Carbothermal synthesis of LiVPO4F and its structural change in a broad potential range observed by in-situ X-ray diffraction

Wang, Pengfei; Yu, Haoxiang; Lin, Xiaoting; Shao, Lianyi; Shui, Miao; Long, Nengbing; Shu, Jie

doi:10.1016/j.ceramint.2015.05.012

Cited by 8 publications

(3 citation statements)

References 30 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, as ex situ XRD directly examined the electrode surface that fully involved in electrochemical process, the shift and vanishing of the peaks at 27.6° and 30.0° that, respectively, correspond to (−120) and (101) lattice planes as well as the emerging of the new peaks at 27.7° and 29.5° during charging process can also be observed. These phenomena involve two phase‐transitions in the de‐lithiation of LVPF, where an intermediate phase of Li x VPO 4 F appears in the first phase‐transition and VPO 4 F in the second . As shown by the ex situ Raman spectra in Figure c, the existence of CNTs is confirmed by their typical D band at 1350 cm −1 , G band at 1583 cm −1 , and 2D band at 2667 cm −1 .…”

Section: Resultsmentioning

confidence: 76%

“…Under such circumstances, developing zinc‐lithium hybrid energy storage systems seems to be an effective strategy to utilize the richness in cathode materials of LIBs, and the opportunity to boost discharge plateau can be sharply increased. As an attractive fluorophosphate compound based on phosphate polyanion, LiVPO 4 F bears a high redox potential at ≈4.25 V (vs Li/Li + ), as well as high capacity density and volumetric energy density compared to the widely used LiCoO 2 and LiFePO 4 . But electronic conductivity of LiVPO 4 F is very poor, researchers have thus adopted a two‐step carbon thermal method with excess carbon black or acetylene black to reach decent electrochemical performances .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

Liu

Yang

Wang

et al. 2019

Advanced Energy Materials

151

118

View full text Add to dashboard Cite

The migration of zinc‐ion batteries from alkaline electrolyte to neutral or mild acidic electrolyte promotes research into their flexible applications. However, discharge voltage of many reported zinc‐ion batteries is far from satisfactory. On one hand, the battery voltage is substantially restricted by the narrow voltage window of aqueous electrolytes. On the other hand, many batteries yield a low‐voltage discharge plateau or show no plateau but capacitor‐like sloping discharge profiles. This impacts the battery's practicability for flexible electronics where stable and consistent high energy is needed. Herein, an aqueous zinc hybrid battery based on a highly concentrated dual‐ion electrolyte and a hierarchically structured lithium‐ion‐intercalative LiVPO4F cathode is developed. This hybrid battery delivers a flat and high‐voltage discharge plateau of nearly 1.9 V, ranking among the highest reported values for all aqueous zinc‐based batteries. The resultant high energy density of 235.6 Wh kg−1 at a power density of 320.8 W kg−1 also outperforms most reported zinc‐based batteries. A designed solid‐state and long‐lasting hydrogel electrolyte is subsequently applied in the fabrication of a flexible battery, which can be integrated into various flexible devices as powerful energy supply. The idea of designing such a hybrid battery offers a new strategy for developing high‐voltage and high‐energy aqueous energy storage systems.

show abstract

Section: Resultsmentioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

Liu

Yang

Wang

et al. 2019

Advanced Energy Materials

151

118

View full text Add to dashboard Cite

show abstract

“…This can be tuned through the inductive effect introduced by the V 3+/4+ couple (~4.28 V [6,7]) to form LiFe 1− x V x PO 4 F (0 ≤ x ≤ 1) solid solutions. Here we noticed that the specific capacity of LiVPO 4 F is almost the same as that of LiFePO 4 F (151.6 vs. 155.9 mAh g −1 ), and the specific energy of LiVPO 4 F [8,9,10,11,12,13,14,15,16,17,18,19,20] is larger than that of LiFePO 4 F [4,21,22,23] (667 vs. 424 Wh kg −1 ).…”

Section: Introductionmentioning

confidence: 83%

Structure, Shift in Redox Potential and Li-Ion Diffusion Behavior in Tavorite LiFe1−xVxPO4F Solid-Solution Cathodes

et al. 2019

View full text Add to dashboard Cite

Solid-solution Li-ion cathode materials transform through a single-phase reaction thus leading to a long-term structural stability and improved cyclability. In this work, a two- to single-phase Li+-extraction/insertion mechanism is studied through tuning the stoichiometry of transition-metal Fe/V cations to trigger a transition in the chemical reactivity path. Tavorite triclinic-structured LiFe1−xVxPO4F (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) solid-solution powders were prepared by a facile one-step solid-state method from hydrothermal-synthesized and commercial raw materials. The broad shape of cyclic voltammetry (CV) peaks, sloping charge/discharge profiles and sloping open-circuit voltage (OCV) profiles were observed in LiFe1−xVxPO4F solid-solution cathodes while 0 < x < 1. These confirm strongly a single-phase behavior which is different from the two-phase behavior in the end-members (x = 0 or 1). The electronegativity of M (M = Fe1−xVx) for the redox potential of Fe2+/3+ couple or the M–O4F2 bond length for the V3+/4+ couple plays respectively a dominant role in LiFe1−xVxPO4F solid-solution cathodes.

show abstract

VPO₄F Fluorophosphates Polyanion Cathodes for High‐Voltage Proton Storage

Liao

Cao

et al. 2022

Angewandte Chemie

View full text Add to dashboard Cite

Proton batteries are emerging in electrochemical energy storage because of the associated fast kinetics, low cost and high safety. However, their development is hindered by the relatively low energy density due to the limited choice of cathode materials. Herein, metal phosphate polyanion cathodes are proposed as the proton cathode for the first time. Combining experimental results and theoretical simulations, a universal criterion for the proton cathode was put forward. Vanadium fluorophosphate (VPO 4 F) was demonstrated as a promising high-voltage proton cathode material with a specific capacity of 116 mAh g À 1 at a high potential of 1.0 V (vs. SHE). The proton insertion/ extraction mechanism in the VPO 4 F electrode was also verified through X-ray diffraction (XRD) and photoelectron spectroscopy (XPS). Furthermore, the stability of VPO 4 F was investigated in various electrolytes and the optimized electrolyte enabled the stable operation of VPO 4 F for 300 cycles. This work provides new inspiration in the exploitation of new electrode materials for electrochemical proton storage devices.

show abstract

Carbothermal synthesis of LiVPO4F and its structural change in a broad potential range observed by in-situ X-ray diffraction

Cited by 8 publications

References 30 publications

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

Structure, Shift in Redox Potential and Li-Ion Diffusion Behavior in Tavorite LiFe1−xVxPO4F Solid-Solution Cathodes

VPO₄F Fluorophosphates Polyanion Cathodes for High‐Voltage Proton Storage

Contact Info

Product

Resources

About

Carbothermal synthesis of LiVPO4F and its structural change in a broad potential range observed by in-situ X-ray diffraction

Cited by 8 publications

References 30 publications

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

A Flexible Solid‐State Aqueous Zinc Hybrid Battery with Flat and High‐Voltage Discharge Plateau

Structure, Shift in Redox Potential and Li-Ion Diffusion Behavior in Tavorite LiFe1−xVxPO4F Solid-Solution Cathodes

VPO4F Fluorophosphates Polyanion Cathodes for High‐Voltage Proton Storage

Contact Info

Product

Resources

About

VPO₄F Fluorophosphates Polyanion Cathodes for High‐Voltage Proton Storage