Lithium-stuffed garnet electrolytes with secondary phase inclusions

• US 10,347,937 B2
• Filed: 06/23/2017
• Issued: 07/09/2019
• Est. Priority Date: 06/23/2017
• Status: Active Grant

• Current Assignee: QuantumScape Subsidiary, Inc. (Quantumscape Corporation)
• Original Assignee: Quantumscape Corporation
• Inventors: Beck, Larry, Chao, Cheng-Chieh, Cheng, Lei, Donnelly, Niall, Gardner, William H., Holme, Tim, Hudson, Will, Iyer, Sriram, Karpenko, Oleh, Li, Yang, Xu, Gengfu
• Primary Examiner(s): Marks, Jacob B
• Application Number:
  US15/631,884
• Publication Number:
  US 20180375149A1
• Time in Patent Office: 746 Days
• CPC Class Codes: C01G 25/006 Compounds containing, besides zirconium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: H01M 2300/0077 based on zirconium oxide
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The instant disclosure sets forth multiphase lithium-stuffed garnet electrolytes having secondary phase inclusions, wherein these secondary phase inclusions are material(s) which is/are not a cubic phase lithium-stuffed garnet but which is/are entrapped or enclosed within a lithium-stuffed garnet. When the secondary phase inclusions described herein are included in a lithium-stuffed garnet at 30-0.1 volume %, the inclusions stabilize the multiphase matrix and allow for improved sintering of the lithium-stuffed garnet. The electrolytes described herein, which include lithium-stuffed garnet with secondary phase inclusions, have an improved sinterability and density compared to phase pure cubic lithium-stuffed garnet having the formula Li₇La₃Zr₂O₁₂.

Claims

1. A multiphase thin film solid-state electrolyte comprising:

a primary cubic phase lithium-stuffed garnet characterized by the chemical formula Li_ALa_BAl_CM″

_DZr_EO_F, wherein 5<

A<

8, 1.5<

B<

4, 0.1<

C<

2, 0≤

D<

2;

1<

E<

3, 10<

F<

13, and M″

is selected from the group consisting of Mo, W, Nb, Y, Ta, Ga, Sb, Ca, Ba, Sr, Ce, Hf, and Rb;

a secondary phase inclusion in the primary cubic phase lithium-stuffed garnet;

wherein;

the primary cubic phase lithium-stuffed garnet is present in the multiphase thin film solid-state electrolyte at about 70-95 vol % with respect to the volume of the multiphase thin film electrolyte; and

the secondary phase inclusion is present in the multiphase thin film solid-state electrolyte at about 30-5 vol % with respect to the volume of the multiphase thin film electrolyte.

2. The multiphase thin film solid-state electrolyte of claim 1, wherein the secondary phase inclusion d₅₀ grain size is less than 10 μ

m.

3. The multiphase thin film solid-state electrolyte of claim 1, wherein the secondary phase inclusion d₅₀ grain size is from about 1 μ

m to about 10 μ

m.

4. The multiphase thin film solid-state electrolyte of claim 1, wherein the primary cubic phase lithium-stuffed garnet d₅₀ grain size is from about 10 μ

m to about 20 μ

m.

5. The multiphase thin film solid-state electrolyte of claim 1, wherein the primary cubic phase lithium-stuffed garnet grain size d₅₀ is from about 0.5 μ

m-10 μ

m.

6. The multiphase thin film solid-state electrolyte of claim 1, wherein the d₉₀ grain size of any phase in the multiphase thin film solid-state electrolyte is from about 1 μ

m to 5 μ

m.

7. The multiphase thin film solid-state electrolyte of any one of claim 1, wherein the secondary phase inclusions are homogenously distributed over a volume of 10000 μ

m³ or more.

8. The multiphase thin film solid-state electrolyte of claim 1, wherein the ratio of the secondary phase inclusion d₅₀ grain size to the primary cubic phase lithium-stuffed garnet d₅₀ grain size is between 0.1 and 10.

9. The multiphase thin film solid-state electrolyte of claim 1, wherein the multiphase thin film solid-state electrolyte has a fracture strength of 200 MPa-2000 MPa as measured a ring-on-ring flexural strength test.

10. The multiphase thin film solid-state electrolyte of claim 1, wherein the thickness of the thin film solid-state electrolyte is between about 0.1 μ

m to about 200 μ

m.

11. The multiphase thin film solid-state electrolyte of any one of claim 1, wherein the thin film solid-state electrolyte has an area of at least 25 cm².

12. The solid electrolyte of any one of claim 1, wherein the secondary phase inclusion is a material selected from the group consisting of:

tetragonal phase garnet;

La₂Zr₂O₇;

La₂O₃;

LaAlO₃;

La₂(Li_0.5Al_0.5)O₄;

LiLaO₂;

LiZr₂O₃;

Li_aZr_bO_c, wherein 1≤

a≤

8, 1≤

b≤

2, and 1≤

c≤

7, and wherein subscripts a, b, and c are selected so that Li_aZr_bO_c is charge neutral;

Li_gAl_hO_i, wherein 1≤

g≤

5, 1≤

h≤

5, and 2≤

i≤

8, and wherein subscripts g, h, i are selected so that Li_gAl_hO_i is charge neutral;

La_dTa_eO_f, wherein 1≤

d≤

3, 1≤

e≤

7, and 4≤

f≤

19, and wherein subscripts d, e, and f are selected so that La_dTa_eO_f is charge neutral;

Li_rTa_sO_t, wherein 1≤

r≤

2, 1≤

s≤

3, and 3≤

t≤

7, and wherein subscripts r, s, and t are selected so that Li_rTa_sO_t is charge neutral;

La_nNb_pO_q, wherein 1≤

n≤

3, 1≤

p≤

7, and 4≤

q≤

19, and wherein subscripts n, p, and q are selected so that La_nNb_pO_q is charge neutral;

Li_uNb_vO_x, wherein 1≤

u≤

3, 1≤

p≤

3, and 3≤

x≤

9, and wherein subscripts u, v, and x are selected so that Li_uNb_vO_x is charge neutral; and

combinations thereof.

