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Sasca, Viorel

doi:10.1023/a:1023904811124

Cited by 18 publications

(3 citation statements)

References 16 publications

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“…XPS demonstrates that the ratio of V IV :V V in NMV is close to 3:10. The presence of V IV was derived from the partial reduction of V V upon heated under vacuum, which is quite common for POMs compounds. , TGA results revealed that the recrystallized NMV contained 22 crystalline water molecules per mole (Na 2 H 8 [MnV 10 V V 3 IV O 38 ]·22H 2 O) and they were completely removed between 30 and 200 °C, accounting for a weight loss of ∼22.5% (Figure S1). Based on all these test results the NMV formula can be determined as Na 2 H 8 [MnV 10 V V 3 IV O 38 ] (NMV) (more details in SI).…”

Section: Resultsmentioning

confidence: 99%

“Electron/Ion Sponge”-Like V-Based Polyoxometalate: Toward High-Performance Cathode for Rechargeable Sodium Ion Batteries

Liu

Chen

et al. 2017

ACS Nano

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One key challenge facing room temperature Na-ion batteries lies in identifying earth-abundant, environmentally friendly and safe materials that can provide efficient Na storage sites in Na-ion batteries. Herein, we report such a material, polyoxometalate NaH[MnVO] (NMV), with entirely different composition and structure from those cathode compounds reported before. Ex-situ XPS and FTIR analyses reveal that NMV cathode behaves like an "electron/Na-ion sponge", with 11 electrons/Na acceptability per mole, which has a decisive contribution to the high capacity. The extraordinary structural features, evidenced by X-ray crystallographic analysis, of NaH[MnVO] with a flexible 2D lamellar network and 1D open channels provide diverse Na ion migration pathways, yielding good rate capability. First-principle calculations demonstrate that a super-reduced state, [MnVO], is formed with slightly expanded size (ca. 7.5%) upon Na insertion compared to the original [MnVO]. This "ion sponge" feature ensures the good cycling stability. Consequently, benefiting from the combinations of "electron/ion sponge" with diverse Na diffusion channels, when revealed as the cathode materials for Na-ion batteries, NaH[MnVO]/G exhibits a high specific capacity (ca. 190 mA h/g at 0.1 C), associates with a good rate capability (130 mA h/g at 1 C), and a good capacity retention (81% at 0.2 C). Our results promote better understanding of the storage mechanism in polyoxometalate host, enrich the existing rechargeable SIBs cathode chemistry, and enlighten an exciting direction for exploring promising cathode materials for Na-ion batteries.

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Section: Resultsmentioning

confidence: 99%

“Electron/Ion Sponge”-Like V-Based Polyoxometalate: Toward High-Performance Cathode for Rechargeable Sodium Ion Batteries

Liu

Chen

et al. 2017

ACS Nano

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“…The loss of the first water molecules was observed at low temperatures, under 100 °C, due to the efflorescence property specific to this type of compound. The exothermic process in the DTA curve in the range 275–360 °C was caused by the structural damage of polyoxometalates [ 17 ]. The final endothermic process in the DTA curve, which was held at a temperature above 460 °C, was due to the oxide formation of atomic components and structural changes resulting from the oxides.…”

Section: Resultsmentioning

confidence: 99%

“…The final endothermic process in the DTA curve, which was held at a temperature above 460 °C, was due to the oxide formation of atomic components and structural changes resulting from the oxides. Thermal transformations between 700 and 800 °C were due to melting oxides [ 17 ].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

et al. 2023

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Five new complexes with metal cations (Mn2+, Fe3+, Co2+, Ni2+, and Cu2+) of monolacunary Keggin monovanado-deca-tungstophosphate, K8[PVW10O39]·15H2O, have been synthesised. The molar ratio of the combination between metal cations and K8[PVW10O39]·15H2O has been established to be 1:1, and its general molecular formulas were found to be: Kn[MPVW10O39(H2O)]·xH2O (n = 5 for M = Fe3+ and n = 6 for M = Mn2+, Co2+, Ni2+, and Cu2+). Optimal conditions for complexes’ synthesis (pH, temperature, and reaction time) have been determined. The characterisation of K8[PVW10O39]·15H2O and of its compounds Kn[MPVW10O39(H2O)]·xH2O have been performed using AAS, TG-DTA-DTG, UV-VIS, IR, Raman, and powder XRD methods. In UV spectra, two maximums of absorption were obtained, at 200 and 250 nm, characteristic of Keggin polycondensate compounds. The coordination of cations Ni2+, Co2+, and Cu2+ through oxygen atoms from K8[PVW10O39]·15H2O in an octahedron system has been reflected with VIS spectroscopy. All these methods have proved the compositions and structures of K8[PVW10O39]·15H2O and Kn[MPVW10O39(H2O)]·xH2O, their similarity with other vanadotungstophosphates, and their achievements in the Keggin class. Additionally, all analysis methods have shown an increase in the degree of structural symmetry and the thermal stability of a polyoxoanion complex after attaching metal cations compared to the monolacunary, K8[PVW10O39]·15H2O.

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Spectroelectrochemical characteristics of poly(3,4-ethylenedioxythiophene)/iron hexacyanoferrate film-modified electrodes

Nowak

Wilamowska

Lisowska-Oleksiak

2009

J Solid State Electrochem

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Untitled

Cited by 18 publications

References 16 publications

“Electron/Ion Sponge”-Like V-Based Polyoxometalate: Toward High-Performance Cathode for Rechargeable Sodium Ion Batteries

“Electron/Ion Sponge”-Like V-Based Polyoxometalate: Toward High-Performance Cathode for Rechargeable Sodium Ion Batteries

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

Spectroelectrochemical characteristics of poly(3,4-ethylenedioxythiophene)/iron hexacyanoferrate film-modified electrodes

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