In this work we have studied the effect of network structure on the transport properties of Li2O-P2O5-MoO3 mixed former glasses. We have used Fourier Transform Infrared (FTIR) and Raman spectroscopy to study the network structure. We have measured ac conductivity and dielectric spectra for a wide range of temperature and frequency. We have observed that the conductivity increases and the activation energy decreases with the increase of Li2O content in the composition. The time temperature superposition has been verified using the scaling formalism of the conductivity spectra. We have calculated microscopic lengths of ion dynamics such as the characteristic mean square displacement of mobile ions and the spatial extent of localized motion within the framework of the linear response theory and correlated them with the ion transport properties. Also we have given a qualitative description for the correlation of the ionic transport with the relative strengths of structural units.

The ab initio projector augmented wave method of the density functional theory is applied for studying energy characteristics of oxygen vacancies and migration pathways in Pr1−xYxBaCo2O6−δ. It is found that the negative formation energy leads to initial appearance of oxygen vacancies in PrO planes thus providing the pathway for oxygen migration at small δ's. The increase of oxygen vacancy population in PrO planes and replacement of Pr by Y both favor a weakening of CoO bonds, which facilitates the increase in the amount of oxygen vacancies in CoO2 layers. Moreover, the yttrium dopants enlarge the bottleneck for oxygen jumps along ⟨101⟩ directions over oxygen vacancies in PrO and CoO2 layers. As a result, the respective ‘zigzag’ oxygen migration pathway becomes predominant with increasing oxygen non-stoichiometry and yttrium doping. Thus, the layered perovskite-like cobaltites give an example of a peculiar diffusion process where minority defects provide the transport channel while majority defects maintain favorable geometry of the migration pathway.

The global research efforts for identification of electrode materials for high energy and high power density rechargeable aqueous/non-aqueous aluminum-ion batteries have gained unprecedented momentum in contemporary times. Herein, we exclusively report the Al3+ ion electrochemistry of Bi2O3 in aqueous electrolyte for the first time. While investigating the electrochemical performance of Bi2O3, we demonstrate a unique method to simultaneously enhance the storage capacity and long-term stability of Bi2O3 as an electrode material for rechargeable aqueous aluminum-ion battery. It is found that a binder free integrated electrode of Bi2O3 on an exfoliated graphite current collector is better suited for improved electrochemical activity. When assembled with an Al metal anode, the integrated Bi2O3 electrode delivers a stable specific capacity of 103 mAhg−1 at a current rate of 1.5 Ag−1 over several charge/discharge cycles.

We investigated the structural and electronic descriptors for atmospheric instability of Li-thiophosphates (β-Li3PS4) using density functional theory. Based on thermodynamic and crystallographic considerations, four stable surfaces such as (111), (101), (001), and (100) were identified in β-Li3PS4 using the equilibrium crystal shape according to Gibbs-Wulff theorem. As such, the p-band center of the S-ion (∆Ep) and segregation energy of S vacancy (EVS∙∙, seg) were utilized as electronic and structural descriptors to evaluate the atmospheric instability of β-Li3PS4. It was determined that the (110) and (111) surfaces led to high surface instability among the four surfaces. Furthermore, it was observed that the p-band center and the segregation energy of S have a linear relationship (i.e., ∆Ep increased as EVS∙∙, seg decreased), which could be used as simple descriptors to evaluate the atmospheric instability of sulfide-based Li-ion conductors.

Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte films are successfully prepared on silicon substrates by radio frequency magnetron sputtering for the first time. X-ray diffraction, energy dispersive spectroscopy, and scanning electron microscopy are used to analyze the composition, structure, and morphology of the LAGP films, respectively. The effects of deposition conditions on the ion transport properties of the LAGP thin films are also evaluated via electrochemical impedance spectroscopy measurements. An evolution from a uniform and smooth amorphous structure to a coarse-grained structure of the surface morphology is observed for the films prepared at different temperatures. The results show that low growth temperature is beneficial to the formation of amorphous LAGP films with smooth surface and uniform thickness, and crystalline films with preferred orientation of (104) crystal plane are successfully deposited when the substrate temperature reaches 500 °C. The LAGP amorphous film with a thickness of 1.2 μm deposited at 200 °C exhibits a high ionic conductivity of 1.29 × 10−6 Scm−1. The ionic activation energy of the sample is determined to be 0.25 eV based on Arrhenius equation, indicating good ionic conductivity of the LAGP film. The good ionic conductivity of amorphous LAGP is attributed to its open and disordered structure with large excessive volumes.

Biomass-derived carbons are attractive and cost-effective anode materials for sodium ion batteries (SIBs), however, they generally suffer from the low capacity and coulombic efficiency. Foreign atom doping has been proved to be an effective approach to tune the chemistry of carbon material and improve their electrochemical performance. In this contribution, nitrogen (N)-doped carbon spheres (NCs) were successfully prepared from onion waste and urea (CH4N2O) by hydrothermal and annealing process, with urea as cheap and additional nitrogen source. The thus-derived NC was used as anode material for SIBs, the optimal sample (NC-800) can harvest a reversible capacity of 152 mAh g−1 at a current density of 0.05 A g−1 after 200 cycles. Impressively, NC-800 can still offer 83 mAh g−1 capacity after 2000 cycles at 1 A g−1, with a capacity retention rate of 69%. The high performance of N-doped carbon (NC-800) can be attributed to the significant increase of defects and the enlargement of interlayer distance caused by nitrogen doping. This work presents a feasible fashion of converting low-value waste into high-value material for energy storage.

