supplementary materials


Acta Cryst. (2013). E69, i11-i12    [ doi:10.1107/S1600536813001499 ]

Reinvestigation of trilithium divanadium(III) tris(orthophosphate), Li3V2(PO4)3, based on single-crystal X-ray data

Y. Kee and H. Yun

Abstract top

The structure of Li3V2(PO4)3 has been reinvestigated from single-crystal X-ray data. Although the results of the previous studies (all based on powder diffraction data) are comparable with our redetermination, all atoms were refined with anisotropic displacement parameters in the current study, and the resulting bond lengths are more accurate than those determined from powder diffraction data. The title compound adopts the Li3Fe2(PO4)3 structure type. The structure is composed of VO6 octahedra and PO4 tetrahedra by sharing O atoms to form the three-dimensional anionic framework [infinity]3[V2(PO4)3]3-. The positions of the Li+ ions in the empty channels can vary depending on the synthetic conditions. Bond-valence-sum calculations showed structures that are similar to the results of the present study seem to be more stable compared with others. The classical charge balance of the title compound can be represented as [Li+]3[V3+]2[P5+]3[O2-]12.

Comment top

Trilithium divanadium(III) tris(orthophosphate), Li3V2(PO4)3, has been investigated as a cathode material of secondary batteries (Yin et al., 2003) and its structure has been reported based on powder diffraction data (Yin et al., 2003; Patoux et al., 2003; Kuo et al., 2008; Yang et al., 2010; Fu et al., 2010). In an attempt to prepare new mixed-metal phosphates using LiCl as a flux, we were able to isolate crystals of Li3V2(PO4)3, and report here the results of the structure analysis based on single-crystal X-ray diffraction data.

The title compound adopts the Li3Fe2(PO4)3 structure type. The general structural features of this compound are the same as reported previously (Patoux et al., 2003; Fu et al., 2010). However, as would be expected, the bond lengths found here from single-crystal diffraction data are more accurate than those reported previously from powder diffraction data. For example, the V—O distances (Table 1) reported by Kuo et al. (2008) range from 1.846 (3) to 2.258 (4) Å compared with 1.904 (2)–2.117 (2) Å here. Figure 1 shows the local coordination environment of the V and P atoms. In the structure, VO6 octahedra are joined to PO4 tetrahedra forming a [V2(PO4)3] unit. These units share a terminal oxygen atom to construct the anionic three-dimensional framework, 3[V2(PO4)3]3- (Fig. 2). The V—O distances are in good agreement with those calculated from their ionic radii (1.99 Å, Shannon, 1976), assuming a valence of +III for V.

The Li+ ions in the empty channels are surrounded by four O atoms in distorted tetrahedral coordination sites. There are three crystallographically independent Li sites for this phase. It has been reported that the positions of the Li atoms can vary depending on the synthetic conditions while those of the V, P, and O atoms comprising the rigid framework remain intact (Yang et al., 2010). The Li positions found from the present single-crystal study are consistent with those reported by Patoux et al.(2003) and of a sample treated with microwave radiation at 1123 K for 3 min by Yang et al. (2010). According to bond valence sum calculations (Adams, 2001) for the various structure determinations, our study gives the lowest global instability index, Gii = 0.027. The Gii values of structures with Li positions similar to ours are likewise relatively low (i.e. 0.079; Yang et al., 2010), while those with Li positions considerably different as those from the present structures are much higher (i.e. 0.175; Yin et al., 2003).

The classical charge balance of the title compound can be represented as [Li+]3[V3+]2[P5+]3[O2-]12.

Related literature top

For the isotypic Li3Fe2(PO4)3 structure, see: Patoux et al. (2003). Structural studies of Li3V2(PO4)3 based on powder diffraction data have been reported previously by Yin et al. (2003); Patoux et al. (2003); Kuo et al. (2008); Yang et al. (2010); Fu et al. (2010). For ionic radii, see: Shannon (1976). For bond-valence calculations, see: Adams (2001). For the Inorganic Crystal Structure Database, see: ICSD (2012).

