Solid-state batteries and methods of making the same

Abstract

Batteries include a cathode, a solid-state electrolyte, an anode, and an interlayer disposed on the cathode with the solid-state electrolyte disposed on the interlayer. The interlayer includes a lithium salt, a nitrile-containing compound, and a sulfone-containing compound. The anode can be a lithium-containing anode. In aspects, the interlayer can further include a polymeric matrix with the lithium salt, the nitrile-containing compound, and the sulfone-containing compound positioned within the polymeric matrix. Methods of forming a battery include disposing a solution including a lithium salt, a sulfone-containing compound, and a nitrile-containing compound on a cathode. Method include disposing a solid-state electrolyte over the cathode with the lithium salt positioned between the cathode and the solid-state electrolyte. In aspects, the solution can further comprise a monomer, and methods can further include curing the monomer to form an interlayer including a polymeric matrix.

Description

SOLID-STATE BATTERIES AND METHODS OF MAKING THE SAME

[0000] This application claims the benefit of priority of Chinese Application Serial No. 202310568867.6 filed on May 19, 2023, the content of which is relied upon and incorporated herein by reference in their entirety.FIELD

[0001] The present disclosure relates to solid-state batteries and methods of manufacturing thereof, and more particularly solid-state batteries comprising an interlayer between a cathode and a solid-state electrolyte and methods of making the same.BACKGROUND

[0002] Solid-state batteries (SSBs) (e.g., SS lithium (Li) metal batteries based on inorganic solid-state electrolytes (SSEs) (such as garnet-type SSE)) have attracted much attention due to their high safety, improved energy density, high ionic conductivity, and stability against Li metal. However, conventional Li-metal batteries often suffer from issues with capacity retention and / or longevity, especially when operated at higher capacities. Consequently, there is a need to address these issues.SUMMARY

[0003] The present disclosure provides solid-state batteries, and methods of making the same comprising a interlayer positioned between a cathode and a solid-state electrolyte. The interlayer comprises a mixture of the nitrile-containing compound and sulfone-containing compound that, discussed in the Examples herein, can provide decreased interfacial resistance and increased cycling performance (e.g., capacity retention) compared to either compound alone. In aspects, the interlayer can comprise a liquid interlayer that can wet the interface between the cathode and the solid-state electrolyte to reduce interfacial resistance therebetween while minimizing a total amount of liquid interlayer in the solid-state battery. Alternatively, in aspects, the interlayer can further comprise a polymeric matrix that can further reduce a corrosion of components of the solid-state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte. Providing the polymeric matrix can balance reducing the mobility of the lithium salt to reduce corrosion of the solid-statebattery (e.g., first current collector) with a potential decrease in ionic conductivity of the interlayer. In aspects, the interlayer can comprise fluoroethylene carbonate that can increase the stability of the interlayer, for example, to high voltage conditions while providing 10 wt% or less of fluoroethylene carbonate can avoid dissolution of transition metals in the interlayer, which can impair the functionality of the cathode. In aspects, the interlayer can further comprise a fiber film that can increase a uniformity of lithium-ion flux by anchoring a position of the components (e.g., lithium salt, sulfone-containing compound, nitrile-containing compound, and / or the polymeric matrix) of the interlayer.

[0004] The interfacial resistance of interlayers and solid-state batteries containing the same in accordance with aspects of the disclosure can be reduced by more than one order of magnitude (e.g., lOOx or more, lOOOx or more) than a solid-state battery without an interlayer, which can have an interfacial resistance on the order of 100,000 cm2. Providing and / or maintaining a low (e.g., about 300 cm2or less, about 100 cm2or less) interfacial resistance of the interlayer and / or the solid-state battery can enable the solid-state battery to have a longer life (e.g., withstand more cycles without failure), reduce losses and heating from increased interfacial resistance, and / or reduce the formation of dendrites (e.g., lithium dendrites) that can lead to failure of the solid-state battery. Providing a high oxidation potential of an interlayer (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable increased capacity (e.g., charging to higher voltages), increased capacity retention of the solid-state battery (e.g., through decreased degradation of the interlayer), and / or increased longevity of the solid-state battery. Also, some lithium salts in the interlayer can corrode other parts of the solid-state battery (e.g., first current collector), which can be accelerated at increased temperatures (e.g., 40°C or more) and / or increased charging voltage cutoffs (e.g., about 4 V or more). Providing an interlayer with an increased oxidation potential (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable the solid-state battery to operate at increased temperatures (e.g., greater than 25°C, 40°C or more) and / or increased charging volage cutoffs (e.g., 4.5 V or more) without increased corrosion of the solid-state battery. Additionally, providing an interlayer comprising a polymeric matrix can further reduce a corrosion of components of the solid-state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte. Providing a thermally stable interlayer (e.g., to 100°C or more, about 150°C or more, about 160°C or more) can increase a range of operating temperatures for the solid-state battery, increase a capacity retention of the solid-state battery, and / or increase a longevity of the solid-state battery.Providing and / or maintaining a high capacity (e.g., 150 mAh / g or more as-formed or after 50 cycles or after 65 cycles or after 165 cycles at 25°C) can enable the solid-state battery to make efficient use of cathode materials (e.g., for an intended use for a longer period of time) than would otherwise be possible.

[0005] Providing a solid-state electrolyte (e.g., in a solid-state battery) can address common safety concerns, for example, leakage, poor chemical stability, and flammability often seen in batteries employing liquid electrolytes. Moreover, providing a solid-state electrolyte can also suppress polysulfide shuttling from the cathode to the anode, thereby leading to improved electrode (e.g., anode, cathode) utilization and a high discharge capacity and energy density. Providing a solid-state electrolyte can reduce a formation of dendrites (e.g., lithium dendrites) that can otherwise result in failure of the battery.

[0006] Some example aspects of the disclosure are described below with the understanding that any of the features of the various aspects may be used alone or in combination with one another.

[0007] Aspect 1. A battery, comprising: a cathode; an interlayer disposed on a first major surface of the cathode, the interlayer comprising a polymeric matrix, a lithium salt, a nitrile-containing compound, and a sulfone-containing compound, wherein the lithium salt, the nitrile-containing compound, and the sulfone-containing compound are positioned within the polymeric matrix; a solid-state electrolyte disposed on the interlayer; and a lithium-containing anode disposed on the solid-state electrolyte opposite the interlayer.

[0008] Aspect 2. The battery of aspect 1, wherein the polymeric matrix comprises an acrylate-based polymer, an epoxy-based polymer, or copolymer or combinations thereof.

[0009] Aspect 3. The battery of any one of aspects 1-2, wherein an interfacial resistance between the cathode and the solid-state electrolyte is about 300 cm2or less at 25°C.

[0010] Aspect 4. The battery of any one of aspects 1-3, wherein the battery comprises a capacity retention of about 95% or more after 50 cycles at 0.2C with a cutoff voltage of 4.3 V and at 25°C.

[0011] Aspect 5. A battery, comprising: a cathode; an interlayer disposed on a first major surface of the cathode, the interlayer comprising a lithium salt, a nitrile-containing compound, and a sulfone-containing compound;a solid-state electrolyte disposed on the interlayer; and a lithium-containing anode disposed on the solid-state electrolyte opposite the interlayer.

[0012] Aspect 6. The battery of aspect 5, wherein an interfacial resistance between the cathode and the solid-state electrolyte is about 135 cm2or less at 25°C.

[0013] Aspect 7. The battery of aspect 5, wherein the battery comprises a capacity retention of about 80% or more after 160 cycles at 0.2C with a cutoff voltage of 4.3 V and at 25°C.

[0014] Aspect 8. The battery of aspect 5, wherein a capacity retention is about 85% or more after 65 cycles at 0.2C with a cutoff voltage of 4.3 V and at 25°C.

[0015] Aspect 9. The battery of any one of aspects 1-8, wherein the battery comprises an average columbic efficiency of about 99% or more after 50 cycles at 0.2 C with a cutoff voltage of 4.3V and at 25°C.

[0016] Aspect 10. The battery of any one of aspects 1-9, wherein the interlayer comprises an oxidation potential of about 5.2V or more at 25°C.

[0017] Aspect 11. The battery of any one of aspects 1-10, wherein an ionic conductivity of the interlayer at 20°C is about 1.1 milli Seimens per centimeter or more.

[0018] Aspect 12. The battery of any one of aspects 1-11, wherein the lithium salt comprises at least one of: lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium perchlorate (LiCICU), lithium tetrafluoroborate (LiBF4), lithium tritiate (LiSChCFs), Li SChCFs or combinations thereof.

[0019] Aspect 13. The battery of any one of aspects 1-12, wherein a concentration of the lithium salt is in a range from about 2 molar to about 5 molar.

[0020] Aspect 14. The battery of any one of aspects 1-13, wherein the nitrile-containing compound comprises succinonitrile.

[0021] Aspect 15. The battery of any one of aspects 1-14, wherein the sulfone-containing compound comprises an alkyl sulfone.

[0022] Aspect 16. The battery of any one of aspects 1-14, wherein the sulfone-containing compound comprises tetramethylene sulfone.

[0023] Aspect 17. The battery of any one of aspects 1-16, wherein a volume ratio of the nitrile-containing compound to the sulfone-containing compound is in a range from about 0.2 to about 5.

[0024] Aspect 18. The battery of aspect 17, wherein the volume ratio is in a range from 0.25 to 4.

[0025] Aspect 19. The battery of any one of aspects 1-18, wherein the interlayer further comprises from about 0.1 wt% to about 10 wt% of fluoroethylene carbonate.

[0026] Aspect 20. The battery of any one of aspects 1-19, wherein the cathode comprises at least one of lithium cobaltite (LCO), lithium manganite spinel (LMO), lithium nickel cobalt aluminate (NCA), lithium nickel manganese cobalt oxide (NCM) (LiNiaCoeMni-d-eCE, where 0 < d < l, 0 < e < l), lithium iron phosphate (LiFePCU) (LFP), lithium cobalt phosphate (LCP), lithium titanate, lithium niobium tungstate, lithium nickel manganate, and lithium titanium sulfide (LiTiS?), or combinations thereof.

[0027] Aspect 21. The battery of any one of aspects 1-20, wherein a ratio of a volume of the interlayer to an area of the first major surface of the cathode from about 5 pL / cm2to about 20 pL / cm2.

[0028] Aspect 22. The battery of any one of aspects 1-21, wherein a ratio of a weight of the cathode to an area of the first major surface is from about 1 mg / cm2to about 5 mg / cm2.

