WO2024097084A2

WO2024097084A2 - Modifying interlayer for lithium battery with crosslinked polymer within pores of 3d polymeric framework including a sulfonic acid

Info

Publication number: WO2024097084A2
Application number: PCT/US2023/036077
Authority: WO
Inventors: Michael Edward Badding; Jun Jin; Zhen Song; Jianmeng Su; Zhaoyin Wen; Tongping XIU; Chujun Zheng
Original assignee: Corning Incorporated; Shanghai Institute Of Ceramics, Chinese Academy Of Sciences
Priority date: 2022-11-01
Filing date: 2023-10-27
Publication date: 2024-05-10
Also published as: WO2024097083A1

Abstract

A solid-state lithium-containing battery includes: (1) an electrode; (2) a solid-state electrolyte; and (3) a modifying interlayer disposed between, and in direct contact with, the electrode and the solid-state electrolyte, the modifying interlayer comprising (a) a three-dimensional (3D) polymeric framework including (i) electrospun polymer nanofibers having a diameter within a range from 10 nm to 50 nm, (ii) a framework additive integrated into the electrospun polymer nanofibers, the framework additive comprising a sulfonic acid containing compound, and (iii) pores between the fibers, (b) a crosslinked polymer within the pores of the 3D polymeric framework, (c) a crosslinking solvent within the pores of the 3D polymeric framework, and (d) a lithium salt within the pores of the 3D polymeric framework.

Description

MODIFYING INTERLAYER FOR LITHIUM BATTERY WITH CROSSLINKED POLYMER WITHIN PORES OF 3D POLYMERIC FRAMEWORK INCLUDING A SULFONIC ACID

[0001] This application claims the benefit of priority of Chinese Application Serial No. 202310859240.6 filed on July 13, 2023, and Chinese Application Serial No. 202211356878.X filed on November 01, 2022, the content of each is relied upon and incorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to lithium-ion batteries, and more particularly, to a modifying interlayer for use with lithium-ion batteries between an electrode and solid-state electrolyte.

BACKGROUND

[0003] Fossil fuels have long been a primary source of energy. However, fossil fuels are finite and, when burned to produce heat, produce a suboptimal amount of air pollution and greenhouse gases. To reduce reliance on fossil fuels as an energy source, renewable energy sources such as solar energy and wind energy are being used to generate electrical energy. The generation of electrical energy spurs demand for rechargeable batteries that can store the electrical energy that renewable energy sources (and fossil fuels too) generate in the form of chemical energy. When connected to a circuit, a chemical reaction occurs within the rechargeable battery that converts the chemical energy into electrical energy. The transformation is reversible such that subsequent electrical energy applied to the rechargeable battery reverses the chemical reaction and generates chemical energy that the rechargeable battery again stores.

[0004] There are a variety of rechargeable batteries that have been developed, each employing different materials to facilitate different chemical reactions to transform the stored chemical energy into electrical energy. Examples include nickel-cadmium (Ni-Cd), nickel-metal hydride (NiMH), lead-acid, and lithium-ion (Li-ion). Li-ion rechargeable batteries (hereinafter, Li-ion batteries) show promise over the other examples in terms of energy density, lifespan, and an absence of a so- called “memory effect.”

[0005] Li-ion batteries typically include an anode, a cathode, and an electrolyte. The first Li-ion batteries included a liquid electrolyte solution. Liquid electrolyte solutions gave way to polymer electrolytes, which are widely used in Li-ion batteries today. Solid-state electrolytes (SSE) for Li- ion batteries are in development and potentially offer benefits in terms of lifespan and energy density over other liquid and polymer electrolytes.

[0006] The compositions of the anode and cathode for use in conjunction with SSEs for Li-ion batteries are also a subject of development. For example, some SSE Li-ion batteries incorporate a cathode and an anode made of lithium cobalt oxide and lithium titanate respectively, among other options. Other SSE Li-ion batteries in development incorporate an anode that includes lithium metal. An SSE Li-ion battery with the lithium metal anode is sometimes referred to as a solid-state lithium metal battery (SSLMB).

[0007] Several SSEs have been explored for incorporation into SSLMBs, such as lithium phosphorus oxynitride (LiPON) or lithium garnet (LiyLasZnOn or “LLZO” for short). In such SSLMBs, the lithium metal anode and the SSE have generally heretofore been made to contact each other directly. However, there is a problem in that SSLMBs that include a lithium metal anode and the LLZO SSE tend to generate lithium dendrites at the anode. Dendrites are projections of lithium metal that grow from the surface of the lithium metal anode and extend into the SSE. The dendrites lead to a variety of issues that decrease the performance of the SSLMB including a decrease in the critical current density (CCD) of the SSMLB.

SUMMARY

[0008] The present disclosure provides a modifying interlayer positioned between the lithium- containing anode and the solid-state electrolyte. The modifying interlayer includes a polymeric three-dimensional framework electrospun in conjunction with a sulfonic acid containing compound. The polymeric three-dimensional framework has pores throughout that are occupied by a crosslinked polymer, a crosslinking solvent, and a lithium salt. The modifying interlayer exhibits superior ionic conductivity due in part to the presence of the sulfonic acid containing compound and its reaction products that facilitate lithium ion transport. An SSLMB incorporating the modifying interlayer exhibits a lack of lithium dendrite formation and superior critical current density.

[0009] The modifying interlayer serves as a continuous transport path for lithium ions between the solid-state electrolyte and the electrode (e.g., anode), ensuring high lithium-ion conductivity. The viscoelastic properties of the modifying interlayer enable it to maintain intimate contact between the solid-state electrolyte and the modifying interlayer, as well as between the modifying interlayer and the electrode (e.g., anode), even during severe lithium morphology evolution (e.g., growth and contraction of the electrode). In aspects, a portion of the modifying interlayer can also enter and/or retract from the pores of the solid-state electrolyte during cycling of the solid-state lithium-containing battery. Moreover, the viscoelastic property of the modifying interlayer allows for the inclusion of a second electrode (e.g., a cathode) of relatively high loading and a higher capacity of lithium plating and stripping at the electrode, as demonstrated by the Examples herein. [0010] Without the modifying interlayer, the contact area between the solid-state electrolyte and the electrode (as a solid-solid interface) would be more limited, resulting in lithium dendrite formation at the interface and lower critical current density. The limited contact area would be further exacerbated by lithium metal at the electrode pulverizing and forming pores during cycling of the solid-state lithium-containing battery. The inclusion of the modifying interlayer prevents those issues from arising.

[0011] In aspects, the modifying layer can be formed by thermally curing a modifying reaction mixture and the electrospun polymer with the modifying reaction mixture and the electrospun polymer positioned between an anode and a solid-state electrolyte. Thermally curing the modifying reaction mixture enables the reaction mixture and the resulting modifying layer to be in intimate contact with a high surface area of the solid-state electrolyte. This can be especially beneficial when the solid-state electrolyte is porous (e.g., etched) since the modifying reaction mixture can enter and/or the modifying layer can be positioned in the pores of the solid-state electrolyte, which can increase a critical current density that the resulting battery can withstand and/or reduce an interfacial resistance of the resulting battery, as demonstrated by the Examples herein. Alternatively, in aspects, the modifying layer can be cured before being positioned between the anode and the solid-state electrolyte, which can simplify final assembly of the resulting lithium- containing solid-state battery.

[0012] 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. [0013] Aspect 1. A solid-state lithium-containing battery comprising: an electrode; a solid-state electrolyte; and a modifying interlayer disposed between, and in direct contact with, the electrode and the solid-state electrolyte, the modifying interlayer comprising: a three-dimensional (3D) polymeric framework comprising (i) electrospun polymer nanofibers having a diameter within a range from 10 nm to 50 nm, (ii) a framework additive integrated into the electrospun polymer nanofibers, the framework additive comprising a sulfonic acid containing compound, and (iii) pores between the electrospun polymer nanofibers, a crosslinked polymer within the pores of the 3D polymeric framework, a crosslinking solvent within the pores of the 3D polymeric framework, and a lithium salt within the pores of the 3D polymeric framework.

[0014] Aspect 2. The solid-state lithium-containing battery of aspect 1, wherein the electrospun polymer nanofibers comprise one or more of poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride), polyurethane, polyacrylonitrile, poly(vinyl alcohol), poly(ethylene glycol), poly(methyl methacrylate), poly(acrylic acid), carboxymethyl cellulose, poly(ethylene oxide), poly(acrylonitrile-co-butadiene-co-styrene), or a polyimide.

[0015] Aspect 3. The solid-state lithium-containing battery of aspect 2, wherein the electrospun polymer nanofibers comprise poly(vinylidene fluori de-co-hexafluor opropylene).

[0016] Aspect 4. The solid-state lithium-containing battery of any one of aspects 1-3, wherein the sulfonic acid containing compound comprises one or more of D(+)-10-camphorsulfonic acid (DCA), DL-10-camphorsulfonic acid, L(-)-camphorsulfonic acid, benzenesulfonic acid, o-cresol- 4-sulfonic acid, or 2-naphthalenesulfonic acid.

[0017] Aspect 5. The solid-state lithium-containing battery of aspect 4, wherein the sulfonic acid containing compound comprises D(+)-10-camphorsulfonic acid.

[0018] Aspect 6. The solid-state lithium-containing battery of any one of aspects 1-5, wherein the 3D polymeric network is substantially free of nodules of the electrospun polymer nanofibers.

[0019] Aspect 7. The solid-state lithium-containing battery of any one of aspects 1-6, wherein the crosslinked polymer comprises a crosslinked polymer network comprising units of one or more of an ether-containing acrylate, an ether- containing methacrylates, an alkyl carbonate, or combinations thereof.

[0020] Aspect 8. The solid-state lithium-containing battery of any one of aspects 1-7, wherein the crosslinked polymer network of the crosslinked polymer comprises a fluoroether additive.

[0021] Aspect 9. The solid-state lithium-containing battery of aspect 8, wherein the fluoroether additive comprises one or more of perfluoropolyether (PFPE), fluorinated ether of bis (2,2- difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3-hexafluoropropyl ether (THE), 1,3,5-trifluorobenzene (3FB), fluorobenzene (FB), or combinations thereof.

[0022] Aspect 10. The solid-state lithium-containing battery of any one of aspects 1-9, wherein the crosslinking solvent comprises one or more of fluoroethylene carbonate (FEC), vinylene carbonate (VC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), fluoroethylene sulfite (FES), difluoroethylene carbonate (DFEC), trifluoroethyl methyl carbonate (FEMC), or combinations thereof.

[0023] Aspect 11. The solid-state lithium-containing battery of any one of aspects 1-10, wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

[0024] Aspect 12. The solid-state lithium-containing battery of any one of aspects 1-11, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte, the modifying interlayer has an uncompressed thickness when not compressed between the electrode and the solid-state electrolyte, and a ratio of the uncompressed thickness to the compressed thickness is from 2 to 10.

[0025] Aspect 13. The solid-state lithium-containing battery of any one of aspects 1-12, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte that is from 2 pm to 20 pm.

[0026] Aspect 14. The solid-state lithium-containing battery of any one of aspects 1-13, wherein the modifying interlayer exhibits an ionic conductivity at 25°C within a range from 4.5 x 10'⁴ S/cm to 7.5 x 10'⁴ S/cm.

