Insights into the TT-Nb2O5 crystal structure behavior

Gomes, Gustavo H.M.; Mohallem, Nelcy Della Santina

doi:10.1016/j.matlet.2022.132136

Cited by 17 publications

(16 citation statements)

References 26 publications

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“…Characteristic peaks for the (100), (210), (310), (400), and (610) reflections can be observed for Nb 2 O 5 , which can be assigned to the pseudohexagonal form of Nb 2 O 5 (TT- Nb 2 O 5 , JCPDS #07-0061). TT-Nb 2 O 5 has a crystal structure similar to that of T-Nb 2 O 5 , but it consists of distorted sub-cells with a pseudohexagonal symmetry in a superlattice. , The diffraction pattern of gCNT shows the typical (002) plane of CNTs at 2θ ≈ 26°, and the Nb 2 O 5 @CNT pattern can be interpreted as a combination of the contributions from TT-Nb 2 O 5 and gCNT . The particle size of Nb 2 O 5 within Nb 2 O 5 @CNT was estimated by the Scherrer equation (see eq S1) to be ∼8.47 nm.…”

Section: Resultsmentioning

confidence: 99%

“…Pseudohexagonal Nb 2 O 5 , glucose-derived-carbon-decorated multiwalled carbon nanotubes (gCNT), and their composites (Nb 2 O 5 @CNT) were synthesized via a one-step hydrothermal method and post-annealing (see Figure S1 , but it consists of distorted sub-cells with a pseudohexagonal symmetry in a superlattice. 39,46 The diffraction pattern of gCNT shows the typical (002) plane of CNTs at 2θ ≈ 26°, and the Nb 2 O 5 @CNT pattern can be interpreted as a combination of the contributions from TT-Nb 2 O 5 and gCNT. 48 The particle size of Nb 2 O 5 within Nb 2 O 5 @CNT was estimated by the Scherrer equation (see eq S1) to be ∼8.47 nm.…”

Section: Resultsmentioning

confidence: 99%

“…Herein, we assess the capability of pseudohexagonal Nb 2 O 5 for use as anodes in KIBs for the first time, enabled via a designed carbon framework. Although TT-Nb 2 O 5 is less ordered than its crystalline analogue (T-Nb 2 O 5 ), it can be synthesized in less extreme conditions, which favors nanostructuring and scale-up. ,, By synthetically combining TT-Nb 2 O 5 and high-conductivity multiwalled carbon nanotubes (MWCNTs), strongly bound together with a glucose-derived carbon to form a well-integrated composite electrode, the conductivity, mechanical strength, stability, and specific capacity of the anode material were optimized. The needle-like Nb 2 O 5 @CNT composites have delivered a high reversible specific capacity of 170 mAh g –1 at 0.2 A g –1 and excellent rate retention when compared to T-Nb 2 O 5 -based KIB systems to date: 102 mAh g –1 at 2 A g –1 and 72 mAh g –1 at 5 A g –1 .…”

Section: Introductionmentioning

confidence: 99%

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Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Chen

Zhao

et al. 2023

ACS Appl. Mater. Interfaces

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High-rate batteries will play a vital role in future energy storage systems, yet while good progress is being made in the development of high-rate lithium-ion batteries, there is less progress with post-lithium-ion chemistry. In this study, we demonstrate that pseudohexagonal Nb 2 O 5 (TT-Nb 2 O 5 ) can offer a high specific capacity (179 mAh g −1 ∼ 0.3C), good lifetime, and an excellent rate performance (72 mAh g −1 at ∼15C) in potassium-ion batteries (KIBs), when it is composited with a highly conductive carbon framework; this is the first reported investigation of TT-Nb 2 O 5 for KIBs. Specifically, multiwalled carbon nanotubes are strongly tethered to Nb 2 O 5 via glucose-derived carbon (Nb 2 O 5 @CNT) by a one-step hydrothermal method, which results in highly conductive and porous needle-like structures. This work therefore offers a route for the scalable production of a viable KIB anode material and hence improves the feasibility of fast-charging KIBs for future applications.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Chen

Zhao

et al. 2023

ACS Appl. Mater. Interfaces

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“…X-ray diffraction patterns for 0%MO (i.e., all TNO, blue), 25%MO (green), 50%MO (orange), 75%MO (red), and 100%MO (purple), with relevant reference patterns below and labeled on the chart. TNO was an overall stoichiometry target of TiNb 2 O 7 , while the as purchased MO was MoO 2 . − …”

Section: Resultsmentioning

confidence: 99%

Stable Multicomponent Multiphase All Active Material Lithium-Ion Battery Anodes

Cai

Gao

Sun

et al. 2023

ACS Appl. Mater. Interfaces

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Due to their high energy density, lithium-ion batteries have been the state-of-the-art energy storage technology for many applications. Energy density can be further improved by engineering of the electrode architecture and microstructure, in addition to more common improvements via materials chemistry. All active material (AAM) electrodes consist of only the electroactive material that stores energy, and such electrodes have advantages to conventional composite processing with regards to improved mechanical stability at increased thicknesses and ion transport properties. However, the absence of binders and composite processing makes the electrode more vulnerable to electroactive materials with volume change upon cycling. Also, the electroactive material must have sufficient electronic conductivity to avoid large matrix electronic overpotentials during electrochemical cycling. TiNb 2 O 7 (TNO) and MoO 2 (MO) are electroactive materials with potential advantages as AAM electrodes due to relatively high volumetric energy density. TNO has higher energy density, and MO has much higher electronic conductivity, and thus a multicomponent blend of these materials was evaluated as an AAM anode. Herein, blends of TNO and MO as AAM anodes were investigated, where this is the first use of a multicomponent AAM anode. Electrodes that had both TNO and MO had the highest volumetric energy density, rate capability, and cycle life relative to single component TNO and MO anodes. Thus, using multicomponent materials provides a route to improve AAM electrochemical systems.

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“…In the literature, the topic of crystalline structures of Nb 2 O 5 polymorphs is surrounded by a long and ongoing discussion. The unit cell of some polymorphs has been long elucidated, while some are still under intense debate . Moreover, due to the large number of Nb 2 O 5 phases described in the literature and the absence of a cohesive nomenclature system, the assignment of the observed diffraction patterns and the respective reference polymorph revealed to be rather than challenging.…”

Section: Resultsmentioning

confidence: 99%

Investigation of Nb₂O₅ and Its Polymorphs as Catalyst Supports for Pyrolysis Oil Upgrading through Hydrodeoxygenation

et al. 2023

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Mild catalytic hydrogenation is an interesting process to upgrade and stabilize raw fast-pyrolysis oil, allowing higher ratios of bio-oil to be coprocessed in conventional refineries. In the search for hydrodeoxygenation (HDO) catalysts with high activity, high selectivity, and long-term stability, Nb 2 O 5 -supported catalysts are stressed owing to their water-resistant acid sites. Due to the Nb 2 O 5 polymorphism, its properties such as acidity, morphology, and crystalline structure are adjustable. This study evaluated the suitability of Nb 2 O 5 as a catalyst support and the impact of its different polymorphs on the upgrading of pyrolysis oil. Four different Nb 2 O 5 polymorphs were prepared by thermal treatment of niobic acid, and nanostructured Nb 2 O 5 was prepared by hydrothermal synthesis with niobium oxalate. The supports were wet impregnated with Pd (1 wt %) and applied for the upgrading of the light phase of beech wood fastpyrolysis oil (FPO-LP) in a batch reactor, pressurized at 80 bar H 2 (room temperature), and heated to 250 °C for 2 hours. The activity and selectivity of catalysts and the dominant reaction pathways were addressed in terms of upgraded product properties (elemental composition, water content, functional groups via 1 H-NMR, and chemical composition via GC−MS/FID), H 2 consumption, generated gases, deoxygenation degree, and catalyst deactivation via coke formation. Nb 2 O 5 showed outstanding potential as a catalyst support for FPO-LP HDO, taking into account the improved properties of the upgraded oil, such as higher carbon content and lower water and oxygen contents. The polymorphs without thermal treatment (Pd/TT&A-Nb 2 O 5 ) or with a low-temperature thermal treatment (Pd/TT&A-Nb 2 O 5 ) presented higher activity than the one obtained at high temperature (Pd/ M&T-Nb 2 O 5 ). The high stability of the Pd/A-Nb 2 O 5 was demonstrated by regeneration and re-use. Finally, the nanostructured TT-Nb 2 O 5 presented a remarkable activity toward hydrogenation and hydrogenolysis, owing to its higher acidity and surface area, resulting in the most improved oil.

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Insights into the TT-Nb2O5 crystal structure behavior

Cited by 17 publications

References 26 publications

Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Stable Multicomponent Multiphase All Active Material Lithium-Ion Battery Anodes

Investigation of Nb₂O₅ and Its Polymorphs as Catalyst Supports for Pyrolysis Oil Upgrading through Hydrodeoxygenation

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Insights into the TT-Nb2O5 crystal structure behavior

Cited by 17 publications

References 26 publications

Pseudohexagonal Nb2O5 Anodes for Fast-Charging Potassium-Ion Batteries

Pseudohexagonal Nb2O5 Anodes for Fast-Charging Potassium-Ion Batteries

Stable Multicomponent Multiphase All Active Material Lithium-Ion Battery Anodes

Investigation of Nb2O5 and Its Polymorphs as Catalyst Supports for Pyrolysis Oil Upgrading through Hydrodeoxygenation

Contact Info

Product

Resources

About

Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Investigation of Nb₂O₅ and Its Polymorphs as Catalyst Supports for Pyrolysis Oil Upgrading through Hydrodeoxygenation