Titanium Niobium Research Articles

Electrochemical performance of TiNb2O7 nanoparticles anchored with different contents of MWCNTs as anode materials for Li-ion batteries

In this study, the electrochemical behavior of titanium niobium oxide (TNO) composites with 1, 3, and 5 wt% of multi-walled carbon nanotubes (MWCNTs) was investigated. The results showed a significant improvement in the electrochemical performance of TNO by the addition of MWCNTs in terms of initial capacity, rate performance, and rate capability. The initial capacity of pure TNO at 0.1C increased from 251.6 mAh/g to 272.4, 302.2, and 265.9 mAh/g by addition of 1, 3, and 5 wt% of MWCNTs, respectively. Furthermore, the cyclic stability of the samples improved considerably by the addition of the MWCNTs; the capacity value of pure TNO after 200 cycling at 1C was only 78.3 mAh/g while for TNO/3 wt% MWCNTs was about 145.6 mAh/g. Similarly, the rate performance of the TNO/MWCNTs nanocomposites was better than pure TNO in all charge/discharge rates. The MWCNTs contents in nanocomposites had significant effects on their performance in which the optimal content of MWCNTs in this study was 3 wt%. The results showed that the presence of MWCNTs in nanocomposites created a conductive network with good ionic and electrical conductivity and thus, improved the rate performance of samples. In addition, the stresses caused by the intercalation/deintercalation of Li-ions were moderated by MWCNTs, improving the cyclic stability.

New Class of Titanium Niobium Oxide for a Li-Ion Host: TiNbO4 with Purely Single-Phase Lithium Intercalation

Entropy-stabilized titanium niobium oxides (TNOs) with crystallographic shear structures (e.g., TiNb2O7 and Ti2Nb10O29) are generally synthesized by high-temperature calcination in an air or an oxygen atmosphere to compensate for their positive enthalpies of formation. In this work, we demonstrate that changing the reaction atmosphere into a slightly reductive environment using in situ carbonization leads to the creation of a new class of TNO with a formula of TiNbO4. Unlike its predecessors, this new lithium reservoir is a rutile phase, and most strikingly, in situ X-ray diffraction analysis revealed that its lithium intercalation occurs via a purely solid-solution process. Since solid-electrolyte-interface-free, high capacity anode materials with long cyclic life are required to meet the stringent requirements of widespread lithium-ion battery utilization, this finding of a new electrode material with purely single-phase lithium intercalation is of great interest for the development of high-performance anode materials. Distinctive electrochemical behavior that is different from that of crystallographic shear structured TNO is revealed by in-depth electrochemical analyses, which is ascribed to the unique structural and electronic properties of TiNbO4. We believe this work opens a new avenue for the development of feasible oxide-based alternatives to graphite, which can be safer and suitable for high-power performance.

High electrocatalytic activity of Pt on porous Nb-doped TiO2 nanoparticles prepared by aerosol-assisted self-assembly.

This study explores an aerosol-assisted method to prepare an efficient support for the Pt catalyst of polymer electrolyte membrane fuel cells (PEMFCs). Titania nanoparticles and mesoporous niobium-doped titania nanoparticles were prepared by aerosol-assisted self-assembly using titanium(iv) isopropoxide and niobium(v) ethoxide as the titanium and niobium sources for application as non-carbon supports for the platinum electrocatalyst. The structural characteristics and electrochemical properties of the supports were investigated by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance, inductively coupled plasma optical emission spectrometry, and dynamic light scattering. The Brunauer–Emmett–Teller method was used to calculate the specific surface areas of the samples, and the pore size distribution was also examined. The results demonstrated that under a radial concentration gradient, the aerosol droplets self-assembled into a spherical shape, and mesoporous supports were obtained after subsequent removal of the surfactant cetyltrimethylammonium bromide by annealing and washing. The hydrothermal technique was then used to deposit platinum on the TiO2-based supports. The electrical conductivity of the non-carbon support was enhanced by the strong metal–support interaction effect between the platinum catalyst particles and the porous niobium-doped TiO2 support. The half-wave potential, electrochemical surface area, mass activity, and specific activity of the obtained Pt/Nb-TiO2 catalyst all surpassed those of commercial Pt/C.