[0027] Aspect 15. The solid-state lithium-containing battery of any one of aspects 1-14, wherein the electrode is a lithium-containing anode, and the modifying interlayer is positioned between the lithium-containing anode and the solid-state electrolyte.

[0028] Aspect 16. The solid-state lithium-containing battery of any one of aspects 1-15, wherein the electrode includes lithium metal.

[0029] Aspect 17. The solid-state lithium-containing battery of aspect 16, further comprising: a second electrode comprising lithium metal, the solid-state electrolyte disposed between the electrode and the second electrode, wherein the solid-state lithium-containing battery is a symmetric cell solid-state lithium metal battery. [0030] Aspect 18. The solid-state lithium-containing battery of any one of aspects 1-16, wherein the solid-state electrolyte comprises a lithium garnet ceramic.

[0031] Aspect 19. The solid-state lithium-containing battery of aspect 18, wherein the lithium garnet ceramic has a major phase according to at least one of the following formulas:

(i) Li₇-3aLa3Zr₂QaOi2, where Q = Al, Ga or Fe and 0 < a < 0.33;

(ii) Li?La3-bZr2MbOi2, where M = Bi or Y and 0 < b < 1; and

(iii) Li7-cLa3Zr2-cN_cOi2, with N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1.

[0032] Aspect 20. The solid-state lithium-containing battery of aspect 18, wherein the lithium garnet ceramic has a major phase according to the formula I^LasZnOn.

[0033] Aspect 21. The solid-state lithium-containing battery of aspect 18, wherein the lithium garnet ceramic has a major phase of LLZO doped with one or more dopants.

[0034] Aspect 22. The solid-state lithium-containing battery of aspect 18, wherein the solid-state electrolyte is a composite that combines two or more ceramics.

[0035] Aspect 23. The solid-state lithium-containing battery of any one of aspects 1-16, further comprising: a cathode comprising one or more of lithium cobalt oxide (LiCoCh), lithium nickel oxide (LiNiCh), lithium manganese oxide represented by the formula Lii+xM -xC (wherein x is 0 to 0.33), Ni site-type lithium nickel oxide represented by the formula LiNii-xMxCh (wherein M is Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x is 0.01 to 0.3), and a lithium nickel cobalt manganese material represented by the formula LiNixCoyMni-x-yCh (wherein x is 0 to 1, y is 0 to 1, and x+y< 1); and a liquid electrolyte solution disposed between the cathode and the solid-state electrolyte, wherein the electrode is an anode, and the solid-state lithium-containing battery is a full cell solid-state lithium-containing battery.

[0036] Aspect 24. The solid-state lithium-containing battery of any one of aspects 1-23, wherein the solid-state lithium-containing battery exhibits a critical current density at 25°C of 3.5 mA/cm² or more.

[0037] Aspect 25. The solid-state lithium-containing battery of aspect 24, wherein the critical current density at 25°C is 4.5 mA/cm² or more.

[0038] Aspect 26. The solid-state lithium-containing battery of any one of aspects 1-25, wherein the solid-state lithium-containing battery exhibits a Coulombic efficiency that is greater than or equal to 90% for at least 50 cycles of charging and discharging at 0.5C and at 25°C. [0039] Aspect 27. The solid-state lithium-containing battery of any one of aspects 1-25, wherein the solid-state lithium-containing battery exhibits a Coulombic efficiency that is greater than or equal to 90% for at least 200 cycles of charging and discharging at 0.5C and at 25°C.

[0040] Aspect 28. The solid-state lithium-containing battery of any one of aspects 1-27, wherein a capacity retention of the solid-state lithium-containing battery is about 80% or more after 50 cycles of charging and discharging at 0.5C and at 25°C.

[0041] Aspect 29. The solid-state lithium-containing battery of any one of aspects 1-28, wherein a capacity retention of the solid-state lithium-containing battery is about 90% or more after 100 cycles of charging and discharging at 0.5C and at 25°C.

[0042] Aspect 30. The solid-state lithium-containing battery of any one of aspects 1-29, wherein an interfacial resistance of the solid-state lithium-containing battery at 25°C is about 400 cm² or less.

[0043] Aspect 31. The solid-state lithium-containing battery of aspect 30, wherein the interfacial resistance of the solid-state lithium-containing battery at 25°C is about 250 cm² or less.

[0044] Aspect 32. The solid-state lithium-containing battery of any one of aspects 1-31, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.

[0045] Aspect 33. A method of manufacturing a solid-state lithium-containing battery comprising: electrospinning a solution comprising a polymer and a framework additive into a three- dimensional (3D) polymeric framework comprising (i) electrospun polymer nanofibers comprising the polymer and the framework additive integrated into the electrospun polymer nanofibers and (ii) pores between the electrospun polymer nanofibers fibers; and contacting the 3D polymeric framework with a monomer reaction mixture, the monomer reaction mixture comprising (i) a crosslinkable monomer or prepolymer, (ii) a crosslinking solvent, and (iii) a lithium salt; reacting the crosslinkable monomer or prepolymer of the monomer reaction mixture to form a modifying interlayer comprising (i) the 3D polymeric framework, (ii) a crosslinked polymer within the pores of the 3D polymeric framework, (iii) a crosslinking solvent within the pores of the 3D polymeric framework, and (iv) a lithium salt within the pores of the 3D polymeric framework, wherein the framework additive comprises a sulfonic acid containing compound. [0046] Aspect 34. The method of aspect 33, wherein the polymer comprises one or more of poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride), polyurethane, polyacrylonitrile, poly(vinyl alcohol), poly(ethylene glycol), poly(methyl methacrylate), poly(acrylic acid), carboxymethyl cellulose, poly(ethylene oxide), poly(acrylonitrile-co- butadiene-co-styrene), or a polyimide.

[0047] Aspect 35. The method of any one of aspects 33-34, wherein a weight percentage of the framework additive in the solution is from 0.1 wt% to 3.0 wt%.

[0048] Aspect 36. The method of any one of aspects 33-35, wherein the sulfonic acid containing compound comprises one or more of D(+)- 10-camphorsulfonic acid (DCA), DL-10- camphorsulfonic acid, L(-)-camphorsulfonic acid, benzenesulfonic acid, o-cresol-4-sulfonic Acid, and 2-naphthalenesulfonic acid.

[0049] Aspect 37. The method of aspect 36, wherein the sulfonic acid containing compound comprises D(+)-l 0-camphorsulfonic acid (DCA).

[0050] Aspect 38. The method of any one of aspects 36-37, wherein the 3D polymeric framework exhibits an absorption capacity of the monomer reaction mixture is greater than or equal to 800%. [0051] Aspect 39. The method of any one of aspects 33-38, wherein the crosslinkable monomer or prepolymer comprises one or more of a glycol-containing acrylate, a glycol- containing methacrylates, a vinyl carbonate, or combinations thereof.

[0052] Aspect 40. The method of any one of aspects 33-38, wherein the crosslinkable monomer or prepolymer comprises one or more of diethylene glycol diacrylate (DEGDA), diethylene glycol dimethacrylate (DEGDMA), triethylene glycol diacrylate (TEGDA), triethylene glycol dimethacrylate (TEGDMA), tetraethylene glycol diacrylate (TTEGDA), glycidyl methacrylate, polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), polypropylene glycol diacrylate (PPGDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dianol diacrylate (DDA), dianol dimethacrylate (DDMA), ethoxylated trimethylolpropane triacrylate (ETPTA), acrylate-functionalized ethylene oxide, butanediol dimethacrylate, ethoxylated neopentyl glycol diacrylate (NPEOGDA), propoxylated neopentyl glycol diacrylate (NPPOGDA), trimethylol propane triacrylate (TMPTA), trimethylol propane trimethacrylate (TMPTMA), pentaerythritol triacrylate (PETA), ethoxylated propoxylated trimethylol propane triacrylate (TMPEOTA)/(TMPPOTA), propoxylated glyceryl triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate (THEICTA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPEPA), ditrimethylol propane tetraacrylate (DTMPTTA), diglycidyl ester, diallylsuberate, acrylamide, divinylbenzene, a poly(ethylene glycol methyl ether methacrylate) (PEGMEMA), or combinations thereof.

[0053] Aspect 41. The method of any one of aspects 33-38, wherein the crosslinkable monomer or prepolymer comprises vinylethylenecarbonate.

[0054] Aspect 42. The method of any one of aspects 33-41, wherein the crosslinking solvent comprises one or more of fluoroethylene carbonate (FEC), vinylene carbonate (VC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), fluoroethylene sulfite (FES), or combinations thereof.

[0055] Aspect 43. The method of any one of aspects 33-42, wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

[0056] Aspect 44. The method of any one of aspects 33-43, wherein the monomer reaction mixture further comprises a fluoroether additive.

[0057] Aspect 45. The method of any one of aspects 33-43, wherein the monomer reaction mixture further comprises one or more of the perfluoropolyether (PFPE), fluorinated ether of bis (2,2- difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3-hexafluoropropyl ether (THE), 1,3,5-trifluorobenzene (3FB), fluorobenzene (FB), or combinations thereof.

[0058] Aspect 46. The method of any one of aspects 33-45, wherein the monomer reaction mixture further comprises a photoinitiator, and the reacting comprises impinging the crosslinkable monomer or prepolymer of the monomer reaction mixture with ultraviolet light.

[0059] Aspect 47. The method of any one of aspects 33-45, further comprising: and disposing the modifying interlayer between a lithium- containing electrode and a solid-state electrolyte.

[0060] Aspect 48. The method of any one of aspects 33-45, wherein the monomer reaction mixture further comprises a thermal initiator, and the reacting comprises heating the monomer reaction mixture.

[0061] Aspect 49. The method of aspect 48, further comprising, after the contacting and before the reacting, positioning the 3D polymeric framework and the monomer reaction mixture between a lithium- containing electrode and a solid-state electrolyte. [0062] Aspect 50. The method of aspect 49, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.

[0063] Aspect 51. The method of aspect 47, 49, or 50, wherein the solid-state electrolyte comprises a lithium garnet ceramic.

[0064] Aspect 52. The method of any one of aspects 33-51, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte, the modifying interlayer has an uncompressed thickness when not compressed between the electrode and the solid-state electrolyte, and a ratio of the uncompressed thickness to the compressed thickness is from 2 to 10.

[0065] Aspect 53. The method of any one of aspects 33-52, wherein the solid-state lithium- containing battery exhibits a critical current density at 25°C of 3.5 mA/cm² or more.

[0066] Aspect 54. The method of any one of aspects 33-53, wherein a capacity retention of the solid-state lithium-containing battery is about 80% or more after 50 cycles of charging and discharging at 0.5C and at 25°C.

[0067] Aspect 55. The method of any one of aspects 33-53, wherein a capacity retention of the solid-state lithium-containing battery is about 90% or more after 100 cycles of charging and discharging at 0.5C and at 25°C.

[0068] Aspect 56. The method of any one of aspects 33-55, wherein an interfacial resistance of the solid-state lithium-containing battery at 25°C is about 400 cm² or less.

[0069] Aspect 57. The method of aspect 56, wherein the interfacial resistance of the solid-state lithium-containing battery at 25°C is about 250 cm² or less.

