Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
closo-Borates, such as Na2B12H12, are an emerging class of ionic conductors that show promising chemical, electrochemical and mechanical properties as electrolytes in all-solid-state batteries. Motivated by theoretical predictions, high-pressure in situ powder X-ray diffraction on Na2B12H12 was performed and two high-pressure phases are discovered. The first phase transition occurs at 0.5 GPa and it is persistent to ambient pressure, whereas the second transition takes place between 5.7 and 8.1 GPa and it is fully reversible. The mechanisms of the transitions by means of group theoretical analysis are unveiled. The primary-order parameters are identified and the stability at ambient pressure of the first polymorph is explained by density functional theory calculations. Finally, the parameters relevant to engineer and build an all-solid-state battery, namely, the bulk modulus and the coefficient of the thermal expansion are reported. The relatively low value of the bulk modulus for the first polymorph (14 GPa) indicates a soft material which allows accommodation of the volume change of the cathode during cycling.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S2052520619004670/ps5076sup1.cif
Contains datablocks publication_text, epsilon, zeta

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S2052520619004670/ps5076epsilonsup2.rtv
Contains datablock profile1

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S2052520619004670/ps5076zetasup3.rtv
Contains datablock profile1

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S2052520619004670/ps5076sup4.pdf
Supplementary material

CCDC references: 1870835; 1870894

Computing details top

sodium dodecahydro-closo-dodecaborate (epsilon) top
Crystal data top
B12H12Na2c = 9.227 (3) Å
Mr = 187.6V = 973.2 (5) Å3
Orthorhombic, PbcaZ = 4
a = 9.720 (2) ÅSynchrotron radiation, λ = 0.71414 Å
b = 10.851 (3) ÅT = 293 K
Data collection top
One-axis goniometer
diffractometer
Data collection mode: transmission
Radiation source: Synchrotron, BM01 SNBLScan method: Stationary detector
Specimen mounting: capillary
Refinement top
Rp = 0.005Profile function: TCHZ
Rwp = 0.00636 parameters
Rexp = 0.002(Δ/σ)max = 0.041
RBragg = 0.07Background function: Chebychev polynomial
3358 data points
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzBiso*/Beq
Na10.3797 (12)0.1453 (13)0.8969 (12)1
B10.330010.015750.542021
B20.461180.020730.678641
B30.553670.142940.449771
B40.386960.084370.400511
B50.424170.120540.585091
B60.401860.078050.378811
H10.210230.025270.572130
H20.435870.037050.804760
H30.592310.244160.416450
H40.306220.143010.331210
H50.371150.207760.642370
H60.335730.866010.291740
sodium dodecahydro-closo-dodecaborate (zeta) top
Crystal data top
B12H12Na2c = 7.0102 (17) Å
Mr = 187.6V = 382.97 (18) Å3
Orthorhombic, PnnmZ = 2
a = 6.301 (2) ÅSynchrotron radiation, λ = 0.71414 Å
b = 8.671 (2) ÅT = 293 K
Data collection top
One-axis goniometer
diffractometer
Data collection mode: transmission
Radiation source: Synchrotron, BM01 SNBLScan method: Stationary detector
Specimen mounting: capillary
Refinement top
Rp = 0.004Profile function: TCHZ
Rwp = 0.00534 parameters
Rexp = 0.002(Δ/σ)max = 0.196
RBragg = 0.03Background function: Chebychev polynomial
3358 data points
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzBiso*/Beq
Na10.243 (6)0.562 (7)02 (3)
B10.048930.905740.799031 (5)
B20.790390.8830201 (5)
B30.210590.942130.875991 (5)
B40.049970.8102601 (5)
H10.083470.842790.654381 (5)
H20.639030.8059401 (5)
H30.361610.904750.790651 (5)
H40.082260.6757901 (5)
 

Subscribe to Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. B
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds