Sulfide and oxy-sulfide glass and glass-ceramic solid state electrolytes for electrochemical cells
An electrolyte system for an electrochemical cell includes an aprotic solvent, such as an ether-based solvent and a lithium salt, and a solid component. The aprotic solvent has a dielectric constant of ≥3. The solid component is in direct communication with the aprotic solvent. The solid component includes a sulfide or oxy-sulfide, glass or glass-ceramic electrolyte. The sulfide or oxy-sulfide, glass or glass-ceramic electrolyte has a weighted average bond dissociation enthalpy of greater than or equal to about 380 kJ/mol, which corresponds to a glass having strong bonds. The sulfide or oxy-sulfide, glass or glass-ceramic electrolyte is therefore insoluble in the aprotic solvent. The solid component is lithium ion-conducting and electrically insulating. The electrolyte system may be disposed between a positive electrode and a negative electrode in an electrochemical cell. In various aspects, the negative electrode includes lithium metal and the positive electrode includes sulfur.
1. An electrolyte system for an electrochemical cell, the electrolyte system comprising:
an aprotic solvent with a dielectric constant of ≥3; and
a solid component in direct communication with the aprotic solvent and comprising a sulfide or oxy-sulfide, glass or glass-ceramic electrolyte having the empirical composition n M (M)-n F (F)-n C (C)-n D (D), where M is a glass modifier comprising a sulfide or a oxide, F is a glass former comprising a glass-forming sulfide or oxide, and C is a glass co-former or a glass co-modifier comprising sulfide or oxide different than the glass former and the glass modifier, D is a dopant, n M is a mole fraction of M, n F is a mole fraction of F, n C is a mole fraction of C, and n D is a mole fraction of D, wherein:
at least one of M, F, and C comprises a sulfide;
n M> 0, n F> 0, n C> 0, and n D> 0;
the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte has a weighted average bond dissociation enthalpy (BDE WA ) of ≥380 kJ/mol, where
BDE
WA
=
w
M
n
M
BDE
M
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
F
n
F
BDE
F
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
C
n
C
BDE
C
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
D
n
D
BDE
D
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
,
wherein BDE M is a bond dissociation enthalpy required to break a single bond of distinct constituents of M, BDE F is a bond dissociation enthalpy required to break a single bond of distinct constituents of F, BDE c is a bond dissociation enthalpy required to break a single bond of distinct constituents of C, BDE D is a bond dissociation enthalpy required to break a single bond of distinct constituents of D, w M is a quantity of sulfur or oxygen bonds that M contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, w F is a quantity of sulfur or oxygen bonds that F contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, we is a quantity of sulfur or oxygen bonds that C contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, w D is a quantity of sulfur, oxygen, iodine, or chlorine bonds that D contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte;
the solid component is lithium ion-conducting and electrically insulating; and
the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises: (Li 2 S) 50 (GeS 2 )45(GeO 2 )5, (Li 2 S)50SiS 2 )45(GeO 2 ) 5 , (Li 2 S) 57 (SiS 2 ) 35 (P 2 S 5 ) 8 , (Li 2 S) 60 (SiS 2 ) 28 (P 2 S 5 ) 12 , (Li 2 S) 53,6 (SiS 2 ) 32,9 (P 2 S 5 ) 7,5 (LiI) 6 , or combinations thereof.
2. The electrolyte system of claim 1 , wherein the aprotic solvent comprises an ether-based solvent selected from the group consisting of: 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-diethoxyethane, ethoxymethoxyethane, tetraethylene glycol dimethyl ether (TEGDME), polyethylene glycol dimethyl ether (PEGDME), and admixtures thereof, and wherein a lithium salt is dissolved in the ether-based solvent, the lithium salt being selected from the group consisting of: LiN(CF 3 SO 2 ) 2 , LiTFSI, LiNO 3 , LiPF 6 , LiBF 4 , LiI, LiBr, LiSCN, LiClO 4 , LiAlCl 4 , LiB(C 2 O4) 2 (LiBOB), LiB(C 6 H5) 4 , LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 O 4 ) (LiFOP), LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiCF 3 SO 3 , LiAsF 6 , and combinations thereof.
3. The electrolyte system of claim 1 , wherein the solid component further comprises a polymer and has one of: (a) a composite structure including the polymer and the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte, or (b) a laminate structure including one or more layers of the polymer and the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte.
