# Fileset
[LLNOF_es1_rev_v3.pdf](https://mdr.nims.go.jp/filesets/bbc6bf53-d603-400d-bb55-98bd23958a36/download)
## Creator
[Randy Jalem](https://orcid.org/0000-0001-9505-771X), [Kazunori Takada](https://orcid.org/0000-0001-7568-1806), Hitoshi Onodera, Shuhei Yoshida
## Rights
[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)
## Other metadata
[Crystal structure, stability and Li superionic conductivity of pyrochlore-type solid electrolyte Li2βxLa(1+x)/3Nb2O6F: a first-principles calculation study](https://mdr.nims.go.jp/datasets/6f5ab240-632e-4766-944b-00a0c151614c)
## Fulltext
Supporting Information Crystal Structure, Stability and Li Superionic Conductivity of Pyrochlore-Type Solid Electrolyte Li2-xLa(1+x)/3Nb2O6F: A First-Principles Calculation Study Randy Jalem,1,* Kazunori Takada,1 Hitoshi Onodera2, and Shuhei Yoshida2 1Center for Green Research on Energy and Environmental Materials (GREEN), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan 2Environment Neutral System Development Division, DENSO CORPORATION, 1 Yoshiike, Kusagi, Agui-cho, Chita-gun, Aichi 470-2298, Japan Email: JALEM.Randy@nims.go.jp Material synthesis The Li1.25La0.58Nb2O6F (LLNOF) solid electrolyte was prepared using the following synthesis conditions. Li2CO3, La2O3 and Nb2O5 reactant powders in stoichiometric ratio were calcined at 773 K and then heated at 1473 K for 6 hours to synthesize the precursor Li0.5La0.5Nb2O6. Next, the synthesized Li0.5La0.5Nb2O6 was mixed with LaF3 and LiF. Here, 91%-excess LiF was added. The mixture was then heated at 1273 K for 6 hours to synthesize the target LLNOF powder. Cyclic voltammetry measurement The LLNOF electrolyte, acetylene black (AB) (conductive additive), and polyvinylidene fluoride (PVDF) (binder) were weighed in a mass ratio of 70:10:20 and then mixed with N-methyl-2-pyrrolidone (NMP) to form a paste. The paste was applied onto a copper foil and dried to make an electrode. The cyclic voltammetry evaluation was conducted using a 2032-type coin cell assembled with a Li anode. The electrolyte used was a solution of 1M LiPFβ dissolved in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DEC) in a volume ratio of 1:1. The coin cells were assembled in an Ar atmosphere inside a glove box. Cyclic voltammetry measurements were performed using a potentiostat/galvanostat device, with a scan voltage range of 0.02 V to 3V and a scan rate of 10 mV/s at 25Β°C. Figure S1. Visualization of the local structure of pyrochlore-type Li2-xLa(1+x)/3Nb2O6F (LLNOF) showing the F-Li/La-F linkage in a zigzag pattern along the characteristic hexagonal tunnel. The octahedral NbO6 units are not displayed for clarity. Figure S2. Cyclic voltammetry curves for the 1st, 2nd, and 3rd cycle of cell with LLNOF solid electrolyte. Figure S3. Mean squared displacement ( πππ· ) plots