BiVO4 nanowire array is fabricated by a hydrothermal method, and the nanowire array and a lithium foil are used as working and counter electrodes, respectively, to assemble a lithium-ion battery. After charging to 4 V, the BiVO4 nanowire array has a strong oxidizing property. The pyrrole can be in-situ polymerized on the surface of the charged BiVO4 nanowire array to form a polypyrrole coating layer in pyrrole solution. The morphology and structure properties of the samples are characterized and analyzed in detail. The lithium storage performances of the samples are also measured and compared. The obtained BiVO4-PPy nanowires have stable cycle performance and a discharge capacity of more than 400 mAh g−1 after 50 cycles. This work provides a new method for synthesizing conductive polymers on charged electrodes.

LiNi0.8Co0.1Mn0.1O2 (LNCM811) is a promising cathode material for lithium ion batteries. However, it is difficult to commercialize on a large scale because of its unstable structure and fast capacity attenuation. To solve above problems, in this paper, the Na-doped LNCM811 material (LNCM811-Na) has been synthesized via hydrothermal method and high temperature solid phase method, and then it is coated with SiO2 ([email protected]2) on the basis of Na doping. The structure, composition, morphology, and microstructure of [email protected]2 are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The results show that the specific capacity of the LNCM811–[email protected]2(3%) sample reaches 209 mAh g−1 at 0.5C (the LNCM811–0.1Na is 195 mAh g−1 and the LNCM811 is 178 mAh g−1). When the rate is increased to 10C, the specific capacity of the LNCM811–[email protected]2(3%) sample still reaches 115 mAh g−1 (the LNCM811–0.1Na is 95 mAh g−1 and the LNCM811 is 72 mAh g−1). The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) prove that Na doping and SiO2 coating can effectively reduce the polarization and the charge transfer impedance, further promote the improvement of electrochemical performance. Thus, the LNCM811–[email protected]2(3%) sample is a very promising material in power batteries.

Cathode material Li(Ni0.5Co0.25Mn0.25)1-xZrxO2 (x = 0, 0.005, 0.01, 0.02, 0.03) and Li(Ni0.5Co0.25-yMn0.25Aly)0.99Zr0.01O2 (y = 0, 0.01, 0.02, 0.03) were synthesized by coprecipitation method. The structure and electrochemical properties of cathode materials were mainly studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), charge/discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of XRD show that Zr doping and Al-Zr co-doping cannot destroy the crystal structure, and they are all beneficial to structural stability. Electrochemical results show that the appropriate amount of Zr4+ doping can improve the rate and cycle performance. However, there is no further increase in the rate performance and cycle stability when Co is replaced with Al. Because of the 3a site occupation of the doped ions, it is possible that the diffusion of lithium ions is hindered. And Al is low electrochemically inert. In particular, x = 0.01 exhibited the best rate performance and cycle stability in all samples. The specific discharge capacity of the material is 151.0 mAh/g at 1C, and it still up to 173.3 mAh/g at 0.1C after experiencing high-rate discharge. And the capacity retention rate is 87.53% at 0.1C after 45 cycles. When Al3+ and Zr4+ are co-doped, the performance of y = 0.01 material is the best. The specific discharge capacity at 0.1C, 0.2C, 0.5C, 1C and 0.1C are 182, 148.3, 123.5, 110.3 and 125.8 mAh/g, respectively.

The effect of co-doping an impurity on the transport parameters and cubic phase stabilization of ZrO2–Sc2O3-based solid solutions has been compared for Y2O3 and Yb2O3 dopants. Solid solution crystals of (ZrO2)1-x-y(Sc2O3)x(Yb2O3)y and (ZrO2)1-x-y(Sc2O3)x(Y2O3)y (x = 0.08–0.10, y = 0.01, 0.02) were grown by directional melt crystallization in a cold crucible. Co-doping of the (ZrO2)1-x(Sc2O3)x crystals (x = 0.08–0.10) with 2 mol% Y2O3 or Yb2O3 for all experimental compositions produced transparent homogeneous single crystals of the t” phase or the cubic phase. For co-doping of the scandia-stabilized zirconia crystals with 1 mol% Y2O3 or Yb2O3, the stabilization of the high-temperature phases depended on the Sc2O3 content in the solid solutions. For co-doping of the solid solutions with 1 mol% Y2O3 or Yb2O3, the conductivity of the crystals increased with the Sc2O3 concentration. For co-doping of the crystals with 2 mol% Y2O3 or Yb2O3, the conductivity decreased with the Sc2O3 concentration. At scandia concentrations of 9–10 mol%, the high-temperature conductivity of the crystals co-doped with ytterbia were higher compared to those with yttria co-doping. The (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01 crystals had the highest conductivity over the entire experimental temperature range.

We introduced a new elastic interface layer (EIL), (Li2S)0.75(P2S5)0.25 glass, in all-solid-state batteries (ASSBs) to improve the solid-state interfacial structure, and analyzed its structural evolution in electrochemical charge/discharge cycles. This EIL had a lower bulk modulus, thereby providing good powder processability and high mechanical deformability against volume changes of the electrode. Compared to a cell configuring EIL, the reference cell exhibited a considerable increase in the electrolyte resistance; moreover, a new resistance component was identified in the high-frequency region (500–50 kHz). This high-resistance component resulting from interfacial deterioration such as metal fragmentation and micropore formation was successfully suppressed by applying a mechanically deformable EIL. We believe that this study would provide insights into the application of EIL for configuring a stable interface with a metallic electrode in ASSBs.