Experimental top

The title compound, Li3V2(PO4)3, was prepared by the reaction of the elements with the use of the reactive halide-flux technique. A combination of the pure elements, Nb powder (Alfa Aesar 99.8%), V powder (STREM CHEMICALS 99.5%) and P powder (CERAC 99.5%) were mixed in a fused silica tube in a molar ratio of Nb:V:P = 1:1:3 and then LiCl (Sigma-Aldrich 99%) was added. The mass ratio of the reactants and the halide was 1:5. The tube was evacuated to 0.133 Pa, sealed, and heated gradually (150 K/h) to 1123 K, where it was kept for 12 h. The tube was cooled to room temperature at a rate of 3 K/h. The excess halide was removed with water and colourless block-shaped crystals were obtained. The crystals are stable in air and water. A qualitative X-ray fluorescence analysis of selected crystal indicated the presence of V, P, and O. The composition of the compound was determined by single-crystal X-ray diffraction.

Refinement top

Although all the previous structural studies of Li3V2(PO4)3 have been performed in space group settings P<ι>1121/n<ι> or P<ι>121/n<ι>1 of space group no. 14, we have chosen the standard setting, P<ι>121/c<ι>1, for this and future studies. For the comparison between the different settings in this and the previous studies, the fractional coordinates transformed to the standard setting for the various entries in the ICSD (2012) can be used. The highest peak (0.58 e/Å-3) and the deepest hole (-0.49 e/ Å-3) are 0.68 Å and 0.77 Å from the atom O12 and P1, respectively.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 2006); cell refinement: RAPID-AUTO (Rigaku, 2006); data reduction: RAPID-AUTO (Rigaku, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. A view showing the local coordination environments of the V and P atoms with the atom labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. Symmetry codes are as given in Table 1.
[Figure 2] Fig. 2. View of Li3V2(PO4)3 down the b axis. VO6 octahedra are shown in blue and PO4 tetrahedra are shown in pink.
Trilithium divanadium(III) tris(orthophosphate) top
Crystal data top
Li3V2(PO4)3F(000) = 784
Mr = 407.61Dx = 3.03 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 8.6201 (4) ÅCell parameters from 5732 reflections
b = 8.6013 (4) Åθ = 3.4–27.6°
c = 14.7465 (7) ŵ = 2.70 mm1
β = 125.204 (3)°T = 290 K
V = 893.39 (7) Å3Block, colourless
Z = 40.08 × 0.04 × 0.04 mm
Data collection top
Rigaku R-AXIS RAPID
diffractometer
1772 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
ω scansθmax = 27.5°, θmin = 3.4°
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
h = 1110
Tmin = 0.741, Tmax = 1.000k = 1011
8328 measured reflectionsl = 1919
2031 independent reflections
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.024Secondary atom site location: difference Fourier map
wR(F2) = 0.062 w = 1/[σ2(Fo2) + (0.0223P)2 + 1.8904P]
