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N-doped T-Nb2O5 microflowers (N-Nb2O5) assembled by [001]-oriented nanoflakes are prepared. The special structure of N-Nb2O5 endows them with improved electronic conductivity and pseudocapacitive behavior, leading to superior Li+ storage properties.

Researchers have recently attempted to monitor pool oscillations using the three-dimensional laser vision method. However, the deficiency of simulation software will result in significant capital expenditure. Both simulations and experiments are performed in this study, and the Bessel equation is used to analyze the oscillation mode of a weld pool. The laser dot matrix images of (0, 1), (1, 1), (2, 1), and (0, 2) oscillation modes at different times are obtained via structured laser optical measurement simulation. The oscillation mode of a stationary gas tungsten arc weld pool is analyzed based on laser dot matrix images obtained from a structure laser experiment. Results show that the simulated laser dot matrix images are consistent with the experiment results. The oscillation mode of the weld pool can be recognized based on the laser dot matrix image. This study not only provides conditions for assessing the penetrating state of a weld pool, but also enable a further understanding of the oscillation mode of a weld pool and the development of more effective observation methods and measurement tools to effectively control and improve welding quality.

Nanoparticle-assembled Ti2Nb10O29 porous microspheres coated by N-doped carbon layers (TNO@N–C-M) have been synthesized using ionic liquid 1-ethyl-3-methylimidazolium dicyanamide ([Emim]DCA) as carbon and nitrogen sources. Owing to the wide liquid range, low vapor pressure, and low surface tension of [Emim]DCA, the as-obtained N-doped carbon layers possess ultrathin thickness (~3 nm) and the primary TNO nanoparticles have ultrasmall sizes (20–30 nm). The synergistic effects from the particular structure lead to high electronic conductivity, fast ion/electron transport kinetics, and increscent pseudocapacitive contribution. Accordingly, the TNO@N–C-M anode has large discharge capacity (309.6, 262.2, 240.6, 216.5 and 204.5 mA h g−1 at 1, 5, 10, 20, and 30 C, respectively), good rate capacity (304.9 and 208.1 mA h g−1 at 1 and 30 C, respectively), and superior cycle stability (219.5 mA h g−1 after 500 cycles at 10 C). Also, the LiNi0.5Mn0.3Co0.2O2//TNO@N–C-M full cell also exhibits superior electrochemical properties with promising application prospect.

As one kind of promising anode materials for Li-ion batteries, titanium niobium oxides have attracted great attention due to their high theoretical capacities and high rate performances. Herein, TiNb6O17/C composite with TiNb6O17 nanocrystals distributed among amorphous carbon has been synthesized via an in situ sol–gel and then thermal decomposition process. The as-synthesized TiNb6O17/C composite presents reduced crystal size and improved electronic conductivity compared with the pristine TiNb6O17. The TiNb6O17/C displays both excellent rate performance (high specific capacity of 129 mA h g−1 at 30 C) and good cyclic performance (low capacity decay rate of 0.016% per cycle for 500 cycles at 10 C). These results indicate that the approach as reported is a simple yet effective way for high-performance anode with high-rate capability.

Well-defined mesoporous TiNb6O17 microspheres are synthesized through a facile solvothermal method in isopropanol followed by a thermal treatment. The mesoporous TiNb6O17 microspheres are monodisperse with uniform morphology and are assembled by interconnected nanocrystals. The hierarchical mesoporous structure of the TiNb6O17 microspheres not only supplies a large electrode/electrolyte interfacial area but also reduces the diffusion distance of Li+, such that the TiNb6O17 microspheres have excellent electrochemical properties, especially a good rate performance. As the rate is increased from 1 to 5, 10, 20, and 30 C, the discharge capacity of the TiNb6O17 microspheres is slowly reduced from 273.7 to 239.5, 228.2, 216.0, and 175.3 mAh g−1, respectively. The good rate performance is mainly caused by the pseudocapacitive effect. These mesoporous TiNb6O17 microspheres are promising anode materials for producing lithium-ion battery with excellent rate capacity and good safety.