As a new mixed conductor with high property, the preparation of Ba0.5La0.5FeO3-δ with cubic perovskite structure was examined under different values of oxygen partial pressure, P(O2). An almost-single-phase Ba0.5La0.5FeO3-δ with cubic perovskite structure was successfully prepared by sintering at 1200 °C under P(O2) values ranging between 1 and 10−9 atm. The existence of two types of cubic Ba0.5La0.5FeO3-δ phases, one with a smaller δ and paramagnetic Fe with valence between 3+ and 4+ and the other with larger δ and antiferromagnetic Fe with valence of almost 3+, was clarified. Moreover, the above two phases could be interchanged with each other by annealing at 1200 °C under controlled P(O2). It was revealed that the oxygen-deficient cubic phase rapidly absorbed oxygen above 300 °C in air and that δ increased with temperature above 400 °C in air. Rapid oxygen absorption or desorption by switching the gas flow between O2 and N2, as well as its cyclic behavior with high reproducibility, was also observed. Under P(O2) values ranging between 1.0 and 1.02 × 10−2 atm, the temperature dependence of electrical conductivity was small regardless of P(O2), and the difference in electrical conductivity by P(O2) was scarcely observed. Log σ reached approximately 1.5 at 400 °C. With P(O2) decreasing to 1.01 × 10−3 or less, a slight increase in electrical conductivity was observed with an almost constant log σ on temperature.

We report AC-impedance studies on a series of high-quality LiMn1−xFexPO4 single crystals with 0 ≤ x ≤ 1. Our results confirm quasi-one-dimensional transport in LiFePO4 with fast Li-diffusion along the b-axis. The conductivities along the crystallographic b-, c- and a-axis differ by a factor of about 10, respectively. Whereas, the activation energy EA of the effective diffusion process is particularly large for the b-axis and smallest for the a-axis. Remarkably, the b-axis ionic bulk conductivity of LiMn0.5Fe0.5PO4 is of the same order of magnitude as in undoped LiFePO4, which implies similarly fast Li-transport even upon 50% Mn-doping which, owing to the higher redox potential of the Mn3+/Mn2+-couple, yields enhanced energy density in lithium-ion batteries. The overall results of our impedance studies draw a far more complex picture than it would be expected from a simple one-dimensional ionic conductor. Our results suggest a strong contribution of crystal defects in actual materials.

The effect of the La2NiO4+δ and Pr2NiO4+δ modifying additives on the electrochemical performance of the La2NiO4+δ oxygen electrodes has been investigated. It has been shown that the introduction of the additives reduces the polarization resistance of the electrodes. The lowest value of the polarization resistance has been obtained for the La2NiO4+δ electrodes modified with Pr2NiO4+δ, which was 0.44 Ω cm2 at 650 °C in an air atmosphere. The introduction of modifying additives is shown to have a significant impact on the electrode reaction stage associated with the oxygen exchange. Probable reasons for the phenomena are discussed.

Synthesis of SnO2 powders with different shapes can be achieved by different approaches including wet and dry methods. One constrain of wet production is the complexity of process control that is not always possible when scale-up of active materials for electrodes is considered. On the other hand, simple solid state methods carried out at low temperatures with active carbon to prevent coarsening of particles are more feasible for industrial production. In this work, graphitic carbon nitride (g-C3N4) is prepared by thermal condensation of urea and directly used to synthesize SnO2@C3N4 for LIB anodes through a scalable solid state reaction. Such fast approach allows to obtain the active material with regular and homogeneous distribution of SnO2 over g-C3N4 phase. SnO2@C3N4 enables the cell to achieve very good rate capability and excellent stability upon prolonged cycling at high rates, suggesting the prospects for next-generation high-power and low cost lithium-based batteries.

Li2MnO3 is critical component in the well-studied Li-excess cathode materials xLi2MnO3·(1- x)LiMO2 for achieving high lithium storage capacity. In this article, the diffusion of Li ions in Li2MnO3 is studied using molecular dynamics (MD) simulation with well-behaved empirical force fields obtained by fitting against the crystal structure from experiment and phonons calculated using Density Function Theory (DFT). We have found two possible tetrahedral hopping channels, 0-TM and 1-TM(Mn4+) channel, which are differentiated by the face sharing octahedral cations. Simulation results show that the 0-TM channel is active for Li hopping, while 1-TM(Mn4+) channel is inactive. During the delithiation process, the Li ions in the transition metal (TM) layer are firstly removed, then those in the Li layer. However, the Li ions will be trapped in the tetrahedral 0-TM channels as long as the four face sharing octahedral sites are cleared. Up to x = 1.0 for Li2-xMnO3, almost all the Li ions are located at the tetrahedral sites, forming a regular array along a axis. The de-intercalation of tetrahedral Li ions requires a high voltage (>5.2 V vs. Li/Li+), limiting the practical capacities measured in lab. The diffusion of Mn ions into the Li layer is observed in a deeper delithiated structure (x = 1.2 for Li2-xMnO3), indicating an initial phase transformation to a spinel-like structure. However, the Mn ions are mainly trapped in the tetrahedral sites in the Li layer, instead of the octahedral sites in spinel-like structure. A few of Mn ions diffusing into the octahedral sites in Li layers have no face sharing tetrahedral Li ions, revealing a further Li de-intercalation is imperative for the complete phase transformation. During the delithation process, the oxygen sublattice shows a strong stability. In the deeply dilithiated structure Li0.8MnO3, the local distortion of the oxygen sublattice is observed, which may indicate the oxygen release at this high delithation stage. Our model is not stable for x ≥ 1.4 in Li2-xMnO3. Other charge compensation mechanism should be considered in this high delithiation stage, eg. oxygen release.