where P = (Fo2 + 2Fc2)/3
S = 1.08(Δ/σ)max = 0.001
2031 reflectionsΔρmax = 0.58 e Å3
181 parametersΔρmin = 0.49 e Å3
Crystal data top
Li3V2(PO4)3V = 893.39 (7) Å3
Mr = 407.61Z = 4
Monoclinic, P21/cMo Kα radiation
a = 8.6201 (4) ŵ = 2.70 mm1
b = 8.6013 (4) ÅT = 290 K
c = 14.7465 (7) Å0.08 × 0.04 × 0.04 mm
β = 125.204 (3)°
Data collection top
Rigaku R-AXIS RAPID
diffractometer
2031 independent reflections
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
1772 reflections with I > 2σ(I)
Tmin = 0.741, Tmax = 1.000Rint = 0.031
8328 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.024Δρmax = 0.58 e Å3
wR(F2) = 0.062Δρmin = 0.49 e Å3
S = 1.08Absolute structure: ?
2031 reflectionsFlack parameter: ?
181 parametersRogers parameter: ?
0 restraints
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Li10.1133 (8)0.5883 (7)0.1934 (4)0.0266 (12)
Li20.1891 (9)0.1919 (7)0.2599 (5)0.0356 (15)
Li30.4730 (7)0.2213 (6)0.1767 (4)0.0186 (10)
V10.13814 (6)0.52846 (5)0.38977 (4)0.00672 (11)
V20.36217 (6)0.53898 (5)0.11037 (3)0.00643 (11)
P10.04417 (9)0.25109 (7)0.00782 (5)0.00655 (14)
P20.45782 (9)0.39759 (8)0.35181 (5)0.00672 (14)
P30.75192 (9)0.38467 (7)0.14738 (5)0.00638 (14)
O10.0267 (3)0.1788 (2)0.09643 (16)0.0126 (4)
O20.0361 (3)0.3649 (2)0.42742 (16)0.0150 (4)
O30.0850 (2)0.0021 (2)0.28038 (15)0.0102 (4)
O40.1152 (3)0.6330 (2)0.06577 (16)0.0111 (4)
O50.1785 (3)0.7151 (2)0.31962 (15)0.0109 (4)
O60.2392 (2)0.3319 (2)0.07040 (16)0.0112 (4)
O70.2789 (3)0.3861 (2)0.35185 (16)0.0125 (4)
O80.3675 (3)0.5514 (2)0.54043 (16)0.0171 (4)
O90.4764 (3)0.2357 (2)0.31413 (15)0.0099 (4)
O100.5906 (3)0.0200 (2)0.23807 (15)0.0116 (4)
O110.5994 (3)0.4098 (2)0.16881 (15)0.0110 (4)
O120.6748 (3)0.4125 (2)0.02723 (15)0.0128 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Li10.030 (3)0.038 (3)0.017 (3)0.008 (3)0.017 (2)0.005 (2)
Li20.042 (3)0.030 (3)0.022 (3)0.020 (3)0.010 (3)0.001 (2)
Li30.018 (2)0.016 (2)0.021 (3)0.003 (2)0.011 (2)0.004 (2)
V10.0067 (2)0.0061 (2)0.0080 (2)0.00005 (16)0.00464 (17)0.00055 (15)
V20.0069 (2)0.0060 (2)0.0073 (2)0.00006 (15)0.00458 (17)0.00017 (15)
P10.0062 (3)0.0055 (3)0.0086 (3)0.0001 (2)0.0046 (2)0.0000 (2)
P20.0066 (3)0.0062 (3)0.0073 (3)0.0005 (2)0.0040 (2)0.0001 (2)
P30.0063 (3)0.0058 (3)0.0078 (3)0.0002 (2)0.0046 (2)0.0005 (2)
O10.0118 (9)0.0150 (9)0.0122 (9)0.0020 (7)0.0076 (8)0.0018 (8)
O20.0147 (9)0.0146 (10)0.0143 (10)0.0023 (8)0.0076 (8)0.0053 (8)
O30.0106 (8)0.0081 (8)0.0093 (9)0.0027 (7)0.0042 (7)0.0009 (7)
O40.0104 (8)0.0107 (9)0.0133 (9)0.0034 (7)0.0074 (8)0.0015 (7)
O50.0163 (9)0.0075 (9)0.0119 (9)0.0022 (7)0.0099 (8)0.0003 (7)
O60.0081 (8)0.0088 (9)0.0140 (10)0.0015 (7)0.0048 (8)0.0002 (7)
O70.0128 (9)0.0105 (9)0.0191 (10)0.0010 (7)0.0120 (8)0.0031 (8)
O80.0094 (9)0.0205 (10)0.0131 (10)0.0009 (8)0.0016 (8)0.0051 (8)
O90.0133 (9)0.0062 (8)0.0106 (9)0.0022 (7)0.0071 (7)0.0002 (7)
