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Different percentages of nanoparticles graphene (G) were mixed with nano-micron sized silicon (Si) particles as follows: 10, 20, 30 and 40 wt% graphene to silicon ratios. The crystal structure of pure Si powder pattern has cubic phase SEM, TEM/SAED and XPS equipments were implemented to study the surface properties of the prepared G@Si composites. Cyclic voltammetry (CV) measurement for the G@Si cell revealed two broad cathodic peaks, related to the deposition of Li2O thin layer on Si particles and the lithiation process of Si to form lithium silicide. Meanwhile, the oxidation of LixSi into Si and Li ionis confirmed by the anodic strong peak at 0.56 V. Electrochemical impedance spectroscopy (EIS) measurements revealed high interfacial resistance ~ 1825 Ω for pure Si anode in comparison with that of G@Si composite anode. It is concluded that graphene acts as a conductive shielding pathway to inhibit the large volume change and minimize the capacity fading during successive galvanostatic cycling of G@Si composite anode materials versus Li/Li+. Accordingly, the specific discharge capacity of 30%G@Si cell delivered about 1240 and 900 mAhg−1 for 1st and 100th charge–discharge cycles, respectively.

In this paper, three different samples of spinel carbon@Sb2SnS4 (C@S) sulphide were successfully synthesized via simple hydrothermal technique using L-cysteine (L-cyst.), thioacetic acid (TAA) and thioacetamide (TAM) compounds as sulphur sources. Physical and surface characterizations for the synthesized sulphide powders, including X-ray diffraction (XRD), field emission electron microscope (FE-SEM), energy dispersive spectroscopy (EDS) and XPS techniques were carried out. The XRD results confirmed the formation of ternary sulphide Sb2SnS4 in the spinel cubic phase associated with graphite and minor phases of binary sulphides. The microstructure investigation of carbon-coated Sb2SnS4/TAA (C@S/TAA) revealed two-dimensional thin sheets collected as bundles that correspond to ternary sulphide phase, while small bright grains are related to the binary sulphides and oxides. Moreover, the existence of Sb3+ and Sn4+ was confirmed from the XPS double peaks of Sb3d and Sn3d orbitals. Galvanostatic cycling of the assembled cells indicated that C@S/TAA anode delivered the maximum discharge capacity of about 880 mA g−1, while the C@S/L-cyst. cell possessed the lowest discharge capacity of about 772 mAh g−1. Finally, the cell with C@S/TAA anode displayed the highest diffusion coefficient of Li+ ions and best rate capability performance due to the unique two-dimensional thin sheets-like morphology of Sb2SnS4 hybridized with carbon nanoplates.

Thin-film deposition using electrodeposition techniques is highly preferable because of its capability to deposit multi-component alloys at low temperatures. In this regard, copper bismuth selenide (CBSe) films were electrodeposited in two various ways, simultaneous and successive electrodeposition processes. The structural and morphological characterizations of the obtained films were performed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and X-ray Photoelectron Spectrometer (XPS). The CBSe alloy films formed by successive electrodeposition revealed better crystallinity and more regular morphology in comparison with simultaneous electrodeposited CBSe films. The prepared CBSe film by successive electrodeposition exhibited high light absorptivity and low band gap energy value (Eg = 1.65 eV) resulting in a higher photoelectrical response. The crystallization of the ternary CBSe film electrodeposited via successive routine obeyed the instantaneous nucleation mechanism, while the CBSe film obtained by simultaneous electrodeposition agreed with the progressive nucleation mechanism. Successive electrodeposition of ternary CBSe alloy film achieved greater values of photocurrent–voltage conversion efficiency (η = 1.26%) in photoelectrochemical systems.Graphic abstract

A negative material for lithium-ion batteries was prepared from graphene and cobalt hydroxide with different ratios by hydrothermal reaction. The crystal structure and crystalline phases of pure Co-hydroxide and 4Co-hydroxide:1 graphene were identified by X-ray diffraction (XRD). The functional groups and structure analysis of Co(OH)2 with graphene were characterized by Fourier transmission infrared (FTIR) spectra and X-ray photoemission spectroscopy (XPS). The surface morphology was studied with field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The cycle life of the cells was carried out with potential windows between 0.01 and 3 V vs. Li/Li+ using a current density of 0.1 C. Furthermore, electrochemical impedance spectra (EIS) measurements were applied. The obtained diffusion coefficient (1.62 × 10−17 m2 s−1) for the Li/4Co(OH)2–1G cell explains the higher mobility of Li+ ion diffusion than that of the other cells. The specific discharge capacity of 4Co(OH)2–1G cell delivered about 690 Ah kg−1 up to more than 100 cycles. Also, this cell has a higher specific discharge capacity rather than the other cells.