Conducting polymers are increasingly attracting the interest of many researchers in different areas due to their good conductivity, stability and easy preparation. Polyaniline is heavily studied in sensors, corrosion protection, electrochromic devices, and supercapacitors, however, even with numerous applications, there are still few pieces of literature that report their electrochemical behavior in regions low-frequency of by electrochemical impedance spectroscopy (EIS). In this work, polyaniline was electropolymerized by galvanic synthesis (chronoamperometry) in stainless steel substrate. Its performance was evaluated by cyclic voltammetry (CV) galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). It was observed in its low-frequency pseudocapacitive analysis, in the benzoquinone and hydroquinone intermediate regions, capacitance values above 100 mF·cm−2, and in the emeraldine state, 295 F·g−1 was obtained. Such results provide a better and detailed understanding of PANI oxidation and reduction processes and could optimize the use of the polymer in various fields of applications.

An XAFS study was performed on the electronic and crystal structure properties of LiGa1-xBxO2 (LGO) material in where boron atoms were substituted at the gallium sites. Studies were carried out by the X-ray powder diffraction (XRD) patterns and supported by the Extended-XAFS data. The analysis on the substituted materials revealed interesting mechanisms at the boron sites that preserved the crystal symmetry in the entire bulk. It was determined that, boron atoms do not lie in the Ga sites due to inequivalent ionic radii and formed a crystal LiB3O5, which has the same crystal geometry and space group of the parent LGO. With the presence of the boron atoms on the vicinity of the gallium atoms, tiny shifts on the main edge spectra resulted from the change in the oxidation of the gallium atoms.

To enhance the performance of an Ni-based cathode in a solid oxide electrolysis cell (SOEC) at medium temperature (600–800 °C), the present study adopted the method of adding Fe to Ni to fabricate Ni-Fe bimetal. Adding Fe can effectively inhibit Ni particles from becoming coarsen to enhance performance of Ni-based cathode. In the present study, the effects of different Fe contents in Ni1-xFex (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) bimetallic materials on the performance of the Ni-based cathode for SOECs were systematically studied, and the optimal Fe content for Ni-Fe bimetallic materials suitable for use as the cathode of a SOEC was ascertained. The optimal Fe molar content is 40%. Under the open circuit voltage, the SDC-Ni0.6Fe0.4 based SOEC has a lower polarization impedance than other SOECs. Besides, at the same cell potential, the SDC-Ni0.6Fe0.4 based SOEC has a higher current than other SOECs. Furthermore, the SDC-Ni0.6Fe0.4 based SOEC exhibits good stability. Accordingly, this study proved that Ni-Fe bimetal with an appropriate proportion can enhance the performance of Ni-based cathode, and it was also demonstrated that at medium temperature, this material acts as an excellent cathode for a SOEC.

Single crystal primary LiNi0.6Mn0.2Co0.2O2 cathode materials were successfully synthesized via a developed ball milled route and followed by a proper reheating process. The influences of ball milling and reheating processes on the structure and electrochemical properties of LiNi0.6Mn0.2Co0.2O2 cathode material were investigated by X-Ray diffraction, scanning electron microscope, high resolution transmission electron microscopy, selected area electron diffraction, cyclic voltammetry, electrochemical impedance spectroscopy and electrochemial tests. The results showed that the reheating process was the key to obtain fine single crystal particles with excellent electrochemical properties. The single crystal primary LiNi0.6Mn0.2Co0.2O2 exhibited a discharge capacity of 179.7 mAh g−1 at 1.0C, and sightly decreased to 173.4 mAh g−1 after 50 cycles, with the excellent capacity retention of 96.5%. The low increases of resistance and high lithium ions diffusion coefficient all illustrated the single crystal particles had good lithium ion kinetic properties.

Titanium-based polyanionic compounds have gained wide attentions as anode materials for room-temperature sodium-ion batteries due to the robust structural framework, reversible redox chemistry, and compositional diversities. However, the effect of chemically-inserted cations on their structural and electrochemical properties is lack of being investigated to date. In this work, structural and electrochemical properties of ATi2(PO4)3/C (A = Li, Na, Mg) compounds are comparatively studied by coupling X-ray diffraction, scanning electron microscope, cyclic voltammetry and galvanostatic measurements. Experimental results reveal that the structural composition is an important factor determining electrochemical properties of titanium-based polyanionic compounds, and the Li-containing composition shows the best charge/discharge performance with high specific capacities of 120.4 mAh g−1 at 20 mA g−1 and 89.7 mAh g−1 at 1000 mA g−1, and outstanding cycling stability without capacity fading after 1000 cycles. In particular, full battery assembled with it and Na3V2(PO4)3 cathode can deliver a specific energy of 124.5 Wh kg−1 at the power of 114.9 W kg−1, and a capacity retention of 84.9% after 100 cycles.

BaO-P2O5 (BP) and BaO-La2O3-Al2O3-P2O5 (BLAP) glass thin films with a thickness of 80–160 nm, which have a high content of residual moisture and a high concentration of non-bridging oxygen (NBO) as a medium for proton movement, were fabricated through sol-gel spin coating using water as a solvent. All the fabricated glass thin films exhibited amorphous phase and glassy, defect-free surfaces. The thickness of the BP thin films decreased as the annealing temperature increased. The increase in the annealing temperature led to a decrease in NBO/BO ratio which is thought to affect proton mobility and an increase in mobile proton concentration. Therefore, it seems that high proton concentration by residual water appears to have a dominant effect on fast proton conduction. The calculated proton concentrations of the fabricated BP thin films were decreased from 55.9 mol/l to 45.5 mol/l as the annealing temperature increased from 300 °C to 400 °C. The conductivity of BP and BLAP thin films annealed at 400 °C were 2.52 × 10−6 S/cm and 1.32 × 10−5 S/cm, respectively, at 300 °C. BLAP thin film showed significantly improved conductivity compared to those of BP glass thin films due to its high proton concentration.

