Enhanced electrochemical performance of Cu-doped LFP compared with bare LFP through the solution combustion synthesis method.

Hydrothermally synthesized mixed-phase tellurium-enriched over-oxidized MoTe2 exhibited a specific capacity of 331.16 mAh/g at 0.1 C with a capacity retention of 88

To address the challenge of low electronic and ionic conductivities in lithium-ion batteries (LIBs), we synthesized MoTe2@Ti3C2Tx via a modified hydrothermal route. This 2D van der Waals composite exhibited a stable reversible specific discharge capacity of 566 mAh/g at 0.1 C (67 mA/g) and retained 71 % of its initial capacity during rate performance tests. Notably, cycling stability tests revealed an increased discharge capacity of 316.4 mAh/g after 564 cycles at 0.4 C (268 mA/g), which improved further to 378.2 mAh/g after 922 cycles at 1 C (670 mA/g). The exceptional electrochemical performance stems from the unique MoTe2@Ti3C2Tx architecture, enhancing Li+ site exposure and ensuring structural stability. This composite emerges as a promising and easily synthesizable advanced anode material for LIBs, offering enhanced conductivity and stability.

The main drawbacks of LiFePO4, 4 , namely low electronic conductivity and slow lithium ion diffusion, are overcome by doping through solution combustion synthesis. This study focuses on altering the properties of LiFePO4 4 cathode material by introducing manganese (Mn) into the Fe site. Using solution combustion synthesis, we successfully created Mn-doped LiFe1-xMnxPO4 1-x Mn x PO 4 samples (where x = 0.04, 0.08, and 0.12) as it provides highly pure and crystalline material with homogeneous incorporation of dopants. Through various analyses including Xray diffraction (XRD), RAMAN spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDAX, X-ray photoelectron spectroscopy (XPS), BET surface area measurement, charge/ discharge tests (CD), stability assessments, and rate performance evaluations, we uncovered insights into the structure, morphology, elemental composition, surface area, and electrochemical properties of the synthesized materials. Notably, the LiFe 0.92 Mn 0.08 PO 4 sample exhibited an average capacity of 166.34 mAh/g over 100 cycles at a 0.1C rate, slightly below its theoretical capacity of 170 mAh/g.

One-step hydrothermally synthesized over-oxidized Mo 3 Se 4 with enriched selenium exhibited a specific capacity of 1006.75 mA h g −1 at 0.1C.

To address the challenge of low electronic and ionic conductivities in lithium-ion batteries (LIBs), we synthesized oxidized mixed-phase Ti3C2Tx MXene nanosheets using a wet chemical etching route. This prepared negative electrode demonstrated a reversible specific discharge capacity of 538.49 mAh/g at 0.1C (67 mA/g), which is significantly higher than the pristine MXene and retained 75.46

The main drawbacks of LiFePO4, namely low electronic conductivity and slow lithium ion diffusion, are overcome by doping through solution combustion synthesis. This study focuses on altering the properties of LiFePO4 cathode material by introducing manganese (Mn) into the Fe site. Using solution combustion synthesis, we successfully created Mn-doped LiFe1-xMnxPO4 samples (where x  = 0.04, 0.08, and 0.12) as it provides highly pure and crystalline material with homogeneous incorporation of dopants. Through various analyses including X-ray diffraction (XRD), RAMAN spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDAX, X-ray photoelectron spectroscopy (XPS), BET surface area measurement, charge/discharge tests (CD), stability assessments, and rate performance evaluations, we uncovered insights into the structure, morphology, elemental composition, surface area, and electrochemical properties of the synthesized materials. Notably, the LiFe0.92Mn0.08PO4 sample exhibited an average capacity of 166.34 mAh/g over 100 cycles at a 0.1C rate, slightly below its theoretical capacity of 170 mAh/g.

The anode materials in Li-ion battery (LIB) are key components that define the performance of the cell. We have developed new selenium enriched and over-oxidized Mo3Se4 decorated MXene (Mo3Se4@Ti3C2Tx) composite as a promising anode material for Li-ion battery (LIB). By using selective experimental conditions, Mo3Se4@ Ti3C2Tx was successfully developed with unique structural and morphological features. When being employed as anode material in LIB, Mo3Se4@Ti3C2Tx delivered high stable reversible specific discharge capacity of 1250 mAh/g at 0.1C, which is significantly higher than traditional carbon-based anode materials. In addition, the composite retained 84.53 % of initial specific capacity when the C-rate was increased from 0.1C to 1.5C, implying excellent rate performance. The Mo3Se4@Ti3C2Tx composite also demonstrated remarkable cycling stability with negligible loss after 378 cycles. This exceptional electrochemical performance can be assigned to the exclusive architecture of Mo3Se4@Ti3C2Tx composite, leading to increase in exposure of active Li+ sites and structural stability.