The new Na/Cr-bisubstituted lithium vanadium monodiphosphate compound (LNVCPP) Li9-xNaxV2.8Cr0.2(P2O7)3(PO4)2, where x = 0.0, 0.5, 1.0, 1.5, and 2.0 have been prepared via simple sol–gel combustion route. The as-prepared materials are characterized by XRD, FESEM, and EDX. The XRD data indicate the presence of single phase of Li9-xNaxV2.8Cr0.2 (P2O7)3(PO4)2 (x = 0.0–2.0) with trigonal structure. Both cycle performance and rate capability have shown improvement with moderate Na-doping content. Cell of Li8.5Na0.5V2.8Cr0.2(P2O7)3(PO4)2 cathode delivers a specific discharge capacity of 53 mAhg−1 after 35 cycles in comparison with the other samples. The optimum ratio Li8.5Na0.5VCPP coated with carbon delivers a specific discharge capacity of about 75 mAhg−1 after 25 cycles. Therefore, it presents the good electrochemical rate and cyclic stability. The enhancement of the rate and cyclic capability may be attributed to the optimizing particle size, morphologies, and structural stability with the proper amount of Na-doping (x = 0.5) in Li sites.

The use of monodiphosphate compounds as renewable sources of energy as positive (cathode) material for lithium-ion batteries (LIB) is considered a great target. Lithium vanadium chromium monodiphosphate (LVCPP)Li9V2.8Cr0.2(P2O7)3(PO4)2 and the Na-doped:Li8.75Na0.25V2.8Cr0.2(P2O7)3(PO4)2 (LNVCPP) compounds have been prepared by using the sol-gel method. The prepared materials are characterized by XRD, FESEM, and EDX. The XRD data is indicated the presence of a single-phase of Li9V2.8Cr0.2 (P2O7)3(PO4)2 and Li8.75Na0.25V2.8Cr0.2(P2O7)3(PO4)2 with trigonal structure. Both cycle performance and rate capability have shown improvement with moderate Na doping content. Li9V2.8Cr0.2(P2O7)3(PO4)2 and Li8.75Na0.25V2.8Cr0.2(P2O7)3(PO4)2 compounds presented the good electrochemical rate and cyclic ability. The cell is prepared with x=0.25 delivered a specific discharge capacity of 50 mAhg-1 after 35 cycles in comparison with the other sample. The enhancement of the rate and cyclic capability may be attributed to the optimizing particle size, morphologies, and structural stability with the proper amount of Na-doping (x =0.25) in Li sites.

A novel negative (anode) material for lithium-ion batteries, tin oxide particles covered with graphene (SnO/graphene) prepared from graphite was fabricated by hydrothermal synthesis. The structure and morphology of the composite were characterized by Raman spectra, FTIR spectra, XRD, XPS and FESEM. It is observed that the G and 2D bands (1581 and 2831 cm−1, respectively) have more intensity in graphene rather than graphite. EIS was carried out. It is observed that the lowest Warburg impedance coefficient, σw, is 24.39 Ω s0.5 for Li/SnO–graphene (3:1) cell. The reversible specific capacity of Li/SnO–graphene (3:1) cell was about 0.950 Ah g−1 after 100 cycles at current density current 10−2 A g−1. These results indicate that 3 SnO:1 graphene possesses superior cycle performance and high rate capability. The enhanced electrochemical performances can be ascribed to the characteristic structure of tin oxide with graphene shells, which buffer the volume change of the metallic tin and prevent the detachment and agglomeration of pulverized tin.

Generally, cadmium zinc telluride Cd1−x Zn x Te nanopowders (x = 0.0, 0.2, 0.5, 0.8 and 1.0) have been purposefully tailored using a facile chemical method based on inexpensive hydroxides p...