Lithium-deficient and Lithium-excess spinels LixMn1.6Ni0.4O4 (x = 1.05, 0.9) were synthesized by co-precipitation method assisted by ethylene glycol-oxalic acid. Control of cooling rates was performed in order to improve the crystallographic order, the lattice parameters and avoid the impurity precipitation. The samples were characterized physically and electrochemically. The best electrochemical performances were obtained for lithium-deficient spinels cooled at intermediate rates (2.2 °C min−1). For this optimized material, the discharge capacity was 122 mA h g−1 at 0.5C rate, retaining >83% of capacity at 10C rate and having good cycle life with >93.5% of initial capacity after 100 cycles at 0.5C rate.

The required long life-cycle of an electric vehicle creates higher demands on the performance and safety of lithium-ion traction batteries over their whole lives. Studies of the life cycle safety of a traction battery must consider all factors of the battery and analyze the complex structure–activity relationship. In this article, we present the analysis of the aging process of a commercialized traction battery using electrochemical methods. Lithium plating on the surface of the anode occurred during the cycling of the battery. Furthermore, the analysis of the electrochemical properties and structural evolution in the materials of the cathode and anode showed that the different decay rates of the cathode and anode are the key factors leading to lithium plating during the aging process, which creates safety hazards during the use of the traction battery.

Solid-state lithium (Li) metal batteries with enhanced safety and high energy density have attracted ever-increasing attention. However, it is challenging to construct an effective ionic conduction pathway in the composite cathode of the solid-state batteries, especially when the mass loading of active materials is high. Herein, we prepare a gel composite cathode by introducing an in-situ polymerized gel polymer electrolyte into the cathode. The voids in the cathode and the gaps between the cathode and the electrolyte layer are filled with the gel electrolyte, and thus a fast Li-ion conduction pathway is established. Solid-state Li metal batteries with LiCoO2 and LiFePO4-based gel composite cathodes show excellent cycling performance. Even at a high mass loading of 11.09 mg cm−2, the cell with a LiCoO2–based gel composite cathode has a long cycle life at 0.088 mA cm−2 at room temperature. The experimental data demonstrate that the conductive gel composite cathode has promising applications in solid-state batteries with high energy density.

Electrical conductivity and dielectric constant have been researched in a series of crystals LiNbO3:Zn(~4.0–9.0 mol% ZnО in a melt) by application of constant voltage with a couple of electrodes (~<500 K) and impedance spectroscopy (~>500 К). In order to compare results we have also researched electrical conductivity σdc of congruent LiNbO3congr and magnesium doped LiNbO3:Mg crystals. We have established that electron contribution to electrical conductivity of doped crystals LiNbO3:Zn and LiNbO3:Mg is greatly smaller than that of a congruent crystal LiNbO3congr. A decrease in conductivity is apparently connected with a restructure of LiNbO3 crystals at high concentrations of magnesium and zinc. Doping of crystals with Zn leads to drastic changes not only in the electron conductivity area (T < 500 K), but also in a lithium ion conductivity area (Т > 500 K). At this, parameters of temperature dependence of lithium ion conductivity depend on both zinc concentration and crystallographic orientation of samples.

The atomic scale reshuffling during oxygen ion conductivity in co-doped ceria lattice at intermediate temperature (400–700 °C) range are investigated by in-situ measurement using spectroscopic tools EXAFS, XANES, Raman and XRD. Oxy-ion hopping site decide migration barrier through ceria lattice and thus activation energy for conductivity; present interest is to extrapolate ionic conductivity by exploring oxy-ion hopping site. Hydrothermally synthesized nanocrystalline Sm-based aliovalent and isovalent co-doped ceria systems with optimized dopant content are used for the study. Charge-size effect of aliovalent and isovalent co-dopant pair on ceria lattice are revealed from Rietveld refinement of XRD data. HR-TEM images confirmed nanoscale dimensions (~15 nm) of grains of as-calcined as well as sintered samples (100–150 nm) with well defined grain boundaries. HT-EXAFS data are extracted to get information of co-ordination number (CN), interatomic spacing (IS) and atomic disorder at 1st shell (NN) and 2nd shell (NNN) site. The rate of change of CN and IS with temperature are closely associated with the rate of oxygen vacancies (i) formation, (ii) relaxation and (iii) dissociation at NN and NNN site of cations; which lead to atomic scale reshuffling at NN and NNN site of cations. Our work demonstrates, in aliovalent doped ceria, NN-site favour oxygen vacancies dissociation; while for isovalent dopant pair, NNN-site is proactive for oxygen vacancies dissociation. HT-Raman spectra also supported these results by disappearance of respective defect associated Raman mode. HT-XANES spectra revealed intrinsic oxygen vacancies dominancy in aliovalent co-dopant. The oxygen ion migration route through NN-site is found lower energetic than that of NNN-site as-confirmed from ionic conductivity data. The ionic conductivities of SmCa and SmSr aliovalent codoped ceria systems are obtained one order more than SmGd, SmDy and SmNd isovalent co-doped ceria systems. As well as activation energy of aliovalent co-doped ceria is lower than isovalent once.

Novel solid polymer electrolytes based on succinonitrile (SN) plastic crystal electrolyte (SN-PCE) and polymerized ionic liquid (PIL) has been successfully synthesized via an in-situ method. The fabricated electrolyte (PIL-SN-PCE) is uniformly inlayed into the supporting matrix of polyimide, which effectively ameliorates the mechanical properties of the electrolyte. PIL can effectively enhance the thermal stability of electrolytes up to 300 °C and mitigate the parasitic reactions between the electrolytes and the electrodes. PIL-SN-PCE exhibits a remarkable oxidation ability up to 5.4 V vs Li/Li+ and a high room temperature ionic conductivity of 6.54 × 10−4 S cm−1. Furthermore, in-situ formed interface in PIL-SN-PCE guarantee an excellent compatibility with different electrodes, which can effectively improve the cycle stability and rate performances of both half-cells and full cells. Thus, PIL-SN-PCE is considered as a promising electrolyte for high energy density lithium-ion batteries.

