Crystal Structure of Na2V2(PO4)3, an Intriguing Phase Spotted in the Na3V2(PO4)3–Na1V2(PO4)3 System

Park, Sunkyu; Wang, Ziliang; Deng, Zeyu; Moog, Iona; Canepa, Pieremanuele; Fauth, François; Carlier, Dany; Croguennec, Laurence; Masquelier, Christian; Chotard, Jean‐Noël

doi:10.1021/acs.chemmater.1c04033

Cited by 47 publications

(40 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While Li 3 V 2 (PO 4 ) 3 is a single-phase material, Na 3 V 2 (PO 4 ) 3 contains less than 2 wt % of the NaVP 2 O 7 admixture, which is often observed in this system. Although the structure of Na 3 V 2 (PO 4 ) 3 is usually refined using a trigonal crystal system with the R 3̅ c S.G., a monoclinic distortion was observed for Na 3 V 2 (PO 4 ) 3 in refs , . The distortion is seen in the XRD patterns shown in Figure S1 as a splitting of the (116) reflection of the R 3̅ c S.G. at ∼32° into (51̅1̅), (42̅2̅), and (31̅3̅) reflections of the C 2/ c S.G.…”

Section: Resultsmentioning

confidence: 99%

“…Polyhedral representations of the structure in two crystal systems (trigonal and monoclinic) are provided in Figure S2, illustrating their difference. Low-intensity unindexed reflections marked with arrows in Figure S1 are believed to characterize an incommensurate modulated structure, , which, however, has not been studied in detail yet. The refined lattice parameters of the as-prepared samples are shown in Table S1, while the general structural information, including refined atomic coordinates, occupancy factors, and ADPs, is provided in Tables S2 and S3.…”

Section: Resultsmentioning

confidence: 99%

“…Doping with 10 at % of d-metals (Zr 4+ , Ti 4+ ) at the vanadium site allows stabilizing the γ-form with the Pbcn S.G., in which Li + ions are distributed over three partially occupied 8d positions. , NASICON-type Na 3 V 2 (PO 4 ) 3 is traditionally described using the R 3̅ c S.G., in which sodium ions are distributed over partially occupied 6b (A1) and 18e (A2) Wyckoff positions. However, a possible monoclinic distortion in Na 3 V 2 (PO 4 ) 3 , named as the β-phase and caused by ordering of sodium ions and vacancies was detected by Masquelier and co-workers using high-resolution synchrotron X-ray diffraction. − The structures of NASICON and anti-NASICON are distinguished by the interconnection of the “lantern” units: in the NASICON phase, the “lanterns” are connected by vertices along the [001] direction (Figure ), while in anti-NASICON, the connections are antiparallel . Different connectivity modes of the lantern units generate different ion migration paths and should influence the electrochemical properties of A 3 V 2 (PO 4 ) 3 (A = Li, Na).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

et al. 2023

View full text Add to dashboard Cite

In the present work, we studied crystal phases in the Li 3−x Na x V 2 (PO 4 ) 3 system over a wide range of x prepared by four synthesis methods: mechanochemically assisted solid-state synthesis, 'soft chemistry' sol−gel approach, chemical (CIE) and electrochemical (EIE) ion exchange starting from Li 3 V 2 (PO 4 ) 3 (anti-NASICON, P2 1 /c S.G.), and Na 3 V 2 (PO 4 ) 3 (NASICON, C2/c S.G.). EIE was studied by operando and ex situ XRD in Li 3 V 2 (PO 4 ) 3 vs Na and Na 3 V 2 (PO 4 ) 3 vs Li electrochemical cells. It was shown that both mechanochemically assisted solid-state and sol−gel synthesis methods do not result in the single-phase Na 3−x Li x V 2 (PO 4 ) 3 . In contrast, CIE and EIE lead to deep substitution degrees and proceed much easier in the NASICON framework (Na 3 V 2 (PO 4 ) 3 ), where more than 2/3 of Na + ions per f.u. are replaced with Li + resulting in Na 0.6 Li 2.4 V 2 (PO 4 ) 3 (R3̅ S.G.), while in the anti-NASICON framework (Li 3 V 2 (PO 4 ) 3 ), only 1/3 of Li + ions are replaced with Na + resulting in Li 2 NaV 2 (PO 4 ) 3 (Pbcn S.G.), which was shown to be a metastable phase, and after high-temperature treatment, it decomposes into two NASICON-type compounds. The ionic conductivity was analyzed both theoretically and experimentally, and the results show that in the NASICON framework, the migration of both Na + and Li + ions is realized, while in the anti-NASICON framework, the Li + migration is preferable. The contribution of the electronic component to total conductivity was determined.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Whilst the NVP cathode is widely reported to undergo two‐phase transformation during Na (de)intercalation, [ 9 ] recent studies highlighted the existence of Na 2 V 2 (PO 4 ) 3 intermediate phase. [ 33 ] On the other hand, the Na 4 VMn(PO 4 ) 3 cathode shows solid‐solution formation followed by two‐phase Na (de)intercalation mechanism during cycling. [ 34 ] Our in operando XRD studies of y = 0.25, 0.5, and 0.75 cathodes show the formation of solid solution followed by a two‐phase transition during electrochemical Na (de)intercalation processes.…”

Section: Resultsmentioning

confidence: 99%

Structural and Electrochemical Sodium (De)intercalation Properties of Carbon‐Coated NASICON‐Na_3+yV_2−yMn_y(PO₄)₃ Cathodes for Na‐Ion Batteries