Lithium excess manganese oxide, namely, Li2MnO3 is under investigations to improve its electrochemical performance as the next generation high capacity electrode material. Partial substitution of Mn by another metal is one of the ways to influence the properties of Li2MnO3. In the present study, vanadium is used to partially substitute Mn in various ratios. Li2VxMn1−xO3 (x = 0.1, 0.2, 0.3 and 0.4) samples are prepared by sol–gel method using stoichiometric ratios weights of Mn(CH3COO)2·4H2O, Li2CO3 and NH4VO3. The crystalline phases are identified by X-ray diffraction. The particles morphology is studied with a scanning electron microscope. Furthermore, impedance measurements (EIS) are applied using frequency range between 106 and 10−2 Hz. The optimum EIS is obtained with for the Li2V0.3Mn0.7O3 cell. Cyclic voltammetric measurements are carried out for the lithium manganate materials between 0.01 and 4.5 V versus Li+ with scan rate 0.1 mV s−1. Also, galvanostatic charging and discharging cycling of the cells are achieved with the same potentials windows using charging and discharging current intensity of 10 mA g−1 between 1.5 and 4.5 V versus Li+. It is observed that Li/Li2V0.3Mn0.7O3 cell has higher specific discharge capacity, 227 mAh g−1 rather than the other cells.

Cu2SnSe3 (CTSe) powders were prepared by solvothermal (SR) and solid state reactions (SSR) using low cost starting materials. The crystal structure, morphology, UV-Vis absorbance, electrochemical and solar energy properties were investigated using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Electrochemical Impedance Spectroscopy (EIS) and solar energy applications using I-V characteristics measurements. Also, the toxicity of elements like cadmium makes these materials lower applicable. A single cubic Cu2SnSe3 was obtained for the two methods of preparations. The calculated crystallite size values for CTSe prepared by SR and SSR are 24.1 and 30.3 nm, respectively. UV-Vis. spectra for SR and SSR preparations showed maximum absorbencies at 240 nm with band gap values of 0.9 and 1.4 eV, respectively. The charge transfer resistances (Rct) were equal to 3.5 and 24 W for photoelectrochemical cells (PEC) and the calculated conductivities were equal to 3x10-2 and 2x10-2 S.cm-1 for samples that prepared by SR and SSR methods, respectively. A good photoelectrochemical cell (PCE) was accomplished power conversion efficiency per unit area of about 0.84 and 0.64 % for cells prepared by SR and SSR, respectively.

Cu2SnSe3 (CTSe) powders were prepared by solvothermal (SR) and solid state reactions (SSR) using low cost starting materials. The crystal structure, morphology, UV-Vis absorbance, electrochemical and solar energy properties were investigated using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Electrochemical Impedance Spectroscopy (EIS) and solar energy applications using I-V characteristics measurements. A single cubic Cu2SnSe3 was obtained for the two methods of preparations. The calculated crystallite size (L) values for CTSe prepared by SR and SSR are 24.1 and 30.3 nm, respectively. UV-Vis. spectra for SR and SSR preparations showed maximum absorbencies at 240 nm with band gap (Eg) values of 0.9 and 1.4 eV, respectively. The charge transfer resistances (Rct) were equal to 3.5 and 24  for photoelectrochemical cells (PEC) and the calculated conductivities were equal to 3x10-2 and 2x10-2 S.cm for samples that prepared by SR and SSR methods, respectively. A good photoelectrochemical cell (PCE) has accomplished power conversion efficiency per unit area of about 0.84 and 0.64 % for cells prepared by SR and SSR, respectively.

$$\hbox {Li}_{2}\hbox {Ni}_{x}\hbox {Fe}_{1-x}\hbox {SiO}_{4}$$ ( $$x = 0$$ , 0.2, 0.4, 0.6, 0.8 and 1) samples were prepared by a sol–gel process. The crystal structure of prepared samples of $$\hbox {Li}_{2}\hbox {Ni}_{x}\hbox {Fe}_{1-x}\hbox {SiO}_{4}$$ was characterized using an X-ray diffractometer. Different crystallographic parameters such as crystallite size and lattice cell parameters have been calculated. Scanning electron microscopy and Fourier transform infrared spectroscopy investigations were carried out, which reveal the morphology and function groups of the synthesized samples. Furthermore, electrochemical impedance spectra measurements are performed. The obtained results indicated that the highest conductivity is achieved for the $$\hbox {Li}_{2}\hbox {Ni}_{0.4}\hbox {Fe}_{0.6}\hbox {SiO}_{4}$$ electrode compound. It was observed that Li– $$\hbox {Li}_{2}\hbox {Ni}_{0.4}\hbox {Fe}_{0.6}\hbox {SiO}_{4}$$ battery has initial discharge capacity of 164 mAh $$\hbox {g}^{-1}$$ at 0.1C rate. The cycle life performance of all $$\hbox {Li}_{2}\hbox {Ni}_{x}\hbox {Fe}_{1-x}\hbox {SiO}_{4}$$ batteries ranged between 100 and 156 mAh $$\hbox {g}^{-1}$$ with coulombic efficiency range between 70.9 and 93.9%.