Li6.6La3Zr1.6Sb0.4O12 has been synthesized by solid state reaction and effect of addition of LiAlO2 on density, structure and ionic conductivity has been studied. XRD pattern is studied for phase confirmation. Density has been calculated and SEM analysis has been done for morphological studies and elemental distribution in the sample. Complex impedance analysis was used to measure ionic conductivity of all samples and transport number measurement has been carried. Highest conductivity of 3.16 × 10−4 Scm−1 at 25°C is observed for 1 wt% LiAlO2 added Li6.6La3Zr1.6Sb0.4O12 ceramic sintered at 1050 °C for 8 h.

A new type of aqueous aluminide ceramic coating polyethylene (ACP) separators is prepared by a simple spreader coating process using aluminum oxide (Al2O3) and boehmite (AlOOH) as the ceramic coating particles. During the preparation of the separator, water is used as the solvent and BYK (Beck Chemical Co., Ltd.) additives are used as the aqueous assistant. The as-prepared ACP separators present more outstanding synthetic properties than commercial polyethylene (PE) separators. In addition, compared with Al2O3-coated PE (PE-Al2O3) separators, AlOOH-coated PE (PE-AlOOH) separators have superior synthetic properties, including a better interface stability and a higher liquid electrolyte uptake due to the presence of hydroxyl groups (-OH). As a consequence, the LiNi0.3Co0.3Mn0.3O| Li metal half-cells with PE-AlOOH separators have a good cycling stability and a high rate performance. The advantages of the PE-AlOOH separators make them promising candidates for applications in high power lithium-ion batteries.

Lithium-ion highly conducting 100Li3PS4-50LiI-xLi3PO4 (0 ≤ x ≤ 20 mol%) solid electrolytes were successfully prepared by liquid-phase synthesis using ethyl propionate as the reaction medium. Li3PO4 could be inserted into the Li3PS4-LiI structure (up to x = 20) without any noticeable segregated peak in the resulting X-ray diffraction patterns. 31P NMR revealed the formation of PO2S2 and POS3 units, which confirmed that Li3PO4 reacted with Li2S-P2S5 system to form Li3PO4-xSx. Solid electrolyte with x = 10 exhibited the highest conductivity of about 8.5 × 10−4 Scm−1 at room temperature.

Polycrystalline cubic Li6.5Al0.22La3Zr1.93O11.94 (LLZO) with garnet structure has been synthesized by solid-liquid method (SLM) with acrylic acid as organic complexing agent, and acetate sol coated nano-ZrO2 powders as template. The polymeric precursors are characterized by means of TG/DTA, the resultant powders and sintered LLZO pellets are characterized by ICP-OES, X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance spectroscopy. It is shown that the morphology of the powders is dependent on the preparation conditions such as molar ratio of acrylic acid to metallic ions (L/M) and the pH values. Prepared powders are purity, single phase, an ellipsoidal shape and a particle size of 2–4 μm with good neck connection. The ionic conductivity of sintered LLZO pellets at 1100 °C for 6 h at room temperature is 3.09 × 10−4 S cm−1 and the relative density is 94.1%. The solid-liquid method can lower the sintering temperature, greatly shortens holding time, and gets relatively good the ionic conductivity and it is suitable for mass synthesis of high performance LLZO powders with the advantages of less amount of organic reagent and friendly environment.

Glasses in xV2O5–(100-x)P2O5 system within x range from 35 to 95 mol% are obtained by a melt-quenching method and characterized by X-ray powder diffraction, atomic emission spectroscopy and red-ox titration. The dependences of density and molar volume of glasses on V2O5 concentration are linear up to 90 mol% of vanadium oxide and can be expressed via formulas: ρ = 2.64 + 0.36·xV2O5 g cm−1 and Vmol = 54.17 + 6.36·xV2O5 cm3 mol−1. The electronic conductivity of glasses is measured by both impedance spectroscopy and direct current methods. The glass composition of 95V2O5·5P2O5 shows the highest electrical conductivity value of ~1.0 × 10−4 S cm−1 at 50 °C. The concentration dependence of the conductivity is described at a qualitative level with non-constant force field molecular dynamics.

The Zr0.84Y0.16O1.92-La0.8Sr0.2Cr0.5Fe0.5O3-δ (YSZ-LSCrF) dual-phase composite membrane is known to possess appreciable oxygen permeability and excellent stability under stringent operation conditions. In the present study, a sandwich-like symmetric YSZ-LSCrF membrane was prepared using the phase-inversion tape casting/lamination/sintering technique. The as-prepared membrane consisted of a 5 μm thick dense oxygen separation layer sandwiched between two 300 μm thick finger-like porous layers. To promote the surface oxygen exchange, the membrane was impregnated with Sm0.2Ce0.8O2-δ (SDC) nanoparticles. The oxygen permeation flux through the membrane was measured by exposing one side of the membrane to a flowing air stream and the other side to a flowing CO stream. An oxygen permeation rate of 1.95 ml (STP) cm–2 min–1 was obtained at 900 °C. The oxygen permeation rate increased with increasing temperature as expected, and the apparent activation energy for oxygen permeation was calculated to be 29.5 kJ mol–1. The membrane remained intact after the oxygen permeation measurement and thermal cycle stability test. The sandwich-like symmetric YSZ-LSCrF membrane with an ultra-thin oxygen separation layer demonstrated desired oxygen permeability and satisfactory durability, promising for membrane reactor applications. The preparation method developed in the present study can be applied to other ceramic membranes and devices requiring the similar sandwich-like symmetric structure.