4. An electrochemical cell comprising:
a positive electrode comprising a positive electroactive material;
a negative electrode comprising a negative electroactive material;
an electrolyte system disposed between the positive electrode and the negative electrode, the electrolyte system comprising:
an aprotic solvent with a dielectric constant of ≥3; and
a solid component in direct communication with the aprotic solvent and comprising a sulfide or oxy-sulfide, glass or glass-ceramic electrolyte having the empirical composition n M (M)-n F (F)-n C (C)-n D (D), where M is a glass modifier comprising a sulfide or a oxide, F is a glass former comprising a glass-forming sulfide or oxide, and C is a glass co-former or glass co-modifier comprising a sulfide or oxide different than the glass former and the glass modifier, D is a dopant, n M is a mole fraction of M, n F is a mole fraction of F, n C is a mole fraction of C, and n D is a mole fraction of D, wherein:
at least one of the M, F, and C comprises a sulfide;
n m >0, n F >0, n C ≥0, and n D ≥0;
the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte has a weighted average bond dissociation enthalpy (BDE WA ) of ≥380 kJ/mol, where
BDE
WA
=
w
M
n
M
BDE
M
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
F
n
F
BDE
F
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
C
n
C
BDE
C
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
+
w
D
n
D
BDE
D
w
M
n
M
+
w
F
n
F
+
w
C
n
C
+
w
D
n
D
,
wherein BDE M is a bond dissociation enthalpy required to break a single bond of distinct constituents of M, BDE F is a bond dissociation enthalpy required to break a single bond of distinct constituents of F, BDE C is a bond dissociation enthalpy required to break a single bond of distinct constituents of C, BDE D is a bond dissociation enthalpy required to break a single bond of distinct constituents of D, w M is a quantity of sulfur or oxygen bonds that M contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, w F is a quantity of sulfur or oxygen bonds that F contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, we is a quantity of sulfur or oxygen bonds that C contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte, and wD is a quantity of sulfur, oxygen, iodine, or chlorine bonds that D contributes to the sulfide or oxy-sulfide glass or glass-ceramic electrolyte;
the solid component is lithium ion-conducting and electrically insulating; and
the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises: (Li 2 S) 50 (GeS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 50 (SiS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 57 (SiS 2 ) 35 (P 2 S 5 ) 8 , (Li 2 S) 60 (SiS 2 ) 28 (P 2 S 5 ) 12 , (Li 2 S) 53,6 (SiS 2 ) 32,9 (P 2 S 5 ) 7,5 (LiI) 6 , or combinations thereof.
5. The electrochemical cell of claim 4 , wherein the positive electroactive material comprises sulfur.
6. The electrochemical cell of claim 4 , wherein:
the aprotic solvent comprises an ether-based solvent;
the negative electroactive material is in communication with the ether-based solvent; and
the negative electroactive material comprises lithium.
7. The electrochemical cell of claim 4 , wherein the aprotic solvent comprises an ether-based solvent selected from the group consisting of: 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-diethoxyethane, ethoxymethoxyethane, tetraethylene glycol dimethyl ether (TEGDME), polyethylene glycol dimethyl ether (PEGDME), and admixtures thereof, and wherein a lithium salt is dissolved in the ether-based solvent, the lithium salt being selected from the group consisting of: LiN(CF 3 SO 2 ) 2 , LiTFSI, LiNO 3 , LiPF 6 , LiBF 4 , LiI, LiBr, LiSCN, LiClO 4 , LiAlCl 4 , LiB(C 2 O 4 ) 2 (LiBOB), LiB(C 6 H 5 ) 4 , LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 O 4 ) (LiFOP), LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiCF 3 SO 3 , LiAsF 6 , and combinations thereof.
8. The electrochemical cell of claim 4 , wherein the solid component further comprises a polymer.
9. The electrochemical cell of claim 8 , wherein the solid component has one of: (a) a composite structure including the polymer and the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte, or (b) a laminate structure including one or more layers of the polymer and the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte.
10. The electrolyte system of claim 1 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises: (Li 2 S) 50 (GeS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 50 (SiS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 53.6 (SiS 2 ) 32.9 (P 2 S 5 ) 7.5 (LiI) 6 , or combinations thereof.
11. The electrolyte system of claim 1 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises: (Li 2 S) 50 (GeS 2 ) 45 (GeO 2 ) 5 .
12. The electrolyte system of claim 1 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises (Li 2 S) 50 (SiS 2 ) 45 (GeO 2 ) 5 .
13. The electrolyte system of claim 1 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises (Li 2 S) 53.6 (SiS 2 ) 32.9 (P 2 S 5 ) 7.5 (LiI) 6 .
14. The electrolyte system of claim 1 , wherein the solid component further includes a reinforcement phase.
15. The electrolyte system of claim 1 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte is at least partially devitrified.
16. The electrolyte system of claim 15 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte is fully devitrified.
17. The electrochemical cell of claim 4 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte comprises: (Li 2 S) 50 (GeS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 50 (SiS 2 ) 45 (GeO 2 ) 5 , (Li 2 S) 53.6 (SiS 2 ) 32.9 (P 2 S 5 ) 7.5 (LiI) 6 , or combinations thereof.
18. The electrochemical cell of claim 4 , wherein the solid component further includes a reinforcement phase.
19. The electrochemical cell of claim 4 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte is at least partially devitrified.
20. The electrochemical cell of claim 19 , wherein the sulfide or oxy-sulfide, glass or glass-ceramic electrolyte is fully devitrified.