[0070] Aspect 58. The method of any one of aspects 33-57, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] 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: [0072] FIG. 1 is a schematic cross-sectional view of a steady-state lithium- containing battery, illustrating a modifying interlayer of the present disclosure disposed between an electrode and a solid-state electrolyte;

[0073] FIG. 2 is a schematic cross-sectional view of the modifying interlayer of FIG. 1, illustrating (i) a 3D polymeric framework made of electrospun polymer nanofibers having a sulfonic acid framework additive dispersed throughout the polymeric network of the nanofibers and (ii) a crosslinked polymer with a crosslinking solvent and a lithium salt dispersed throughout the network of the crosslinked polymer disposed in pores between the electrospun polymer nanofibers of the 3D polymeric framework;

[0074] FIG. 3 is a flowchart of a method of manufacturing the modifying interlayer of FIG. 1, illustrating an electrospinning step where the 3D polymeric framework is made, a contacting step where a monomer reaction mixture is made to contact and enter the pores of the 3D polymeric framework, and a crosslinking step where the monomer reaction mixture is crosslinked into the crosslinked polymer;

[0075] FIG. 4 is a schematic diagram of an electrospinning apparatus being utilized to perform the electrospinning step of FIG. 3;

[0076] FIG. 5 is a schematic diagram of the 3D polymeric framework being made to contact the monomer reaction mixture during the contacting step of the method of FIG. 3;

[0077] FIG. 6 is a schematic diagram of ultraviolet light facilitating the crosslinking of the components of the monomer reaction mixture while the monomer reaction mixture is disposed within the pores of the 3D polymeric framework to generate the modifying interlayer of FIG. 1;

[0078] FIG. 7, pertaining to Example 1, is a scanning electron microscopy (SEM) image of a 3D polymeric framework electrospun from a solution including 1.0 wt% of a sulfonic acid, illustrating electrospun polymer nanofibers and pores between the electrospun polymer nanofibers;

[0079] FIG. 8, pertaining to Example 1, is a cross-sectional SEM image of the 3D polymeric framework, illustrating the 3D polymeric framework having a thickness of 38 pm;

[0080] FIG. 9, pertaining to Example 1 , is an SEM image of the modifying interlayer made after the crosslinking step crosslinked the components of the monomer reaction mixture within the pores of the 3D polymeric framework; [0081] FIG. 10, pertaining to Example 1, is a cross-sectional SEM image of the modifying interlayer, illustrating the modifying interlayer having a thickness of 40 pm, which is slightly thicker than the 3D polymeric framework as made after the electrospinning step;

[0082] FIG. 11, pertaining to Example 1, are optical images of the modifying interlayer being subjected to a twisting force and the modifying interlayer after the twisting force is release, illustrating the lack of substantial permanent deformation from the twisting force;

[0083] FIG. 12 is a schematic diagram of heating the monomer reaction mixture while the monomer reaction mixture is disposed within the pores of the 3D polymeric framework to generate the modifying interlayer of FIG. 1;

[0084] FIG. 13, pertaining to Example 1 , is a Nyquist plot generated for the modifying interlayer at different temperatures, illustrating low real impedance especially at higher temperatures;

[0085] FIG. 14, pertaining to Example 1 , is a graph plotting the voltage and current density as a function of time during a critical current density test of a symmetric cell solid-state lithium- containing battery utilizing the modifying interlayer, illustrating a critical current density of about 4.0 mA/cm²;

[0086] FIG. 15, pertaining to Example 1, is a graph plotting the voltage as a function of time during a prolonged galvanostatic cycling test of the symmetric cell solid-state lithium-containing battery utilizing the modifying interlayer, illustrating no voltage drop that would be indicative of dendrite formation;

[0087] FIG. 16, pertaining to Example 1, includes at top-left an SEM image of lithium foil taken from a symmetric cell solid-state lithium-containing battery including the modifying interlayer after cycling of the battery and Energy-Dispersive X-ray Spectroscopy (EDS) analyses that identified the presence of sulfur (S), oxygen (O), and fluorine (F) atoms on the lithium foil that had deposited there from the presence of the sulfonic acid and its reaction products;

[0088] FIG. 17, pertaining to Example 1#, is a graph plotting specific capacity and Columbic efficiency percentages plotted as a function of cycle number and C-rate during a rate performance and cycling stability test of a full cell solid-state lithium-containing battery including the modifying interlayer;

[0089] FIG. 18, pertaining to Example 1#, is a graph plotting voltage as a function of the specific capacity and C-rate for the same full cell solid-state lithium-containing battery; [0090] FIG. 19, pertaining to Example 1#, is a graph similar to the graph of FIG. 17 but for an extended test of 200 cycles;

[0091] FIG. 20, pertaining to Example 1#, is a graph similar to the graph of FIG. 18 but for an extended test of 200 cycles;

[0092] FIG. 21, pertaining to Example 1*, is a graph plotting specific capacity and Columbic efficiency of another full cell solid-state lithium-containing battery including the modifying interlayer but this time with a higher NCM loading of the cathode, illustrating maintenance of the capacity after 50 cycles;

[0093] FIG. 22, pertaining to Example 1*, is a graph plotting voltage as a function of specific capacity and cycle number for the 50-cycle test;

[0094] FIG. 23, pertaining to Example 1*, is a Nyquist plot for the full cell solid-state lithium- containing battery with the higher NCM loaded cathode, illustrating that the battery had an interfacial resistance of about 304 Q cm²;

[0095] FIG. 24, pertaining to Example 2, is a Nyquist plot generated for a modifying interlayer including a 3D polymeric framework electrospun from a solution including 0.5 wt% of a sulfonic acid;

[0096] FIG. 25, pertaining to Example 2, is a graph plotting voltage and current density as a function of time during a critical current density test of a symmetric cell solid-state lithium- containing battery constructed using the modifying interlayer;

[0097] FIG. 26, pertaining to Examples 1 -4, is a graph plotting ionic conductivity for modifying interlayers made from 3D polymeric frameworks electrospun from solutions with varying weight percentages of a sulfonic acid, illustrating that 0.5wt% sulfonic acid results in the highest ionic conductivity;

[0098] FIG. 27, pertaining to Comparative Example 1, where no sulfonic acid was used in the making of the modifying interlayer, is an SEM image of the 3D polymeric framework, illustrating nanofibers of much larger diameter and many more nodules than the modifying interlayers of the present disclosure;

[0099] FIG. 28, pertaining to Comparative Example 2, where no modifying interlayer was included in a symmetric cell solid-state lithium-containing battery, is a graph plotting voltage as a function of specific capacity and cycle number during a rate performance test, illustrating failure of the battery during the second cycle; [0100] FIG. 29, pertaining to Examples 5 and 7, is a cross-sectional SEM image of the solid-state electrolyte comprising a porous layer with a depth of 13 pm;

[0101] FIG. 30, pertaining to Example 7*, is a graph plotting specific capacity and Columbic efficiency of another full cell solid-state lithium-containing battery including the modifying interlayer, illustrating maintenance of the capacity after 100 cycles;

[0102] FIG. 31, pertaining to Example 7*, is a graph plotting voltage as a function of specific capacity and cycle number for selected cycles of the test shown in FIG. 30;

[0103] FIG. 32, pertaining to Example 6*, is a graph plotting specific capacity and Columbic efficiency of another full cell solid-state lithium-containing battery including the modifying interlayer, illustrating maintenance of the capacity for 67 cycles before short circuiting; and [0104] FIG. 33, pertaining to Example 6*, is a graph plotting voltage as a function of specific capacity and cycle number for selected cycles of the test shown in FIG. 32.

DETAILED DESCRIPTION

[0105] Referring to FIGS. 1-2, a solid-state lithium-containing battery 10 includes an electrode 12, a solid-state electrolyte 14, and a modifying interlayer 16 disposed between the electrode 12 and the solid-state electrolyte 14. The modifying interlayer 16 is in direct contact with the electrode 12 and the solid-state electrolyte 14. Among other things, the modifying interlayer 16 acts as a bridge between the electrode 12 and the solid-state electrolyte 14 for lithium ions to pass through. [0106] The modifying interlayer 16 includes a three-dimensional (3D) polymeric framework 18. The 3D polymeric framework 18 includes electrospun polymer nanofibers 20, a framework additive 22, and pores 24 between the electrospun polymer nanofibers 20. The electrospun polymer nanofibers 20 are formed via an electrospinning step (described below), which forms nanofibers having characteristics that are different than fibers formed via other methods. Such characteristics of the nanofibers made via electrospinning include a diameter in the nanometer range, the collection of nanofibers in a mat-like form with pores between the nanofibers. The electrospun polymer nanofibers 20 of the present disclosure have a diameter 26. The diameter 26 of the electrospun polymer nanofibers 20 are within a range from 10 nm to 50 nm, although an occasional individual electrospun polymer nanofiber 20 may be outside of that range.

[0107] As shown in FIG. 2, the electrospun polymer nanofibers 20 include a polymer 28. In aspects, the electrospun polymer nanofibers 20 include, as the polymer 28, one or more of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride) (PVDF), polyurethane (PU), polyacrylonitrile (PAN), poly(vinyl alcohol) (PVA), polyethylene glycol (PEG), poly(methyl methacrylate) (PMMA), poly(acrylic acid), carboxymethyl cellulose (CMC), poly(ethylene oxide) (PEO), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), a polyimide (PI), and/or copolymers or derivatives thereof. In aspects, the electrospun polymer nanofibers 20 include poly(vinylidene fluoride-co-hexafluoropropylene) as the polymer 28. This list provides examples of polymers 28 that may be used to make the electrospun polymer nanofibers 20 and the list is not meant to be exclusive.

[0108] Throughout the disclosure, the “molecular weight” of a polymer chain is measured by high- performance liquid chromatography (HPLC) calibrated using polystyrene (PS) standards. As used herein, “molecular weight” refers to the number average molecular weight (Mn). A number average molecular weight is calculated for a polymer by summing the products of a molecular weight and the fraction of polymers with that molecular weight. In aspects, the molecular weight (Mn) of the polymer in the polymer nanofibers 20 can be about 50,000 Daltons (Da) or more, about 100,000 Da or more, about 150,000 Da or more, about 200,000 Da or more, about 250,000 Da or more, about 300,000 Da or more, about 350,000 Da or more, about 400,000 Da or more, about 1,000,000 Da or less, about 800,000 Da or less, about 600,000 Da or less, about 500,000 Da or less, about 450,000 Da or less, or about 400,000 Da or less. In aspects, the molecular weight (Mn) of the polymer in the polymer nanofibers 20 can be in a range from about 50,000 Da to about 1,000,000 Da, from about 100,000 Da to about 800,000 Da, from about 200,000 Da to about 600,000 Da, from about 300,000 Da to about 500,000, or any range or subrange therebetween.

[0109] As shown in FIG. 2, the framework additive 22 is integrated into the electrospun polymer nanofibers 20. As further explained below, during the electrospinning step, the polymer 28 of the electrospun polymer nanofibers 20 and molecules of the framework additive 22 come together and form a solid nanofiber structure - the electrospun polymer nanofibers 20.