O100.0173 (9)0.0088 (9)0.0110 (9)0.0016 (7)0.0096 (8)0.0016 (7)
O110.0109 (8)0.0124 (9)0.0119 (9)0.0027 (7)0.0078 (8)0.0020 (7)
O120.0136 (9)0.0155 (9)0.0100 (9)0.0013 (8)0.0072 (8)0.0014 (7)
Geometric parameters (Å, º) top
Li1—O41.930 (6)V2—O12iv1.9099 (19)
Li1—O51.940 (6)V2—O61.9810 (18)
Li1—O3i2.094 (6)V2—O42.0012 (18)
Li1—O10ii2.215 (6)V2—O112.0316 (18)
Li1—O72.584 (6)V2—O10ii2.0343 (19)
Li2—O31.968 (6)V2—O9ii2.0618 (18)
Li2—O11.974 (6)V2—Li3ii3.032 (5)
Li2—O72.004 (6)P1—O2v1.5199 (19)
Li2—O92.153 (7)P1—O4vi1.5297 (19)
Li2—O5iii2.678 (7)P1—O11.5310 (19)
Li3—O61.944 (5)P1—O61.5400 (18)
Li3—O101.946 (5)P2—O8vii1.492 (2)
Li3—O111.994 (5)P2—O91.5419 (19)
Li3—O92.014 (6)P2—O71.5458 (18)
V1—O21.9040 (19)P2—O10ii1.5497 (19)
V1—O81.954 (2)P3—O121.5101 (19)
V1—O1i2.0163 (19)P3—O111.5343 (19)
V1—O72.0168 (18)P3—O5viii1.5454 (19)
V1—O52.0450 (18)P3—O3ii1.5506 (18)
V1—O3i2.1172 (18)
O4—Li1—O5131.6 (3)O2v—P1—O1114.61 (12)
O4—Li1—O3i135.8 (3)O4vi—P1—O1112.35 (11)
O5—Li1—O3i80.6 (2)O2v—P1—O6107.88 (11)
O4—Li1—O10ii80.9 (2)O4vi—P1—O6110.77 (10)
O5—Li1—O10ii95.2 (2)O1—P1—O6106.40 (11)
O3i—Li1—O10ii132.1 (3)O8vii—P2—O9113.49 (11)
O4—Li1—O7134.8 (3)O8vii—P2—O7114.38 (12)
O5—Li1—O778.88 (19)O9—P2—O7104.68 (10)
O3i—Li1—O771.26 (18)O8vii—P2—O10ii108.68 (12)
O10ii—Li1—O761.21 (16)O9—P2—O10ii109.75 (10)
O3—Li2—O194.3 (3)O7—P2—O10ii105.50 (11)
O3—Li2—O7128.3 (4)O12—P3—O11111.68 (11)
O1—Li2—O7126.8 (3)O12—P3—O5viii110.34 (11)
O3—Li2—O9128.1 (3)O11—P3—O5viii106.92 (10)
O1—Li2—O9108.5 (3)O12—P3—O3ii108.32 (11)
O7—Li2—O971.9 (2)O11—P3—O3ii108.17 (11)
O3—Li2—P2146.7 (3)O5viii—P3—O3ii111.42 (10)
O1—Li2—P2117.9 (3)P1—O1—Li2132.1 (2)
O7—Li2—P236.57 (11)P1—O1—V1iii140.21 (12)
O9—Li2—P236.48 (10)Li2—O1—V1iii87.60 (18)
O3—Li2—O5iii66.43 (19)P1ix—O2—V1153.03 (13)
O1—Li2—O5iii69.03 (19)P3viii—O3—Li2109.4 (2)
O7—Li2—O5iii97.6 (3)P3viii—O3—Li1iii128.10 (19)
O9—Li2—O5iii165.3 (3)Li2—O3—Li1iii103.1 (3)
P2—Li2—O5iii130.8 (3)P3viii—O3—V1iii136.75 (11)
O6—Li3—O10146.1 (3)Li2—O3—V1iii84.99 (19)
O6—Li3—O1184.4 (2)Li1iii—O3—V1iii84.27 (16)
O10—Li3—O11126.5 (3)P1vi—O4—Li1108.2 (2)
O6—Li3—O9100.9 (2)P1vi—O4—V2147.84 (12)
O10—Li3—O983.4 (2)Li1—O4—V2101.8 (2)
O11—Li3—O9108.5 (3)P3ii—O5—Li1132.7 (2)
O2—V1—O894.48 (9)P3ii—O5—V1136.88 (11)
O2—V1—O1i88.48 (8)Li1—O5—V190.28 (19)
O8—V1—O1i97.50 (8)P3ii—O5—Li2i110.77 (16)
O2—V1—O794.88 (8)Li1—O5—Li2i85.6 (2)
O8—V1—O790.02 (8)V1—O5—Li2i70.11 (15)
O1i—V1—O7171.50 (8)P1—O6—Li3121.90 (18)
O2—V1—O5165.80 (8)P1—O6—V2142.76 (11)
O8—V1—O598.04 (8)Li3—O6—V294.12 (17)
O1i—V1—O583.28 (8)P2—O7—Li292.9 (2)
O7—V1—O591.80 (8)P2—O7—V1136.13 (12)
O2—V1—O3i90.55 (8)Li2—O7—V1129.4 (2)
O8—V1—O3i172.14 (8)P2—O7—Li189.28 (15)
O1i—V1—O3i88.65 (8)Li2—O7—Li198.8 (2)
O7—V1—O3i83.53 (8)V1—O7—Li174.63 (14)
O5—V1—O3i77.75 (7)P2vii—O8—V1168.23 (14)
O12iv—V2—O698.48 (8)P2—O9—Li3118.30 (18)
O12iv—V2—O493.92 (8)P2—O9—V2viii136.43 (11)