The cubic phase of lithium lanthanum zirconium oxide (LLZO) is a solid electrolyte based on the garnet crystal structure which has shown promise in enabling batteries with significantly higher energy density compared to lithium-ion. Owing to its stability against lithium, LLZO is compatible with metallic lithium electrodes that, when paired with state-of-the-art cathodes, can achieve >1000 Wh/l. The preferred cubic LLZO phase is stabilized at room temperature by doping LLZO, which results in the formation of lithium vacancies (VLi′) that can achieve ionic conductivities in the 1 mS/cm range. While much attention has been paid to optimizing VLi′, discrepancies in lanthanum to zirconium (La:Zr) ratios provide an indication of the existence of vacancies at one or both of these sites. As La is the largest cation present, La vacancies should show the most dramatic effects on lattice parameter, which should affect lithium-ion transport within the LLZO sublattice. In turn, changes in lithium-ion site occupancy and solvation should affect activation energy and conductivity. However, the effects of the sub stoichiometric use of La on the crystal structure of LLZO have yet to be characterized. In this work, La content is varied in the LLZO structure Li6.5La2+xZr1.5Ta0.5O12 from x = 0 to x = 1.2. X-ray diffraction, SEM imaging, Raman Spectroscopy, electrochemical impedance measurements, and DC cycling were performed in order to correlate the effect of La deficiency on crystal structure and electrochemical properties of LLZO. Vacancy and decomposition mechanism are proposed. A linear increase in lattice parameter is observed over the range of La content measured. An increase in conductivity and CCD are also observed ranging from 0.649 mS/cm and 0.5 mA/cm2 at x = 0.2 to 0.789mS/cm and 0.80 mA/cm2 at x = 1.0.

Fe2O3-doped 50Li2O-10B2O3-40P2O5 glasses were prepared using conventional melt-quenching method. FT-IR and Raman spectroscopy show that the partial substitution of Fe2O3 has slight effect on the glass network structure. The thermal behavior of Fe2O3-doped borophosphate glasses was investigated by Differential Scanning Calorimeter (DSC). The effects of partial substitution of Fe2O3 on the chemical stability and electrical properties of borophosphate glasses and glass-ceramics were investigated. The glass-ceramics obtained after nucleation at 450 °C for 10 h and crystallization at 560 °C for 8 h are crystallized completely and the main crystallized phase is Li4P2O7. With increase of Fe2O3 content, the diffraction peak intensity of Li4P2O7 crystal phase is gradually decreased, and the diffraction peak intensity of Li9Fe3P8O29 is gradually increased. The electrical conductivity (at room temperature) of the glass-ceramics with 4 mol% Fe2O3 reaches a maximum value of 1.09 × 10−5 S/cm, which is about 10 times higher than that of the glass-ceramics without Fe2O3. Moreover, the glass-ceramics have a high chemical stability to water. The addition of Fe2O3 to 50Li2O-10B2O3-40P2O5 glass-ceramics improves the ionic conductivity, which has a potential application as Li+ glass and glass-ceramic electrolyte materials.

Lithium metal anode is a promising anode for next-generation lithium-based batteries. However, the lithium dendrite growth due to uneven Li-ion deposition could cause safety problem, and the unceasing formation of solid electrolyte interphase layer leads to capacity fading of anode. Here, we report a mechanism of Li electrodeposition under a magnetic field with the direction perpendicular or parallel to electric field in the cell systematically. We for the first time observe that at the initial nuclei stage the deposited Li metal is needlelike; for the later growth stage, a very compact deposits with dendrite-free structure can be obtained. Compared with perpendicular magnetic field, the parallel one can facilitate more uniform and dense lithium growth. The Lorentz force and the electric field force during Li platting are calculated and compared. It also indicates that the magnetic field can contribute to a smooth Li deposits after cycling at various current densities and deposited capacities. The polarization of the Li symmetrical cells is reduced in the magnetic field resulting in more stable cycling performance. In addition, improved electrochemical performance of the Li|LiCoO2 half cells can be achieved by applying a magnetic field. The study demonstrates that the electromagnetic environment is critical to stabilizing Li-metal anode in high-energy-rechargeable batteries.

In this study, the chemical states of a powder type and an impregnated type of the La0.4Sr0.6Ti0.8Mn0.2O3±d (LSTM) oxide system were investigated along with its electrical conductivities in order to apply these materials as alternative anode materials for high temperature-operating Solid Oxide Fuel Cells (HT-SOFCs). The Ni/8YSZ samples with LSTM impregnated into the pores created by partially removing nickel, Ni/8YSZ (Ni (R)/8YSZ), showed much higher electrical conductivity values than those of unimpregnated Ni/8YSZ (Ni (E)/8YSZ) samples under dry H2 fuel condition. Reduction of Mn4+ to Mn3+ was observed when LSTM was reduced. Additional reduction properties of Mn2+ from Mn3+ and satellite peaks were found when impregnated LSTM was coated onto a Ni/8YSZ substrate. The reduction of the charge state of Ti contained in LSTM showed the same behavior as the reduction property of Mn. However, a satellite peak identified as metal Ti was only observed when impregnated LSTM was coated on a selectively Ni-removed Ni/8YSZ (Ni (R)/8YSZ) substrate.