[0110] In aspects, the framework additive 22 includes a sulfonic acid containing compound. In further aspects, the sulfonic acid containing compound includes one or more of D(+)-10- camphorsulfonic acid (DCA), DL-10-camphorsulfonic acid, L(-)-camphorsulfonic acid, benzenesulfonic acid, o-cresol-4-sulfonic acid, and 2-naphthalenesulfonic acid. In aspects, the sulfonic acid containing compound is or includes D(+)-l 0-camphorsulfonic acid. It is believed that the presence of the sulfonic acid from the sulfonic acid containing compound improves the structural stability of the electrospun polymer nanofibers 20. For example, due at least in part to the sulfonic acid containing compound as the framework additive 22, the 3D polymeric framework 18 is substantially free of nodules of the electrospun polymer nanofibers 20. Nodules are irregularly shaped or spherical aggregates of electrospun nanofibers. The nodules are often larger than the surrounding nanofibers and can be visually distinguished from the uniform, continuous nanofiber structure. The sulfonic acid containing compound provides additional benefits, which are discussed below.

[0111] As shown in FIG. 2, the modifying interlayer 16 further includes a crosslinked polymer 30, a crosslinking solvent 32, and a lithium salt 34 within the pores 24 of the 3D polymeric framework 18. In aspects, the crosslinked polymer 30 includes a crosslinked polymer network including units of one or more monomers and/or prepolymers. In further aspects, the one or more monomers and/or prepolymers can be a glycol- containing acrylate, a glycol-containing methacrylate, a vinyl carbonate, or polymers, copolymers, or derivatives thereof. For example, a polymer containing a monomers of a glycol-containing acrylate would have ether-containing acrylates in the resulting polymer. Consequently, the polymer can contain one or more of an ether- containing acrylate, an ether-containing methacrylates, an alkyl carbonate, or combinations thereof. Examples of the one or more monomers and/or prepolymers include di ethylene glycol diacrylate (DEGDA), diethylene glycol dimethacrylate (DEGDMA), triethylene glycol diacrylate (TEGDA), triethylene glycol dimethacrylate (TEGDMA), tetraethylene glycol diacrylate (TTEGDA), glycidyl methacrylate, poly(ethylene glycol diacrylate) (PEGDA), poly(ethylene glycol dimethacrylate) (PEGDMA), poly(propylene glycol diacrylate) (PPGDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dianol diacrylate (DDA), dianol dimethacrylate (DDMA), ethoxylated trimethylolpropane triacrylate (ETPTA), acrylate- functionalized ethylene oxide, butanediol dimethacrylate, ethoxylated neopentyl glycol diacrylate (NPEOGDA), propoxylated neopentyl glycol diacrylate (NPPOGDA), trimethylol propane triacrylate (TMPTA), trimethylol propane trimethacrylate (TMPTMA), pentaerythritol triacrylate (PETA), ethoxylated propoxylated trimethylol propane triacrylate (TMPEOTA)/(TMPPOTA), propoxylated glyceryl triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate (THEICTA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPEPA), ditrimethylol propane tetraacrylate (DTMPTTA), diglycidyl ester, diallylsuberate, acrylamide, and divinylbenzene. In aspects, the crosslinked polymer 30 includes a crosslinked polymer network including units of poly(ethylene glycol methyl ether methacrylate) (PEGMEMA). Examples of vinyl carbonates include vinylethylenecarbonate (VEC) and polymers, copolymers, and derivatives thereof. This list is not meant to be exclusive and the crosslinked polymer network of the crosslinked polymer 30 can include units of other monomers and/or prepolymers.

[0112] In aspects, the crosslinked polymer network of the crosslinked polymer 30 of the modifying interlayer 16 includes additives of a fluorinated organic compound, such as a fluoroether. In further aspects, the fluorinated organic compound and/or fluoroether includes one or more of perfluoropolyether (PFPE), fluorinated ether of bis (2,2-difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3-hexafluoropropyl ether (THE), 1,3, 5 -trifluorobenzene (3FB), and fluorobenzene (FB). These compounds are an additive for increasing a critical current density of the modifying interlayer 16.

[0113] In aspects, the crosslinking solvent 32 of the modifying interlayer 16 includes one or more of fluoroethylene carbonate (FEC), vinylene carbonate (VC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), fluoroethylene sulfite (FES), difluoroethylene carbonate (DFEC), and trifluoroethyl methyl carbonate (FEMC). The crosslinking solvent may enhance the electrochemical properties of the modifying interlayer 16.

[0114] In aspects, the lithium salt 34 of the modifying interlayer 16 is incorporated into the crosslinked polymer 30 of the modifying interlayer 16. The lithium salt 34 can includes one or more of various compounds, such as lithium bisoxalate borate (LiBOB), lithium difluorooxalate borate (LiDFOB), lithium bis(difluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPFe), lithium hexafluoroarsenate (LiAsFe), lithium perchlorate (LiClO-i), lithium trifluoromethanesulfonate (LiOTf), lithium tetrafluoroborate (LiBF4), lithium bis(pentafluoroethanesulfonyl)imide (LiBETI), lithium bis(oxalato)borate tetrafluoroborate (LiBOB LiBEi), and lithium difluorophosphate (LiDFP). In aspects, the lithium salt 34 can be lithium bistrifluoromethanesulfonimide (LiTFSI). By incorporating the lithium salt 34 into the crosslinked polymer 30, the modifying interlayer 16 may achieve improved ionic conductivity.

[0115] In aspects, the modifying interlayer 16 has a compressed thickness 36 (as shown in FIG. 1) and an uncompressed thickness 38 (as shown in FIG. 2). The compressed thickness 36 of the modifying interlayer 16 may include when the modifying interlayer 16 is within the solid-state lithium-containing battery 10 and compressed between the electrode 12 and the solid-state electrolyte 14. In aspects, the compressed thickness 36 of the modifying interlayer 16 is within a range from 2 gm to 20 gm, for example, from 3 pm to 18 pm, from 4 pm to 16 pm, from about 5 pm to about 14 pm, from about 6 pm to about 12 pm, or any range or subrange therebetween. The compressed thickness 36 can be 2 pm, 3 pm, 4 pm, 5 pm, 6 pm, 7 pm, 8 pm, 9 pm, 10 pm, 11 pm, 12 pm. 13 pm, 14 pm, 15 pm, 16 pm, 17 pm, 18 pm, 19 pm, or 20 pm, or within any range bound by any two of those values (e.g., from 6 pm to 13 pm, from 7 pm to 14 pm, and so on). The compressed thickness 36 can be less than 2 pm or greater than 20 pm.

[0116] The uncompressed thickness 38 is the thickness of the modifying interlayer 16 when it is not compressed between two solid objects, such as between the electrode 12 and the solid-state electrolyte 14. In aspects, the uncompressed thickness 38 of the modifying interlayer 16 is within a range from 30 pm to 100 pm, for example, from 35 pm to 90 pm, from 35 pm to 80 pm, from 40 pm to 70 pm, from 40 pm to 60 pm, from 40 pm to 50 pm, or any range or subrange therebetween. The uncompressed thickness 38 can be 30 pm, 35 pm, 40 pm, 45 pm, 50 pm, 55 pm, 60 pm, 65 pm, 70 pm, 75 pm, 80 pm, 85 pm, 90 pm, 95 pm, or 100 pm, or within any range bound by any two of those values (e.g., from 35 pm to 45 pm, from 40 pm to 50 pm, and so on. The uncompressed thickness 38 can be less than 30 pm or greater than 100 pm.

[0117] In aspects, a ratio of the uncompressed thickness to the compressed thickness can be 2 or more, 3 or more, 3.5 or more, 4 or more, 10 or less, 8 or less, 6 or less, or 5 or less. In aspects, a ratio of the uncompressed thickness to the compressed thickness can be from 2 to 10, from 3 to 8, from 3.5 to 8, from 4 to 6, or any range or subrange therebetween. This ratio reflects the viscoelastic properties of the polymeric framework and/or the cross-linking in the modifying layer. The viscoelastic properties of the modifying interlayer 16 enable it to maintain intimate contact between the solid-state electrolyte 14 and the modifying interlayer 16, as well as between the modifying interlayer 16 and the electrode 12, even during severe lithium morphology evolution (e.g., growth and contraction of the electrode 12).

[0118] The ionic conductivity of the modifying interlayer 16 is a quantification of the ability of the modifying interlayer 16 to transport ions, such as lithium ions, between the electrode 12 and the solid-state electrolyte 14. In aspects, the modifying interlayer 16 exhibits an ionic conductivity at 25°C within a range from 4.5 x 10'⁴ S/cm to 7.5 x 10'⁴ S/cm. The ionic conductivity at 25°C that the modifying interlayer 16 exhibits can be 4.5 x 10'⁴ S/cm, 5.0 x 10'⁴ S/cm, 5.5 x 10'⁴ S/cm, 6.0 x 10'⁴ S/cm, 6.5 x 10'⁴ S/cm, 7.0 x 10'⁴ S/cm, or 7.5 x 10'⁴ S/cm, or within any range bound by any two of those values (e.g., from 5.0 x 10'⁴ S/cm to 6.0 x 10'⁴ S/cm, or 5.5 x 10'⁴ S/cm to 6.5 x 10'⁴ S/cm, and so on). The ionic conductivity at 25°C that the modifying interlayer 16 exhibits can be less than 4.5 x 10'⁴ S/cm or greater than 7.5 x 10'⁴ S/cm. Throughout the disclosure, an “ionic conductivity” of the modifying interlayer is measured using for the modifying interlayer positioned between a pair of stainless steel electrodes based on the behavior at 1 MegaHertz (MHz) using electrical impedance spectroscopy (EIS) at the stated temperature. Unless otherwise indicated, ionic conductivity is measured at 25°C.

[0119] 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 interlayer that is in turn disposed on the first major surface of the solid-state electrolyte and the cathode disposed on the second major surface of the solid-state electrolyte opposite the first major surface. In aspects, the interfacial resistance of the solid-state lithium-containing battery 10 and/or the modifying interlayer 16 can be about 400 cm² or less, about 350 Q cm² or less, about 320 cm² or less, or about 310 cm² or less.

[0120] In aspects, the electrode 12 includes lithium (e.g., lithium metal or a lithium-containing alloy). In aspects, the electrode 12 includes lithium metal. In aspects, the electrode 12 is an anode of the solid-state lithium-containing battery 10.

[0121] The solid-state electrolyte 14 can comprise a lithium garnet and/or be a composite of two or more ceramics. In aspect, the solid-state electrolyte 14 is a composite that combines two or more ceramics. For example, the solid-state electrolyte 14 can be a composite of Ta-doped and W-doped lithium garnet ceramic (e.g., LLZT-2LWO). Other examples of composites for the solid-state electrolyte 14 include lithium-lanthanum-zirconium oxide and lithium phosphate (e.g., LLZO- LiiPO-i), lithium aluminum germanium phosphate and polyvinylidene fluoride (e.g., LAGP- PVDF), poly(ethylene oxide) and lithium bis(oxalato)borate (e.g., PEO-LiBOB), and lithium- lanthanum-titanate oxide and lithium bis(trifluoromethanesulfonyl)imide (e.g., LLTO-LiTFSI). [0122] In aspects, the solid-state electrolyte 14 includes a lithium garnet ceramic, which can provide stability against lithium (e.g., lithium ions, lithium metal) and high ionic conductivity to provide efficient lithium-ion transport. The lithium garnet ceramic can have a major phase of LivLasZnOn. The major phase can be doped with one or more dopants. For example, the lithium garnet ceramic can have a major phase of LiT-viLa^ZnQaO 12, where Q = Al, Ga, or Fe and 0 < a < 0.33; (ii) LivLas-bZnMbOn, where M = Bi or Y and 0 < b < 1. Alternatively, the lithium garnet ceramic can have a major phase of Liv^LasZn-cNcOn, where N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1.