Hypoallergenic unicompartmental knee arthroplasty and return to sport: comparison between Oxidized Zirconium and Titanium Niobium Nitride.

Background:The present study aims to compare the rate of return to sports in patients who underwent surgery for mobile-bearing UKA with either hypoallergenic TiNbN or with oxidized zirconium alloy implants.Methods:The records of two consecutive cohorts for a total of 90 hypoallergenic implants were prospectively analysed. The first cohort consisted of 41 consecutive series of medial mobile-bearing hypoallergenic TiNbN UKA, whereas the second cohort consisted of 49 consecutive medial fixed-bearing hypoallergenic Uni Oxinium. The clinical evaluation involved evaluating each patient’s University of California, Los Angeles (UCLA) activity scores and the High-Activity Arthroplasty Score (HAAS). Each patient was clinically evaluated on the day before surgery (T0), then after a minimum follow-up period of 12 months (T1), and finally after 24 months (T2).Results:The only pre-operative difference between the two groups involved pre-operative BMI with significantly higher BMI in TiNbN Group (p<0.001). Both groups reported significant improvement at each follow-up compared with the previous and also at the final follow up with respect to UCLA and HAAS (p<0.05), except for UCLA in TiNbN between T1 and T2 (p>0.05). Moreover, BMI improved significantly at the final follow up, but only in TiNbN group (p<0.05).Conclusions:Both TiNbN and Oxinium UKA procedures enabled patients to return to an acceptable level of sports activity with excellent radiographic outcomes after the final follow up regardless of the age, gender, BMI, and bearing type.

Facile synthesis of carbon and oxygen vacancy co-modified TiNb6O17 as an anode material for lithium-ion batteries.

Titanium niobium oxides (TNOs), benefitting from their large specific capacity and Wadsley–Roth shear structure, are competitive anode materials for high-energy density and high-rate lithium-ion batteries. Herein, carbon and oxygen vacancy co-modified TiNb6O17 (A-TNO) was synthesized through a facile sol–gel reaction with subsequent heat treatment and ball-milling. Characterizations indicated that A-TNO is composed of nanosized primary particles, and the carbon content is about 0.7 wt%. The nanoparticles increase the contact area of the electrode and electrolyte and shorten the lithium-ion diffusion distance. The carbon and oxygen vacancies decrease the charge transfer resistance and enhance the Li-ion diffusion coefficient of the obtained anode material. As a result of these advantages, A-TNO exhibits excellent rate performance (208 and 177 mA h g−1 at 10C and 20C, respectively). This work reveals that A-TNO possesses good electrochemical performance and has a facile preparation process, thus A-TNO is believed to be a potential anode material for large-scale applications.

Coordination Cage-Based Emulsifiers: Templated Formation of Metal Oxide Microcapsules Monitored by In Situ LC-TEM.

Metallo‐supramolecular self‐assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chemical reactions. However, the potential of low‐molecular bottom‐up self‐assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo‐supramolecular surfactant with the ability to stabilize non‐aqueous emulsions for a significant period. The molecular design of the surfactant is based on a heteroleptic coordination cage (CGA‐3; CGA=Cage‐based Gemini Amphiphile), assembled from two pairs of organic building blocks, grouped around two Pd(II) cations. Shape‐complementarity between the differently functionalized components generates discrete amphiphiles with a tailor‐made polarity profile, able to stabilize non‐aqueous emulsions, such as hexadecane‐in‐DMSO. These emulsions were used as a medium for the synthesis of spherical metal oxide microcapsules (titanium oxide, zirconium oxide, and niobium oxide) from soluble, water‐sensitive alkoxide precursors by allowing a controlled dosage of water to the liquid‐liquid phase boundary. Synthesized materials were analyzed by a combination of electron microscopic techniques. In situ liquid cell transmission electron microscopy (LC‐TEM) was utilized for the first time to visualize the dynamics of the emulsion‐templated formation of hollow inorganic titanium oxide and zirconium oxide microspheres.