Influence of the preparation method and different precursors are important for the absorber photovoltaic layer parameters of SnS. Synthesis of SnS compounds was carried out via two preparation methods; solid state reaction and hydrothermal; using different sulfur precursors. The morphology of particles and phase identification were studied using Field Emission Scanning Electron Microscope (FESEM) and X-ray diffraction (XRD) techniques. The XRD diffraction pattern of SnS revealed the existence of two crystal structure phases: the major is orthorhombic and the minor phase is tetragonal. The optical properties were determined using UV-Vis spectrophotometer showing absorbance peaks around 485 nm. The lowest bandgap of 1.74 eV is for SnS sample prepared from L-cystine. Electrochemical impedance spectroscopy (EIS) revealed that SnS cell prepared from L-cystine gave the lowest resistance of 171W. The photoelectrochemical measurements of this cell showed the highest power conversion efficiency per unit area of 2.5%.

CdSe and CdTe are electrodeposited using 0.1 M Cd 2+ and different ion concentrations of Se and Te. The effect of the temperature on the electrodeposition process is also studied. The crystal structure of the deposited CdSe and CdTe is investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) of samples deposited at optimized parameters reveals that CdSe has spongy spherical grains while CdTe has coralloid morphology. Optical absorption shows the presence of direct transition with band gap energy 1.96 and 1.51 eV for CdSe and CdTe, respectively. The highest photo-conversion efficiencies of electrodeposited CdSe and CdTe films per unit area are 6% and 9.6%, respectively that achieved under simple laboratory conditions. � 2014 Production and hosting by Elsevier B.V. on behalf of Ain Shams University.

Li2NixFe1−xSiO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) samples were prepared by sol–gel process. The crystal structure of prepared samples of Li2NixFe1−xSiO4 was characterized by XRD. The different crystallographic parameters such as crystallite size and lattice cell parameters have been calculated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) investigations were carried out explaining the morphology and function groups of the synthesized samples. Furthermore, electrochemical impedance spectra (EIS) measurements are applied. The obtained results indicated that the highest conductivity is achieved for Li2Ni0.4Fe0.6SiO4 electrode compound. It was observed that Li/Li2Ni0.4Fe0.6SiO4 battery has initial discharge capacity of 164 mAh g−1 at 0.1 C rate. The cycle life performance of all Li2NixFe1−xSiO4 batteries was ranged between 100 and 156 mAh g−1 with coulombic efficiency range between 70.9% and 93.9%.

Two photoactive chalcogenide compounds, copper bismuth selenide (CBSe) and copper antimony selenide (CASe), have successfully been prepared via a robust and facile solvothermal route. The phase transformation characteristics from the triclinic to orthorhombic crystal structure were clearly evinced by replacing Bi3+ with Sb3+ ions. The changes in the microstructure and electronic composition of each compound have been monitored using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy characterization techniques. The fabricated CBSe film showed large values of absorption coefficient >105 cm−1, good electrical conductivity, and charge carrier mobilities. The values of optical bandgap energy were estimated to be 0.99 and 1.18 eV for CBSe and CASe alloys, respectively. The electrochemical impedance spectroscopy measurements possessed lower resistance for CBSe electrodes. The photovoltaic performance results for the fabricated CBSe photoelectrochemical cells exhibited the maximum short-circuit current (Isc) of 6.22 mA, open-circuit voltage (Voc) of 0.492 V, fill factor of 63.9%, and power conversion efficiency of 1.94%. Finally, the as-prepared CBSe and CASe ternary alloys have possessed a good capability for dye sensitized solar cell and superconductor’s applications.

Cd 1− x In x Te ( x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) samples have been synthesized chemically using wet chemical method from precursor compounds, CdSO 4 , InCl 3 , and TeCl 4 . The hydroxide form of the solution mixture was obtained by using ammonia solution and the pH of the mixture was adjusted to 9. A suitable amount of NaBH 4 solution was added to reduce the hydroxide phase to the metalloid alloy. The crystal structure has been studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The 300 °C annealed samples revealed a cubic crystal structure. The morphology of the prepared samples is very fine and the average diameter is between 1 and 2.5 μm. The optical properties were determined using UV–vis–NIR spectrophotometer and band gap energy of 1.37 eV for Cd 0.6 In 0.4 Te was obtained. The best photovoltaic conversion efficiency of 1.89% was obtained for the Cd 0.6 In 0.4 Te sample with a short circuit current density ( J sc ) of 15.3 mA cm −2 , an open circuit voltage ( V oc ) of 0.668 V, and a filling factor (FF) of 69.31%.