Ghosh

Barman

Patra

et al. 2022

Adv Energy and Sustain Res

View full text Add to dashboard Cite

Sodium-ion batteries are emerging as frontrunner candidates for grid storage application due to inexpensive and Earthabundant sodium precursor. [1] The present Na-ion prototype, which uses layered sodium-ion oxide cathode and hard carbon anode, provides moderate energy density (%150 Wh kg À1 ) compared with its Li-ion counterpart with few hundreds of cycles. [2] Albeit the layered oxides offer high intercalation capacities, they undergo multiple phase transitions during Na (de)intercalation which limit their cycle life, besides other issues such as lower insertion voltage and air instability. [3] Alternatively, polyanionic cathodes offer numerous advantages over their layered oxide counterparts such as rich crystal chemistry, chemical tunability, enhanced structural, chemical and thermal stabilities, and higher sodium-ion mobilities. [4] Among them, NASICON-Na 3 V 2 (PO 4 ) 3 (NVP) offers attractive operating voltage (V 4þ /V 3þ at 3.38 V vs Na þ /Na 0 ) with moderate storage capacity (%100 mAh g À1 ). [5,6] While the micrometer-sized NVP cathode delivers limited capacity (90 mAh g À1 at 1C rate), two major methodologies are utilized to improve its electrochemical performances, namely, 1) synthesizing carbon-coated NASICON-Na 3 V 2 (PO 4 ) 3 nanomaterials [7][8][9][10][11][12][13][14] and 2) tuning chemical composition through chemical doping /substitution. [15][16][17][18][19][20][21] Different alio-and isovalent cationic substitutions in the NVP yielded vanadium-lean multielectron redox cathodes (e.g., Na 3 VFe(PO 4 ) 3 and Na 4 VMn(PO 4 ) 3 ). [21,22] In particular, the V/Mn-based NASICON cathodes offer relatively higher operating voltage, lower cost, and toxicity compared with the NVP. Recently, our group systemically studied the impact of Mn 2þ substitution on the structural and electrochemical properties of micrometer-sized bulk Na 3þy V 2Ày Mn y (PO 4 ) 3 cathodes which were prepared by solid-state route. [23] In the voltage window of 3.8-2.75 V versus Na þ /Na 0 , the y ¼ 0.75 cathode delivered highest capacity of %104 mAh g À1 with good cycling stability (86% of retention after 100 cycles) and better rate performances (91 mAh g À1 at 5C). However, the Mn-rich cathodes displayed severe capacity decay upon extending the cycling window to 4.2-2.75 V versus Na þ /Na 0 due to irreversible structural transformation occurring at higher voltage. [23] The NASICON cathodes with micrometer-sized particles exhibited limited reversibility, cycling stability, and rate

show abstract

“…In this open 3D framework, interconnected channels provide a high-speed transmission pathway for the ions encapsulated in the 'A' site. Intriguingly, its content is between 1 and 5 [31,32]. In addition, it can be de-intercalated continuously without structural collapse.…”

Section: Structurementioning

confidence: 99%

Unlocking the multi-electron transfer reaction in NASICON-type cathode materials

2023

View full text Add to dashboard Cite

The growing concern about scarcity and large-scale applications of lithium resources has attracted efforts to realize cost-effective phosphate-based cathode materials for next-generation Na-ion batteries (NIBs). In previous work, a series of materials (such as Na4Fe3(PO4)2(P2O7), Na3VCr(PO4)3, Na4VMn(PO4)3, Na3MnTi(PO4)3, Na3MnZr(PO4)3, etc.) with ~120 mAh·g-1 specific capacity and high operating potential have been proposed. However, the mass ratio of the total transition metal in the above compounds is only ~22 wt%, which means that one electron transfer for each transition metal shows a limited capacity (the mass ratio of Fe is 35.4 wt% in LiFePO4). Therefore, a muti-electron transfer reaction is necessary to catch up or beyond the electrochemical performance of LiFePO4. This review summarizes the reported NASICON-type and other phosphate-based cathode materials. On the basis of the aforementioned experimental results, we pinpoint the muti-electron behavior of transition metals and shed light on designing rules for developing high-capacity cathodes in NIBs.

show abstract

Crystal Structure of Na₂V₂(PO₄)₃, an Intriguing Phase Spotted in the Na₃V₂(PO₄)₃–Na₁V₂(PO₄)₃ System

Cited by 47 publications

References 55 publications

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

Structural and Electrochemical Sodium (De)intercalation Properties of Carbon‐Coated NASICON‐Na_3+yV_2−yMn_y(PO₄)₃ Cathodes for Na‐Ion Batteries

Unlocking the multi-electron transfer reaction in NASICON-type cathode materials

Contact Info

Product

Resources

About

Crystal Structure of Na2V2(PO4)3, an Intriguing Phase Spotted in the Na3V2(PO4)3–Na1V2(PO4)3 System

Cited by 47 publications

References 55 publications

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li3–xNaxV2(PO4)3 System

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li3–xNaxV2(PO4)3 System

Structural and Electrochemical Sodium (De)intercalation Properties of Carbon‐Coated NASICON‐Na3+yV2−yMny(PO4)3 Cathodes for Na‐Ion Batteries

Unlocking the multi-electron transfer reaction in NASICON-type cathode materials

Contact Info

Product

Resources

About

Crystal Structure of Na₂V₂(PO₄)₃, an Intriguing Phase Spotted in the Na₃V₂(PO₄)₃–Na₁V₂(PO₄)₃ System

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the Li_3–xNa_xV₂(PO₄)₃ System

Structural and Electrochemical Sodium (De)intercalation Properties of Carbon‐Coated NASICON‐Na_3+yV_2−yMn_y(PO₄)₃ Cathodes for Na‐Ion Batteries