Partially Reduced Titanium Niobium Oxide: A High-Performance Lithium-Storage Material in a Broad Temperature Range.

The existing electrode materials for lithium‐ion batteries (LIBs) generally suffer from poor rate capability at low temperatures, severely limiting their applications in winter and cold climate area. Here, partially reduced TiNb24O62 (PR‐TNO) are reported that demonstrates excellent electrochemical performance in a broad temperature range, notably at low temperatures. Its crystal structure is similar to that of Ti2Nb10O29 upon partial reduction in H2. The titanium and niobium ions in PR‐TNO enable multielectron transfer, safe operation, and high Coulombic efficiencies. Benefiting from the increased electronic conductivity of the partially reduced phase and its robust crystal structure with a large interlayer spacing, PR‐TNO shows fast electron and Li+ transport, small volume change associated with Li+ storage, and notable capacitive behavior, resulting in good electrochemical performance even at very low temperatures. At −20 °C, a large reversible capacity of 313 mAh g−1 is obtained at 0.1C, reaching 83.3% of that at 25 °C. At 5C, high rate capability (58.3% of that at 0.5C) is achieved, only slightly lower than that at 25 °C (60.7%). Furthermore, PR‐TNO demonstrates excellent cyclic stability with 99.2% of the initial capacity after 1680 cycles, confirming its excellent suitability for low‐temperature LIBs.

Comparative investigation of the properties of graphene nanoplatelet reinforced titanium diboride and niobium diboride ceramics

In this study, the effect of GNP concentration on the mechanical properties of spark plasma sintered TiB2 and NbB2 ceramics was investigated. GNP reinforced TiB2 and NbB2 specimens were aimed to produce with nearly full densification. Herein, SEM investigations, Raman analysis, and oxidation behavior of the samples were reported. GNP addition into the TiB2 and NbB2 matrices showed a different effect on various properties of the composites. GNP loading tends to enhance densification by removing native oxides of both TiB2 and NbB2 matrices. GNPs were more effective in the oxygen removal mechanism for TiB2 composites than NbB2. The highest relative density was obtained for TiB2-GNP and NbB2-GNP composites as 98.6% with 7 vol% and 5 vol% GNP additions, respectively. The Vickers microhardness decreased with increasing GNPs loading for both matrices. NbB2-GNP composites possessed higher fracture toughness and better oxidation resistance than TiB2-GNP composites.

Application of EPR Spectroscopy in TiO2 and Nb2O5 Photocatalysis

The interaction of light with semiconducting materials becomes the center of a wide range of technologies, such as photocatalysis. This technology has recently attracted increasing attention due to its prospective uses in green energy and environmental remediation. The characterization of the electronic structure of the semiconductors is essential to a deep understanding of the photocatalytic process since they influence and govern the photocatalytic activity by the formation of reactive radical species. Electron paramagnetic resonance (EPR) spectroscopy is a unique analytical tool that can be employed to monitor the photoinduced phenomena occurring in the solid and liquid phases and provides precise insights into the dynamic and reactivity of the photocatalyst under different experimental conditions. This review focus on the application of EPR in the observation of paramagnetic centers formed upon irradiation of titanium dioxide and niobium oxide photocatalysts. TiO2 and Nb2O5 are very well-known semiconductors that have been widely used for photocatalytic applications. A large number of experimental results on both materials offer a reliable platform to illustrate the contribution of the EPR studies on heterogeneous photocatalysis, particularly in monitoring the photogenerated charge carriers, trap states, and surface charge transfer steps. A detailed overview of EPR-spin trapping techniques in mechanistic studies to follow the nature of the photogenerated species in suspension during the photocatalytic process is presented. The role of the electron donors or the electron acceptors and their effect on the photocatalytic process in the solid or the liquid phase are highlighted.