Mesoporous Ti2Nb10O29 microspheres are prepared through a solvothermal method in isopropanol-glycerol solvent followed by calcination treatment. The Ti2Nb10O29 microspheres with diameter in the range between 1.0 and 2.0 µm are assembled from nanoparticles. The special hierarchical mesoporous structure of Ti2Nb10O29 microspheres can reduce the Li+ ions diffusion distance and supply large interfacial area between electrolyte and electrode, endowing them with better electrochemical properties compared to Ti2Nb10O29 nanoparticles. At different current densities of 1, 5, 10, 20 and 30 C, the first discharge capacity of mesoporous microspheres is respectively 268.9, 218.5, 205.3, 180.5, and 158.1 mA h g−1. By contrast, the corresponding values of Ti2Nb10O29 nanoparticles are quickly reduced from 254.6, 196.3, 159.4, 127.5, to 99.0 mA h g−1. It worth noting that Ti2Nb10O29 microspheres exhibit excellent rate capacities. Furthermore, at a current density of 10 C, the specific capacity of Ti2Nb10O29 microspheres can be maintained at 173.5 mA h g−1 after 500 cycles, with 86.8% retention of the first discharge capacity. These results suggest that the Ti2Nb10O29 mesoporous microspheres would be developed as potential anodic materials for high performance lithium-ion batteries.

Hierarchical α-Fe2O3 hollow microspheres are synthesized through a convenient and effective solvothermal method. The α-Fe2O3 hollow microspheres have a mean diameter of 1 μm and they are composed of ultra-thin nanoflakes with an average thickness of only 5 nm. More importantly, the primary α-Fe2O3 nanoflakes are preferentially enclosed by (241) high-index facet. When the α-Fe2O3 hollow microspheres are served as anodes for lithium-ion batteries, their first discharge capacities is 1749.1 mAh g−1 at 0.1 A g−1, and the corresponding values are 914.0, 628.7, and 420.5 mAh g−1 at high current densities of 0.2, 0.5, and 1 A g−1, respectively. The improved electrochemical performance can be attributed to the synergistic effect of the hierarchical hollow microstructure, exposed high-index (241) facet, and thin primary nanoflakes. Additionally, the α-Fe2O3 hollow microspheres have superparamagnetic properties due to the ultra-thin thickness of the primary α-Fe2O3 nanoflakes.

Well-defined porous Ti2Nb10O29/C microspheres have been synthesized by a one-pot solvothermal method. The as-formed Ti2Nb10O29/C microspheres possess good dispersity and are constructed by interconnected nanoparticles. The unique porous microstructure and modification of conduction carbon can provide large electrode-electrolyte contact areas and improve the Li+ diffusion coefficient and electronic conductivity of Ti2Nb10O29/C microspheres, endowing them with excellent Li+ storage properties. Ti2Nb10O29/C porous microspheres can deliver prominent discharge capacity of 278.7, 239.7, 236.8, 220.5 and 208.1 mAh g−1 at 1, 5, 10, 20, and 30 C, respectively. On the contrary, the discharge capacity of Ti2Nb10O29 porous microspheres can be quickly reduced from 278.6 to 140.5 mAh g−1 (1 vs. 30C). Most importantly, Ti2Nb10O29/C microspheres display good rate capacity, such as 276.8 mAh g−1 at 1 C, 245.6 mAh g−1 at 10 C, 226.7 mAh g−1 at 20 C, and even 217.9 mAh g−1 at 30 C. It is deduced that the excellent rate performance is mainly caused by the pseudocapacitive effect. In addition, the discharge capacity of Ti2Nb10O29/C microspheres is retained to 186.7 mAh g−1 at a high current density of 10 C after 200 cycle, with 89.5% retention of the 1st cycle capacity.

Hierarchical 1D Nb 2 O 5 nanobelts are successfully synthesized via a facile solvothermal method and following thermal treatment. The as-formed Nb 2 O 5 nanobelts are characterized by XRD, FESEM, TEM, and BET, and the results indicate that they possess pseudohexagonal structure and are composed of ultranarrow nanorods with an average diameter of ca. 15 nm. When used as anodic materials for lithium ion batteries, the obtained Nb 2 O 5 nanobelts can deliver initial discharge capacities of 209.3 mAh g −1 at the current density of 0.5 C. In addition, the Nb 2 O 5 nanobelts exhibit a reversible capacity of 95.8 mAh g −1 after 200 cycles at relatively high current density of 5 C. The good electrochemical performance of the Nb 2 O 5 nanobelts may be ascribed to their good monodispersity, high specific surface areas, and narrow rod-like building blocks. The Nb 2 O 5 nanobelts can be developed as promising anodes for high-rate 2 V LIBs with good safety.