The least surface electrode resistance is a key in maturing low-temperature solid oxide fuel cells (SOFCs). The current article addresses the effect of crystallinity on electrode kinetics of La0.6Sr0.4Co0.2Fe0.8O3-delta using annealing in 650-1000 degrees C range. Increased polaron activity and hence conductivity due to in-situ crystallization in 273-380 degrees C range, with highest conductivity of 9.62 Scm(-1), is evidenced the strain induced in low temperature annealed electrodes were higher sourcing the driving force for diffusion of carriers in thin films. To understand this effect comprehensively, the thin film surfaces were studied for degree of crystallinity, elemental atomic distribution, in- and cross-plane electrical performances.

Ni-based cermet as solid oxide fuel cell (SOFC) anodes suffers from redox instability issues when operated with hydrocarbon as fuel. This paper investigates the Cu impregnated NiO-GDC as anode electrode for intermediate temperature (IT-) SOFCs using structural and morphological characterizations along with the dc conductivity measurement in hydrogen and biogas. The bulk of Cu impregnated NiO-GDC composite and its reduced (heat-treated in H2 at 850 °C for 3 h) counterpart samples were analyzed after exposing different layers within the bulk of samples to different characterization tools. Cu particles are observed at all three layers investigated, suggesting the distribution of Cu in the bulk of composite anode samples. Also, the porous morphology of fabricated samples was decreased with increased depth into the sample. The BSE and EDS characterization show that Cu and Ni particles are distributed within the bulk of the reduced composite anode sample while the Cu particles are largely located in the middle layer. Relatively higher (lower) dc conductivity (activation energy) was observed for the reduced composite anode sample in biogas than that of hydrogen and were 9.9 × 10−3 (0.81 eV) and 4.5 × 10−3 S/cm (0.88 eV), respectively.

In the present research, NiO-GDC nano-composite and Ni-GDC cermet are studied comparatively. The change in microstructure and conductivity before and after reduction has been reported. NiO-GDC nano-composite samples are prepared by solution combustion synthesis. As-synthesized powders are reduced in H-2 atmosphere at 500 degrees C for 5 hr. These samples are characterized by XRD and FE-SEM to confirm phase purity and microstructure respectively. The conductivity measurement of both NiO-GDC and Ni-GDC samples is measured by two probe and four probe method respectively. Drastic change in conductivity is observed after reduction of NiO-GDC to Ni-GDC. (C) 2020 Elsevier Ltd. All rights reserved.

Li-ion batteries are extensively used in portable electronics due to high energy, power density and superior electrochemical performance. For this, Li4Ti5O12 a zero strain anode material with excellent reversibility for the Li-ion insertion and de-insertion and flat potential plateau, serves as an ideal anode material. However, it has low conductivity which hampers its commercialization. In the present work, Li4Ti5O12 is prepared by sol-gel method. It's structural analysis confirms the formation of nanoparticles with uniformly aligned grains and exhibits high discharge capacity of 181 mA.h/g at 0.1C. It is the synergetic effect of nanoparticles size and surface area, which imparts it the outstanding electrochemical performance in terms of long term stability and charge storage capacity. (c) 2020 Elsevier B.V. All rights reserved.

In the current research work, submicron size single-phase NaFePO4 (NFP) nanoparticles are successfully synthesized using the solution combustion method. The calcination of as synthesized NFP powder is done at 700 degrees C for 5h in the air atmosphere and it shows the maricite phase crystallized into an orthorhombic structure with a surface area of 9.29 m(2)/g. The intermolecular vibrations of the (PO4)(3-) group are identified in the FTIR spectra. The XPS spectra of NFP confirms the presence of Fe and P in +2 and +5 oxidation states, respectively. The coin cell assembled using calcined NFP powder shows a pair of redox peaks at 2.42 and 2.69 V vs. Na/Na+ owing to Na-ion insertion and extraction. NFP material delivers a specific capacity of 28 mAh/g at 0.1 C with 92% capacity retention after 35 cycles.

Due to sluggish oxygen reduction reactions, development in the solid oxide fuel cell (SOFC) field is stagnant. Two solutions, increasing the active surface or use of precious materials, can stimulate the oxygen reduction kinetics on electrodes. Thus, to gain both these benefits, the present article addressed the synthesis of high surface-area mixed oxide ionic-electronic conductor La0.6Sr0.4Co0.8Fe0.2O3-delta (LSCF) using chemistry of the propellant glycine-nitrate reaction. In this study, different fuel to oxidant ratios (psi), 2.0, 2.6, and 3.0 were used to control the exothermicity of reaction and powder properties. The maximum reaction temperature of 1337 K at psi = 3.0 resulted in coarsened powder. In contrast, comparatively less exothermicity of reaction at psi = 2.0 resulted in powder with substantial Brunauer-Emmett-Teller surface area of 10.97 m(2) g(-1), with maximum powder compaction achieved at sintering of 1273 K. With optimal direct current in-plane electrical conductivity of 341 S cm(-1), H-2-temperature-programmed reduction showed excellent catalytic activity for the sample obtained at psi = 2.0. The electrochemical performance comparisons of electrodes in two different cell geometries - with and without a gold catalytic current collecting layer (Au-CCCL) - revealed the least polarization and cell resistance in the cell with Au-CCCL. The electrode area specific resistance and cell conductivity using Au-CCCL were 0.097 Omega cm(-2) and 0.15 S cm(-1), respectively.