Kinetics modulation of titanium niobium oxide via hierarchical MXene coating for high-rate and high-energy density lithium-ion half/full batteries

Titanium niobium oxide has great potential in fast charging and discharging due to the high capacity at large rate. But its poor capacity retention rate seriously restricts the further development. MXene, a two-dimensional transition metal carbide with high conductivity, was adopted to complex with TiNb2O7 (TNO) to improve the electrochemical performance. TNO coated with MXene exhibits better conductivity and limited volume expansion, which benefits the capacity and stability of TNO in the cycle process. The capacity of TNO@MXene remains 153 mAh g−1 after 2000 cycles at 10 C, and the capacity retention rate is 81.4%. The capacity of TNO@MXene can reach 145 mAh g−1 after 5000 cycles at 20 C, and the capacity retention rate is 77.1%. The full battery was assembled using commercial NCM811 as the cathode material, and its energy density was 241.7 Wh kg−1, further verifying its potential application.

Closely Compacted TiNb2O7-C Assembly for Fast-Charging Battery Anodes

The fast-charging capability of lithium-ion batteries (LIBs) is becoming more important than before to meet the increasing requirements in practical applications. Because of safe working potential (above 1 V) and moderately high specific capacity, titanium niobium oxide (TiNb2O7, TNO) shows great potential as a fast-charging anode. Herein, a TNO-C assembly consisting of active initial TNO nanoparticles with conformal carbon coating is fabricated. The small size of TNO nanoparticles provides a short diffusion distance for lithium ions, and surficial carbon layers enable good electronic conductivity within the entire assembly. Moreover, the compact structure within the TNO assembly and efficient space packing of spheroidal secondary particles are beneficial for close packing, leading to an overall short distance for electron transport and ion diffusion. As expected, the as-designed TNO-C electrode delivers a high capacity of 194 mAh g–1 under 10C, and 71% of capacity was achieved under 0.2C. Moreover, the TNO-C electrode shows stable cycling performance with capacity retention of 92.2% after 100 cycles under 2C. In addition, by pairing with a lithium nickel–cobalt manganate (LiNi0.6Co0.2Mn0.2O2, NCM) cathode, the full cell exhibits a high capacity of 140 mAh g–1 under 3C and a high capacity retention of 97.4% after 100 cycles. The rational design of a TNO-C assembly makes it an excellent anode candidate for fast-charging LIBs.

"Systematic review and meta-analysis of ceramic coated implants in total knee arthroplasty. Comparable mid-term results to uncoated implants."

Nitride-based ceramic coatings, such as titanium nitride (TiN) and titanium niobium nitride (TiNbN), have been introduced in total knee arthroplasty (TKA) to enhance the mechanical properties and biocompatibility of knee components, harden the metal surface and reduce CoCrMo exposure and metal ion release. However, the theoretical advantages of these ceramic coatings in TKA have yet to be fully elucidated. This systematic review aimed to provide clinical evidence on mid-term outcomes of ceramic-coated knee prostheses in comparison with uncoated standard CoCrMo knee prostheses in primary TKA. The hypothesis was that ceramic-coated implants can be used in primary TKA with no inferior outcomes compared to uncoated CoCrMo implants. A systematic review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to find all clinical studies regarding primary TKA with ceramic-coated knee prostheses. MEDLINE (PubMed), Embase and Cochrane Library were searched from 1990 to October 2020 to identify relevant studies for the first qualitative analysis. Using PICOS eligibility criteria, a subgroup of the selected studies was used to perform a meta-analysis. Fifteen studies were included in this systematic review, of which six were included in the meta-analysis: 3 randomized controlled trials, 2 retrospective comparative studies and 1 prospective cross-sectional study. Pooled data overall included 321 coated TKAs vs. 359 uncoated TKAs and a mean follow-up of 4.6years (range, 2-10years). No significant difference in the implant survival risk ratio with revision or reoperation due to any reason was found between coated and uncoated TKAs, even considering the RCT study subgroup with a risk ratio of 1.02 (P = 0.34). No significant differences were found for postoperative complications, clinical scores, or metal blood concentrations at 1year. The findings of this systematic review and meta-analysis support the statement that ceramic-coated TKAs are not inferior to uncoated TKAs, showing comparable survival rates, complication rates and clinical outcomes. There is strong evidence that ceramic-coated TKA does not improve the clinical results or survival rate in comparison with uncoated TKA. II, Therapeutic.