In lithium ion batteries anode material is very crucial. Exploring the high-performance anode materials remains a great challenge. Here, Ti2Nb10O29/Ag composite was obtained. Electrochemical measurements demonstrate that Ti2Nb10O29/Ag composite shows good electrochemical performance than pure Ti2Nb10O29, mostly due to enhanced electronic conductivity after Ag-coating. The specific capacities of Ti2Nb10O29/Ag composite can be as high as 253 and 173 mAh g−1 at 1 and 10C, respectively, and the specific capacity is 132 mAh g−1 at 20C. Moreover, the Ti2Nb10O29/Ag composite exhibited excellent cyclic stability, even after 500 cycles, its specific capacity at 10C still stabilized at a large value of 142 mAh g−1, which was in sharp contrast to the corresponding values of pure Ti2Nb10O29 (68 mAh g−1). The high electrochemical performance demonstrated that Ti2Nb10O29/Ag composite is highly promising anode materials for Li-ion batteries.

Ti 2 Nb 10 O 29 (TNO) microspheres are fabricated combining a solvothermal method with a subsequent heat-treatment. Structural and morphological properties of the as-prepared material have been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption/desorption. The electrochemical performance is evaluated by performing cyclic voltammograms and galvanostatic discharge/charge tests. The electrochemical characterization demonstrates that the as-prepared TNO microspheres exhibit a good electrochemical performance with a discharge capacity of 185 mAh g −1 after 200 cycles and a capacity retention of 94% at 10 C. Furthermore, since TNO may react with Li at a voltage above 1.0 V vs. Li + /Li, TNO microspheres could be the promising high-power anode materials for 2 V vs. Li + /Li lithium-ion batteries applications.

Orthorhombic Nb2O5 is a promising material for the anodes of lithium-ion batteries (LIBs) owing to its pseudocapacitive features, stability, and safety. However, the practical applications for Nb2O5 are limited due to its poor electrical conductivity. In this work, three-dimensional (3D) urchin-like microspheres coated with N-doped carbon were synthesized by hydrothermal synthesis and then polymerized in dopamine. When evaluated as anode for LIBs, the 3D urchin-like Nb2O5@N-C composites exhibited excellent high-rate capability (146 mAh g−1 at 20 C) and stability (78 mAh g−1 at 10 C after 2900 cycles). The remarkable electrochemical performance of the Nb2O5@N-C composites was ascribed to their unique structure and the N-doped carbon coating, which prevents the electrode from structural damage, mitigates volume expansion during the charge/discharge process, and enhances the conductance of the active material.

Porous Nb2O5 microspheres have been prepared by a facile solvothermal method and subsequent heat-treatment using cheap NbCl5 as a starting material. As anode materials for lithium-ion batteries (LIBs), porous Nb2O5 microspheres show good electrochemical performance with discharge capacities of 199 mA h g−1 after 50 cycles at a current density of 100 mA g−1 and 126 mA h g−1 after 150 cycles at a current density of 500 mA g−1, respectively. The good electrochemical performance of porous Nb2O5 microspheres can be ascribed to the distinct structure of the microspheres consisted of nanoparticles with short transport route for ion and electron, large specific surface and mesoporous structure. The electrochemical testing results demonstrate that porous Nb2O5 microspheres are the promising alternate as anode materials for LIBs.

A novel heterojunction CoTiO 3 /BiOBr nanocomposite with enhanced photocatalytic performance was synthesized by a precipitation-deposition method. The samples were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectrophotometry. Moreover, the photocatalytic activities were evaluated by decomposing the dye molecule Rhodamine B under visible light irradiation. The results showed that high photocatalytic performance can be achieved on the heterojunction photocatalysts, with the 0.15CoTiO 3 /0.85BiOBr composite displaying the highest activity. The results of the study concluded that it was the introduction of CoTiO 3 into the catalyst that mainly enhanced the activity of the photocatalyst by promoting the separation of the electron-hole group on the interface between BiOBr and CoTiO 3 .

We report the synthesis and application of ordered mesoporous TiNb6O17 microspheres (M-TNO) using a one-step solvothermal method for the first time in lithium-ion batteries. The diameters of TiNb6O17 microspheres are in the range from 2.2 to 2.4 μm with a mesopore size of about 35 nm, which promotes the electron and ion migration in charge/discharge processes. M-TNO shows a high specific capacitance (307.2 mA h g−1) at a low current density of 0.2 C and a long-term cycle life over 500 cycles as an electrode. The retentive capacity of the batteries is 77% of the initial cycle after 500 cycles. It is worth noting that M-TNO exhibits excellent rate capacity, which decreases slowly from 265.7 to 172.4 mA h g−1 with the current density increasing from 1 C to 30 C. The retentive capacity at a current density of 30 C is 65% compared to that at 1 C.