FeNbO4 is a layered oxide containing Fe3+ and Nb5+ cations on either side of a hexagonal close-packed O2– plane. This layered oxide can be reduced at 800 °C under hydrogen to form a composite of Fe0 and a FeNb2O6 tri-rutile of similar structure. The isothermal conductivity of FeNbO4 against oxygen partial pressure, PO2, indicates that the critical phase-switching oxygen pressure is around 10−16 bar at 800 °C and the conductivity of the resultant composite shows a p-type conductivity under a PO2 between 10−20 and 10−17 bar. The composite of FeNb2O6 and Fe0 from FeNbO4 reduced in 5% H2/Ar gas can maintain a stable performance as the cathode for the electrolysis of steam. In addition, we demonstrate that FeNbO4 can be transformed to FeNb2O6 and Fe/Fe(O) under a cathodic current without prior H2 reduction and a high current density of 0.32 A cm−2 can be obtained at 1.5 V for the electrolysis of 5% H2O/Ar. Nb5+ in FeNb2O6 can be reduced to Nb4+ under a bias of 1.5 V at 800 °C.

High temperature Na2O vapor conversion of α-Al2O3 with different concentrations of yttria stabilized zirconia (YSZ) was used to produce Na-β″-Al2O3 solid electrolyte (BASE) materials. The influence of different ratios of yttria (YSZ-3 and YSZ-8) on conversion and material properties (ionic conductivity and flexural strength) was also investigated. Extent of conversion to Na-β″-Al2O3 was calculated by semi-quantitative XRD phase analysis. Al2O3 composites with 20% or less YSZ were incompletely converted to Na-β″-Al2O3 after 2 h at 1450 °C. Al2O3 composites with 30–40% YSZ-3 appear fully converted by XRD but have lower conductivity and higher strength compared to conventionally sintered Na-β″-Al2O3 composites with the same concentration of YSZ-3. SEM of the materials indicated differences in morphology and grain size. XRD of Al2O3 composites with YSZ-8 showed significantly lower conversion than those with YSZ-3. This is attributed to the larger grain size of YSZ-8, which limits the homogeneity of composites with Al2O3 and thus does not assist in oxygen diffusion as well as YSZ-3. Although the vapor converted BASE materials tended to have lower conductivities at 300 °C, they have lower activation energies (0.20 eV) compared to conventionally sintered Na-β″-Al2O3 composites (0.30 eV) and comparatively higher conductivity at ambient temperature. Vapor converted BASE materials also have better mechanical properties, which should allow fabrication of thinner electrodes.

Solid polymer electrolytes (SPEs) are prepared through thiol-ene polymerization with functionalized, potentially bio-based, aromatic monomers. Differing functionality and aromatic content of the monomers vary the glass transition temperatures (Tgs) and crosslink densities of the resulting polymers, allowing for analysis of the structure-property relationships. Though the SPEs contain repeating PEO segments, the formation of crystalline regions is avoided through the crosslinked nature of the networks. The solid polymer electrolytes exhibit high conductivity values at room temperature, the highest reaching 7.65 × 10−4 S cm−1 for the DAVA-containing SPE with 50 mol% LiPF6, and moderate lithium ion transference numbers, the highest reaching 0.39 for the DAGd-containing SPE with 25 mol% LiPF6. Lower polymer Tg is associated with higher overall conductivity, but, the SPEs with higher crosslink densities display higher cationic transport, though the Tgs are higher. Therefore, it is determined that there exists an optimal range of polymer Tgs, crosslink densities and neat polymer dielectric constants for high cationic transport through the SPEs; extremes of these parameters are not necessarily beneficial. The promising conductivity and ion transference results, in addition to high initial decomposition temperatures in N2 (>300 °C) and great electrochemical stability, reveal potential for these crosslinked, aromatic, thiol-ene polymers in electrolyte applications in lithium-ion batteries.

Water-stable and high lithium-ion conductivity solid electrolytes have potential for application as the separator in aqueous lithium-air batteries and as the electrolyte in all-solid-state batteries. Herein we have systematically examined the electrical and mechanical properties of water-stable NASICON-type Li1+xAlxGe0.2Ti1.8-x(PO4)3 (LAGTP; x = 0.25–0.55) sintered at 900–1000 °C. The highest lithium-ion conductivity of 1.58 × 10−3 S cm−1 at 25 °C was observed for Li1.35Al0.35Ge0.2Ti1.45(PO4)3 sintered at 950 °C, the conductivity of which is the highest in the NASICON-type lithium-ion conductivity solid electrolytes reported previously. The high conductivity could be explained by the high grain boundary conductivity of 6.58 × 10−3 S cm−1 at 25 °C. The conductivity showed no effect of aging after more than one month immersed in saturated LiCl aqueous solution. A 3-point bending strength of 110 N mm−2 was also recorded for Li1.35Al0.35Ge0.2Ti1.45(PO4)3 sintered at 950 °C.

Solid polymer electrolytes (SPEs) with new functionalized ethyl cellulose bearing a lithium/sodium fluorosulfonylimide group (Ethyl cellulose-LiFSI/NaFSI) is proposed as quasi single ion (Li+/Na+) conducting polymer electrolyte for all-solid-state lithium and sodium batteries. The degree of ethyl cellulose functionalization by anion of lithium and sodium salt measured by elemental analysis was 48 and 53%, respectively. The complex of Li(FSI-ethyl cellulose)/PEO exhibits a Li-ion transference number of TLi+ = 0.9, and a Na ion transference number of TNa+ = 0.6 for Na(FSI-ethyl cellulose),which are much higher than those reported for ambipolar LiFSI or NaFSI/PEO SPEs under the same measurement conditions. The generated SPEs showed a high electrochemical and mechanical stability as well as a practical ionic conductivity value of ~10−4 S·cm−1 at 80 °C. All solid-state lithium, sodium and Li/Sulfur cells cycled with quasi single ion conducting hybrid SPE exhibit reversible cycling and good performance at 70 °C, making them promising, environmentally benign and cost-effective candidates for use in advanced energy storage systems.