[0029] Aspect 23. The battery of any one of aspects 1-22, wherein the solid-state electrolyte comprises at least one of:(i) Li7-3aLa3Zr2LaOi2, with L = Al, Ga, or Fe and 0 < a < 0.33;(ii) Li7La3-bZr2MbOi2, with M = Bi or Y and 0 < b < 1;(iii) Li7-cLa3(Zr2-c,Nc)Oi2, with N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1;(iv) protonated LLZO (e.g., HxLi6.5-xLa3Zr1.5I0.5O12, with I = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < x < 4 or HxLi6.25-xEo.25La3Zr20i2, with E = Al, Ga, or Fe and 0 < x < 4); or a combination thereof.

[0030] Aspect 24. A method of forming a battery comprising: disposing a solution comprising a lithium salt, a sulfone-containing compound, and a nitrile-containing compound on a first major surface of a cathode; and disposing a solid-state electrolyte over the first major surface of the cathode, the lithium salt positioned between the cathode and the solid-state electrolyte.

[0031] Aspect 25. The method of aspect 24, wherein the solution further comprises a monomer, and the method further comprises curing the monomer to form an interlayer comprising polymeric matrix with the lithium salt, the sulfone-containing compound, and the nitrile-containing compound positioned within the polymeric matrix.

[0032] Aspect 26. The method of aspect 25, wherein the precursor solution comprises from about 2 wt% to about 20 wt% of the monomer.

[0033] Aspect 27. The method of any one of aspects 25-26, wherein the monomer is an acrylic monomer, an epoxy monomer, or combinations thereof, and the polymeric matrix comprises an acrylate-based polymer, an epoxy-based polymer, or copolymers or combinations thereof.

[0034] Aspect 28. The method of any one of aspects 24-27, wherein a volume ratio of the nitrile-containing compound to the sulfone-containing compound is in a range from about 0.2 to about 5.

[0035] Aspect 29. The method of aspect 28, wherein the volume ratio is in a range from 0.25 to 4.

[0036] Aspect 30. The method of any one of aspects 24-29, wherein an ionic conductivity of the interlayer at 20°C is about 1.1 milli Seimens per centimeter or more.

[0037] Aspect 31. The method of any one of aspects 24-30, wherein the nitrile-containing compound comprises succinonitrile, the sulfone-containing compound comprises an alkyl sulfone, the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or combinations thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and other features and advantages of aspects of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0039] FIG. 1 schematically illustrates a general structure of a solid-state battery including a liquid interlayer in accordance with aspects of the disclosure;

[0040] FIG. 2 illustrates a simplified solid-state battery with the solid-state electrolyte including a liquid interlayer in accordance with aspects of the disclosure;

[0041] FIG. 3 schematically illustrates a general structure of a solid-state battery including a polymer matrix in an interlayer in accordance with aspects of the disclosure;

[0042] FIG. 4 illustrates a simplified solid-state battery with the solid-state electrolyte including a polymer matrix in an interlayer in accordance with aspects of the disclosure;

[0043] FIG. 5 illustrates a step in an exemplary method comprising disposing a liquid electrolyte over a cathode;

[0044] FIG. 6 illustrates a step in an exemplary method comprising disposing the solid- state electrolyte over the cathode;

[0045] FIG. 7 illustrates a step in an exemplary method comprising disposing a precursor liquid over a cathode;

[0046] FIG. 8 illustrates a step in an exemplary method comprising curing a precursor liquid to form an interlayer including a polymeric matrix;

[0047] FIG. 9 illustrates a step in an exemplary method comprising disposing the solid- state electrolyte over the cathode;

[0048] FIG. 10 illustrates curves corresponding to thermogravimetric analysis (TGA) of liquid interlayers for Examples 1 and 5 and Comparative Example AA;

[0049] FIG. 11 illustrates curves correspond to linear sweep voltammetry (LSV) of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solutions with different ratios of a sulfone- containing compound to a nitrile-containing compound for Examples 1-5 and Comparative Examples DD;

[0050] FIG. 12. illustrates Nyquist plots for Examples 6-10 and Comparative Examples AA-BB;

[0051] FIG. 13 illustrates a Nyquist plot for Example 11;

[0052] FIG. 14 illustrates capacity retention for Examples 9-10 and Comparative Example DD;

[0053] FIG. 15 illustrates capacity retention for Examples 6-8 and Comparative Example EE; and

[0054] FIG. 16 illustrates capacity retention and Columbic efficiency for Example 11.

[0055] Throughout the disclosure, the drawings are used to emphasize certain aspects. As such, it should not be assumed that the relative size of different regions, portions, and substrates shown in the drawings are proportional to its actual relative size, unless explicitly indicated otherwise.DETAILED DESCRIPTION

[0056] Aspects will now be described more fully hereinafter with reference to the accompanying drawings in which example aspects are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts.

[0057] FIGS. 1-4 illustrate views of a solid-state battery 101, 201, 301, or 401 comprising an interlayer 114 or 314 comprising at least a lithium salt, a nitrile-containing compound, and a sulfone-containing compound positioned between a cathode 104 and a solid-state electrolyte 108. In aspects, the interlayer 114 can further comprise a polymeric matrix. In aspects, the nitrile- containing compound can be succinonitrile, and / or the sulfone-containing compound can be an alkyl sulfone. In aspects, a volume ratio of the nitrile-containing compound to the sulfone- containing compound can be in a range from about 0.2 to about 5, from about 0.25 to about 4, orany range or subrange therebetween. Unless otherwise noted, a discussion of features of aspects of one solid-state electrolyte or battery can apply equally to corresponding features of any aspects of the disclosure. For example, identical part numbers throughout the disclosure can indicate that, in some aspects, the identified features are identical to one another and that the discussion of the identified feature of one aspect, unless otherwise noted, can apply equally to the identified feature of any of the other aspects of the disclosure.

[0058] FIGS. 1 and 3 schematically illustrate a general structure of a solid-state battery 101 or 301, and FIGS. 2 and 4 illustrate a simplified solid-state battery 201 or 401 in a coin-cell form. As shown in FIGS. 1-4, the solid-state battery 101, 201, 301, or 401 can include, sequentially, a first current collector 102 (e.g., substrate), the cathode 104 disposed on the first current collector 102, the interlayer 114 or 314 disposed on the cathode 104, an optional first coating 106, the solid-state electrolyte 108, an optional second interlayer or coating 110, and an anode 112, and a second current collector 116 disposed on the anode 112. As shown in FIGS. 1 and 3, the solid-state battery 101 can optionally comprise the optional first coating 106 positioned between the cathode 104 and the solid-state electrolyte 108 and / or positioned between the interlayer 114 or 314 and the solid-state electrolyte 108, and / or the solid-state battery 101 can optionally comprise the optional second interlayer or coating 110 positioned between the anode 112 and the solid-state electrolyte 108. As shown in FIGS. 1-4, the solid-state electrolyte 108 is positioned between the cathode 104 and the anode 112. In aspects, as shown in FIGS. 1-2, the interlayer 114 can be a liquid interlayer. Alternatively, in aspects, as shown in FIGS. 3-4, the interlayer 314 can comprise a polymeric matrix. The components of the solid-state battery 101 can be disposed horizontally in relation to each other or vertically.

[0059] The first current collector 102 comprises an electrically conductive material. As used herein, electrically conductive materials have an electronic conductivity of 100 Siemens per meter (S / m) measured at 20°C in accordance with ASTME1004-17. In aspects, the first current collector can comprise nickel (Ni) foam, carbon fiber, or a solid metal contact (e.g., aluminum, stainless steel, copper, platinum, nickel, gold, zinc, cobalt, nickel, ruthenium, lithium, lead, titanium, nichrome, etc.). In aspects, the first current collector 102 can be a mechanically stable and / or dimensionally stable substrate that supports the other elements of the solid-state battery 101 or 201. In aspects, the first current collector 102 can comprise the same material as the cathode 104 (discussed below) such that the first current collector 102 is part of the cathode 104.

[0060] The cathode 104 comprises an electrically conductive material. In aspects, the cathode 104 can be configured to release and reincorporate a cation (e.g., alkali metal - lithium orsodium, alkali earth metal - magnesium or calcium). In aspects, the cathode 104 can comprise at least one of an alkali metal (e.g., lithium, sodium) or an alkaline earth metal (e.g., magnesium, calcium). In aspects, the cathode 104 can comprise one or more of the materials discussed below for the anode 112. In further aspects, the cathode 104 can comprise the same material as the anode 112. In aspects, the cathode 104 can comprise a fluoride compound. In further aspects, the cathode 104 can comprise at least one transition metal, for example, cobalt, manganese, nickel, niobium, tantalum, vanadium, titanium, copper, chromium, tungsten, molybdenum, tin, germanium, antimony, bismuth, iron, or combinations thereof. In aspects, the cathode 104 can comprise a lithium-based electrode, for example lithium cobaltite (LCO), lithium manganite spinel (LMO), lithium nickel cobalt aluminate (NCA), lithium nickel manganese cobalt oxide (NCM) (LiNidCoeM -d-eCh, where 0 < d < l, 0 < e < l, for example, LiNio.5Coo.2Mno.3O2 (NCM523), LiNio.6Coo.2Mno.2O2 (NCM622), etc.), lithium iron phosphate (LiFePOd) (LFP), lithium cobalt phosphate (LCP), lithium titanate, lithium niobium tungstate, lithium nickel manganate, lithium titanium sulfide (LiTiS2), or combinations thereof. In aspects, the cathode 104 can comprise a sodium -based electrode, for example, NaVPOdF, NaMnO2, Na2 / 3Mni.yMgyO2 (0 < y < 1), Na2Li2TisOi2, Na2Ti3O?, or combinations thereof. In aspects, the cathode 104 can comprise a magnesium-based electrode, for example, magnesiochromite (MgC^CU), MgMn20d, or combinations thereof. The cathode 104 can be a sintered electrode. Alternatively, the cathode 104 can be unsintered. An exemplary aspect of a cathode 104 is a NCM cathode. In aspects, a ratio of a weight of the cathode 104 to a cathode surface area (e.g., first major surface 105 of the cathode 104 shown in FIGS. 5-6) of the cathode 104 can be about 5 milligrams per centimeter squared (mg / cm2), about 8 mg / cm2or more, about 10 mg / cm2or more, about 15 mg / cm2or more, about 20 mg / cm2or more, about 50 mg / cm2or less, about 30 mg / cm2or less, about 25 mg / cm2or less, about 20 mg / cm2or less, or about 15 mg / cm2or less. In aspects, a ratio of a weight of the cathode 104 to a cathode surface area of the cathode 104 can range from about 5 mg / cm2to about 50 mg / cm2, from about 8 mg / cm2to about 30 mg / cm2, from about 10 mg / cm2to about 25 mg / cm2, from about 15 mg / cm2to about 20 mg / cm2, or any range or subrange therebetween.