[0123] In aspects, the solid-state electrolyte 14 is a lithium garnet ceramic composed of a lithium garnet major phase and a minor phase additive. The minor phase additive may be an additive oxide, such as Li-Zr-oxide (e.g., Li_xZrO(_X+4)/2, where 2 < x < 10), Li-Ti-oxide (Li_xTiO(_X+4)/2, where 0.66 < x < 4), Li-tungstate (e.g., Li_xWO(_X+6)/2, where 1/3 <x < 6), Li-silicate (e.g., Li_xSiO(_X+4)/2, where 0.5

< x < 8), Li-Ga-oxide (e.g., Li_xGaO(_X+3)/2, where 1 < x < 5), Li-aluminate (e.g., Li_xA10(_X+3)/2, where 1 < x < 5), Li-molybdate (e.g., Li_xMoO(_X+6)/2, where 1 < x < 4), Li-Ta oxide (e.g., Li_xTaO, where 1

< x < 7), Li-Nb-oxide (LiNbCh), Li-Sn-oxide (e.g., Li_xSnO(_X+4)/2, where 2 < x < 8), Li-In-oxide (e.g., Li_xInO(_x+3)/2, where 1 < x < 3), Li-As-oxide (e.g., Li_xAsO(_x+5)/2, where 1 < x < 3), Li-Sb- oxide (e.g., Li_xSbO(_X+5)/2, where 1 < x < 7), or an oxide such as MgO, CaO, Y2O3, La2C>3, ZrCh, AI2O3, Ga2C>3, Ta2C>5, bfeCL, B2O3, ZnO, or EnCh. In aspects, the solid-state electrolyte 14 further includes lithium tungsten oxide.

[0124] The solid-state electrolyte 14 can comprise pores facing the first electrolyte 12. In aspects, a portion of the modifying interlayer 16 can be positioned within one or more of the pores in the solid-state electrolyte. In further aspects, the portion of the modifying interlayer 16 can enter and retract from the pores of the solid-state electrolyte 14 during cycling of the solid-state lithium- containing battery 10. Alternatively, in further aspects, the portion of the modifying interlayer 16 can be within the pores of the solid-state electrolyte 14 throughout cycling of the solid-state lithium-containing battery 10 to ensure continuous, intimate contact and ion transport therebetween.

[0125] The solid-state lithium-containing battery 10 is additionally equipped with a second electrode 40. In aspects, the solid-state lithium-containing battery 10 can be a symmetric cell solid- state lithium metal battery 10 with a lithium metal first electrode 12 and a lithium metal second electrode 40. Unlike other types of lithium-ion batteries, which typically use different materials for the positive and negative electrodes, a symmetric cell solid-state lithium metal battery uses the same material for both electrodes 12 and 40. One advantage of this design is that the solid-state lithium-containing battery 10 can be charged and discharged more rapidly because there is no need to balance the charge between two dissimilar electrodes.

[0126] Alternatively, in other aspects, the solid-state lithium-containing battery 10 includes a cathode as the second electrode 40, making it a full cell solid-state lithium-containing battery 10. The cathode can be made of various materials, such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiCh), lithium manganese oxide represented by the formula Lii+xM -xC (where x is 0 to 0.33). Other options are a Ni site-type lithium nickel oxide represented by the formula LiNii-_xM_x02 (where M is Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x is 0.01 to 0.3), and a lithium nickel cobalt manganese material represented by the formula LiNi_xCoyMni-_x-yO2 (where x is 0 to 1, y is 0 to 1, and x+y< l). For example, when x is 0.6 and y is 0.2, the cathode can comprise LiNio.6Coo.2Mno.2O2 (NCM). The cathode may alternatively be made of some other material.

[0127] In some aspects, a liquid electrolyte solution can be positioned between the cathode (as the second electrode 40) and the solid-state electrolyte 14. In further aspects, the liquid electrolyte solution can comprise a lithium salt, which can include one or more of the compounds discussed above with reference to the lithium salt 34. In even further aspects, the liquid electrolyte solution can further comprise a sulfone compound. Exemplary aspects of sulfone compounds include sulfolane, 3 -methylsulfolane, dimethyl sulfone, ethyl methyl sulfone, or combinations thereof. In aspects, a molar ratio of the lithium salt to the sulfone compound can be about 0.125 (1 : 8) or more, about 0.143 (1:7) or more, about 0.167 (1:6) or more, about 0.20 (1:5) or more, about 0.25 (1:4) or more, about 1 (1:1) or less, about 0.5 or less (1:2), about 0.4 or less, or about 0.333 (1 :3) or less. In aspects, a molar ratio of the lithium salt to the sulfone compound can range from about 0.125 to about 1, from about 0.143 to about 1, from about 0.167 to about 1, from about 0.20 to about 1, from about 0.25 to about 0.5, from about 0.25 to about 0.4, from about 0.25 to about 0.333, or any range or subrange therebetween. In further aspects, a ratio of a volume of the liquid electrolyte solution to a surface area of cathode can be about 5 pL/cm² or more, about 10 pL/cm² or more, about 15 pL/cm² or more, about 20 pL/cm² or less, about 18 pL/cm² or less, or about 15 pL/cm² or less. In further aspects, a ratio of a volume of the liquid electrolyte solution to a surface area of cathode can range from about 5 pL/cm² to about 20 pL/cm², from about 10 pL/cm² to about 18 pL/cm², from about 12 pL/cm² to about 18 pL/cm², from about 15 pL/cm² to about 18 pL/cm², or any range or subrange therebetween.

[0128] In aspects, as shown in FIG. 1, the solid-state lithium-containing battery 10 can further include one or more current collectors 42, 44. In further aspects, the electrode 12, the solid-state electrolyte 14, and the second electrode 40 can be positioned between a pair of current collectors 42, 44. The current collectors can be made of a conductive material such as copper or aluminum, and are located at opposite ends of the solid-state lithium-containing battery 10. As lithium ions flow from the electrode 12 through the solid-state electrolyte 14 to the second electrode 40 during operation of solid-state lithium-containing battery 10, the current collectors 42, 44 facilitate the transfer of electrons to and from the electrodes 12, 40 to power external devices. Alternatively, one or both of the electrodes may function as a current collector in addition to being an electrode.

[0129] The modifying interlayer 16 serves as a continuous transport path for lithium ions between the solid-state electrolyte 14 and the electrode 12, ensuring high lithium-ion conductivity. The viscoelastic properties of the modifying interlayer 16 enable it to maintain intimate contact between the solid-state electrolyte 14 and the modifying interlayer 16, as well as between the modifying interlayer 16 and the electrode 12, even during severe lithium morphology evolution (e.g., growth and contraction of the electrode 12). In aspects, a portion of the modifying interlayer 16 also enters and retracts from the pores of the solid-state electrolyte 14 during cycling of the solid-state lithium-containing battery 10. Alternatively, a portion of the modifying interlayer 16 can be within the pores of the solid-state electrolyte 14 throughout cycling of the solid-state lithium-containing battery 10 to ensure continuous, intimate contact and ion transport therebetween. Moreover, the viscoelastic property of the modifying interlayer 16 allows for the inclusion of a second electrode 40 (e.g., a cathode) of relatively high loading and a higher capacity of lithium plating and stripping at the electrode 12, as demonstrated by the Examples herein.

[0130] Without the modifying interlayer 16, the contact area between the solid-state electrolyte 14 and the electrode 12 (as a solid-solid interface) would be more limited, resulting in lithium dendrite formation at the interface and lower critical current density. The limited contact area would be further exacerbated by lithium metal at the electrode 12 pulverizing and forming pores during cycling of the solid-state lithium-containing battery 10. The inclusion of the modifying interlayer 16 prevents those issues from arising. 1 [0131] During use of the solid-state lithium-containing battery 10, the framework additive 22 of sulfonic acid and its reaction products (e.g., LiF and -SOiLi) gather at the interface of the modifying interlayer 16 and the electrode 12 and the interface of the modifying interlayer 16 and the solid-state electrolyte 14. This accumulation facilitates transfer of lithium ions between the interfaces, resulting in a more uniform deposition and movement of lithium ions. Additionally, the crosslinking solvent 32 present within the pores 24 of the 3D polymeric framework 18 of the modifying interlayer 16 is thought to improve its lithium-ion transport and dendrite-suppression abilities. These attributes help suppress the formation of lithium dendrites, which can form due to the uneven deposition and dissolution of lithium ions on the electrode 12 during charging and discharging cycles. The modifying interlayer 16 evens out the deposition and dissolution of lithium ions on the electrode 12 during these cycles, thereby suppressing dendrite formation and improving the critical current density of the solid-state lithium-containing battery 10.

[0132] The modifying interlayer 16 of the present disclosure surpasses other efforts aimed at suppressing dendrite formation at the electrode. For example, some approaches have proposed the use of a lithium-ion conductive polymer-lithium salt in a polymer matrix (e.g., Li(CF3SO2)2N (LiTFSI) in poly(vinylidene fluoride) (PVDF), succinonitrile (SCN), or polyethylene oxide (PEO)) and lithiophilic coating layers (e.g., Au, Al, Si, graphite, AI2O3, LisN, SnF2, CU3N) between the electrode and the solid-state electrolyte to reduce interfacial impedance and inhibit lithium dendrite formation. However, those efforts have led to low lithium-ion conductivity at room temperature, resulting in high impendence to the flow of electrical current, and insufficient inhibition of dendrite formation.

[0133] Accordingly, the solid-state lithium-containing battery 10 including the modifying interlayer 16 of the present disclosure exhibits exemplary performance. Specifically, the solid-state lithium-containing battery 10 exhibits a critical current density within a range from 3.5 mA/cm² to

5.5 mA/cm² at 25°C. Critical current density refers to the maximum current density that the solid- state lithium-containing battery 10 can handle without causing damage or degradation to the solid- state electrolyte 14 or other components. The critical current density for the solid-state lithium- containing battery 10 can be 3.5 mA/cm², 4.0 mA/cm², 4.5 mA/cm², 5.0 mA/cm², or 5.5 mA/cm², or within any range bound by any two of those values (e.g., from 4.0 mA/cm² to 5.0 mA/cm², from

4.5 mA/cm² to 5.5 mA/cm², and so on). Critical current density is determined via galvanostatic cycling, as described below. [0134] In addition, the solid-state lithium- containing battery 10 with the modifying interlayer 16 exhibits good cycling stability. Cycling stability refers to the ability of a battery to be charged and discharged numerous times without exhibiting a significant decrease in its capacity or efficiency. A high cycling stability is indicative of the modifying interlayer 16 having a high stability against lithium metal. Unless otherwise indicated, cycling occurred at a charging rate of 0.2C and a discharge rate of 0.5C at 25°C using a Neware battery test system (NEWARE CT-4008, Shenzhen, China) in the voltage range of 2.8 to 4.5V. For example, the solid-state lithium-containing battery 10 exhibits a Columbic efficiency at 25°C that is greater than or equal to 90% for at least 50 cycles of charge and discharge. In aspects, the solid-state lithium-containing battery 10 exhibits a Columbic efficiency at 25°C that is greater than or equal to 90% for at least 200 cycles of charge and discharge. In further aspects, the Columbic efficiency greater than or equal to 90% for at least 50 cycles (e.g., at least 200 cycles) with charging and discharging rates of 0.2C, 0.4C, 0.5C, 0.6C, 0.8C, and/or 1C. The Columbic efficiency is the ratio of the actual amount of charge delivered or extracted during a cycle to the theoretical amount of charge that could be delivered or extracted if the battery operated with 100% efficiency. To determine a value, the solid-state lithium-containing battery 10 is cycled at a specific current and voltage range, and the amount of charge delivered or extracted during each cycle is measured using coulometry. Coulometry involves measuring the current flowing through the solid-state lithium-containing battery 10 and integrating the current over time to determine the amount of charge delivered or extracted. The Coulombic efficiency is then calculated as the ratio of the actual charge delivered or extracted to the theoretical charge that could be delivered or extracted if the battery operated with 100% efficiency.