13. The multiphase thin film solid-state electrolyte of any one of claim 1, wherein the total amount of secondary phase inclusion is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 vol %.

14. The multiphase thin film solid-state electrolyte of claim 1, wherein the secondary phase inclusion comprises La₂Zr₂O₇;

LiAlO₂;

LaAlO₃;

tetragonal garnet; and

Li₂ZrO₃.

15. The multiphase thin film solid-state electrolyte of claim 1, wherein the secondary phase inclusion in the multiphase thin film solid-state electrolyte comprises LiAlO₂ present in the multiphase thin film solid-state electrolyte at about 3-8 vol %, Li₂ZrO₃ present in the multiphase thin film solid-state electrolyte at about 1-10 vol % and LaAlO₃ present in the multiphase thin film solid-state electrolyte at about 1-8 vol %, as measured by quantitative XRD.

16. The multiphase thin film solid-state electrolyte of claim 1, where the bulk conductivity is greater than 1×

10<sup>−

4</sup> S/cm at 20°

C.

17. The multiphase thin film solid-state electrolyte of claim 1, wherein the interfacial area specific resistance (ASR) of the multiphase thin film solid-state electrolyte with lithium metal is 1-200 Ω

cm² at −

15°

C.

18. The multiphase thin film solid-state electrolyte of claim 1, where the multiphase thin film solid-state electrolyte has a total porosity of less than 5 vol % as determined by SEM.

19. An electrochemical cell comprising the multiphase thin film solid-state electrolyte according to claim 1.

20. A composition comprising:

a primary cubic phase lithium-stuffed garnet characterized by the chemical formula Li_ALa_BAl_CM″

_DZr_EO_F, wherein 5<

A<

8, 1.5<

B<

4, 0.1<

C<

2, 0≤

D<

2;

1<

E<

3, 10<

F<

13, and M″

is selected from the group consisting of Mo, W, Nb, Y, Ta, Ga, Sb, Ca, Ba, Sr, Ce, Hf, and Rb;

a secondary phase inclusion in the primary cubic phase lithium-stuffed garnet;

wherein;

the primary cubic phase lithium-stuffed garnet is present at about 70-95 vol % with respect to the volume of the composition; and

the secondary phase inclusion is present at about 30-5 vol % with respect to the volume of the composition.

21. The composition of claim 20, wherein the secondary phase inclusion d₅₀ grain size is less than 10 μ

m.

22. The composition of claim 20, wherein the secondary phase inclusion d₅₀ grain size is from about 1 μ

m to about 10 μ

m.

23. The composition of claim 20, wherein the primary cubic phase lithium-stuffed garnet d₅₀ grain size is smaller than the secondary phase inclusion d₅₀ grain size.

24. The composition of claim 20, wherein the primary cubic phase lithium-stuffed garnet d₅₀ grain size is from about 10 μ

m to about 20 μ

m.

25. The composition of claim 20, wherein the primary cubic phase lithium-stuffed garnet grain size d₅₀ is from about 0.5 μ

m-10 μ

m.

26. The composition of claim 20, wherein the d₉₀ grain size of any phase in the composition is from about 1 μ

m to 5 μ

m.

27. The composition of claim 20, wherein the composition is present in a pellet.

28. The solid electrolyte of claim 20, wherein the secondary phase inclusion is a material selected from the group consisting of:

tetragonal phase garnet;

La₂Zr₂O₇;

La₂O₃;

LaAlO₃;

La₂(Li_0.5Al_0.5)O₄;

LiLaO₂;

LiZr₂O₃;

Li_aZr_bO_c, wherein 1≤

a≤

8, 1≤

b≤

2, and 1≤

c≤

7, and wherein subscripts a, b, and c are selected so that Li_aZr_bO_c is charge neutral;

Li_gAl_hO_i, wherein 1≤

g≤

5, 1≤

h≤

5, and 2≤

i≤

8, and wherein subscripts g, h, i are selected so that Li_gAl_hO_i is charge neutral;

La_dTa_eO_f, wherein 1≤

d≤

3, 1≤

e≤

7, and 4≤

f≤

19, and wherein subscripts d, e, and f are selected so that La_dTa_eO_f is charge neutral;

Li_rTa_sO_t, wherein 1≤

r≤

2, 1≤

s≤

3, and 3≤

t≤

7, and wherein subscripts r, s, and t are selected so that Li_rTa_sO_t is charge neutral;

La_nNb_pO_q, wherein 1≤

n≤

3, 1≤

p≤

7, and 4≤

q≤

19, and wherein subscripts n, p, and q are selected so that La_nNb_pO_q is charge neutral;

Li_uNb_vO_x, wherein 1≤

u≤

3, 1≤

p≤

3, and 3≤

x≤

9, and wherein subscripts u, v, and x are selected so that Li_uNb_vO_x is charge neutral; and

combinations thereof.

29. The composition of claim 20, wherein the secondary phase inclusion in the composition comprises LiAlO₂ present in the composition at about 0.1-25 vol %, Li₂ZrO₃ present in the composition at about 0.1-15 vol % and LaAlO₃ present in the composition at about 0.1-15 vol %, as measured by quantitative XRD.

30. The composition of claim 20, where the composition has a total porosity of less than 5 vol % as determined by SEM.