[0061] As shown in FIGS. 1-4, the solid-state battery 101 comprises the interlayer 114 or 314 positioned between the cathode 104 and the solid-state electrolyte 108. The interlayer 114 or 314 comprises at least a lithium salt, a nitrile-containing compound, and a sulfone-containing compound. In aspects, the lithium salt can comprise one or more of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium perchlorate (LiCICh), lithium tetrafluorob orate (LiBF4), lithium triflate (LiSCLCFs), LiC(SO2CF3)3,or combinations thereof. In further aspects, a concentration of the lithium salt can be about 2 molar (M) or more, about 2.5 M or more, about 3 M or more, about 3.5 M or more, about 5 M or less, about 4.5 M or less, or about 4 M or less, for example, in a range from about 2 M to about 5 M, from about 2.5 M to about 4.5 M, from about 3 M to about 4 M, or any range or subrange therebetween. An exemplary aspect of the nitrile-containing compound is succinonitrile. In aspects, the sulfone-containing compound can be an alkyl sulfone. An exemplary aspect of the alkyl sulfone is tetramethylene sulfone.

[0062] As used herein, a “volume ratio” refers to a volume of a first component divided by a volume of a second component. In aspects, a volume ratio of the nitrile-containing compound to the sulfone-containing compound in the interlayer can be about 0.2 (1 :5) or more, about 0.25 (1 :4) or more, about 0.33 (1 :3) or more, about 0.5 (1 :2) or more, about 0.8 (4:5) or more, about 1 (1 : 1) or more, about 1.5 (3:2) or more, about 2 (2: 1) or more, about 5 (5: 1) or less, about 4 (4: 1) or less, about 3 (3: 1) or less, about 2 (2: 1) or less, about 1.5 (3:2) or less, aboutl or less, about 0.8 (4:5) or less, or about 0.5 (1 :2) or less. In aspects, a volume ratio of the nitrile-containing compound to the sulfone-containing compound in the interlayer can be in a range from about 0.2 to about 5, from about 0.25 to about 4, from about 0.33 to about 3, from about 0.5 to about 2, from about 0.8 to about 1.5, or any range or subrange therebetween. In aspects, the interlayer can have a greater volume of the sulfone-containing compound than a volume of the nitrile-containing compound, for example, with a volume ratio of the nitrile-containing compound to the sulfone-containing compound in a range from about 0.2 to less than 1, from about 0.25 to about 0.8, from about 0.33 to about 0.5, or any range or subrange therebetween. Alternatively, in aspects, the interlayer can have a greater volume of the nitrile-containing compound than a volume of the sulfone-containing compound, for example, with a volume ratio of the nitrile-containing compound to the sulfone- containing compound in a range from greater than 1 to about 5, from about 1.5 to about 4, from about 2 to about 3, or any range or subrange therebetween. As discussed below in the Examples, the mixture of the nitrile-containing compound and sulfone-containing compound can provide decreased interfacial resistance and increased cycling performance (e.g., capacity retention) compared to either compound alone.

[0063] In aspects, the interlayer 114 or 314 can optionally comprise fluoroethylene carbonate. In further aspects, an amount of fluoroethylene carbonate, as a wt% of the interlayer, can be about 0.1 wt% or more, about 0.5 wt% or more, about 1 wt% or more, about 2 wt% or more, about 10 wt% or less, about 7 wt% or less, about 5 wt% or less, or about 3 wt% or less. In further aspects, an amount of fluoroethylene carbonate, as a wt% of the interlayer, can be in a range fromabout 0.1 wt% to about 10 wt%, from about 0.5 wt% to about 7 wt%, from about 1 wt% to about 5 wt%, from about 2 wt% to about 3 wt%, or any range or subrange therebetween. Providing fluoroethylene carbonate can increase the stability of the interlayer, for example, to high voltage conditions. Providing 10 wt% or less of fluoroethylene carbonate can avoid dissolution of transition metals in the interlayer, which can impair the functionality of the cathode.

[0064] In aspects, as shown in FIGS. 1-2, the interlayer 114 can be a liquid interlayer. For example, the interlayer 114 can be a liquid at room temperature (i.e., 25°C) and / or at an operating temperature of the solid-state battery 101 or 201 (e.g., from about 50°C to about 60°C). In aspects, the interlayer 114 can be substantially free (e.g., free) of polymeric compounds. In aspects, the interlayer 114 can consist essentially of and / or consist of the lithium salt, the sulfone- containing compound, the nitrile-containing compound, and optionally fluoroethylene carbonate. Providing an interlayer 114 comprising a liquid interlayer can wet the interface between the cathode 104 and the solid-state electrolyte to reduce interfacial resistance therebetween while minimizing a total amount of liquid interlayer in the solid-state battery 101.

[0065] In aspects, as shown in FIGS. 3-4, the interlayer 314 can further comprise a polymeric matrix. In further aspects, the lithium salt, the nitrile-containing compound, and the sulfone-containing compound can be positioned within the polymeric matrix. In further aspects, the polymeric matrix can comprise an acrylate-based polymer, an epoxy-based polymer, or a copolymer or combination thereof. An exemplary aspects of the acrylate-based polymer are multifunctional acrylate polymers (e.g., poly(ethylene glycol diacrylate) (PEGDA), polyethylene dimethacrylate) (PEGMAA), poly(ethoxylated trimethylolpropane triacrylate) (PETPTA)) and / or methacrylates (e.g., poly(methyl methacrylate) (PMMA), poly(trifluoroethyl methacrylate) (PTFEMA)). As discussed below, the polymeric matrix can be formed by curing a monomer or other polymeric precursor after a precursor solution is disposed on the cathode. Providing an interlayer comprising a polymeric matrix can further reduce a corrosion of components of the solid- state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte.

[0066] In aspects, the polymeric matrix, as a wt% of the interlayer 314, can be about 2 wt% or more, 5 wt% or more, about 6 wt% or more, about 7 wt% or more, about 20 wt% or less, about 15 wt% or less, about 12 wt% or less, 10 wt% or less, about 9 wt% or less, or about 8 wt% or less. In aspects, the polymeric matrix, as a wt% of the interlayer 314, can range from about 2 wt% to about 20 wt%, from about 2 wt% to about 15 wt%, from about 5 wt% to about 12 wt%,from about 5 wt% to about 10 wt%, from about 6 wt% to about 9 wt%, from about 7 wt% to about 8 wt%, or any range or subrange therebetween. Providing the polymeric matrix within one or more of the amounts mentioned in this paragraph can balance reducing the mobility of the lithium salt to reduce corrosion of the solid-state battery (e.g., first current collector) with a potential decrease in ionic conductivity of the interlayer.

[0067] In aspects, a volume of the interlayer 114 or 314 to a cathode surface area (e.g., first major surface 105 of the cathode 104 shown in FIGS. 5-6) of the cathode 104 can be about 5 pL / cm2or more, about 8 pL / cm2or more, about 10 pL / cm2or more, about 12 pL / cm2or more, about 15 pL / cm2or more, about 20 pL / cm2or less, about 15 pL / cm2or less, about 12 pL / cm2or less, or about 10 pL / cm2or less. In aspects, a volume of the interlayer 114 or 314 to a cathode surface area of the cathode 104 can range from about 5 pL / cm2to about 20 pL / cm2, from about 8 pL / cm2or to about 15 pL / cm2or, from about 10 pL / cm2to about 12 pL / cm2, or any range or subrange therebetween.

[0068] In aspects, the interlayer 114 or 314 can optionally further comprise a fiber film. In further aspects, the fiber film can comprise a fluoropolymer (e.g., poly(tetrafluoroethylene) (PTFE), poly(vinylidene fluoride) (PVDF), poly(hexafluoropropylene) (PHFP), or copolymers such as poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP) or combinations thereof). An exemplary aspect of the fiber film includes a PVDF-co-HFP film that can be prepared, for example, by electrospinning a high molecular weight polymer (e.g., with a weight-average molecular weight of about 100,000 Daltons or more, about 250,000 Daltons or more, or about 400 Daltons or more) in a solvent (e.g., dimethylformamide (DMF)). Providing the fiber film can increase a uniformity of lithium-ion flux by anchoring a position of the components (e.g., lithium salt, sulfone-containing compound, nitrile-containing compound, and / or the polymeric matrix) of the interlayer.

[0069] As shown in FIGS. 1-2, the solid-state battery 101 and 201 comprises the solid- state electrolyte 108 positioned between the cathode 104 and the anode 112. Throughout the disclosure, “solid-state batteries” comprise a solid-state electrolyte. As used herein, a solid-state electrolyte is a material that is solid at room temperature and at an operating temperature (e.g., about 50°C) of the solid-state battery. In aspects, the solid-state electrolyte 108 can comprise an inorganic solid-state electrolyte. Providing a solid-state electrolyte can address common safety concerns, for example, leakage, poor chemical stability, and flammability often seen in batteries employing liquid electrolytes. Moreover, providing a solid-state electrolyte can also suppress poly sulfide shuttling from the cathode to the anode, thereby leading to improved electrode (e.g.,anode, cathode) utilization and a high discharge capacity and energy density. Providing a solid- state electrolyte can reduce a formation of dendrites (e.g., lithium dendrites) that can otherwise result in failure of the battery.