Polyvinylpyrrolidone regulated synthesis of mesoporous titanium niobium oxide as high-performance anode for lithium-ion batteries

TiNb2O7 (TNO) as a promising candidate anode for lithium-ion batteries (LIBs) shows obvious advantages in terms of specific capacity and safety, but which undergoes the intrinsic poor electrical and ionic conductivity. Herein, we propose a simple synthesis strategy of mesoporous TNO via a polymeric surfactant-mediated evaporation-induced sol-gel method, using polyvinylpyrrolidone (PVP) with different molecular weights (average Mw: 10000/58000/1300000) as the regulating agent, which greatly affects the lithium storage performance of the as-prepared TNO. The optimized TNO (i.e., PVP of 58000) delivers a high reversible capacity of 303.1 mAh/g at 1 C, with a retention rate of 73.4% (222.5 mAh/g) after 300 cycles. Even at 5 C, a high reversible capacity of 185.6 mAh/g can be achieved, with a retention rate of 72.3% after 1000 cycles. The superior lithium storage behavior is attributed to the fine mesoporous framework consisting of interconnected TNO nanocrystallites with high specific surface area and high mesoporosity, which greatly increases the active sites, improves the Li+ diffusion kinetics and alleviates volume fluctuation induced by the repetitive Li+ insertion-extraction processes.

Insight into the effects of dislocations in nanoscale titanium niobium oxide (Ti2Nb14O39) anode for boosting lithium-ion storage

Defect engineering through induction of dislocations is an efficient strategy to design and develop an electrode material with enhanced electrochemical performance in energy storage technology. Yet, synthesis, comprehension, identification, and effect of dislocation in electrode materials for lithium-ion batteries (LIBs) are still elusive. Herein, we propose an ethanol-thermal method mediated with surfactant-template and subsequent annealing under air atmosphere to induce dislocation into titanium niobium oxide (Ti2Nb14O39), resultant nanoscale-dislocated-Ti2Nb14O39 (Nano-dl-TNO). High-resolution transmission electron microscope (HRTEM), fast Fourier transform (FFT), and Geometrical phase analysis (GPA) denote that the high dislocation density engraved with stacking faults forms into the Ti2Nb14O39 lattice. The presence of dislocation could offer an additional active site for lithium-ion storage and tune the electrical and ionic properties of the Ti2Nb14O39. The resultant Nano-dl-TNO delivers superior rate capability, high specific capacity, better cycling stability, and making Ti2Nb14O39 a suitable candidate among fast-charging anode materials for lithium-ion batteries. Moreover, In-situ High-resolution transmission electron microscope (HRTEM) and Geometrical phase analysis (GPA) evinces that the removal of the dislocated area in the Nano-dl-TNO leads to the contraction of the lattice, alleviation of the total volume expansion, causing the symmetrization and preserves structural stability. The present findings and designed approach reveal the rose-colored perspective of dislocation engineering into mixed transition metal oxides as next-generation anodes for advanced lithium-ion batteries and all-solid-state lithium-ion batteries.