This paper reports the effect of Sr2+ addition on the structural, microstructural properties of Ce0.8Gd0.2O2-delta(GDC) electrolyte for low temperature solid oxide fuel cell application. The Sr2+ (0, 0.5, 1 and 2 mol %) doped GDC solid electrolytes have been prepared by solid state method. The sintered densities of the samples are around 95%. XRD study reveals the cubic fluorite structure. The microstructure of the samples resulted into grain sizes in the range of 4.3 to 0.868 mu m. Raman spectra also confirms the presence of GDC single phase.

TiO2 is a good alternative anode material for lithium-ion battery application because of its incomparable high structural stability and safety during the charge/discharge cycles. However, the low intrinsic conductivity of TiO2 has been a limiting factor affecting its cycling and rate capability performance. Here in this work, we present Co-doped TiO2 nanoparticles based anode with good reversibility, cycling stability and rate capability performance for its envisaged application in lithium-ion battery. The Co-doped TiO2 nanoparticles with different Co concentrations (3%, 5%, and 7%) are synthesized using simple and economic biomediated green approach, wherein TiCl4 and Co precursors are allowed to react in Bengal gram bean extract containing biomolecules which act as natural capping agents to control the size of nanoparticles. Among the pure TiO2 and different Co-doped TiO2 samples, the 7% Co-doped TiO2 anode show the highest capacity of 167 mAh g−1 (88.3%) after 100 cycles at the 0.5C current density. The Co-doped TiO2 shows higher and stable coulombic efficiency up to 100 GCD cycles indicating good reversibility. Based on the results, it is expected that the Co-doped TiO2 nanoparticles might be contributing to the enhanced electronic conductivity providing an efficient pathway for fast electron transfer.

LiFePO4 (LFP) has been developed as a cathode for lithium ion batteries (LIBs) by solution combustion method. The present work includes effect of fuel, residual carbon and graphene oxide on the phase purity and electrochemical performance of combustion synthesized LiFePO4. As revealed in XRD, single phase LiFePO4 is obtained in glycine assisted combustion (G-LFP) and it delivers 97 mA h/g discharge capacity, which is higher than urea assisted combustion (U-LFP). Further, the G-LFP was calcined for different lengths of time (4, 5 and 7 h). The amount of in-situ carbon is observed to decrease from 2.57 to 1.40% and specific capacity increases from 97 (4 h) to 106 mA h/g (7 h). The composites with 4 wt % GO were formed and they show enhanced electrochemical performance. 5LFP/GO delivers discharge capacity of 164 mA h/g at 0.1 C, which is 96% of its theoretical capacity. (C) 2018 Elsevier B.V. All rights reserved.

Wide-spread and extended applications of Li-ion secondary batteries necessitate the development of advanced electrode materials with exceptional electrochemical performances, which mostly depends on the cathode materials. LiFePO4 (LFP) has been extensively considered as promising cathode materials due to its high stability, abundance and environmentally friendliness. Herein, a simple solution combustion technique is developed to prepare single phase LFP material with submicron particles. The XPS studies ascertain + 2 and + 5 oxidation states of Fe and P, respectively. The cyclic voltammetry of LiFePO4 reveals redox mechanism of Fe2+ / Fe3+. The LiFePO4 delivers specific capacity of 106 mAh g(-1) for 1st cycle with 96.36% coulombic efficiency. Moreover, the presence of graphene oxide (GO), in LFP/GO composite, control the growth and agglomeration of LiFePO4. On evaluation, LFP/GO shows superior electrochemical performance possessing the specific capacity of 162 mAh g(-1) at 0.1 C, owing to the effective conducting network formed by GO reducing Li-ion diffusion path for LiFePO4.

Recently, graphene oxide (GO) has gained more attention because of its various physicochemical properties, which can be tailored by optimizing the functional groups present at the edges of carbon atoms. The current research work reports on the synthesis of GO by modified Hummers method and its thermal reduction. Go is stable after 187 degrees C as revealed in TG-DTA analysis; therefore, it was reduced at 300 degrees C. After reduction, the interlayer spacing decreases from 0.92 to 0.30 nm with increase in sp(2) and sp(3) carbon atoms as observed in XRD and XPS, respectively. The presence of functional groups has been investigated by spectroscopic tools. R-GO is few-layer graphene sheets as revealed in Raman spectroscopy. Also, separate and enhanced wrinkle sheets are observed in FESEM image. The effect of electron concentration, structural ordering, and restoration of sp(2) carbon atoms on the optical properties are investigated by photoluminescence (PL) and ultraviolet-visible (UV) spectra.