[0070] In aspects, the solid-state electrolyte 108 can comprise a lithium-phosphorous- oxynitride (LiPON), lithium garnet (LiyLasZ^On), lithium phosphosulfide, or combinations thereof. In further aspects, a LIPON material can comprise the structure Li3+yPO4-xNx, where y > 0 and 0 < x < 4. In further aspects, the solid-state electrolyte 108 can comprise lithium, lanthanum, zirconium, oxygen, or combinations thereof (e.g., each of lithium, lanthanum, zirconium, and oxygen - a LLZO compound). As used herein, “LLZO” refers to compounds including lithium, lanthanum, zirconium, and oxygen. In even further aspects, the solid-state electrolyte 108 can comprise a lithium-garnet, for example, at least one of: (i) Li7-3a a3Zr2LaOi2, with L = Al, Ga or Fe and 0 < a < 0.33; (ii) LiyLas-bZ^MbOn, with M = Bi or Y and 0 < b < 1; (iii) Li7-cLa3(Zr2- c,Nc)Oi2, with N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1; (iv) protonated LLZO (e.g., HxLi6.5-xLa3Zr1.5I0.5O12, with I = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < x < 4 or HxLie.25-xEo.25La3Zr20i2, with E = Al, Ga or Fe and 0 < x < 4), or a combination thereof. In aspects, the solid-state electrolyte 108 can comprise at least one of LiioGeP2Si2, Lii.sAlo.sGei PC Lii.4Alo.4Tii.6(P04)3, Lio.55Lao.35Ti03, interpenetrating polymer networks of poly(ethyl acrylate) (ipn-PEA) electrolyte, three-dimensional ceramic / polymer networks, in-situ plasticized polymers, composite polymers with well-aligned ceramic nanowires, PEO-based solid-state polymers, flexible polymers, polymeric ionic liquids, in-situ formed Li3PS4, LiePSsCl, or combinations thereof.

[0071] As shown in FIGS. 1-2, the solid-state electrolyte 108 comprises the first major surface 109 and the second major surface 107 opposite the first major surface 109, and a thickness of the solid-state electrolyte 108 can be defined between the first major surface 109 and the second major surface 107. In aspects, the thickness of the solid-state electrolyte 108 can be about 20 pm or more, about 40 pm or more, about 60 pm or more, about 80 pm or more, about 100 pm or more, about 150 pm or more, about 300 pm or more, about 500 pm or more, about 600 pm or more, about 700 pm or more, about 800 pm or more, about 1 mm or more, about 2 mm or less, about 1.5 mm or less, about 1.2 mm or less, about 1 mm or less, about 800 pm or less, about 500 pm or less, about 300 pm or less, about 250 pm or less, about 200 pm or less, about 150 pm or less, about 120 pm or less, or about 100 pm or less. In aspects, the thickness of the solid-state electrolyte 108 can range from about 20 pm to about 2 mm, from about 40 pm to about 1.5 mm, from about 60 pm to about 1 mm, from about 80 pm to about 800 pm, from about 100 pm to about 500 pm, from about150 pm to about 300 pm, from about 150 pm to about 250 pm, or any range or subrange therebetween. In aspects, the thickness of the solid-state electrolyte 108 can be about 300 pm or less, for example, from about 20 pm to about 300 pm, from about 40 pm to about 250 pm, from about 60 pm to about 200 pm, from about 80 pm to about 150 pm, from about 100 pm to about 150 pm, or any range or subrange therebetween. In aspects, the thickness of the solid-state electrolyte 108 can be about 500 pm or more, for example, from about 500 pm to about 2 mm, from about 600 pm to about 1.5 mm, from about 700 pm to about 1 mm, from about 800 pm to about 1 mm, or any range or subrange therebetween.

[0072] In aspects, the optional first coating 106 can comprise a carbon-based interlayer (e.g., interlinked freestanding, micro / mesopore containing, functionalized, biomass-derived), a polymer-based interlayer, a metal-based coating (e.g., Ni foam, etc.), a liquid electrolyte (e.g., LiPFe in ethylene carbonate (EC) / dimethyl carbonate (DMC)), ionic liquid-based (e.g., LiCF3SO3 / CH3CONH2, LiTFSI / N-methylacetamide (NMA), PEOi8LiTFSI-10%SiO2-10%IL, etc., where LiTFSI is bis(trifluoromethane) sulfonimide lithium salt (LiN(CF3SO2)2), SiCE may be nanoparticles, and IL is an ionic liquid), or a combination thereof. Exemplary aspects of polymer- based interlayers include carbon polysulfides (CS), polyethylene oxides (PEO), polyaniline (PANI), polypyrrole (PPY), poly(3,4-ethylenedi oxythiophene) (PEDOT), poly(styrene sulfonic acid) (PSS), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyallylamine hydrochloride (PAH), poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP)), poly(m ethyl methacrylate) (PMMA), polyvinylidene fluoride (PVDF), poly(diallyldimethyl ammonium) bis(trifluoromethanesulfonyl)imide (TFSI) (PDDATFSI), or combinations thereof. In aspects, the optional first coating 106 can comprise at least one of, or at least two of, or at least three elements selected from a group consisting of nitrogen, carbon, cobalt, titanium, tantalum, and tungsten.

[0073] In aspects, the optional second interlayer or coating 110 can comprise the materials or aspects discussed above the optional first coating 106 and / or the interlayer 114. In aspects, the optional second interlayer or coating 110 can comprise an anode protector, for example, electrolyte additives (e.g., LiNO3, lanthanum nitrate, copper acetate, P2S5, etc.), artificial interfacial layers (e.g., Li3N, (CH3)3SiCl, A12O3, LiAl, etc.), composite metallics (e.g., Li?B6, Li-rGO (reduced graphene oxide), layered Li-rGO, etc.), or combinations thereof. In aspects, the optional second interlayer or coating 110 can comprise a thin layer of metal (e.g., Au) that may be ion-sputter coated to form a contact interface between the anode 112 the solid-state electrolyte 108 and another material of the optional second interlayer or coating 110. In aspects, the optional second interlayer or coating 110 can comprise a coating of lithium fluoride. In aspects, as shown in FIG. 2, the solid-state battery 201 may not have the optional second interlayer or second coating such that the anode 112 contacts the solid-state electrolyte 108.

[0074] As shown in FIGS. 1-2, the anode 112 can be disposed on the solid-state electrolyte 108. In aspects, as shown in FIG. 2, the first major surface 113 of the anode 112 can be disposed on the first major surface 109 of the solid-state electrolyte 108. As shown, the anode 112 comprises a second major surface 115 opposite the first major surface 113 with an anode thickness 119 defined as an average distance therebetween when the solid-state battery 201 is in a fully charged state. In aspects, the anode thickness 119 can be about 1 micrometer (pm) or more, about 10 pm or more, about 50 pm or more, about 100 pm or more, about 150 pm or more, about 500 pm or less, about 400 pm or less, about 300 pm or less, or about 250 pm or less. In aspects, the anode thickness 119 can range from about 1 pm to about 500 pm, from about 10 pm to about 400 pm, from about 50 pm to about 300 pm, from about 100 pm to about 300 pm, from about 150 pm to about 250 pm, or any range or subrange therebetween.

[0075] The anode 112 is a lithium-containing anode. In aspects, the lithium-containing anode can consist essentially of lithium metal. Alternatively, in aspects, the lithium-containing anode can comprise an alloy of lithium and at least one of magnesium (Mg), silver (Ag), or combinations thereof. In further aspects, the lithium-containing alloy can further comprise a second component selected from a group consisting of calcium (Ca), aluminum (Al), gallium (Ga), boron (B), carbon (C), silicon (Si), tin (Sn), zinc (Zn), indium (In), antimony (Sb), silver (Ag), and combinations thereof. Exemplary aspects of the second component include calcium (Ca), tin (Sn), and silver (Ag). Providing a lithium-containing anode comprising a lithium alloy can increase a wettability of the anode on the coating, which can decrease interfacial resistance of the battery (e.g., by achieving and / or maintaining good contact with the solid-state electrolyte through the coating), facilitate a high area capacity of the battery, and / or facilitate a high charging current density of the battery.

[0076] FIGS. 2 and 4 illustrate the solid-state battery 201 or 401. As shown in FIGS. 2 and 4, the solid-state battery 201 or 401 can comprise a coin-cell form, although the battery can comprise another form in other aspects. Compared to FIGS. 1 and 3, FIGS. 2 and 4 are simplified solid-state batteries 201 or 401 because the optional first coating 106 is omitted. Consequently, the interlayer 114 can be in direct contact with the cathode 104 and the solid-state electrolyte 108, for example, because the optional first coating 106 is omitted. In aspects, as shown in FIGS. 2 and 4, the area of the first major surface 113 of the anode 112 can be less than or equal to (e.g., less than) the area of the first major surface 109 of the solid-state electrolyte 108. In further aspects, as shown,the area of the first major surface 113 of the anode 112 can be substantially equal to a corresponding area of the cathode 104. Alternatively, as shown in FIGS. 1 and 3, the area of the first major surface 113 of the anode 112 can be substantially equal to the area of the first major surface 109 of the solid-state electrolyte 108. In aspects, as shown in FIGS. 2 and 4, an electrically insulating layer 205a and 205b can be positioned between the first current collector 102 and the second current collector 116 to prevent a short circuit in the solid-state battery 201 or 401 and / or to form a barrier protecting the contents of the solid-state battery 201 or 401. As used herein, the electrically insulating layer 205a and 205b comprises an electronic conductivity of 10'5S / cm or less. In even further aspects, as shown, the electrically insulating layer 205a and 205b can be configured to maintain a configuration of the solid-state battery 201, for example, by preventing the solid-state electrolyte 108 from contacting the second current collector 116. In further aspects, the electrically insulating layer 205a and 205b can comprise a polymeric material, for example, a fluoropolymer, a rubber, a polyurethane, or a silicone. In aspects, as shown, the solid-state battery 201 can further comprise an electrically conductive spacer 203 positioned between the anode 112 and the second current collector 116. In further aspects, the electrically conductive spacer 203 can comprise a foam (e.g., Ni foam), which can help maintain contact between adjacent components of the solid-state battery and / or control an amount of stress that the components of the solid-state battery are subjected to. Although not shown, an electrically conductive spacer can be positioned between the cathode and the first current collector.