Return to physical activity and change in body mass index after hypoallergenic medial mobile-bearing unicompartmental knee arthroplasty

BackgroundThe primary purpose of the present prospective study was to consecutively analyse the outcomes of the return to sports activity of patients with positive patch tests undergoing a medial mobile-bearing titanium niobium nitride (TiNbN) unicompartmental knee arthroplasty (UKA). The secondary purpose was to ascertain if a higher grade of physical activity leads to a reduction in the body mass index (BMI) of the patients.Material and methodsForty-one patients with positive skin patch tests were included in this prospective study. The clinical evaluation consisted of the University of California, Los Angeles (UCLA) activity scale and the High-Activity Arthroplasty Score (HAAS). Each patient was evaluated the day before surgery (T0), after 12.37 ± 0.70 months (T1), and on the day of the final follow-up, after 67.03 ± 18.2 months (T2). Furthermore, the BMI of each patient was analysed before surgery and during the final follow-up.ResultsThe UCLA and HAAS mean preoperative values ranged from 3.68 ± 1.1.7 and 6.15 ± 0.76 to 6.1 ± 0.76 and 10.34 ± 1.3, respectively, at T1 (p < 0.0001) and to the final values of 6.34 ± 0.62 and 11.0 ± 8.9, respectively, at T2 (UCLA: T2 versus T1: p = 0.132; T2 versus T0: p < 0.0001; HAAS: T2 versus T1: p = 0.0027; T2 versus T0: p < 0.001). BMI ranged from a preoperative value of 27.97 ± 3.63 to a final value of 26.84 ± 3.11 (p < 0.0001). The only differences within the subgroups concerned patients with BMI ≥ 28, showing a superior HAAS at each follow-up (p < 0.05). A positive correlation was found between BMI and HAAS at T0 and T2 (p < 0.05).ConclusionsThis is the first study to evaluate the rate of the return to sports activities and change in BMI following hypoallergenic UKA. The majority of patients reduced their weight following UKA and improved their physical activity, showing outcomes that were comparable to the standard cobalt–chrome (CoCr) prostheses, regardless of gender, age, BMI and implant size.Level of evidenceIV – Prospective Cohort Study.Trial registration researchregistry5978—Research Registry www.researchregistry.com

No Clinical or Radiographic Differences Between Cemented Cobalt-Chromium and Titanium-Niobium Nitride Mobile-Bearing Unicompartmental Knee Arthroplasty.

This study aimed to compare the clinical and radiographic outcomes of patients with positive patch tests undergoing a medial mobile-bearing titanium-niobium nitride (TiNbN) unicompartmental knee arthroplasty (UKA) to patients undergoing standard UKA (cobalt-chromium [CoCr] implants). Two successive groups of patients, amounting to a total of 246 individuals, who received Oxford (Zimmer-Biomet, Warsaw, Indiana, USA) UKA were included. The first group was composed of a series of 203 consecutive standard CoCr UKAs (Standard Group), while the second group comprised 43 consecutive hypoallergenic TiNbN UKAs (HA group). The patients of the second group had a positive epicutaneous patch test result for metals. Each patient was evaluated using the Oxford Knee Score (OKS) and Knee Society Score (KSS) a day prior to the surgery (T 0) and at two consecutive follow-ups, namely T 1 (minimum follow-up of 12months) and T 2 (minimum follow-up of 34months). Radiographic measurements were performed at the final follow-up (T 2). No statistical differences were noted between the two groups regarding demographic data (p > 0.05). No clinical or radiographic differences were found between the HA and standard groups at any follow-up (p > 0.05). A statistically significant improvement was found at any follow-up for both OKS and KSS (p < 0.05). No clinical or radiographic differences between the hypoallergenic and standard cobalt-chromium groups at any follow-up were found, with a clinically significant improvement being experienced by both groups during the entire follow-up. Level II-comparative prospective study. The online version contains supplementary material available at 10.1007/s43465-021-00486-3.

