Solid ion conductor compound, electrochemical cell comprising the same, and preparation method thereof
A solid ion conductor compound represented by Formula 1, an electrochemical cell including the same, and a method of preparing the solid ion conductor compound. The solid ion conductor is a compound of Formula 1 Li a M b Zr c X d T e Formula 1 wherein in Formula 1, 1<a<3.5, 0<b<1.5, 0<c<1.5, 0<d<7, 0≤e<1, 0<b/d<0.03, and 0.05<c/d<0.18, M is at least one monovalent metal element other than lithium, and T is a metal element different from M, a transition metal element, a post-transition metal element, a metalloid element, or a combination thereof, wherein an ionic radius of M satisfies 90 pm<M r ≤180 pm, wherein M r is an ionic radius of M, and X is at least one halogen.
1 . A solid ion conductor compound represented by Formula 1:
Li a M b Zr c X d T e Formula 1
wherein in Formula 1, 1<a<3.5, 0<b<1.5, 0<c<1.5, 0<d<7, 0≤e<1, 0<b/d<0.03, and 0.05<c/d<0.18,
M is at least one monovalent metal element other than lithium, and
T is a metal element different from M, a transition metal element, a post-transition metal element, a metalloid element, or a combination thereof,
wherein an ionic radius of M satisfies 90 pm<M r ≤180 μm, wherein M r is an ionic radius of M, and X is at least one halogen.
2 . The solid ion conductor compound of claim 1 , wherein M comprises Na, K, Rb, Mo(I), Cu(I), Hg, Ag, Au, Tl, or a combination thereof.
3 . The solid ion conductor compound of claim 1 , wherein T is B, Be, Mg, Ca, Sr, Se, Y, Ti, Hf, V, Nb, Ta, Cr, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Zn, Cd, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Po, or a combination thereof.
4 . The solid ion conductor compound of claim 1 , wherein X comprises Cl, Br, or a combination thereof.
5 . The solid ion conductor compound of claim 1 , wherein M r satisfies 90 pm<M r ≤160 pm.
6 . The solid ion conductor compound of claim 1 , wherein a satisfies 1.5≤a≤2.5, b satisfies 0<b<0.5, c satisfies 0.1≤c<1.5, and d satisfies 5<d<7.
7 . The solid ion conductor compound of claim 1 , wherein e satisfies 0<e<1.
8 . The solid ion conductor compound of claim 1 , wherein 0.01≤b/d≤0.02.
9 . The solid ion conductor compound of claim 1 , wherein 0.06≤c/d≤0.17.
10 . The solid ion conductor compound of claim 1 , wherein 1<a/c<5.
11 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound has at least one diffraction peak at diffraction angles of about 15°2θ to about 17°2θ, about 30° 2θ to about 32°2θ, and about 40° 2θ to about 42°2θ, when analyzed by X-ray diffraction using CuKα radiation.
12 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound has a diffraction peak at diffraction angles of 16.0°2θ+2.0°2θ, 30.4°2θ+2.0°2θ, 31.8°2θ+2.0°2θ, 34.1°2θ+2.0°2θ, 41.3°2θ+2.0° 2θ, and 49.4°2θ +2.0° 2 θ when analyzed by X-ray diffraction using CuKα radiation.
13 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound comprises a crystalline phase, or a combination of crystalline phase and amorphous phase.
14 . The solid ion conductor compound of claim 13 , wherein the crystalline phase comprises a layered rock-salt crystal structure.
15 . The solid ion conductor compound of claim 13 , wherein the crystalline phase comprises a crystal of a C2/m space group, a crystal of a P3m1 space group, or a combination thereof.
16 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound has an a-axis lattice constant and a c-axis lattice constant that are each greater than an a-axis lattice constant and a c-axis lattice constants when the at least one monovalent metal element M is not present.
17 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound has an ionic conductivity of 2.4×10 −4 S/cm or more at 25° C.
18 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound is Li 1.96 Na 0.03 ZrCl 6 , Li 1.96 Na 0.04 ZrCl 6 , Li 1.9 Na 0.1 ZrCl 6 , Li 2 Na 0.04 Zr 0.99 Cl 6 , Li 2 Na 0.1 Zr 0.98 Cl 6 , Li 1.96 Cu 0.04 ZrCl 6 , Li 2 Cu 0.04 Zr 0.99 Cl 6 , Li 1.96 Ag 0.04 ZrCl 6 , Li 1.96 K 0.04 ZrCl 6 , Li 1.96 Na 0.04 Y 0.5 Zr 0.5 Cl 6 , Li 1.9 K 0.1 ZrCl 6 , Li 1.85 K 0.15 ZrCl 6 , Li 2.36 Na 0.04 Zr 0.9 Cl 6 , or Li 2.45 Na 0.05 Zr 0.5 Cl 6 Y 0.5 .
19 . A method of preparing a solid ion conductor compound, the method comprising:
providing a mixture of a zirconium precursor compound, a lithium precursor compound, and a metal element M precursor compound, wherein the metal element M is at least one monovalent metal element other than lithium, and an ionic radius of the metal element M satisfies 90 pm<M r ≤180 μm, wherein M r is an ionic radius of M; and
treating the mixture to form the solid ion conductor compound.
20 . The method of claim 19 , wherein the treating comprises ball-milling the mixture in a dry and inert atmosphere.