[0077] As used herein, “interfacial resistance” is measured using electrical impedance spectroscopy (EIS) at 25°C for frequencies from 0.1 Hertz (Hz) to 1 MegaHertz (MHz). Unless otherwise indicated, EIS was measured using a PGSTAT320N (Metrohm Autolab) impedance analyzer at 25°C. A Nyquist plot is constructed with the real component of impedance (Z’ measured in cm2) on a horizontal axis and the imaginary component of impedance (Z” measured in cm2) on a vertical axis. Throughout the disclosure, “interfacial resistance” is defined as the difference between the real components of the impedance for the end-points of an arc shape in EIS results (i.e., Nyquist plot), where the higher end-point is taken as an inflection point in the impedance results. For determining “interfacial resistance”, the battery is configured to be used with a lithium-containing anode disposed on the first major surface of the solid-state electrolyte and the interlayer positioned between the second major surface of the solid-state electrolyte and a cathode. Examples of Nyquist plots are shown in FIGS. 12-13. Without wishing to be bound by theory, the predominant contribution to interfacial resistance in the configuration described above for interfacial resistance is between the cathode and the solid-state electrolyte. In aspects, theinterfacial resistance (e.g., between the cathode and the solid-state electrolyte) can be about 300 cm2or less, about 200 cm2or less, about 150 cm2or less, about 135 cm2or less, about 100 cm2or less, about 80 cm2or less, or about 60 cm2or less. In further aspects, the interfacial resistance using the interlayer 114 comprising a liquid interlayer can be about 135 cm2or less, about 100 cm2or less, about 80 cm2or less, or about 60 cm2or less, for example, in a range from about 10 cm2to about 135 cm2, from about 30 cm2to about 100 cm2, from about 50 cm2to about 80 cm2, from about 60 cm2to about 80 cm2, or any range or subrange therebetween. The interfacial resistance of interlayers and solid-state batteries containing the same in accordance with aspects of the disclosure can be reduced by more than one order of magnitude (e.g., lOOx or more, lOOOx or more) than a solid-state battery without an interlayer, which can have an interfacial resistance on the order of 100,000 cm2. Providing and / or maintaining a low (e.g., about 300 cm2or less, about 100 cm2or less) interfacial resistance of the interlayer and / or the solid-state battery can enable the solid-state battery to have a longer life (e.g., withstand more cycles without failure), reduce losses and heating from increased interfacial resistance, and / or reduce the formation of dendrites (e.g., lithium dendrites) that can lead to failure of the solid-state battery.

[0078] Throughout the disclosure, an “oxidation potential” of an interlayer is measured using linear sweep voltammetry (LSV) at 5 milliVolts (mV) per second (mV / s) as a potential at which there is an inflection point in current corresponding to be beginning of a sharp increase in current detected from the interlayer. As used herein, the oxidation potential is measured by positioning the interlayer between one stainless steel electrode and one lithium metal electrode. In aspects, the interlayer can comprise an oxidation potential of about 4.5V or more, about 5 V or more, about 5.2 V or more, about 5.3 V or more, about 5.4 V or more, or about 5.5 V or more. As discussed below in the Examples with reference to FIG. 11, the interlayers of Examples 1-4 and Comparative Examples BB-CC comprise an oxidation potential of 4.5 V or more, 5 V or more, and 5.2 V or more, Examples 1-3 and Comparative Examples BB-CC comprise an oxidation potential of 5.3 V or more, and Example 1 and Comparative Example BB comprises an oxidation potential of 5.5V or more. The results demonstrate that the mixture of a sulfone-containing compound and a nitrile-containing compound does not impair the oxidation potential associated with the lithium salt. Providing a high oxidation potential of an interlayer (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable increased capacity (e.g., charging to higher voltages), increased capacity retention of the solid-state battery (e.g., through decreased degradation of the interlayer), and / or increased longevity of the solid-state battery. Also, somelithium salts in the interlayer can corrode other parts of the solid-state battery (e.g., first current collector), which can be accelerated at increased temperatures (e.g., 40°C or more) and / or increased charging voltage cutoffs (e.g., about 4 V or more). Providing an interlayer with an increased oxidation potential (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable the solid-state battery to operate at increased temperatures (e.g., greater than 25°C, 40°C or more) and / or increased charging voltage cutoffs (e.g., 4.5 V or more) without increased corrosion of the solid-state battery. Additionally, providing an interlayer comprising a polymeric matrix can further reduce a corrosion of components of the solid-state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte.

[0079] Throughout the disclosure, an “ionic conductivity” of an interlayer is measured using for the interlayer positioned between a pair of stainless steel electrodes based on the behavior at 1 MegaHertz (MHz) using electrical impedance spectroscopy (EIS). The ionic conductivity is the inverse of the high-frequency impedance multiplied by the thickness of the interlayer. In aspects, the interlayer can have an ionic conductivity at 20°C of about 1.1 milliSeimens per centimeter (mS / cm) or more, about 1.15 mS / cm or more, about 1.2 mS / cm or more, about 1.25 mS / cm or more, about 2 mS / cm or less, about 1.5 mS / cm or less, about 1.4 mS / cm or less, or about 1.3 mS / cm or less. In aspects, the interlayer can have an ionic conductivity at 20°C in a range from about 1.1 mS / cm to about 2 mS / cm, from about 1.15 mS / cm to about 1.5 mS / cm, from about 1.2 mS / cm to about 1.4 mS / cm, from about 1.25 mS / cm to about 1.3 mS / cm, or any range or subrange therebetween. In aspects, the interlayer can have an ionic conductivity at 50°C of about 2.5 mS / cm or more, about 2.6 mS / cm or more, about 2.65 mS / cm or more, about 2.75 mS / cm or more, about 3 mS / cm or more, about 3.15 mS / cm or more, about 3.3 mS / cm or more, about 3.5 mS / cm or more, or about 3.65 mS / cm or more. In aspects, the interlayer can have an ionic conductivity at 50°C in a range from about 2.5 mS / cm to about 5 mS / cm, from about 2.65 mS / cm to about 4.5 mS / cm, from about 3 mS / cm to about 4 mS / cm, from about 3.3 mS / cm to about 3.9 mS / cm, from about 3.5 mS / cm to about 3.8 mS / cm, from about 3.65 mS / cm to about 3.75 mS / cm or any range or subrange therebetween.

[0080] Throughout the disclosure, a “thermally stable” interlayer comprises a mass loss of 5 wt% or less based on thermogravimetric analysis (TGA) from 25°C to a predetermined temperature at a heating rate of 10°C / min. As used herein, TGA is conducted with a Netzsch STA 409PC Luxx (Netzsch-Geratebau GmbH). In aspects, the interlayer 114 or 314 can be thermally stable to a temperature of 100°C or more, about 120°C or more, about 140°C or more, about 150°Cor more, or about 160°C or more. As discussed below in the Examples with reference to FIG. 10, interlayers comprising LiTFSI and a mixture of succinonitrile and tetramethylene sulfone were thermally stable to about 160°C (curves 1007 and 1009) while curve 1005 (Comparative Example AA) is not thermally stable at even 100°C. Providing a thermally stable interlayer (e.g., to 100°C or more, about 150°C or more, about 160°C or more) can increase a range of operating temperatures for the solid-state battery, increase a capacity retention of the solid-state battery, and / or increase a longevity of the solid-state battery.

[0081] Throughout the disclosure, “capacity” refers to the charge stored in a battery when charged at 0.2C to cutoff voltage of 4.3 V at 25°C unless another temperature is specified, and the capacity is measured as milliAmp-hours per gram of cathode (e.g., cathode active material) (mAh / g). As used herein, “as-formed capacity” or “nominal capacity” is measured on the second cycle rather than the first cycle. In aspects, the solid-state battery can comprise an as-formed capacity of about 100 mAh / g or more, about 150 mAh / g or more, about 160 mAh / g or more, about 170 mAh / g or more, about 175 mAh / g or more, about 180 mAh / g or more, about 185 mAh / g or more, about 190 mAh / g or more, about 300 mAh / g or less, about 250 mAh / g or less, about 220 mAh / g or less, about 210 mAh / g or less, about 200 mAh / g or less, about 190 mAh / g or less, or about 185 mAh / g or less. In aspects, the solid-state battery can comprise an as-formed capacity ranging from about 100 mAh / g to about 300 mAh / g, from about 150 mAh / g to about 250 mAh / g, from about 160 mAh / g to about 220 mAh / g, from about 170 mAh / g to about 220 mAh / g, from about 175 mAh / g to about 210 mAh / g, from about 180 mAh / g to about 200 mAh / g, from about 185 mAh / g to about 190 mAh / g, or any range or subrange therebetween. In aspects, the solid-state battery can exhibit a capacity after 50 cycles or more, after 60 cycles or more, after 100 cycles or more, or after 160 cycles or more (at 0.2 with a cutoff voltage of 4.3 V at 25°C) within one or more of the ranges discussed above in this paragraph. Providing and / or maintaining a high capacity (e.g., 150 mAh / g or more as-formed or after 50 cycles or after 65 cycles or after 165 cycles at 25°C) can enable the solid-state battery to make efficient use of cathode materials (e.g., for an intended use for a longer period of time) than would otherwise be possible.

[0082] Throughout the disclosure, “capacity retention” refers to the percent of an as- formed capacity that the solid-state battery can achieve after a predetermined cycle using the same charge-discharge cycle for all cycles. Unless otherwise specified, as discussed above, a cycle corresponds to a charge-discharge cycle at 0.2C with a cutoff voltage of 4.3 V while the solid-state battery is maintained at 25°C. Unless otherwise indicated, battery testing including capacity retention and cycling at various nominal areal capacity is performed using the battery test systemBTS-4000 (Neware) at 25°C. As used herein, “withstand” indicates that the battery did not exhibit a short circuit or non-ohmic behavior during cycling. In aspects, the solid-state battery can comprise a capacity retention of about 88% or more, about 90% or more, about 92% or more, about 95% or more, about 96% or more, about 97% or more, or about 98% or more after 50 cycles at 0.2C with a cutoff voltage of 4.3V and at 25°C. In further aspects, a solid-state battery with the interlayer 314 comprising the polymeric matrix can comprise a capacity retention within one or more of the ranges mentioned in the previous sentence after 50 cycles or more at 0.2C with a cutoff voltage of 4.3 V and at 25°C. In aspects, the solid-state battery can comprise a capacity retention of about 80% or more, about 82% or more, about 85% or more, about 88% or more, about 90% or more, about 91% or more, about 92% or more after 65 cycles or more at 0.2C with a cutoff voltage of 4.3 V and at 25°C. In aspects, the solid-state battery can comprise a capacity retention of about 80% or more, about 82% or more, about 85% or more, about 88% or more, about 90% or more, about 91% or more, about 92% after 160 cycles or more at 0.2C with a cutoff voltage of 4.3 V and at 25°C. Maintaining a high capacity retention (e.g., 95% or more after 50 cycles at 25°C, 85% or more after 65 cycles at 25°C, 80% or more after 165 cycles at 25°C) can enable the solid-state battery to be functional for an intended use for a longer period of time than would otherwise be possible.

[0083] As used herein, “Columbic efficiency” refers to a ratio of a total charge extracted from a battery to a total charge put into the battery during a cycle. In aspects, the solid-state battery can have a Columbic efficiency of about 95% or more, about 97% or more, about 98% or more, about 99% or more, about 99.5% or more, or about 99.7% or more for the solid-state battery as- formed (during the second cycle), after 50 cycles, after 65 cycles, after 100 cycles, after 150 cycles, or after 165 cycles.