Urchin-like hierarchical Nb2O5 microspheres are successfully synthesized through a facile solvothermal method in glycerol–isopropanol mixed media followed by thermal treatment. The sample is characterized by XRD, FESEM, TEM, HRTEM, BET, and XPS, and the results reveal that the as-formed Nb2O5 microspheres have a pseudohexagonal structure and are composed of nanorods with an average diameter of ca. 20 nm. It is found that glycerol not only serves as a solvent but also acts as a reactant; furthermore, isopropanol plays an important part in the morphologies of the products. When used as anodic materials for lithium ion batteries, the Nb2O5 microspheres deliver initial discharge capacities of 201.7, 159.7, 148.5, 123.7, and 98.5 mA h g−1 at the current densities of 0.5, 1, 2, 5, and 10C, respectively. Additionally, the discharge capacity of Nb2O5 remains at 105.5 mA h g−1 even after 500 cycles at a high rate of 5C. The good electrochemical properties of the products may be ascribed to their large surface areas and hierarchical structures.

Ultrathin two-dimensional (2D) nanomaterials offer unique advantages compared to their counterparts in other dimensionalities. O-vacancies in such materials allow rapid electron diffusion. Carbon doping often improves the electric conductivity. Considering these merits, the WO3−x /C ultrathin 2D nanomaterial is expected to exhibit excellent electrochemical performance in Li-ion batteries. Here, ultrathin WO3−x /C nanosheets were prepared via an acid-assisted one-pot process. The as-prepared WO3−x /C ultrathin nanosheets showed good electrochemical performance, with an initial discharge capacity of 1,866 mA·h·g−1 at a current density of 200 mA·g−1. After 100 cycles, the discharge and charge capacities were 662 and 661 mA·h·g−1, respectively. The reversible capacity of the WO3−x /C ultrathin nanosheets exceeded those of WO3 and WO3−x nanosheets. The electrochemical testing results demonstrated that WO3−x /C ultrathin nanosheets are promising alternative anode materials for Li-ion batteries.

Hierarchical Li 4 Ti 5 O 12 -TiO 2 microspheres are synthesized via an oil/water interface method with the assistance of cetyltrimethylammonium bromide (CTAB) and following calcination. The as-prepared Li 4 Ti 5 O 12 -TiO 2 microspheres are consisted of nanoflakes ( ca. 15 nm in thickness); moreover, Li 4 Ti 5 O 12 and anatase TiO 2 in the nanoflake building blocks are bounded by (011) and (001) facets, respectively. More especially, it is found that CTAB plays a very important role in the phase and morphology of the Li 4 Ti 5 O 12 -TiO 2 composite. When employed as the anode materials for lithium-ion batteries, the Li 4 Ti 5 O 12 -TiO 2 microspheres show initial discharge capacities of 234, 170, 151 and 140 mAh g −1 at charge/discharge rate of 1, 5, 10, and 20C, respectively; furthermore, after 100 cycles at 5C, the discharge capacity remains at 158 mAh g −1 with a capacity retention of 92.9%. The excellent electrochemical properties of the product can be ascribed to the synergistic effect of the exposed Li 4 Ti 5 O 12 (011) and anatase TiO 2 (001) facets, abundant phase interfaces, hierarchical structures, and thin flake-like building blocks.

TiNb 6 O 17 /C composites were obtained via a facile solid-state reaction with TiO 2 , Nb 2 O 5 and glucose as the starting materials. The lattice structure and morphology of the composite were investigated by X-ray diffraction, scanning electronic microscopy and transmission electron microscopy. The electrochemical properties were characterized by rate charge/discharge measurements and cyclic voltammetry. Electrochemical measurements demonstrate that the TiNb 6 O 17 /C composite exhibits electrochemical properties superior to those of pure TiNb 6 O 17 , especially at high current rates. The initial discharge capacities of TiNb 6 O 17 /C are 239, 225.1 and 199.8 mAh g −1 at 1, 5 and 10 C, respectively. Even after 500 cycles at 10 C, the capacity still remains 165.1 mAh g −1 , while the capacity of TiNb 6 O 17 is only 74.8 mAh g −1 . The excellent electrochemical performance of TiNb 6 O 17 /C is attributed to the improvement of the electrical conductivity resulting from carbon coating.

