ALL SULFIDE ELECTROCHEMICAL CELL

1 . A process for making a solid-state battery comprising:

providing at least two layered stacks;

wherein each layered stack, individually in each instance, comprises a current collector layer having at least one exposed tab and at least one member selected from the group consisting of a positive electrode layer and a solid-state separator layer; and

compressing the at least two layered stacks at a pressure in the range of 30 MPa to 5000 MPa and at a temperature of 50° C. to 250° C.

2 . The process of claim 1 , wherein the providing step comprises assembling a layered stack.

3 . The process of claim 1 or 2 , comprising compressing a surface of a positive electrode layer of one of the at least two layered stacks against a surface of a solid-state separator layer of one of the at least two layered stacks.

4 . The process of any one of claims 1 - 3 , comprising calendering at least one of the at least two layered stacks prior to the compressing step.

5 . The process of any one of claims 1 - 4 , wherein at least one layered stack comprises a current collector layer and a positive electrode layer; wherein the current collector layer is in electrical contact with the positive electrode layer.

6 . The process of claim 5 , wherein the current collector layer is a positive electrode current collector layer.

7 . The process of any one of claims 1 - 6 , wherein at least one layered stack comprises a current collector and a solid-state separator layer; wherein the solid-state separator layer is in electrical contact with the current collector.

8 . The process of claim 7 , wherein one of the at least one layered stacks comprises a negative electrode layer.

9 . The process of claim 8 , wherein the negative electrode layer is a lithium (Li) metal electrode layer.

10 . The process of any one of claims 1 - 9 , wherein the positive electrode layer comprises a sulfide single ion conductor and an active material.

11 . The process of any one of claims 1 - 10 , wherein the solid-state separator layer comprises a sulfide single ion conductor.

12 . The process of any one of claims 1 - 11 , wherein the solid-state separator layer comprises LPSI.

13 . The process of any one of claims 5 - 13 , wherein at least one current collector layer comprises a material selected from the group consisting of carbon (C)-coated nickel (Ni), nickel (Ni), copper (Cu), aluminum (Al), and stainless steel.

14 . The process of claim 13 , wherein at least one current collector layer is a negative electrode current collector layer, wherein the negative electrode current collector layer is made of a material selected from the group consisting of carbon (C)-coated nickel (Ni), nickel (Ni), and copper (Cu).

15 . The process of claim 13 or 14 , wherein at least one current collector layer is a positive electrode current collector layer, wherein the positive electrode current collector layer comprises a material selected from the group consisting of carbon (C)-coated aluminum.

16 . The process of claim 14 , wherein the negative electrode current collector layer is C-coated Ni.

17 . The process of any one of claims 1 - 16 , wherein the solid-state separator layer is rectangular shaped.

18 . The process of any one of claims 1 - 17 , wherein the positive electrode layer is rectangular shaped.

19 . The process of any one of claims 1 - 16 wherein the solid-state separator layer is circular shaped.

20 . The process of any one of claim 1 - 16 or 19 , wherein the positive electrode layer is circular shaped.

21 . The process of any one of claims 1 - 20 , wherein the geometric surface area of the positive electrode layer and the geometric surface area solid-state separator layer are substantially the same.

22 . The process of any one of claims 17 - 18 and 21 , wherein one edge of the positive electrode layer is 10 cm in length.

23 . The process of any one of claims 17 - 18 and 21 - 22 , wherein one edge of the solid-state separator layer is 10 cm in length.

24 . The process of any one of claims 19 - 20 , wherein the positive electrode layer has a diameter that is 10 cm in length.

25 . The process of any one of claims 19 - 20 and 24 , wherein the solid-state separator layer has a diameter that is 10 cm in length.

26 . The process of any one of claims 1 - 25 , wherein the solid-state separator layer is a sulfide electrolyte.

27 . The process of claim 26 , wherein the sulfide electrolyte comprises lithium (Li), phosphorus (P), and sulfur (S).

28 . The process of claim 27 , wherein the sulfide electrolyte further comprises iodine (I).

29 . The process of any one of claims 26 - 28 , wherein the sulfide electrolyte further comprises a member selected from the group consisting of Tin (Sn), germanium (Ge), arsenic (As), silicon (Si), chlorine (Cl), bromine (Br), and a combination thereof.

30 . The process of claim 26 , wherein the sulfide electrolyte is LSTPS.

31 . The process of claim 26 , wherein the sulfide electrolyte is LPSI.

32 . The process of any one of claims 1 - 31 , wherein the positive electrode layer comprises a catholyte.

33 . The process of any one of claims 1 - 32 , wherein the positive electrode layer comprises a percolating network of ion conductors.

34 . The process of any one of claims 1 - 33 , wherein the solid-state separator layer comprises a percolating network of ion conductors.

35 . The process of any one of claims 1 - 34 , wherein the solid-state separator comprises a polymer-sulfide composite.