[0084] Aspects of methods of making the battery (e.g., solid-state battery) in accordance with aspects of the disclosure will be discussed with reference to example method steps illustrated in FIGS. 5-10. Methods can comprise providing a solid-state electrolyte and / or a cathode.

[0085] In aspects, as shown in FIGS. 5 and 7, methods comprise disposing a solution 503 or 703 on a first major surface 105 of a cathode 104. In further aspects, the solution 503 or 703 comprise one or more of the components discussed above (e.g., lithium salt, nitrile-containing compound, sulfone-containing compound). In further aspects, as shown, disposing the solution 503 or 703 can comprise dispensing a predetermined amount of the solution 503 or 703 from a container 501 or 701 (e.g., conduit, flexible tube, micropipette, or syringe) to form a layer of liquid 505 or 705 on a first major surface 105 of the cathode 104. In further aspects, the predeterminedamount of the solution 503 or 703 as a ratio of a volume of the solution to an area of the first major surface of the cathode can be within one or more of the corresponding ranges discussed above for the amount of the interlayer 114 or 314. Providing the ratio of the volume of the interlayer to the area of the first major surface of the cathode can be sufficient to wet the interface between the cathode and the solid-state electrolyte while minimizing concerns associated with traditional liquid electrolytes (e.g., in liquid-based batteries or in hybrid liquid-solid batteries). Although not shown, the cathode can be disposed on the first current collector while the interlayer is disposed on the cathode. Although not shown, the cathode can be disposed on the first current collector while the interlayer is disposed on the cathode.

[0086] In further aspects, the solution 503 can be free of a monomer that could be cured to form a polymeric matrix. In further aspects, the solution 503 can consist essentially of and / or consist of the lithium salt, the sulfone-containing compound, the nitrile-containing compound, and optionally fluoroethylene carbonate. Alternatively, in further aspects, the solution 703 can further comprise a monomer and / or other precursor materials for the polymeric matrix. In even further aspects, the monomer can include one or more of a multi-functional acrylate monomer (e.g., ethylene glycol diacrylate, ethylene dimethacrylate, ethoxylated trimethylolpropane triacrylate) and / or a methacrylate monomer (e.g., methyl methacrylate, trifluoroethyl methacrylate). In even further aspects, the monomer, as a wt% of the solution, can range from about 5 wt% to about 15 wt%, from about 6 wt% to about 12 wt%, from about 7 wt% to about 11 wt%, from about 8 wt% to about 10 wt%, or any range or subrange therebetween. In even further aspects, the solution 703 can optionally comprise a photoinitiator, as wt% of the precursor solution, of greater than 0% to about 1 wt%, from about 0.02 wt% to about 0.5 wt%, from about 0.05 wt% to about 0.2 wt%, from about 0.07 wt% to about 0.1 wt%, or any range or subrange therebetween. In still further aspects, the initiator can comprise a free radical photoinitiator, for example, azodiisobutyronitrile (AIBN). An exemplary aspect of a photoinitiator is 2-hydroxy-2-methylpropionphenone (HMPP).

[0087] In aspects, as shown in FIG. 8, methods can proceed to curing the solution (e.g., layer 705 in FIG. 7) to form the interlayer 314. In further aspects, as shown in FIG. 8, curing the precursor solution can comprise heating the precursor solution and the cathode 104 at a predetermined temperature for a predetermined period of time, for example, by placing the precursor solution and the cathode 104 in an oven 801. In even further aspects, the predetermined temperature can range from about 40°C to about 100°C, from about 60°C to about 80°C, or any range or subrange therebetween. In even further aspects, the predetermined period of time can range from about 5 minutes to about 6 hours, from about 8 minutes to about 2 hours, from about10 minutes to about 60 minutes, from about 10 minutes to about 30 minutes, from about 15 minutes to about 20 minutes, or any range or subrange therebetween. Alternatively, in further aspects, as shown, curing the precursor solution can comprise irradiating the precursor solution with radiation 805 emitted from a radiation source 803 to form the interlayer 314, for example, when the precursor solution comprises a photoinitiator. The radiation source 803 can comprise a light-emitting diode (LED), an organic light-emitting diode (OLED), a laser, an incandescent bulb, and / or a fluorescent bulb (e.g., a cold cathode fluorescent lamp (CCFL)). The radiation source 803 can be configured to emit radiation 805 comprising one or more wavelengths that the photoinitiator is sensitive to.

[0088] As shown in FIGS. 6 and 9, after dispensing the solution 503 or 703, methods can proceed to disposing the solid-state electrolyte 108 over the first major surface 105 of the cathode 104, as indicated by arrow 601 or 901. The solid-state electrolyte 108 can comprise any of the aspects discussed above for the solid-state electrolyte 108. In further aspects, as shown, the second major surface 107 of the solid-state electrolyte 108 can face the first major surface 105 of the cathode 104 with the interlayer 114 or 314 positioned therebetween. In aspects, as shown in FIG. 6, the layer 505 of the solution 503 (see FIG. 5) can be formed into the interlayer 114 comprising a liquid when the solid-state electrolyte 108 is disposed thereon. Alternatively, as shown in FIGS. 7-8, the layer 705 can be cured into the interlayer 314 comprising the polymeric matrix. As shown, the anode 112 can be disposed on the solid-state electrolyte 108 while the solid-state electrolyte 108 is disposed over the first major surface 105 of the cathode 104. Although not shown, the anode could be disposed on the solid-state electrolyte after the solid-state electrolyte is disposed on the cathode. Although not shown, it is to be understood that elements (e.g., second current collector, optional second interlayer or coating, electrically conductive spacer) can be disposed on the solid- state electrolyte opposite the second major surface while the solid-state electrolyte is disposed over the first major surface of the cathode. Alternatively, the anode can be disposed on the solid-state electrolyte after the solid-state electrolyte is disposed over the cathode. Although not shown, it is to be understood that methods of making the solid-state battery can comprise (1) disposing the interlayer comprising the lithium salt, the sulfone-containing compound, and the nitrile-containing compound on the second major surface of the solid-state electrolyte and (2) disposing the cathode (e.g., first major surface) over the second major surface of the solid-state electrolyte. However, when the area of the first major surface is less than an area of the second major surface, more of the interlayer is at the interface when the interlayer is disposed on the cathode instead of the solid- state electrolyte.EXAMPLES

[0089] Various aspects will be further clarified by the following examples. Examples 1- 10 and Comparative Examples AA-EE comprised a liquid interlayer. Example 11 comprised an interlayer with a polymeric matrix. Comparative Examples. Examples 1-5 and Comparative Examples comprised the liquid interlayer between a steel electrode and a lithium metal electrode for measuring ionic conductivity and the oxidation potential. Examples 6-10 and Comparative Examples DD-EE comprised solid-state batteries with a NCM811 cathode (discussed below), a garnet solid-state electrolyte (discussed below), and a lithium metal anode assembled into a CR2025 coin cell form (see FIGS. 2 and 4) for measuring capacity and capacity retention at 25°C.

[0090] NCM811 refers to LiNio.8Coo.1Mno.1O2 (precursor commercially available from Landt Instruments). A slurry was formed with a 8:0.5:0.5: 1 weight ratio of the NCM811 powder, super P carbon black (available from Timcal - Imerys), vapor grown carbon fiber (VGCF), and poly(vinylidene fluoride) (PVDF) (dissolved in N-methylpyrrolidone) that was coated on aluminum (Al) foil with a predetermined thickness and dried under vacuum. The lithium- containing material for the anode was disposed on the coating and heated for 5 minutes at 300°C.

[0091] The lithium garnet solid-state electrolyte was cubic phase Li6.5La3Zr1.4Tao.5O12 (LLZTO), which was synthesized from a stoichiometric ratio of starting powders of LiOH’EEO (AR), La2O3(99.99%), ZrO2(AR), Ta2O5(99.99%). 2 wt% excess of LiOH«H2O added to compensate the lithium loss during processing. La2O3was heated at 900°C for 12 hours to remove any moisture and / or CO2. The raw materials were mixed via a wet grinding process in which yttrium-stabilized zirconium oxide (YSZ) balls and isopropanol (IP A) were used as the milling media. For the consolidated pellets, the pellets were formed by drying and calcining the mixture at 950°C for 6 hours in an alumina crucible, producing pure cubic garnet phase powder. These powders were pressed into green pellets and sintered at 1230°C for 1 hour, covered with LLZTO powder with 15 wt% Li excess in platinum crucibles. For the sintered tape, the mixture was mixed with an organic binder system comprising a propionate solvent, a dispersant, a plasticizer, and an acrylate-based polymer, which was tape cast with a doctor blade to form a green tape. The green tape was sintered at from 1000°C to 1300°C for 10 minutes.Examples 1-5 and Comparative Examples AA-CC

[0092] The interlayers of Examples 1-5 and Comparative Example A were formed by dissolving the lithium salt (i.e., LiTFSI) in the materials listed in Table 1 to form a 3M solution of the lithium salt at 25°C along with 5 wt% fluoroethylene carbonate. FIG. 10 presents TGA results for Example 1, Example 5, and Comparative Example AA. As discussed above, the TGA wasconducted using a Netzsch STA 409PC Luxx (Netzsch-Geratebau GmbH) starting at 25°C with the temperature increased at 10°C / min. In FIG. 10, the horizontal axis 1001 corresponds to temperature in °C, and the vertical axis 1003 is the wt% of the sample remaining. Curve 1005 corresponds to the results for Comparative Example AA. Curve 1005 already lost mass at 50°C, lost more than 10 wt% by 100°C, and lost more than 20 wt% at 150°C. This demonstrates that Comparative Example AA is not suitable for operating temperatures much above room temperature (e.g., 45°C or more) and can represent a flammability risk because of a high vapor pressure that can be associated with liquid materials that lose mass over an extended temperature range. Curves 1007 and 1009 correspond to Examples 1 and 5, respectively. Curves 1007 and 1009 maintain substantially 100 wt% beyond 100°C (and beyond 120°C). Also, curves 1007 and 1009 demonstrate a mass loss of 5% or less (thermally stable) at temperatures of 150°C or more or 160°C or more. Both curves 1007 and 1009 demonstrate that Examples 1 and 5 are thermally stable at temperatures much higher than Comparative Example AA, as indicated by curve 1005.