[0135] 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 chargedischarge cycle for all cycles. 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 lithium-containing battery 10 can comprise a capacity retention of 75% or more, about 78% or more, 80% or more82% or more, 85% or more, 88% or more, 90% or more after 50 cycles or more (at 0.5C or at 0.45 mA/cm²). In aspects, the solid-state lithium-containing battery 10 can comprise a capacity retention of 75% or more, about 78% or more, 80% or more, 82% or more, 85% or more, 88% or more, 90% or more after 200 cycles (at 0.5C or at 0.45 mA/cm²). In aspects, the solid-state lithium- containing battery 10 can withstand 100 cycles or more, 200 cycles or more, 400 cycles or more, 600 cycles or more, 800 cycles or more, or 900 cycles or more with charging and discharging at 2C with a 30 minute charge-discharge cycle at 25°C. In aspects, the solid-state lithium-containing battery 10 can withstand 100 hours or more, 200 hours or more, 300 hours or more, 350 hours or more, 400 hours or more, or 420 cycles or more with charging and discharging at 2C with a 30 minute charge-discharge cycle at 25°C.

[0136] Referring now to FIG. 3, a method 100 of manufacturing the solid-state lithium-containing battery 10 is herein described. The method 100 includes an electrospinning step 102, which involves electrospinning a solution 104 to create the 3D polymeric framework 18. The solution 104 includes the polymer 28 and a weight percentage of the framework additive 22, which is or includes a sulfonic acid. The electrospun polymer nanofibers 20 include the polymer 28 and the framework additive 22 from the solution 104. The solution 104 can comprise any one or more aspects (e.g., polymer, molecular weight, wt% of the framework additive, framework additive) and/or be identical to the solution discussed below with reference to step 118.

[0137] Referring additionally to FIG. 4, the electrospinning step 102 for producing the 3D polymeric framework 18 can be performed using an electrospinning apparatus 106. The electrospinning apparatus 106 can include a power supply 108, a syringe pump 110, a spinneret 112, a charged electrode 114, and a grounded collector 116. The power supply 108 creates an electric potential between the charged electrode 114 and the grounded collector 116, while the syringe pump 110 controls the flow rate of the solution 104 dispensed from the spinneret 112. The charged electrode 114, which can be a metal plate as in the illustrated embodiment, is connected to the high-voltage power supply 108, is positioned opposite the grounded collector 116, and serves as the source of the electrostatic field. The grounded collector 116, which can also be a metal plate, is the target for the electrospun polymer nanofibers 20. Other electrospinning set ups can be used to perform the electrospinning step 102.

[0138] During the electrospinning step 102, the solution 104 is drawn from the spinneret 112 towards the grounded collector 116 by the electrostatic field generated by the power supply 108. As the solution 104 moves through the electrostatic field, the chains of the polymer 28 in the solution 104 elongate and align with the direction of the electrostatic field, and the solvent in the solution 104 evaporates. As the solvent evaporates, the viscosity of the solution 104 increases, causing the polymer chains to become immobile and entangled, which results in the formation of the electrospun polymer nanofibers 20. These electrospun polymer nanofibers 20 collect on the grounded collector 116 and form the 3D polymeric framework 18. In aspects, the molecular weight (Mn) of the polymer 28 in the solution 104 used to form the electrospun polymer nanofibers can be within any of the corresponding ranges discussed above for the molecular weight (Mn) of the polymer nanofibers 20.

[0139] In aspects, the method 100 further includes a solution preparation step 118 that occurs before the electrospinning step 102. During the solution preparation step 118, the polymer 28 and the desired weight percentage of the framework additive 22 are dissolved within the solvent to form the solution 104. The polymer 28 used for this step can be any of those previously mentioned that form the polymeric matrix of the electrospun polymer nanofibers 20 of the 3D polymeric framework 18. This step can ensure a consistent and uniform mixture of the polymer and framework additive, leading to a more reliable electrospinning process and a higher quality 3D polymeric framework 18.

[0140] The weight percentage of the framework additive 22 within the solution 104 can be within a range from 0.1 wt% to 3.0 wt%, for example, in a range from 0.25 wt% to 2.5 wt%, from 0.5 wt% to 2 wt%, from 0.5 wt% to 1.5 wt%, from 0.5% to 1.25 wt%, from 0.5 wt% to 1 wt%, or any range or subrange therebetween. In aspects, the weight percentage of the framework additive 22 is 0.10 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.50 wt%, 1.75 wt%, 2.0 wt%, 2.25 wt%, 2.50 wt%, 2.75 wt%, or 3.0 wt%, or within any range bound by any two of those values (e.g., from 0.75 wt% to 1.50 wt%, from 1.0 wt% to 2.0 wt%, and so on). It is envisioned that the weight percentage of the framework additive 22 within the solution 104 can be less than 0.1 wt% or greater than 3.0 wt%.

[0141] As mentioned, the framework additive 22 is or includes a sulfonic acid, and can be any of those previously discussed, such as D(+)-10-Camphorsulfonic acid (DCA). The presence of the sulfonic acid in the sulfonic acid containing compound plays a critical role in the electrospinning process and the performance of the 3D polymeric framework 18. During the electrospinning step 102, the presence of the sulfonic acid enhances the ability of the polymer 28 in the solution to be electrospun, resulting in more uniform electrospun polymer nanofibers 20 with a narrow diameter range of 10 nm to 50 nm and minimal nodules. This increased uniformity in the electrospun polymer nanofibers 20 ultimately leads to improved lithium-ion conductivity at the interfaces between the modifying interlayer 16, the electrode 12, and the solid-state electrolyte 14. [0142] Referring additionally to FIG. 5, the method 100 further includes a contacting step 120, in which the 3D polymeric framework 18 is contacted with a monomer reaction mixture 122 containing a crosslinkable monomer or prepolymer, the crosslinking solvent 32, and the lithium salt 34. The monomer reaction mixture 122 can be prepared within a vessel 124. The 3D polymeric framework 18 can then be placed within the vessel 124 and submerged within the monomer reaction mixture 122. Alternatively or additionally, although not shown, the monomer reaction mixture 122 can be dispensed (e.g., added dropwise) from the vessel onto the 3D polymeric framework. In any event, during the contacting step 120, the monomer reaction mixture 122 enters the pores 24 between the electrospun polymer nanofibers 20 of the 3D polymeric framework 18. In aspects, during the contacting step 120, the 3D polymeric framework 18 exhibits an uptake (r|) of the monomer reaction mixture 122 of greater than or equal to 800% or greater than or equal to 900%. The uptake (r|) is calculated as r| =100%x(Mwet-Mdry)/Mdry, where Mdry is the initial mass of the 3D polymeric framework and Mwet is the mass of the 3D polymeric framework 18 after contacting with monomer reaction mixture 122 for 2 hours.

[0143] In aspects, an amount of the monomer reaction mixture 122 held (i.e., uptake) by the 3D polymeric framework 18 can be about 3 pL/cm² or more, about 6 pL/cm² or more, about 13 pL/cm² or more, about 19 pL/cm² or more, about 26 pL/cm² or more, about 60 pL/cm² or less, about 45 pL/cm² or less, about 40 pL/cm² or less, 35 pL/cm² or about 30 pL/cm² or less, about 26 pL/cm² or less, or about 20 pL/cm² or less. In aspects, an amount of the monomer reaction mixture 122 held (i.e., uptake) by the 3D polymeric framework 18 can be in a range from about 3 pL/cm² to about 60 pL/cm², from about 3 pL/cm² or to about 40 pL/cm², from about 6 pL/cm² to about 35 pL/cm², from about 13 pL/cm² to 30 pL/cm², from about 13 pL/cm² to about 26 pL/cm², from about 13 pL/cm² to about 20 pL/cm², or any range or subrange therebetween.

[0144] In aspects, a molecular weight (Mn) of crosslinkable monomer or prepolymer in the monomer reaction mixture 122 can be about 500 Da or more, about 700 Da or more, about 800 Da or more, about 900 Da or more, about 10,000 Da or less, about 4,000 Da or less, about 2,000 Da or less, about 1,500 Da or less, or about 1,000 Da or less. In aspects, molecular weight (Mn) of crosslinkable monomer or prepolymer in the monomer reaction mixture 122 can be in a range from about 500 Da to about 10,000 Da, from about 700 Da to about 4,000 Da, from about 800 Da to about 2,000 Da, from about 900 Da to about 1,500, or any range or subrange therebetween. 1 [0145] In aspects, an amount of crosslinkable monomers or prepolymers, as a wt% of the monomer reaction mixture 122, can be about 3 wt% or more, about 5 wt% or more, about 7 wt% or more, about 9 wt% or more, about 20 wt% or less, about 18 wt% or less, about 15 wt% or less, or about 12 wt% or less. In aspects, an amount of crosslinkable monomers or prepolymers, as a wt% of the monomer reaction mixture 122, can be in a range from about 3 wt% to about 20 wt%, from about 5 wt% to about 18 wt%, from about 7 wt% to about 15 wt%, from about 9 wt% to about 12 wt%, or any range or subrange therebetween.

[0146] In aspects, a median diameter of the electrospun polymer nanofibers 20 of the 3D polymeric framework 18 can be about 10 nm or more, about 12 nm or more, about 15 nm or more, about 17 nm or more, about 20 nm or more, about 50 nm or less, about 40 nm or less, about 30 nm or less, about 25 nm or less, or about 20 nm or less. In aspects, the median diameter of the electrospun polymer nanofibers 20 can be in a range from about 10 nm to about 50 nm, from about 12 nm to about 40 nm, from about 15 nm to about 30 nm, from about 17 nm to about 25 nm, or any range or subrange therebetween. In aspects, 50% or more, 60% or more, 70% or more, or 80% or more of a distribution of diameters of the electrospun polymer nanofibers 20 can be about within one or more of the ranges mentioned above in this paragraph for the median diameter.

