x0D; Main results of research: in the course of experimental studies, it was found that the temperatures of metaldielectric phase transitions determined by different methods are close in their values. The dependences of the phase transition temperature on the parameters of the crystal lattice, changes in magnetic susceptibility for pure and doped vanadium oxide, as well as the dependence of the transition temperature and the electrical resistivity jump on the Debye temperature are obtained. The influence of alloying metals and vanadium concentration on the properties of the studied samples in the phase transition region was determined by the temperature dependences of magnetic susceptibility, electrical resistance and heat capacity.

On the interplay of thermodynamic and structural properties of LiZn-based half-Heusler alloys

The half-Heusler LiZnX (X = As, P, and Sb) alloys have gained a significant attention due to their exceptional thermoelectric and magnetic properties, making them a promising material for various applications. In this study, we employ density functional theory to investigate the data on structural and thermodynamics properties of the LiZnX (X = As, P, and Sb) half-Heusler alloys. First-principles calculations as implemented in quantum Espresso simulation software were used. We observed that LiZnX (X = As, P, and Sb) will be easily compressed due to the small value of its bulk modulus. We obtained that the structure is stable and corresponds a half-Heusler crystal one. The Debye model correctly predicts the observed low-temperature dependence of heat capacity, which is proportional to the Debye T3 law. At room temperature, Debye specific heat Cv = 70 J / (K⋅N⋅mol).

Zn-Mo-O system: Insights into the thermodynamic stability and applicability in lithium ion batteries

A detailed experimental investigation on the thermochemical stability of Zn2Mo3O8(s) in the Zn-Mo-O system was reported for the first time using high temperature oxide melt solution calorimetry in conjunction with solid oxide based electrochemical measurements. The temperature dependence of molar heat capacity of this compound was determined employing thermal relaxation calorimetry and differential scanning calorimetry. The values of standard molar enthalpy of formation (∆fH298.15°), standard molar entropy (S298.15°), molar heat capacity (Cp) and Debye temperature (θD) for Zn2Mo3O8(s) were determined for the first time in this study. The present study also focuses on the investigation of electrochemical performance of α-ZnMoO4(s) for lithium ion battery applications which demonstrated the effective utilization of this compound as anode material due to its remarkable cycling stability and rate capability.