[0093] Table 1 also presents the oxidation potential and ionic conductivity that was measured for Examples 1-5 and Comparative Examples BB-CC by sandwiching the interlayer between a stainless steel electrode and a lithium metal electrode, where a ratio of a volume of the interlayer to a surface area of one of the stainless steel electrode is about 17.7 pL / cm2. Values not reported (“— ”) in Table 1 were not measured. As described above, the oxidation potential was measured using LSV at 25°C. FIG. 11 presents the result of LSV for Examples 1-5 and Comparative Examples BB-CC. In FIG. 11, the horizontal axis 1101 is voltage in Volts, and the vertical axis 1103 is current in Amps. Curves 1117, 1115, 1113, 1111, and 1109 correspond to Examples 1-5, respectively. Curve 1105 corresponds to comparative Example CC, and curve 1107 corresponds to comparative Example BB. The oxidation potential generally increases as the volume ratio decreases, with noticeable changes between Examples 4 and 5. The oxidation potential for Examples 1-4 is between those for Comparative Examples BB-CC. These results demonstrate that the mixture of a sulfone-containing compound and a nitrile-containing compound does not impair the oxidation potential associated with the lithium salt.Table 1 : Properties of Examples 1-5 and Comparative Examples AA-CC

[0094] Ionic conductivity was measured based on the behavior at high-frequency (at 1 MHz) measured as part of generating the Nyquist plot, as described above. The ionic conductivity is the inverse of the high-frequency impedance multiplied by the thickness of the interlayer (i.e., between the pair of stainless steel electrodes). The ionic conductivity of Examples 1-5 is between those for Comparative Examples BB-CC. These results demonstrate that the mixture of a sulfone- containing compound and a nitrile-containing compound does not impair the oxidation potential associated with the lithium salt. Taking the conflicting trends for oxidation potential and ionic conductivity together, mixtures of the sulfone-containing compound and a nitrile-containing compound (e.g., with a volume ratio from 2:3 to 3:2) can achieve a balance with improved performance compared to Comparative Examples BB-CC with only one of the sulfone-containing compound or the nitrile-containing compound.Examples 6-11 and Comparative Examples DD-EE

[0095] The interlayers of Examples 6-10 and Comparative Examples DD-EE were formed by dissolving the lithium salt (i.e., LiTFSI) in the materials listed in Table 2 to form a 3M solution of the lithium salt at 25°C along with 5 wt% fluoroethylene carbonate. Table 2 presents the properties of Examples 6-10 and Comparative Examples DD-EE. Examples 6-10 comprised solid- state batteries with a NCM811 cathode, a garnet solid-state electrolyte, and a lithium metal anode assembled into a CR2025 coin cell form at 25°C. Examples 6-11 comprised an electrospun PVDF- HFP polymer fiber film positioned in the interlayer. The electrospun PVDF-HFP polymer fiber film was formed by electrospinning a 20 wt% solution of the polymer with a weight-averaged molecular weight of 400,000 Daltons in dimethylformamide. Likewise, Comparative ExamplesDD-EE comprised solid-state batteries with a NCM811 cathode, a garnet solid-state electrolyte, and a lithium metal anode assembled into a CR2025 coin cell form at 25°C.

[0096] Before assembly, the lithium garnet solid-state electrolyte sheets were dry polished. After that, in an argon-filled glovebox, fresh Li foils were melted onto one side of the lithium garnet solid-state electrolyte and was allowed to naturally cool to room temperature (i.e., 25°C). The interlayer comprising the liquid electrolyte stated in Table 2 was disposed on the cathode with a ratio of a volume of the interlayer (20 pL) to an area of the first major surface of the cathode of 17.7 pL / cm2, and then the exposed surface of the lithium garnet solid-state electrolyte (opposite the lithium anode) was placed on the liquid electrolyte wetted cathode. The Ni foam with the same diameter as Li anode was placed on the top of the anode, and the battery was sealed in a CR2025 coin cell with an applied pressure of 5 MPa.

[0097] FIG. 12 shows a Nyquist plot for Examples 6-10 and Comparative Example DD; and FIG. 13 shows a Nyquist plot for Example 11. As discussed above, the data shown in FIGS. 12-13 were measured by EIS using PGSTAT320N (Metrohm Autolab) impedance analyzer at 25°C for frequencies from 0.1 Hertz (Hz) to 1 MegaHertz (MHz). In FIGS. 12-13, the horizontal axis 1201 and 1301 corresponds to the real component of impedance (Z’ measured in cm2), and the vertical axis 1203 and 1303 corresponds to the imaginary component of impedance (Z” measured in cm2). As discussed above, the interfacial resistance shown in Table 2 is measured as the difference between the real components of the impedance for the end-points of an arc shape of the curve corresponding to the EIS results in the Nyquist plot.

[0098] Curve 1207 corresponds to Comparative Example DD, respectively, with an interfacial resistance greater than 200 Q cm2(or greater than 250 Q cm2). Curve 1209 corresponds to Example 6 with an interfacial resistance less than 200 Q cm2(or less than 150 Q cm2or even less than or equal to 135 Q cm2). Curves 1215, 1213, and 1211 correspond to Examples 7-9, respectively, with an interfacial resistance less than 200 Q cm2(or less than 150 Q cm2or even less than or equal to 135 Q cm2). Curve 1217 corresponds to Example 10 with an interfacial resistance less than 200 Q cm2(or less than 150 Q cm2or even less than or equal to 135 Q cm2). Consequently, the mixture of the sulfone-containing compound and the nitrile-containing compound provides a reduced interfacial resistance (by about 50% or more, by about 150 Q cm2) compared to using the nitrile-containing compound without the nitrile-containing compound (Comparative Example DD).Table 2: Properties of Examples 6-11 and Comparative Examples DD-EE at 25°C

[0099] Table 2 presents the initial capacity (e.g., nominal capacity) capacity retention and Columbic efficiency for Examples 6-10 and Comparative Examples DD-EE that were cycled at 0.2C with a cutoff voltage of 4.3V and at 25°C. Comparative Example DD comprised an initial capacity of less than 170 mAh / g while Examples 6-10 comprised an initial capacity greater than 175 mAh / g and greater than or equal to 180 mAh / g. Comparative Example EE comprised an initial capacity of less than 190 mAh / g while Example 6 comprised an initial capacity of greater than 195 mAh / g.

[0100] FIGS. 14-16 show capacity retention in terms of a measured discharge capacity in mAh / g for each cycle on the vertical axis 1403, 1503, or 1603 as a function of the number of cycles on the horizontal axis 1401, 501, or 1601. Curve 1407 corresponds to Comparative Example DD that comprised a capacity retention of 82.4% after 65 cycles and a capacity retention of 61.2% after 160 cycles (cycled at 0.2C with a cutoff voltage of 4.3 V and at 25°C). Curve 1505 corresponds to Comparative Example EE that comprised a capacity retention of 88.1% after 65 cycles and a capacity retention of 63.7% after 160 cycles (cycled at 0.2C with a cutoff voltage of 4.3 V and at 25°C). Curves 1415 and 1417 correspond to Examples 14 and 15, respectively, with capacity retention of 90% or more after 65 cycles and greater than 70% after 160 cycles. Curves 1513, 1911, and 1509 correspond to Examples 6-8, respectively, with a capacity retention of 90% or more after 65 cycles and a capacity retention of greater than 70% and greater than 75% after 165 cycles(cycled at 0.2C with a cutoff voltage of 4.3 V and at 25°C). Overall, Comparative Examples DD- EE comprised a capacity retention of less than 90% after 65 cycles while Examples 6-10 comprised a capacity retention greater than or equal to 90% after 65 cycles with Examples 7 and 9 comprising a capacity retention of greater than 92% after 65 cycles. Comparative Examples DD-EE comprised a capacity retention less than 70% and less than 65% after 165 cycles while Examples 6-10 comprised a capacity retention greater than 70% and greater than 73% after 165 cycles with Examples 12 and 14 comprised a capacity retention greater than 80% after 165 cycles. Examples 6-10 have capacity retention after 65 cycles and after 165 cycles greater than that of Comparative Examples DD-EE. Specifically, Examples 6-10 have a capacity retention of 90% or more (after 65 cycles) and a Columbic efficiency of 98.4% or more; and Examples 6-8 and 10 have a Columbic efficiency greater than 99% and capacity retention of 85.5% or more. Based on Table 2, providing a volume ratio of 0.67 (2:3) or more (e.g., from 0.67 to 4) can provide a capacity retention of 90% or more and a Columbic efficiency of greater than 98%.

[0101] The interlayer of Example 11 comprised an acrylate-based polymeric matrix that was formed by curing a precursor solution comprising 3 M LiTFSI in a 1 : 1 ratio of the sulfone- containing compound to the nitrile-containing compound with 5 wt% fluoroethylene carbonate, 10wt% ethylene glycol methacrylate as a monomer, and 0.1 wt% of hydroxy-2 - methylpropionphenone (HMPP) (also known as 2-hydroxy-2-methyl-l -phenyl- 1 -acetone) as a photoinitiator with the electrospun PVDF-HFP polymer fiber film positioned in the interlayer. As shown in Table 2 and FIG. 13, curve 1305 (Example 11) exhibited an interfacial resistance of about 300 Q cm2, which is comparable that of Comparative Example DD even though the polymeric matrix formed by curing the precursor solution of Example 11 that decreases a mobility of the lithium salt contained therein. As shown in Table 2 and FIG. 16, curve 1605 (Example 11) exhibited an initial capacity of 181 mAh / g and a capacity retention of 93.3% after 50 cycles. Only 50 cycles were measured for Example 11 because a power failure during cycle 51 interrupted the testing. FIG. 16 also includes another vertical axis 1613 corresponding to Columbic efficiency with curve 1615 showing a Columbic efficiency of 99%. Example 11 has a capacity retention of greater than 80%, greater than 90%, greater than 95%, and greater than 98% after 50 cycles.