O6—V2—O488.86 (8)Li3—O9—V2viii96.15 (16)
O12iv—V2—O1194.63 (8)P2—O9—Li287.4 (2)
O6—V2—O1182.50 (8)Li3—O9—Li2105.6 (2)
O4—V2—O11168.64 (8)V2viii—O9—Li2109.31 (19)
O12iv—V2—O10ii171.87 (8)P2viii—O10—Li3113.29 (19)
O6—V2—O10ii89.34 (8)P2viii—O10—V2viii141.17 (12)
O4—V2—O10ii83.96 (8)Li3—O10—V2viii99.23 (17)
O11—V2—O10ii88.56 (8)P2viii—O10—Li1viii103.99 (17)
O12iv—V2—O9ii92.40 (8)Li3—O10—Li1viii97.5 (2)
O6—V2—O9ii167.76 (8)V2viii—O10—Li1viii91.67 (15)
O4—V2—O9ii96.01 (8)P3—O11—Li3117.36 (18)
O11—V2—O9ii91.09 (7)P3—O11—V2139.65 (12)
O10ii—V2—O9ii80.05 (7)Li3—O11—V291.10 (16)
O2v—P1—O4vi104.81 (11)P3—O12—V2iv166.44 (13)
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x+1, y+1/2, z+1/2; (iii) x, y1/2, z+1/2; (iv) x+1, y+1, z; (v) x, y+1/2, z1/2; (vi) x, y+1, z; (vii) x+1, y+1, z+1; (viii) x+1, y1/2, z+1/2; (ix) x, y+1/2, z+1/2.
Selected bond lengths (Å) top
Li1—O41.930 (6)V2—O12iii1.9099 (19)
Li1—O51.940 (6)V2—O61.9810 (18)
Li1—O3i2.094 (6)V2—O42.0012 (18)
Li1—O10ii2.215 (6)V2—O112.0316 (18)
Li2—O31.968 (6)V2—O10ii2.0343 (19)
Li2—O11.974 (6)V2—O9ii2.0618 (18)
Li2—O72.004 (6)P1—O2iv1.5199 (19)
Li2—O92.153 (7)P1—O4v1.5297 (19)
Li3—O61.944 (5)P1—O11.5310 (19)
Li3—O101.946 (5)P1—O61.5400 (18)
Li3—O111.994 (5)P2—O8vi1.492 (2)
Li3—O92.014 (6)P2—O91.5419 (19)
V1—O21.9040 (19)P2—O71.5458 (18)
V1—O81.954 (2)P2—O10ii1.5497 (19)
V1—O1i2.0163 (19)P3—O121.5101 (19)
V1—O72.0168 (18)P3—O111.5343 (19)
V1—O52.0450 (18)P3—O5vii1.5454 (19)
V1—O3i2.1172 (18)P3—O3ii1.5506 (18)
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x+1, y+1/2, z+1/2; (iii) x+1, y+1, z; (iv) x, y+1/2, z1/2; (v) x, y+1, z; (vi) x+1, y+1, z+1; (vii) x+1, y1/2, z+1/2.
Acknowledgements top

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (grant No. 2011–0011309).

references
References top

Adams, St. (2001). Acta Cryst. B57, 278–287.

Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.

Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.

Fu, P., Zhao, Y., Dong, Y. & Hou, X. (2010). J. Phys. Chem. Solids, 71, 394–399.

Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.

ICSD (2012). Inorganic Crystal Structure Database. FIZ-Karlsruhe, Germany. http://www.fiz-karlsruhe.de/fiz/products/icsd/welcome.html

Kuo, H. T., Bagkar, N. C., Liu, R.-S., Shen, C. H., Shy, D. S., Xing, X. K., Lee, J.-F. & Chen, J.-M. (2008). J. Phys. Chem. B, 112, 11250–11257.

Patoux, S., Wurm, C., Morcrette, M., Rousse, G. & Masquelier, C. (2003). J. Power Sources, 119, 278–284.

Rigaku (2006). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan.

Shannon, R. D. (1976). Acta Cryst. A32, 751–767.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Yang, G., Ji, H. M., Liu, H., Qian, B. & Jiang, X. (2010). Electrochim. Acta, 55, 3669–3680.

Yin, S. C., Grondey, H., Strobel, P., Anne, M. & Nazar, L. F. (2003). J. Am. Chem. Soc. 125, 10402–10411.