36 . The process of any one of claims 1 - 35 , wherein the positive electrode layer comprises an active material at a mass loading of about 75—about 90% by mass.

37 . The process of claim 36 , wherein the active material comprises a lithium intercalation material, a lithium conversion material, or both a lithium intercalation material and a lithium conversion material.

38 . The process of claim 37 , wherein the intercalation material is selected from the group consisting of a nickel manganese cobalt oxide (NMC), a nickel cobalt aluminum oxide (NCA), Li(NiCoAl)O 2 , a lithium cobalt oxide (LCO), a lithium manganese cobalt oxide (LMCO), a lithium nickel manganese cobalt oxide (LMNCO), a lithium nickel manganese oxide (LNMO), Li(NiCoMn)O 2 , LiMn 2 O 4 , LiCoO 2 , and LiMn 2−a Ni a O 4 , wherein a is from 0 to 2, or LiMPO 4 , wherein M is Fe, Ni, Co, or Mn.

39 . The process of any one of claims 37 - 38 , wherein the lithium conversion material is selected from the group consisting of FeF 2 , NiF 2 , FeO x F 3−2x , FeF 3 , MnF 3 , CoF 3 , CuF 2 , alloys thereof, and combinations thereof.

40 . The process of any one of claim 36 - 39 , wherein the active material is NCA.

41 . The process of any one of claim 36 - 39 , wherein the active material is NMC.

42 . The process of any one of claims 1 - 41 , wherein the positive electrode layer comprises a catholyte at a mass loading of about 10—about 25%.

43 . The process of claim 42 , wherein the catholyte is LSTPS or LSPSCl.

44 . The process of claim 42 , wherein the catholyte is LSTPS.

45 . The process of claim 42 , wherein the catholyte is LSPSCl.

46 . The process of any one of claims 1 - 45 , wherein the positive electrode layer comprises a carbon at a mass loading of about 0 to about 1%.

47 . The process of claim 46 , wherein the carbon is C65 or vapor-grown carbon fibers (VGCF).

48 . The process of any one of claims 1 - 47 , wherein the positive electrode layer comprises a binder at a mass loading of about 0 to about 2.5%.

49 . The process of claim 48 , wherein the binder comprises POB3.

50 . The process of any one of claims 1 - 49 , wherein the thickness of the positive electrode layer is from about 10 μm to about 500 μm.

51 . The process of claim 50 , wherein the thickness of the positive electrode layer is from 100 μm to about 500 μm.

52 . The process of any one of claims 1 - 51 , wherein the thickness of the solid-state separator layer is from about 1 μm to about 200 μm.

53 . The process of any one of claims 1 - 52 , wherein the thickness of the positive electrode current collector layer is from about 5 μm to about 100 μm.

54 . The process of claim 53 , wherein the thickness of the positive electrode current collector layer is about 15 μm.

55 . The process of any one of claims 1 - 52 , wherein the thickness of the negative electrode current collector layer is from about 5 μm to about 100 μm.

56 . The process of claim 55 , wherein the thickness of the positive electrode current collector layer is about 15 μm.

57 . The process of any one of claims 1 - 56 , wherein the thickness of the tabs on the current collector layer is from about 5 μm to about 100 μm.

58 . The process of any one of claims 1 - 57 , comprising compressing the at least two layered stacks at a pressure less than 600 MPa.

59 . The process of any one of claims 1 - 57 , comprising compressing the at least two layered stacks at a pressure in the range of 50 MPa to 5,000 MPa.

60 . The process of any one of claims 1 - 59 , comprising compressing the at least two layered stacks at a temperature less than 170° C.

61 . The process of any one of claims 1 - 60 , wherein the solid-state separator is made by a process which comprises milling a solid-state separator material and casting the milled solid-state separator material as a thin layer.

62 . The process of any one of claims 1 - 61 , wherein the compressing step occurs in a die.

63 . The process of any one of claims 1 - 62 , wherein the compressing step is uniaxial.

64 . The process of any one of claims 1 - 62 , wherein the compressing step is isostatic.

65 . The process of any one of claims 1 - 64 , wherein the solid-state separator comprises a polymer-sulfide composite.

66 . The process of any one of claims 1 - 65 , wherein the die comprises cut-outs for the exposed tabs.

67 . The process of any one of claims 1 - 66 , wherein two of the at least two electrochemical stacks share either a positive current collector layer or a negative current collector layer.

68 . The process of any one of claims 1 - 67 , wherein the compressing step applies both uniaxial force and isostatic force.

69 . The process of any one of claims 1 - 68 , wherein the die has at least one feature accommodating the volume of at least one current collector tab.

70 . An electrochemical cell prepared by the process of any one of claims 1 - 69 .

71 . A rechargeable battery comprising the electrochemical cell of claim 70 .

72 . An electric vehicle comprising the electrochemical cell of claim 70 or the rechargeable battery of claim 71 .