[0102] The above observations can be combined to provide solid-state batteries, and methods of making the same comprising a interlayer positioned between a cathode and a solid- state electrolyte. The interlayer comprises a mixture of the nitrile-containing compound and sulfone-containing compound that, discussed in the Examples herein, can provide decreased interfacial resistance and increased cycling performance (e.g., capacity retention) compared toeither compound alone. In aspects, the interlayer can comprise a liquid interlayer that can wet the interface between the cathode and the solid-state electrolyte to reduce interfacial resistance therebetween while minimizing a total amount of liquid interlayer in the solid-state battery. Alternatively, in aspects, the interlayer can further comprise a polymeric matrix that can further reduce a corrosion of components of the solid-state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte. Providing the polymeric matrix can balance reducing the mobility of the lithium salt to reduce corrosion of the solid-state battery (e.g., first current collector) with a potential decrease in ionic conductivity of the interlayer. In aspects, the interlayer can comprise fluoroethylene carbonate that can increase the stability of the interlayer, for example, to high voltage conditions while providing 10 wt% or less of fluoroethylene carbonate can avoid dissolution of transition metals in the interlayer, which can impair the functionality of the cathode. In aspects, the interlayer can further comprise a fiber film that can increase a uniformity of lithium-ion flux by anchoring a position of the components (e.g., lithium salt, sulfone-containing compound, nitrile-containing compound, and / or the polymeric matrix) of the interlayer.

[0103] The interfacial resistance of interlayers and solid-state batteries containing the same in accordance with aspects of the disclosure can be reduced by more than one order of magnitude (e.g., lOOx or more, lOOOx or more) than a solid-state battery without an interlayer, which can have an interfacial resistance on the order of 100,000 cm2. Providing and / or maintaining a low (e.g., about 300 cm2or less, about 100 cm2or less) interfacial resistance of the interlayer and / or the solid-state battery can enable the solid-state battery to have a longer life (e.g., withstand more cycles without failure), reduce losses and heating from increased interfacial resistance, and / or reduce the formation of dendrites (e.g., lithium dendrites) that can lead to failure of the solid-state battery. Providing a high oxidation potential of an interlayer (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable increased capacity (e.g., charging to higher voltages), increased capacity retention of the solid-state battery (e.g., through decreased degradation of the interlayer), and / or increased longevity of the solid-state battery. Also, some lithium salts in the interlayer can corrode other parts of the solid-state battery (e.g., first current collector), which can be accelerated at increased temperatures (e.g., 40°C or more) and / or increased charging voltage cutoffs (e.g., about 4 V or more). Providing an interlayer with an increased oxidation potential (e.g., about 4.5 V or more, about 5 V or more, about 5.3 V or more) can enable the solid-state battery to operate at increased temperatures (e.g., greater than 25°C, 40°C or more)and / or increased charging volage cutoffs (e.g., 4.5 V or more) without increased corrosion of the solid-state battery. Additionally, providing an interlayer comprising a polymeric matrix can further reduce a corrosion of components of the solid-state battery (e.g., first current collector) can decrease a mobility of the lithium salt contained therein and / or that decrease an amount of the lithium salt can travel away from the interface between the cathode and the solid-state electrolyte. Providing a thermally stable interlayer (e.g., to 100°C or more, about 150°C or more, about 160°C or more) can increase a range of operating temperatures for the solid-state battery, increase a capacity retention of the solid-state battery, and / or increase a longevity of the solid-state battery. Providing and / or maintaining a high capacity (e.g., 150 mAh / g or more as-formed or after 50 cycles or after 65 cycles or after 165 cycles at 25°C) can enable the solid-state battery to make efficient use of cathode materials (e.g., for an intended use for a longer period of time) than would otherwise be possible.

[0104] Providing a solid-state electrolyte (e.g., in a solid-state battery) can address common safety concerns, for example, leakage, poor chemical stability, and flammability often seen in batteries employing liquid electrolytes. Moreover, providing a solid-state electrolyte can also suppress polysulfide shuttling from the cathode to the anode, thereby leading to improved electrode (e.g., anode, cathode) utilization and a high discharge capacity and energy density. Providing a solid-state electrolyte can reduce a formation of dendrites (e.g., lithium dendrites) that can otherwise result in failure of the battery.

[0105] Directional terms as used herein — for example, up, down, right, left, front, back, top, bottom — are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0106] It will be appreciated that the various disclosed aspects may involve features, elements, or steps that are described in connection with that aspect. It will also be appreciated that a feature, element, or step, although described in relation to one aspect, may be interchanged or combined with alternate aspects in various non-illustrated combinations or permutations.

[0107] It is also to be understood that, as used herein the terms “the,” “a,” or “an,” mean “at least one,” and should not be limited to “only one” unless explicitly indicated to the contrary. For example, reference to “a component” comprises aspects having two or more such components unless the context clearly indicates otherwise. Likewise, a “plurality” is intended to denote “more than one.”

[0108] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may beapproximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, aspects include from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. Whether or not a numerical value or endpoint of a range in the specification recites “about,” the numerical value or endpoint of a range is intended to include two aspects: one modified by “about,” and one not modified by “about.” It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint.

[0109] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, as defined above, “substantially similar” is intended to denote that two values are equal or approximately equal. In aspects, “substantially similar” may denote values within about 10% of each other, for example, within about 5% of each other, or within about 2% of each other.

[0110] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that any particular order be inferred.

[0111] While various features, elements, or steps of particular aspects may be disclosed using the transitional phrase “comprising,” it is to be understood that alternative aspects, including those that may be described using the transitional phrases “consisting of’ or “consisting essentially of,” are implied. Thus, for example, implied alternative aspects to an apparatus that comprises A+B+C include aspects where an apparatus consists of A+B+C and aspects where an apparatus consists essentially of A+B+C. As used herein, the terms “comprising” and “including”, and variations thereof shall be construed as synonymous and open-ended unless otherwise indicated.

[0112] The above aspects, and the features of those aspects, are exemplary and can be provided alone or in any combination with any one or more features of other aspects provided herein without departing from the scope of the disclosure.

[0113] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of the aspects herein provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. A battery, comprising: a cathode; an interlayer disposed on a first major surface of the cathode, the interlayer comprising a lithium salt, a nitrile-containing compound, and a sulfone-containing compound; a solid-state electrolyte disposed on the interlayer; and a lithium-containing anode disposed on the solid-state electrolyte opposite the interlayer.

2. The battery of claim 1, wherein the interlayer further comprises a polymeric matrix with the lithium salt, the nitrile-containing compound, and the sulfone-containing compound positioned within the polymeric matrix.

3. The battery of claim 2, wherein the polymeric matrix comprises an acrylate-based polymer, an epoxy-based polymer, or copolymer or combinations thereof.

4. The battery of any one of claims 2-3, wherein an interfacial resistance between the cathode and the solid-state electrolyte is about 300 cm2or less at 25°C.

5. The battery of any one of claims 2-3, wherein the battery comprises a capacity retention of about 95% or more after 50 cycles at 0.2C with a cutoff voltage of 4.3 V and at 25°C.

6. The battery of any one of claims 2-3, wherein the battery comprises an average columbic efficiency of about 99% or more after 50 cycles at 0.2 C with a cutoff voltage of 4.3 V and at 25°C.

7. The battery of claim 1, wherein an interfacial resistance between the cathode and the solid- state electrolyte is about 135 cm2or less at 25°C.

8. The battery of claim 1, wherein the battery comprises at least one of: a capacity retention of about 80% or more after 160 cycles at 0.2C with a cutoff voltage of4.3 V and at 25°C; or a capacity retention is about 85% or more after 65 cycles at 0.2C with a cutoff voltage of 4.3V and at 25°C.

9. The battery of any one of claims 1 or 7-8, wherein the battery comprises an average columbic efficiency of about 99% or more after 50 cycles at 0.2 C with a cutoff voltage of 4.3 V and at 25°C.

10. The battery of any one of claims 1-3 or 7-8, wherein the interlayer comprises an oxidation potential of about 5.2V or more at 25°C.

11. The battery of any one of claims 1-3 or 7-8, wherein an ionic conductivity of the interlayer at 20°C is about 1.1 milliSeimens per centimeter or more.

12. The battery of any one of claims 1-3 or 7-8, wherein the lithium salt comprises at least one of: lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium perchlorate (LiCICU), lithium tetrafluoroborate (LiBF4), lithium tritiate (LiSChCFs), Li SChCFs or combinations thereof.

13. The battery of any one of claims 1-3 or 7-8, wherein a concentration of the lithium salt is in a range from about 2 molar to about 5 molar.

14. The battery of any one of claims 1-3 or 7-8, wherein the nitrile-containing compound comprises succinonitrile.

15. The battery of any one of claims 1-3 or 7-8, wherein the sulfone-containing compound comprises an alkyl sulfone.

16. The battery of any one of claims 1-3 or 7-8, wherein a volume ratio of the nitrile-containing compound to the sulfone-containing compound is in a range from about 0.2 to about 5.

17. The battery of any one of claims 1-3 or 7-8, wherein the interlayer further comprises from about 0.1 wt% to about 10 wt% of fluoroethylene carbonate.

18. The battery of any one of claims 1-3 or 7-8, wherein the solid-state electrolyte comprises at least one of:(i) Li7-3aLa3Zr2LaOi2, with L = Al, Ga, or Fe and 0 < a < 0.33;(ii) Li7La3-bZr2MbOi2, with M = Bi or Y and 0 < b < 1;(iii) Li7-cLa3(Zr2-c,Nc)Oi2, with N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1;(iv) protonated LLZO (e.g., HxLi6.5-xLa3Zr1.5I0.5O12, with I = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < x < 4 or HxLi6.25-xEo.25La3Zr20i2, with E = Al, Ga, or Fe and 0 < x < 4); or a combination thereof.

19. A method of forming a battery comprising: disposing a solution comprising a lithium salt, a sulfone-containing compound, and a nitrile-containing compound on a first major surface of a cathode; and disposing a solid-state electrolyte over the first major surface of the cathode, the lithium salt positioned between the cathode and the solid-state electrolyte.

20. The method of claim 19, wherein the solution further comprises a monomer, and the method further comprises curing the monomer to form an interlayer comprising polymeric matrix with the lithium salt, the sulfone-containing compound, and the nitrile-containing compound positioned within the polymeric matrix.

21. The method of claim 20, wherein the precursor solution comprises from about 2 wt% to about 20 wt% of the monomer.

22. The method of any one of claims 20-21, wherein the monomer is an acrylic monomer, an epoxy monomer, or combinations thereof, and the polymeric matrix comprises an acrylate-based polymer, an epoxy-based polymer, or copolymers or combinations thereof.

23. The method of any one of claims 19-21, wherein a volume ratio of the nitrile-containing compound to the sulfone-containing compound is in a range from about 0.2 to about 5.

24. The method of any one of claims 19-21, wherein the nitrile-containing compound comprises succinonitrile, the sulfone-containing compound comprises an alkyl sulfone, the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or combinations thereof.

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