Solid ion conductor compound, solid electrolyte comprising same, electrochemical cell comprising same, and manufacturing method thereof
The present invention relates to a solid ion conductor compound represented by Li a M x T y P b S c Cl d X e and having an argyrodite crystal structure, a solid electrolyte including the same, and an electrochemical cell including the same.
1 . A solid ion conductor compound represented by Formula 1 and having an argyrodite crystal structure:
Li a M x T y P b S c Cl d X e Formula 1
wherein, in Formula 1,
Mis Na, K, Rb, Cs, Fr, or a combination thereof,
Ti s Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, or a combination thereof,
X is Br, I, or a combination thereof, and
4<a<7, 0<x<1, 0<y<1, 0<b≤1, 4<c≤5, 1≤d+e<2, and 1≤d/e.
2 . The solid ion conductor compound of claim 1 , wherein 0<x≤0.5.
3 . The solid ion conductor compound of claim 1 , wherein 0<y<0.5.
4 . The solid ion conductor compound of claim 1 , wherein 1.3≤d+e<2.
5 . The solid ion conductor compound of claim 1 , wherein 1≤d/e<18.
6 . The solid ion conductor compound of claim 1 , wherein I B /I A is <0.15 where I B /I A is a ratio (I B /I A ) of peak intensity (I B ) at diffraction angle (2θ)=29.07°±0.5° to a peak intensity (I A ) at 2θ=30.09°+0.5° in the solid ion conductor compound in an X-ray diffraction (XRD) spectrum using CuKα rays.
7 . The solid ion conductor compound of claim 5 , wherein I B /I A satisfies the condition of I B /I A ≤0.1.
8 . The solid ion conductor compound of claim 1 , wherein Formula 1 is represented by Formula 2:
(Li 1-x1 M1 x1 ) 7+α-β (P 1-y1 T1 y1 ) α S 6-β (Cl 1-e1 X1 e1 ) β Formula 2
wherein, in Formula 2,
M1 is Na, K, Rb, Cs, Fr, or a combination thereof,
T1 is Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, or a combination thereof,
X1 is Br, I, or a combination thereof, and
0<x1<1, 0<y1<1, 0<e1≤0.5, 0<α≤1, and 0<β≤2.
9 . The solid ion conductor compound of claim 8 , wherein M1 is Na, K, or a combination thereof.
10 . The solid ion conductor compound of claim 8 , wherein T1 is Ge.
11 . The solid ion conductor compound of claim 8 , wherein X1 is Br.
12 . The solid ion conductor compound of claim 8 , wherein β satisfies 1≤β≤2.
13 . The solid ion conductor compound of claim 1 , wherein Formula 1 is represented by Formula 3:
Li 7−x2+y2−d2−e2 M2 x2 P 1−y2 T2 y2 S 6-d2-e2 Cl d2 X e2 Formula 3
wherein, in Formula 3,
M2 is Na, K, Rb, Cs, Fr, or a combination thereof,
T2 is Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, or a combination thereof,
X2 is Br, I, or a combination thereof, and
0<x2<1, 0<y2<1 1<d2+e2<2, and d2/e2≥1.
14 . The solid ion conductor compound of claim 13 , wherein 0<x2≤0.5, 0<y2<0.5 and 1.3≤d2+e2<2.
15 . The solid ion conductor compound of claim 13 , wherein 0.8≤d2<2 and 0<e2≤0.8.
16 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound is Li 5.57 Na 0.03 P 0.9 Ge 0.1 S 4.5 ClBr 0.5 , Li 5.57 Na 0.03 P 0.9 Ge 0.1 S 4.5 Cl 0.4 Br 0.7 , Li 5.57 Na 0.03 P 0.8 Ge 0.2 S 4.5 Cl 1.4 I 0.1 , or Li 5.57 Na 0.03 P 0.8 Si 0.2 S 4.4 Cl 1.4 Br 0.2 .
17 . The solid ion conductor compound of claim 1 , wherein the solid ion conductor compound has a pellet density/powder density ratio of 85% or more.
18 . A solid electrolyte comprising the solid ion conductor compound according to claim 1 .
19 . An electrochemical cell comprising:
a positive electrode layer comprising a positive electrode active material layer;
a negative electrode layer comprising a negative electrode active material layer;
an electrolyte layer disposed between the positive electrode layer and the negative electrode layer; and
the solid ion conductor compound according to claim 1 .
20 . The electrochemical cell of claim 19 , wherein the positive electrode active material layer comprises the solid ion conductor compound.
21 . The electrochemical cell of claim 20 , wherein the solid ion conductor compound has an average particle diameter (D 50 ) of 2 μm or less.
22 . The electrochemical cell of claim 19 , wherein the electrolyte layer comprises the solid ion conductor compound.
23 . The electrochemical cell of claim 22 , wherein the solid ion conductor compound has an average particle diameter D 50 of 5 μm or less.
24 . The electrochemical cell of claim 19 , wherein the positive electrode active material layer and the electrolyte layer comprise the solid ion conductor compound.
25 . The electrochemical cell of claim 19 , wherein the electrochemical cell is an all-solid secondary battery.
26 . The electrochemical cell of claim 19 , wherein
the negative electrode active material layer includes a negative electrode active material and a binder, and
the negative electrode active material layer includes a mixture of amorphous carbon with at least one selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).
27 . The electrochemical cell of claim 19 , wherein
the negative electrode layer includes a negative electrode current collector,
a metal layer is further disposed between the negative electrode current collector and the negative electrode active material layer, and
the metal layer includes lithium or lithium alloy.