[0147] In the monomer reaction mixture 122, the crosslinkable monomer or prepolymer can be a glycol-containing acrylate, a glycol-containing methacrylate, a vinyl carbonate, or polymers, copolymers, or derivatives thereof. For example, the cross-linkable monomer or prepolymer can be chosen from the ones previously mentioned, such as diethylene glycol diacrylate (DEGDA), diethylene glycol dimethacrylate (DEGDMA), vinylethylenecarbonate (VEC), and others, to provide the necessary units for the crosslinked polymer network of the crosslinked polymer 30 of the modifying interlayer 16. Additionally, the monomer reaction mixture 122 can include a fluorinated organic compound (e.g., fluoroether), such as perfluoropolyether (PFPE), fluorinated ether of bis (2,2-difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3- hexafluoropropyl ether (THE), 1,3, 5 -trifluorobenzene (3FB), or fluorobenzene (FB). These fluorinated organic compounds can be incorporated into the crosslinked polymer 30 formed within the pores 24 of the 3D polymeric framework 18. Among other benefits previously mentioned, the use of a fluorinated organic compound can improve the critical current density of the modifying interlayer 16, which enhances performance the of the solid-state lithium-containing battery 10. [0148] The crosslinking solvent 32 can include any of those previously mentioned, such as fluoroethylene carbonate (FEC), vinylene carbonate (VC), and other similar solvents. These solvents can dissolve the crosslinkable monomer or prepolymer to form the network structure of the crosslinked polymer 30 within the pores 24 of the 3D polymeric framework 18.

[0149] In aspects, an amount of the fluorinated organic compound, as wt% of the monomer reaction mixture 122, can be about 1.5 wt% or more, about 2 wt% or more, about 2.5 wt% or more, about 4.5 wt% or more, about 18 wt% or less, about 12 wt% or less, about 9 wt% or less, or about 6 wt% or less. In aspects, an amount of the fluorinated organic compound, as wt% of the monomer reaction mixture 122, can be in a range from about 1.5 wt% to about 18 wt%, from about 1.5 wt% to about 12 wt%, from about 2 wt% to about 9 wt%, from about 2.5 wt% to about 6 wt%, or any range or subrange therebetween.

[0150] Similarly, the lithium salt 34, which can improve the ion conductivity of the crosslinked polymer 30 and thus the modifying interlayer 16, includes any of those previously mentioned, such as lithium bisoxalate borate (LiBOB), lithium difluorooxalate borate (LiDFOB), LiFSI, or LiTFSI, among others. The lithium salt 34 can dissolve in the crosslinking solvent 32 and become uniformly dispersed throughout the monomer reaction mixture 122, enabling it to penetrate the pores 24 of the 3D polymeric framework 18. In aspects, an amount of the lithium salt, as concentration in the monomer reaction mixture, can be about 1 molar (mol/L, M) or more, about 2 M or more, about 3 M or more, about 4 M or more, about 8 M or less, about 7 M or less, about 6 M or less, or about 6 M or less, for example, in a range from about 1 M to about 8 M, from about 2 M to about 7 M, from about 3 M to about 6 M, from about 4 M to about 6 M, or any range or subrange therebetween.

[0151] In aspects, the monomer reaction mixture 122 contains an initiator, which is used to initiate the crosslinking of the crosslinkable monomer or prepolymer. In further aspects, the initiator can be a photo initiator, although the initiator can be a thermal initiator as discussed below. For example, a photoinitiator can be provided in the monomer reaction mixture when methods are to proceed to step 126 (as opposed to following arrow 131 to step 132). Photoinitiators are configured to generate one or more free radicals or ions that can start the cross-linking reaction when the photoinitiator is impinged with a wavelength that the photoinitiator is sensitive to. Some suitable photo initiators for use in the monomer reaction mixture 122 include 2-hydroxy-2-methyl-l- phenyl- 1 -propanone (HMPP), methyl benzoylformate (MBF), 2-hydroxy-4’-(2-hydroxyethoxy)- 2-methyl-propiophe, ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate, diphenyl(2,4,6- trimethylbenzoyl)phosphine oxide (TPO), 2-methyl-4’-(methylthio)-2-morpholino- propiophenone, and 1 -hydroxy cyclohexyl phenyl ketone. This list of photoinitiators is not exclusive, and other photoinitiators may be used as well.

[0152] Alternatively, in further aspects, the initiator can comprise a thermal initiator. For example, a thermal initiator can be provided in the monomer reaction mixture when methods are to follow arrow 131 to proceed to step 132 (as opposed to proceeding to step 126). A thermal initiator is configured to generate one or more free radicals or ions that can start the cross-linking reaction when the thermal initiator is heated at a temperature equal to or greater than a predetermined temperature. Some suitable thermal initiators for used in the monomer reaction mixture 122 include 2,2’-azobis(2-methylpropionitrile) (AIBN), 2,2’-azobis(2,4-dimethylpentanonitrile) (AVBN) and azo bis(dimethyl-valeronitrile) (AMVN), 2,2 ’-azobis(2-methylpr opionic acid) dimethyl ester, 2,2’-azobis[2-(2-imidazolin-2-yl)-propane] dihydrochloride, isopropylbenzene peroxide, and di-tert-butyl peroxide.

[0153] In further aspects, a concentration of the initiator (e.g., photo initiator, thermal initiator), as a wt% of an amount of the crosslinkable monomer or prepolymer, can be about 0.1 wt% or more, about 0.25 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 1 wt% or less, about 0.75 wt% or less, about 0.6 wt% or less. In further aspects, a concentration of the initiator (e.g., photoinitiator, thermal initiator), as a wt% of an amount of the crosslinkable monomer or prepolymer, can be in a range from about 0.1 wt% to about 1 wt%, from about 0.25 wt% to about 0.75 wt%, from about 0.4 wt% to about 0.6 wt%, or any range or subrange therebetween.

[0154] Referring additionally to FIG. 6, after step 120, the method 100 can proceed to a crosslinking step 126 in which the crosslinkable monomer or prepolymer of the monomer reaction mixture 122 is crosslinked. This forms the modifying interlayer 16 (see FIG. 2), with the crosslinkable monomer or prepolymer of the monomer reaction mixture 122 becoming the crosslinked polymer 30 within the pores 24 of the 3D polymeric framework 18. The crosslinking solvent 32 and the lithium salt 34 from the monomer reaction mixture 122 are also distributed throughout the matrix of the crosslinked polymer 30 in the pores 24. In aspects, ultraviolet light 128 is utilized to facilitate the crosslinking of the crosslinkable monomer or prepolymer of the monomer reaction mixture 122. [0155] Referring back to FIG. 1, the method 100 further includes a disposing step 130 after the crosslinking step 126. The disposing step 130 includes disposing the modifying interlayer 16 between the electrode 12 and the solid-state electrolyte 14. Once the modifying interlayer 16 is properly positioned, the remaining components of the solid-state lithium-containing battery 10 can be assembled.

[0156] Alternatively, after step 120, the method 100 can proceed follow arrow 131 (see FIG. 3) to an assembly step 132, as shown in FIG. 12. As shown, assembly step 132 comprises disposing an interlayer precursor 1211 comprising the monomer reaction mixture 122 and the 3D polymeric framework 18 on the solid-state electrolyte 14. In aspects, as schematically shown, this arrangement can allow the interlayer precursor 1211 to penetrate pores 1203 of the solid-state electrolyte 14 such that a portion of the interlayer precursor 1211 (e.g., monomer reaction mixture 132) is positioned in the pores 1203 of the solid-state electrolyte 14. In aspects, as shown, assembly step 132 can further comprise disposing the first electrode 12 or a precursor (e.g., lithium metal foil) on the interlayer precursor 1211 such that the interlayer precursor is positioned between the first electrode 12 and the solid-state electrolyte 14.

[0157] After step 132, as further shown n FIG. 12, the method 100 can proceed to a crosslinking step 134 comprising heating the interlayer precursor 1211. As shown, the interlayer precursor 1211, the solid-state electrolyte 14, and the first electrode 12 can be heated in an oven 1201 maintained at a predetermined temperature for a predetermined period of time. Heating the interlayer precursor 1211 in step 134 can activate the thermal initiator and cause the crosslinkable monomer or prepolymer of the monomer reaction mixture 122 to crosslink. In aspects, the predetermined period of time can be about 10 minutes or more, 0.5 hours or more, about 1 hour or more, about 1.5 hours or more, about 2 hours or more, about 8 hours or less, about 4 hours or less, about 3 hours or less, about 2.5 hours or less, or about 2 hours or less. In aspects, the predetermined period of time can be in an a range from about 10 minutes to about 8 hours, from about 0.5 hours to about 8 hours, from about 1 hour to about 4 hours, from about 1.5 hours to about 3 hours, or any range or subrange therebetween. In aspects, the predetermined temperature can be about 50°C or more, about 55°C or more, about 60°C or more, about 65°C or more, about 70°C or more, about 120°C or less, about 100°C or less, about 90°C or less, about 80°C or less, about 75°C or less, or about 70°C or less. In aspects, the predetermined temperature can be in a range from about 50°C to about 120°C, from about 55°C to about 100°, from about 60°C to about 80°C, from about 65°C to about 75°C, or any range or subrange therebetween. At the end of step 130 or 134, the method 100 can be complete.

[0158] One of the main advantages of method 100 is its speed of execution. All the steps of the process, including the solution preparation step 118, electrospinning step 102, contacting step 120, crosslinking step 126, and disposing step 130, can be performed rapidly. Moreover, the polymers 28 used to create the 3D polymeric framework 18 and the crosslinkable monomers or prepolymers of the monomer reaction mixture 122 can be sourced inexpensively.

[0159] EXAMPLES

[0160] Various aspects will be further clarified by the following examples. Examples 1-7 and Comparative Examples 1-2 comprised a LLZT-2LWO solid-state electrolyte (described below) and a lithium metal electrode (e.g., anode). In Examples 1-4 and 6 and Comparative Examples 1- 2, the solid-state electrolyte was polished with 1200 grit SiC sandpaper to achieve a smooth surface (“SiC”). In contrast, the solid-state electrolyte in Examples 5 and 7 was etched with a 2 molar HC1 solution for 1 minute (“etch”). Comparative Example 2 did not comprise a modifying interlayer between the lithium metal electrolyte and the solid-state electrolyte. For Examples 1-7 and Comparative Example 1, a modifying interlayer comprising an PVDF-HFP electrospun polymer and a cross-linked polymer was positioned between the lithium metal electrolyte and the solid- state electrolyte. The amount of DCA used in the solution that was electrospun varied: 0 wt% in Comparative Example 1; 0.25 wt% in Example 3; 0.5 wt% in Example 2; 1 wt% in Examples 1 and 5-7; and 2 wt% in Example 4. For Examples 1-5 and Comparative Example 1, the crosslinked polymer comprised a methacrylate polymer formed by curing a methacrylate prepolymer (PEGMEMA) with a photo initiator (HMPP) using ultraviolet (UV) light. For Examples 6-7, the crosslinked polymer comprised a polymer formed by curing a vinyl carbonate prepolymer (vinylethylenecarbonate) with a thermal initiator (AIBN) by heating it at 70°C for 2 hours. Table 1 presents properties of symmetric cells assembled for Examples 1-2 and 5-7 and Comparative Example 2. Table 2 presents properties of full, non-symmetric cells assembled for Examples 1*, 6*, and 7* and Comparative Example 2. Examples 1*, 6*, and 7* correspond to Examples 1, 6, and 7, respectively, other than the use of the NCM cathode and the liquid electrolyte solution between the NCM cathode and the solid-state electrolyte. Comparative Example 2 corresponds to Comparative Example 2* other than the use of the NCM cathode and the liquid electrolyte solution between the NCM cathode and the solid-state electrolyte. [0161] UV cured methacrylate-containing modifying interlayer

[0162] Example 1 (1.0 wt% DCA) - In Example 1, a solution preparation step was carried out to form a solution for a subsequent electrospinning step. Poly(vinylidene fluoride-co- hexafluoropropylene) (PVDF-HFP) and D(+)- 10-camphorsulfonic acid (DCA) were dissolved in N,N-Dimethylformamide (DMF) as the solvent. The PVDF-HFP used had a molecular weight of approximately 400,000 Da. The weight percentage of DCA was 1.0% based on the weight of PVDF-HFP. The mixture was stirred for 12 hours to achieve homogeneity before proceeding to the electrospinning step.