A simple synthesis of Ti2Nb10O29/C (TNO/C) composite has been developed, based on a solid state reaction method. The as-prepared TNO/C composite displays good discharge capacity, cycle stability and rate capability with the discharge capacity of 255.7 mAh g−1 over 100 cycles at 1 C, and even at 5 and 10 C, the discharge capacities of 224.8 and 194 mAh g−1 can be obtained after 100 cycles, respectively. The good electrochemical performance demonstrates that TNO/C could be a promising candidate as an anode material for high-energy-density lithium-ion batteries.

Porous nanosheet-based hierarchical ZnO aggregations are prepared on compacted stainless steel meshes (CSSMs) using a facile precursor template method. The coverage density and morphology of the film are controlled by the concentration of alkaline in the precursor solution. Relative to the traditional planar substrate, CSSMs with multi-layered structure have larger surface area and higher porosity to capture more light from all directions. The three-dimensional (3D) hierarchical ZnO aggregations assembled by porous nanosheets could take both the advantages of nanosheets and micrometer-sized assemblies. As expected, combining the virtues of ZnO aggregations and CSSMs, the ZnO aggregations/CSSMs structure exhibit the significantly improved conversion efficiency as photoelectrode of flexible dye-sensitized solar cells and photocatalytic performance in the photodegradation of pollutants with a better recyclability. Furthermore, our work would offer idea for the growth of complex 3D hierarchical micro-/nanoarchitecture on the high curvature surface of the substrates.

We report a facile approach to synthesize nano-Li4Ti5O12 anode material by a biphasic interfacial reaction route at the cyclohexane/water interface and a subsequent calcination process. The resultant materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption/desorption, and electrochemical experiment. As an anode material for lithium-ion batteries, the resultant nano-Li4Ti5O12 displays excellent rate capability and cycling stability, its specific capacity can remain at 150 and 126.6 mAh g−1 after 50 cycles at 10 and 20 C, indicating its potential application for high-power lithium ion batteries.

Nanoindentation analysis of FCC single crystal copper with different crystal orientations under Berkovich indenter was carried out by molecular dynamics simulation. The influence of crystal orientation on load distribution under Berkovich indenter was studied and compared with the experiment. Simultaneously, by establishing the relationship between the load–displacement curve and the instantaneous defect structure, the defect formation and slip processes under different crystal orientations were analyzed. Finally, the dislocation density of different orientations was calculated. Meantime, the relationship between the dislocation density and the hardness was explored. The results show that the 〈1 0 0〉 orientation shows a slightly different anisotropy difference, and the load value is lower than the 〈1 1 0〉 and 〈1 1 1〉 orientations. The 〈1 1 1〉 load value is slightly greater than 〈1 1 0〉 and the hardness values also show the same trend as the load value. The launch time of the initial dislocation loop of 〈1 0 0〉 orientation is earlier than 〈1 1 0〉, 〈1 1 1〉. The crystallographic orientation has a great influence on the change of dislocation morphology during the indentation process. With different orientations, the main plastic deformation is incomplete dislocation nucleation. Under different orientations, different forms of dislocation proliferation, such as quadruple, double and triple symmetry, and different stacking slip directions activated during indentation are observed. The 〈1 1 0〉 orientation has a relatively small dislocation density value, the dislocation density ρ0.5 is proportional to the hardness, and the coefficient values are different with different orientations.

TiNb2O7 is considered as a promising anode material for high-power lithium-ion batteries (LIBs) due to its significantly high rate performance, safety, and reversible capacity. However, its application is limited by its sluggish Li-ion diffusion kinetics and poor electrical conductivity. Herein, N-doped carbon-coated porous TiNb2O7 microspheres were successfully synthesized via solvothermal route and the subsequent carbonization process using polydopamine as a nitrided and carbon precursor. The resulting TiNb2O7@N-C composite exhibited a significant high-rate capability (201 mAh g−1 at 30 C) and superior cycling stability (capacity retention of 97.1% at 10 C after 500 cycles). Additionally, the TiNb2O7@N-C composite also performed well in a LiNi0.5Mn0.3Co0.2O4||TiNb2O7@N-C full cell (128 mAh g−1 at 10 C after 500 cycles with a capacity retention of 91.7%). These results indicate that the TiNb2O7@N-C composite possesses significant potential for application as an anode material for next-generation high-rate LIBs.