for the Li atoms of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1) from by NVT-AIMD calculations. Figure S4. Supercell operation of the 16d-site cation sublattice in the Li2-xLa(1+x)/3Nb2O6F crystal structure for use in the calculation of Li+ percolation threshold. Figure S5. Li-Li radial distribution function (RDF) profiles derived from 1000-K NVT AIMD calculations for (a) pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1) and (b) garnet-type cubic Li7La3Zr2O12. Figure S6. Plot for DFT decomposition energy as a function of the number of LiF Schottky defect units. The initial reference structure was based on Li1.3125La0.5625Nb2O6F composition (L1 structure, supercell formula is Li21La9Nb32O96F16 which is for x = 0). Figure S7. DFT-GGA electronic density of states (DOS) of pyrochlore-type Li1.3125La0.5625Nb2O6F (LLNOF-L1 structure). The Fermi energy is referenced as zero in the horizontal axis. Table S1. Crystal structure coordinate data of LLNOF by XRD Rietveld analysis, as reported in Ref. 12. Space group: Fd3Μ
m (cubic), lattice parameter a: 1.0445(1) nm, cell volume: 1.1396(1) nm3. Atom Site Occupancy (g) Coordinates x y z La 16d 0.2771(6) 1/2 1/2 1.2 Li 16d 0.365(15) x(La) y(La) z(La) Nb 16c 1.0 0 0 0 O 48f 1.0 0.3151(2) 1/8 1/8 F 8b 0.989(8) 3/8 3/8 3/8 Table S2. Summary of DFT-predicted decomposition reactions related to the voltage stability window of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.54 Li21La9Nb32(O6F)16 + 160 Li ο 4.5 La2O3 + 16 LiF + 82.5 Li2O + 32 Nb 0.54 β 0.62 Li21La9Nb32(O6F)16 + 64 Li ο 4.5 La2O3 + 32 LiNbO2 + 16 LiF + 18.5 Li2O 0.62 β 0.96 Li21La9Nb32(O6F)16 + 49.2 Li ο 3.7 Li8Nb2O9 + 4.5 La2O3 + 24.6 LiNbO2 + 16 LiF 0.96 β 0.99 Li21La9Nb32(O6F)16 + 45.5 Li ο 4.5 La2O3 + 22.75 LiNbO2 + 9.25 Li3NbO4 + 16 LiF 0.99 β 1.33 Li21La9Nb32(O6F)16 + 41 Li ο 20.5 LiNbO2 + 11.5 Li3NbO4 + 7 LiF + 9 LaOF 1.33 β 1.74 Li21La9Nb32(O6F)16 + 32 Li ο 16 LiNbO2 + 9 LaNbO4 + 7 Li3NbO4 + 16 LiF 1.74 β 1.92 Li21La9Nb32(O6F)16 + 18 Li ο 14 LiNbO3 + 9 LiNbO2 + 9 LaNbO4 + 16 LiF 1.92 β 2.35 Li21La9Nb32(O6F)16 + 2.571 Li ο 7.571 LiNbO3 + 1.286 Nb12O29 + 9 LaNbO4 + 16 LiF 2.35 β 2.49 Li21La9Nb32(O6F)16 + 0.8889 Li ο 5.889 LiNb3O8 + 0.4444 Nb12O29 + 9 LaNbO4 + 16 LiF 2.49 β 3.92 Li21La9Nb32(O6F)16 ο 5 LiNb3O8 + 9 LaNbO4 + 4 Nb2O5 + 16 LiF 3.92 β 3.93 Li21La9Nb32(O6F)16 ο 9 LaNbO4 + 11.5 Nb2O5 + 16 LiF + 1.25 O2 + 5 Li 3.93 β Li21La9Nb32(O6F)16 ο 3.667 LaNbO4 + 14.17 Nb2O5 + 5.333 LaF3 + 5.25 O2 + 21 Li Table S3. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Li3Nb3O8 which is one of the decomposition phases of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.54 4 LiNb3O8 + 60 Li ο 32 Li2O + 12 Nb 0.54 β 0.62 4 LiNb3O8 + 24 Li ο 12 LiNbO2 + 8 Li2O 0.62 β 0.96 4 LiNb3O8 + 17.6 Li ο 1.6 Li8Nb2O9 + 8.8 LiNbO2 0.96 β 1.74 4 LiNb3O8 + 16 Li ο 4 Li3NbO4 + 8 LiNbO2 1.74 β 1.92 4 LiNb3O8 + 8 Li ο 8 LiNbO3 + 4 LiNbO2 1.92 β 2.35 4 LiNb3O8 + 1.143 Li ο 5.143 LiNbO3 + 0.5714 Nb12O29 2.35 β 3.92 4 LiNb3O8 ο 4 LiNb3O8 3.92 β 4 LiNb3O8 ο 6 Nb2O5 + O2 + 4 Li Table S4. Summary of DFT-predicted decomposition reactions related to the voltage stability window of LiF which is one of the decomposition phases of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 6.36 LiF ο LiF 6.36 β LiF ο 0.5 F2 + Li Table S5. Summary of DFT-predicted decomposition reactions related to the voltage stability window of LaNbO4 which is one of the decomposition phases of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.54 2 LaNbO4 + 10 Li ο 5 Li2O + La2O3 + 2 Nb 0.54 β 0.62 2 LaNbO4 + 4 Li ο 2 LiNbO2 + Li2O + La2O3 0.62 β 0.96 2 LaNbO4 + 3.2 Li ο 1.6 LiNbO2 + 0.2 Li8Nb2O9 + La2O3 0.96 β 1.06 2 LaNbO4 + 3 Li ο 0.5 Li3NbO4 + 1.5 LiNbO2 + La2O3 1.06 β 1.30 2 LaNbO4 + 2 Li ο 0.3333 Li3NbO4 + 0.6667 La3NbO7 + LiNbO2 1.30 β 2 LaNbO4 ο 2 LaNbO4 Table S6. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Nb2O5 which is one of the decomposition phases of pyrochlore-type Li1.3125La0.5625Nb2O6F with the L1 structure (LLNOF-L1). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.54 14 Nb2O5 + 140 Li ο 70 Li2O + 28 Nb 0.54 β 0.62 14 Nb2O5 + 56 Li ο 28 LiNbO2 + 14 Li2O 0.62 β 0.96 14 Nb2O5 + 44.8 Li ο 2.8 Li8Nb2O9 + 22.4 LiNbO2 0.96 β 1.74 14 Nb2O5 + 42 Li ο 7 Li3NbO4 + 21 LiNbO2 1.74 β 1.92 14 Nb2O5 + 28 Li ο 14 LiNbO3 + 14 LiNbO2 1.92 β 2.35 14 Nb2O5 + 4 Li ο 4 LiNbO3 + 2 Nb12O29 2.35 β 2.49 14 Nb2O5 + 3.111 Li ο 3.111 LiNb3O8 + 1.556 Nb12O29 2.49 β 14 Nb2O5 ο 14 Nb2O5 Table S7. Summary of DFT-predicted decomposition reactions related to the voltage stability window of garnet-type cubic Li7La3Zr2O12. Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.04 4 Li7La3Zr2O12 + 28 Li ο 2 Zr4O + 28 Li2O + 6 La2O3 0.04 β 0.05 4 Li7La3Zr2O12 + 26.67 Li ο 2.667 Zr3O + 27.33 Li2O + 6 La2O3 0.05 β 2.90 4 Li7La3Zr2O12 ο 4 Li6Zr2O7 + 2 Li2O + 6 La2O3 2.90 β 3.16 4 Li7La3Zr2O12 ο 4 Li6Zr2O7 + Li2O2 + 6 La2O3 + 2 Li 3.16 β 3.24 4 Li7La3Zr2O12 ο 7 Li2O2 + 4 La2Zr2O7 + 2 La2O3 + 14 Li 3.24 β 3.72 4 Li7La3Zr2O12 ο 1.75 LiO8 + 4 La2Zr2O7 + 2 La2O3 + 26.25 Li 3.72 β 4 Li7La3Zr2O12 ο 4 La2Zr2O7 + 2 La2O3 + 7 O2 + 28 Li Table S8. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Li6Zr2O7 which is one of the decomposition phases of garnet-type Li7La3Zr2O12 (LLZO). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.04 2 Li6Zr2O7 + 14 Li ο Zr4O + 13 Li2O 0.04 β 0.05 2 Li6Zr2O7 + 13.33 Li ο 1.333 Zr3O + 12.67 Li2O 0.05 β 3.21 2 Li6Zr2O7 ο 2 Li6Zr2O7 3.21 β 3.24 2 Li6Zr2O7 ο 4 Li2ZrO3 + Li2O2 + 2 Li 3.24 β 3.39 2 Li6Zr2O7 ο 4 Li2ZrO3 + 0.25 LiO8 + 3.75 Li 3.39 β 3.72 2 Li6Zr2O7 ο 0.75 LiO8 + 4 ZrO2 + 11.25 Li 3.72 β 2 Li6Zr2O7 ο 4 ZrO2 + 3 O2 + 12 Li Table S9. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Li2O which is one of the reductive decomposition phases of garnet-type Li7La3Zr2O12 (LLZO). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 2.90 Li2O ο Li2O 2.90 β 3.24 Li2O ο 0.5 Li2O2 + Li 3.24 β 3.72 Li2O ο 0.125 LiO8 + 1.875 Li 3.72 β Li2O ο 0.5 O2 + 2 Li Table S10. Summary of DFT-predicted decomposition reactions related to the voltage stability window of La2O3 which is one of the reductive decomposition phases of garnet-type Li7La3Zr2O12 (LLZO). Voltage / V vs. Li/Li+ Decomposition reaction 0 β La2O3 ο La2O3 Table S11. Summary of DFT-predicted decomposition reactions related to the voltage stability window of garnet-type Li5La3Ta2O12 (LLTO). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.35 4 Li5La3Ta2O12 + 40 Li ο 30 Li2O + 6 La2O3 + 8 Ta 0.35 β 0.55 4 Li5La3Ta2O12 + 10 Li ο 6 Li5TaO5 + 6 La2O3 + 2 Ta 0.55 β 0.65 4 Li5La3Ta2O12 + 2.5 Li ο 7.5 Li3TaO4 + 6 La2O3 + 0.5 Ta 0.65 β 3.23 4 Li5La3Ta2O12 ο 6.667 Li3TaO4 + 1.333 La3TaO7 + 4 La2O3 3.23 β 3.24 4 Li5La3Ta2O12 ο 4 La3TaO7 + 2 Li2O2 + 4 Li3TaO4 + 4 Li 3.24 β 3.47 4 Li5La3Ta2O12 ο 0.5 LiO8 + 4 La3TaO7 + 4 Li3TaO4 + 7.5 Li 3.47 β 3.72 4 Li5La3Ta2O12 ο 1.25 LiO8 + 2 La3TaO7 + 6 LaTaO4 + 18.75 Li 3.72 β 4 Li5La3Ta2O12 ο 2 La3TaO7 + 6 LaTaO4 + 5 O2 + 20 Li Table S12. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Li3TaO4 which is one of the reductive decomposition phases of garnet-type Li5La3Ta2O12 (LLTO). Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.35 Li3TaO4 + 5 Li ο 4 Li2O + Ta 0.35 β 0.55 Li3TaO4 + Li ο 0.8 Li5TaO5 + 0.2 Ta 0.55 β 3.59 Li3TaO4 ο Li3TaO4 3.59 β 3.72 Li3TaO4 ο LiTaO3 + 0.125 LiO8 + 1.875 Li 3.72 β 3.94 Li3TaO4 ο LiTaO3 + 0.5 O2 + 2 Li 3.94 β 4.03 Li3TaO4 ο 0.3333 LiTa3O8 + 0.6667 O2 + 2.667 Li 4.03 β Li3TaO4 ο 0.5 Ta2O5 + 0.75 O2 + 3 Li Table S13. Summary of DFT-predicted decomposition reactions related to the voltage stability window of Li5TaO5 which is one of the reductive decomposition phases of Li3TaO4. Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.35 Li5TaO5 + 5 Li ο 5 Li2O + Ta 0.35 β 3.10 Li5TaO5 ο Li5TaO5 3.10 β 3.24 Li5TaO5 ο 0.5 Li2O2 + Li3TaO4 + Li 3.24 β 3.59 Li5TaO5 ο Li3TaO4 + 0.125 LiO8 + 1.875 Li 3.59 β 3.72 Li5TaO5 ο LiTaO3 + 0.25 LiO8 + 3.75 Li 3.72 β 3.94 Li5TaO5 ο LiTaO3 + O2 + 4 Li 3.94 β 4.03 Li5TaO5 ο 0.3333 LiTa3O8 + 1.167 O2 + 4.667 Li 4.03 β Li5TaO5 ο 0.5 Ta2O5 + 1.25 O2 + 5 Li Table S14. Summary of DFT-predicted decomposition reactions related to the voltage stability window of La3TaO7 which is one of the reductive decomposition phases of Li3TaO4. Voltage / V vs. Li/Li+ Decomposition reaction 0 β 0.35 La3TaO7 + 5 Li ο 2.5 Li2O + 1.5 La2O3 + Ta 0.35 β 0.55 La3TaO7 + 2.5 Li ο 0.5 Li5TaO5 + 1.5 La2O3 + 0.5 Ta 0.55 β 0.65 La3TaO7 + 1.875 Li ο 0.625 Li3TaO4 + 1.5 La2O3 + 0.375 Ta 0.65 β La3TaO7 ο La3TaO7