This study reports a process to prepare Co x Ni 1− x S ( x = 0, 0.25, 0.5, 0.75 and 1) samples by hydrothermal process at 250 °C using stoichiometric weight ratios of raw materials. The prepared powder samples were annealed in Ar atmosphere at 450 °C for 3 h. The crystal structure of prepared annealed Co x Ni 1− x S samples was characterized by XRD. SEM investigations were carried out explaining the morphology of these samples. Electrochemical impedance spectra (EIS) measurements, Cyclic voltammetric (CV) and galvanostatic measurements were carried out. The life cycle performance was carried out for the cells and Li/Co 0.25 Ni 0.75 S cell gave specific discharge capacities of about 330 mA h g −1 .

Different ratios of Mn3O4/CNT (carbon nano tubes) samples were prepared by ultrasonic and hydrothermal reactions. The added ratios of CNT: Mn wt./wt. were 0, 5, 15, 25, 35 and 50%. The phases of the samples were identified by X-ray diffraction (XRD). The particle morphology was studied with a field emission scanning electron microscope (FESEM). The lowest charge transfer resistance, Rct was 19.18 Ω with cell of Mn3O4/35% CNT. For Li / Mn3O4-35% CNT cell, the specific discharge capacity was about 688 mAhg−1 after 100 cycles, which was the highest value among the other cells at discharge current density 0.02Acm−2.

Li2CuSnO4 and Li2CuSnSiO6 were prepared from their precursors compounds using Brij surfactant and a hydrothermal autoclave method. X-ray diffraction characterization revealed that the crystal structures of these compounds were tetragonal. Scanning electron microscope investigation showed the particle size morphology of Li2CuSnSiO6 is larger than that of Li2CuSnO4. Electrochemical impedance spectroscopy (EIS) explained that Li2CuSnO4 cell had higher charge transfer resistance (Rct = 2936Ω) than that of Li2CuSnSiO6 (38Ω). Furthermore, the reversible specific discharge capacity of the Li2CuSnSiO6 cell was 870 mAh/g in comparison with 780 mAh/g for the Li2CuSnO4 cell after 100 cycles, which is even higher than the theoretical value of Sn, 783 mAh/g.

The effects of zinc oxide doping on LiFePO 4 have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic measurements. The XRD patterns demonstrate that the samples have the phase of LiFePO 4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. Also, XRD patterns show with the presence of LiZnPO 4 phase for zinc oxide doped samples. The EIS results showed that the conductivity is enhanced by zinc oxide doping. The 2.5% ZnO-doped LiFePO 4 demonstrated higher conductivity than the 1.5% ZnO and 5% ZnO-doped LiFePO 4 or the un-doped sample. The CV curves show that 2.5% ZnO-doped LiFePO 4 has higher electrochemical reactivity for lithium insertion and extraction than the un-doped material. The mean redox potential is E 1/2 = 3.45 V vs. Li + /Li. The first discharge curve of the 2.5% ZnO-doped LiFePO 4 shows a mainly flat voltage plateau over the 3.45–3.5 V range, indicating the lithium extraction and insertion reactions between LiFePO 4 and FePO 4 . A specific discharge capacity of about 177 mAh g −1 was achieved, with little decrease during cycling.

Tin borophosphate compounds doped with antimony, Sn 2 BP 1− x Sb x O 6 ( x = 0–0.3), have been prepared and studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) and galvanostatic measurements. XRD patterns of all the samples were indexed to the tetragonal system. The EIS showed that the conductivities are enhanced by antimony doping. It was observed that the Warburg impedance coefficient ( σ w ) was 1163.265 Ω cm 2 s −0.5 for the Sn 2 BP 0.9 Sb 0.1 O 6 ( x = 0.1) sample, and this was the lowest value compared to those of the other samples. Sn 2 BP 0.9 Sb 0.1 O 6 ( x = 0.1) showed the highest specific discharge capacity of 1050 mAh g −1 among all the samples and a reversible capacity of 540 mAh g −1 at the 150th cycle.

Several substituted titanates of formula Li 4− x Mg x Ti 5− x V x O 12 (0 ≤ x ≤ 1) were synthesized (and investigated) as anode materials in rechargeable lithium batteries. Five samples labeled as S1–S5 were calcined (fired) at 900 °C for 10 h in air, and slowly cooled to room temperature in a tube furnace. The structural properties of the synthesized products have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transmission infrared (FTIR). XRD explained that the crystal structures of all samples were monoclinic while S1 and S3 were hexagonal. The morphology of the crystal of S1 was spherical while the other samples were prismatic in shape. SEM investigations explained that S4 had larger grain size diameter of 15–16 μm in comparison with the other samples. S4 sample had the highest conductivity 2.452 × 10 −4 S cm −1 . At a voltage plateau located at about 1.55 V (vs. Li + ), S4 cell exhibited an initial specific discharge capacity of 198 mAh g −1 . The results of cyclic voltammetry for Li 4− x Mg x Ti 5− x V x O 12 showed that the electrochemical reaction was based on Ti 4+ /Ti 3+ redox couple at potential range from 1.5 to 1.7 V. There is a pair of reversible redox peaks corresponding to the process of Li + intercalation and de-intercalation in the Li–Ti–O oxides.

New vanadate compounds having the molecular structure LixMg1−xV2−xMoxO6 (0 ≤ x ≤ 1) were studied. Six samples were prepared by sol–gel process from precursor using the following ratios of x = 0, 0.2, 0.4, 0.6, 0.8 and 1, respectively. These samples were labeled S1, S2, S3, S4, S5 and S6. The final process of firing occurred at 750 °C for 18 h in air. The prepared materials were characterized by XRD, SEM, IR, electron spin resonance (ESR) and magnetic measurements. The morphologies of S1, S2, S5 and S6 are prismatic as they have monoclinic crystal structures. S3 and S4 differ in the crystal morphology from the other previous samples due to their triclinic crystal lattice structure. IR spectra revealed that the bond lengths of the vanadyl groups νV O, νsy V–O and σV–O increase in the same direction from S1 to S6. The data of the ESR explain the existence of V4+ beside V5+ in S1, S4 and S6 and also presence of Mo5+ with Mo6+ in S4 and S6. S4 exhibited better magnetic susceptibility and saturated magnetization than the other samples. The first specific discharge capacities of the samples were performed. S4 showed the maximum specific capacity of 265 mAh g−1 in comparison with the other samples. Cyclic voltammogram of S4 exhibited the highest current intensity in comparison with the other samples. This sample showed two peaks at 0.53 and 1.3 V versus Li/Li+ characterizing double de-insertions of two lithium atoms from Li1.6Mg0.4V1.4Mo0.6O6−x and Li0.6Mg0.4V1.4Mo0.6O6, respectively. Also, two additional peaks were characterized for the oxidation of Mo5+ to Mo6+ and V4+ to V5+ at 3.5 and 4 V, respectively.

Samples of the title compound with 0 ≤ x ≤ 1.0 are prepared by reaction of CdSO4, InCl3, and TeCl4 in aqueous NH3 solution (pH 9) followed by addition of NaBH4 solution (85 °C, 2 h) to reduce the formed hydroxide phase to the alloy.

Lithium copper tin silicon oxide was prepared from their precursor compounds using Brij surfactant and different sources of Si such as SiO 2 , SiC, and Si 3 N 4 . A hydrothermal autoclave method was used in the first stage of the preparation. X-ray diffraction characterization revealed that the crystal structures of these compounds were tetragonal. Scanning electron microscope investigation showed that the particle size morphology of Li 2 CuSnSiO 6 is larger than that of Li 2 CuSnO 4 . Electrochemical impedance spectroscopy explained that the cell prepared from the Li 2 CuSnSiO 6 electrode using Si 3 N 4 precursor had a lower charge-transfer resistance (38 Ω) than that of Li 2 CuSnO 4 (R et = 2936 Ω). Furthermore, the reversible specific discharge capacity of the Li 2 CuSnSiO 6 cell was 870 mAh/g in comparison with 780 mAh/g for the Li 2 CuSnO 4 cell after 100 cycles.

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The author regrets that a typing error occurred in Section 3.2. The third paragraph should begin as follows: Themagneticmeasurements were also made. Bulk magnetic susceptibility ( ) and the coercive force (Hc) are plotted against temperature as shown in Figs. 6 and 7. All the samples increase in their susceptibilities with increasing temperature except S4 has opposite behavior. A clearer version of Fig. 6 is given here.