Orderly defective superstructure for enhanced pseudocapacitive storage in titanium niobium oxide

Orderly defective superstructure for enhanced pseudocapacitive storage in titanium niobium oxide

Smart construction of Ti2Nb10O29 /carbon nanofiber core-shell composite arrays as anode materials for lithium-ion batteries

With high capacity and its safety, titanium niobium oxide (Ti2Nb10O29, TNO) has been reported as a potential anode for high power lithium ion batteries. However, insufficient diffusion coefficient of Lithium-ions and poor electronic conductivity for this electrode material significantly constrains its rate capability. To solve this issue, we propose a simple strategy to encapsulate Ti2Nb10O29 in porous carbon nanofiber arrays (porous TNO/CNF) and to prepare heterogeneous Ti2Nb10O29/carbon nanofiber core-shell composite arrays (TNO NPs-CNF) using polyamic acid (PAA) as the polymer precursor. TNO NPs-CNF electrode exhibits significantly superior electrochemical performance (286 mA h g−1 at 10 C and 225 mA h g−1 at 20 C), much better than the TNO and porous TNO/CNF. For the electrode of porous TNO/CNF and TNO NPs-CNF, the omni-directional conducting networks of CNF skeleton greatly enhances electron transport of the whole electrode, reduces energy barrier of lithium ion transport, and maintains the structure’s stability.

Reducing Crystallinity of Micrometer-Sized Titanium–Niobium Oxide through Cation Substitution for High-Rate Lithium Storage

As promising anode materials for lithium-ion batteries, titanium–niobium oxides still suffer from the bottleneck of ion transport, which severely limits their practical usage. In this work, the ion-transport kinetics of micrometer-sized Ti2Nb10O29 is improved by crystallinity mediation. The crystallinity of Ti2Nb10O29 is intrinsically reduced through cation substitution (Nb5+ → Ti4+ and W6+), with Ti2.5Nb9W0.5O29 obtained. The amorphous phases not only optimize the ion transport through isotropic ion diffusion path but also introduce more oxygen vacancies, which can serve as nucleation sites for phase changing and improve electron conductivity. As a result, Ti2.5Nb9W0.5O29 exhibits superior kinetics and remarkable rate performance. Even with large particle sizes from 5 to 20 μm, Ti2.5Nb9W0.5O29 can achieve a reversible specific capacity of 110 mAh g–1 at a high current density of 10 A g–1, much higher than Ti2Nb10O29 (11.1 mAh g–1). This work provides a novel view for the development of practical, high-performance anode materials for LIBs.

Electrospinning oxygen-vacant TiNb24O62 nanowires simultaneously boosts electrons and ions transmission capacities toward superior lithium storage

The intercalation pseudocapacitive anode material TiNbxOx+2.5x (x = 2,5,24) has attracted much attention owing to its high theoretical specific capacity (388–402 mAh g−1) and relatively safe working voltage. However, Ti4+/Nb5+ has a 3d/4d empty orbital that leads to a lower electronic conductivity, which limits its practical application. Therefore, reasonable design and adjustment of an effective electron/ion transfer path is the key to the realization of high-performance anode material, which is of great significance to improve the multiplier performance and cycle life for lithium-ion batteries. In this work, we employ a facile electrospinning and subsequent hydrogenation process to synthesize one-dimensional TiNb24O62 (H-TNO) nanowires with oxygen vacancies. The rapid Li+ diffusion path and high Li+ diffusion coefficient are achieved by nano engineering, besides, hydrogen treatment brings oxygen vacancy to improve the electronic conductivity, together with providing more Li+ active sites for TNO materials. As a result, the as-prepared H-TNO-1h (treatment with 1 h) electrode delivers a high reversible specific capacity (305.2 mAh g−1 at 0.1 A g−1), safer working voltage (~ 1.7 V vs. Li/Li +), high initial Coulombic efficiency (91.9%), excellent rate properties (180.5 mAh g−1 at 5 A g−1) and superior cycle stability, making it become one of the best choices in titanium niobium electrode material used for lithium-ion batteries.