[0163] The electrospinning step was performed using an electrospinning apparatus (ET-2535H, Beijing Ucalery Co., Ltd.) with a working voltage of 8 kV, a working distance of 16 cm, and a propulsion of 0.3 mL/h. The solution was electrospun to form the 3D polymeric framework that contained pores between the electrospun polymer nanofibers. An SEM image of the electrospun polymer nanofibers was captured using an S-3400 N SEM from Hitachi, which is shown in FIG. 7. The diameter of the electrospun polymer nanofibers was between 10 nm to 50 nm. Additionally, a cross-sectional SEM image of the 3D polymeric framework was captured, as shown in FIG. 8, which revealed a thickness of 38 pm.

[0164] After the electrospinning step, the resulting 3D polymeric framework was dried in a vacuum oven for 24 hours at 70°C, then cut into 14 mm diameter discs and quickly transferred into a glove box. This step ensured that the 3D polymeric framework remained free from air and moisture, which could affect its performance as a modifying interlayer in a solid-state lithium- containing battery.

[0165] To prepare the monomer reaction mixture, poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) was used as the crosslinkable prepolymer, fluoroethylene carbonate (FEC) as the crosslinking solvent, and lithium bistrifluoromethanesulfonimide (LiTFSI) as the lithium salt. Firstly, 10 wt.% PEGMEMA monomer with a molecular weight Mn~950 Da was stirred with 5 mol/L (M) LiTFSI in fluoroethylene carbonate (FEC, 99%) solution in a sealed container for 2 hours. Then, the resulting solution was further stirred for 2 hours with perfluoropolyether (PFPE) in a weight ratio of -40:1 (-2.44 wt%). A photoinitiator, 0.5 wt.% 2-hydroxy-2- methylpropiophenone (HMPP) based on the weight of PEGMEMA prepolymer, was added to the monomer reaction mixture before a cross-linking step with UV-irradiation. [0166] A contacting step was performed by adding the monomer reaction mixture dropwise onto samples of the 3D polymeric framework. Approximately 20 pL (13 pL/cm²) of the monomer reaction mixture solution was applied onto the surface of the 3D polymeric framework.

[0167] A separate circular sample of the 3D polymeric framework with a 16 mm diameter was obtained and weighed under dry conditions (Mdry). The sample was then soaked in the monomer reaction mixture for 2 hours in a glove box. After removing any excess mixture from the surface with filter paper, the weight was recorded as Mwet. The 3D polymeric framework exhibited a high uptake (r|) of 920% due to its high porosity.

[0168] A crosslinking step was then conducted on the 3D polymeric framework with the monomer reaction mixture having been added dropwise within the pores of the 3D polymeric framework. Ultraviolet light from a 365nm Hg-UV lamp was used to facilitate crosslinking of the crosslinkable prepolymer of the monomer reaction mixture.

[0169] Next, the 3D polymeric framework was subjected to a crosslinking step. The crosslinkable prepolymer within the monomer reaction mixture was crosslinked within the pores of the 3D polymeric framework using ultraviolet light from a 365nm Hg-UV lamp. During this step, the crosslinkable prepolymer of the monomer reaction mixture transformed into the crosslinked polymer, forming a matrix within the pores of the 3D polymeric framework. This resulted in a stable and mechanically robust modifying interlayer of the present disclosure.

[0170] SEM images of the top and cross-sectional views of the modifying interlayer were captured and are reproduced in FIGS. 9 and 10, respectively. The modifying interlayer had a thickness of 40 pm, with the crosslinked polymer within the pores of the 3D polymeric framework causing a 2 pm increase in thickness compared to the 3D polymeric framework before the monomer reaction mixture was added. As shown in the cross-sectional image of FIG. 10, the crosslinked polymer completely fills the pores of the 3D polymeric framework.

[0171] Various mechanical properties of the modifying interlayer were measured. For example, the modifying interlayer was subjected to a twisting force and then the twisting force was released. The modifying interlayer exhibited minimal deformation because of the twisting force and was restored to its original shape after release of the twisting force. Optical images were captured of the modifying interlayer during application of the twisting force and after release of the twisting force. The images are reproduced in FIG. 11. [0172] In addition, the thickness of the modifying interlayer was measured both uncompressed and compressed with Vernier calipers, confirming the SEM-derived thickness of 40 pm in the uncompressed state and 10 pm in the compressed state. The modifying interlayer was found to be elastic, flexible, and deformable, which are important attributes for ensuring excellent contact with the solid-state electrolyte interface.

[0173] The electrochemical properties of the modifying interlayer were also investigated. Nyquist plots were generated for the modifying interlayer at different temperatures and plotted on the same graph (see FIG. 13). Nyquist plots are graphs of the imaginary part of impedance (Z”) versus the real part of impedance (Z’), and for this disclosure, obtained by AC impedance analysis using the Metrohm Autolab (PGSTAT302 N) high-current potentiostat/galvanostat with a frequency range of 0.1 Hz to 1 MHz.

[0174] In addition, measurement of the ionic conductivity of the modifying interlayer was conducted. The results showed that at 60°C, the ionic conductivity was 16.09 x 10^-4 S/cm, while at 30°C, it was 6.15 x 10^-4 S/cm. Both values are considered high. The measurements were taken using the Metrohm Autolab (PGSTAT302 N) with a frequency range of 0.1 Hz to 1 MHz. The modifying layer was sandwiched between two stainless steel plates and sealed in a CR2025 coin cell.

[0175] A symmetric cell solid-state lithium metal battery was constructed. The symmetric cell solid-state lithium metal battery included a solid-state electrolyte that was a LLZT-2LWO composite and the modifying interlayer.

[0176] To create the solid-state electrolyte, precursor powders of LiOH H2O (analytical reagent with 2% stoichiometric excess), La2O? (99.99% purity, calcined at 900°C for 12 hours), ZrCh (analytical reagent), and Ta2Os (99.99% purity) were weighed and mixed in stoichiometric ratios for Li6.5La3Zn.5Tao.5O12. The mixture was wet ball milled for 12 hours using isopropanol as the solvent and yttrium-stabilized zirconia balls as the grinding medium. The resulting powder was calcined in an alumina crucible at 950°C for 6 hours to obtain pure cubic Li-garnet electrolyte (LLZT) powder.

[0177] The Li2WO4 (LWO) component of the composite was prepared by weighing LiOH H2O (AR) and WO3 (AR) at a molar ratio of 2. The mixture was wet ball milled for 24 hours using isopropanol as the solvent and yttrium-stabilized zirconia beads as the grinding medium at a speed of 250 rpm. The resulting dried mixture was then calcined in an alumina crucible at 500°C for 2 hours to obtain pure LWO powder.

[0178] To form the LLZT-2LWO composite, the LLZT powder and LWO powder were weighed in a certain ratio (100:2 wt%). The powders were then wet-milled at 250 rpm for 12 hours using a solvent. Afterward, the mixture was dried at 70°C for 12 hours and passed through a 200 grit sieve to obtain fine particles. Next, green pellets were formed by uniaxial pressing the fine particles at a pressure of 100 MPa. The green pellets had a diameter of 18 mm and weighed 1.25 grams each. The green pellets were then placed in a Pt crucible and sintered at 1190°C for 30 minutes to obtain LLZT-2LWO pellets. Finally, all of the LLZT-2LWO pellets were polished with 400 grit, 800 grit, and then 1200 grit SiC sandpaper to obtain a smooth surface for better contact with the modifying interlayer.

[0179] To assemble the symmetric cell solid-state lithium metal battery, the modifying layer was then placed directly between the primary surface of the LLZT-2LWO pellet and Li foil. An additional modifying layer was placed over the other primary surface of the LLZT-2LWO pellet and another Li foil placed over the additional modifying layer. The components were then sealed in a CR2025 coin cell. To prevent the effects of H2O and O2, the assemblage was carried out in an argon- filled glove box with H2O and O2 levels below 0.1 ppm.

[0180] The symmetric cell solid-state lithium metal battery underwent a critical current density test to determine the maximum current density that the battery can handle without significant degradation in its performance or lifespan. The battery was charged and discharged repeatedly at increasing current densities (in steps of 0.2 mA/cm² ranging from 0.2 to 6 mA/cm²) until a critical point was reached. The critical point is where the battery either fails or exhibits significant performance degradation, indicating that the maximum safe current density has been exceeded. The highest current density at which the battery can maintain its performance and capacity without significant degradation or damage is defined as the critical current density. The critical current density test showed that the critical current density can exceed 4.0 mA/cm². A graph depicting the voltage and current density as a function of time during the test was prepared and is shown in FIG. 14

[0181] In addition, the symmetric cell solid-state lithium metal battery underwent prolonged galvanostatic cycling to evaluate its long-term cycling stability and capacity retention. The battery was charged and discharged at a constant current density (CCD) of 1.0 mA/cm² for over 420 hours with 30-minute intervals between each cycle while measuring the voltage. The test revealed the battery’s exceptional cycling stability and high stability against lithium (e.g., lithium ions, lithium metal) at higher current densities. Furthermore, no sudden voltage drops were observed after 420 hours of testing, indicating the superior dendrite-suppressing ability of the modifying interlayer. A graph plotting the voltage as a function of time during the prolonged galvanostatic cycling test is shown in FIG. 15.

[0182] Further, the symmetric cell solid-state lithium metal battery was subjected to a deposition experiment where it was charged at a current density of 1.0 mA/cm² at an areal capacity of 3 mAh/cm² for 3 hours. After the experiment, the battery was disassembled, and an SEM image of the lithium foil was taken. Additionally, an Energy-Dispersive X-ray Spectroscopy (EDS) analysis was performed on the lithium foil to identify the presence of sulfur (S), oxygen (O), and fluorine (F) atoms. The SEM image and EDS analyses are shown in FIG. 16. The EDS analyses revealed that each of S, O, and F atoms were present on the lithium foil surface, indicating the presence of DCA and its reaction products (LiF and -SO3Li) on the surface. The -SO3Li with high Li-ion conductivity can further suppress Li dendrite formation and improve the critical current density.

[0183] Full cell solid-state lithium metal batteries were additionally constructed for further testing (Example 1# and Example 1*). The assembly of the full cell solid-state batteries with a LiNio.6Coo.2Mno.2O2 (NCM) cathode was completed as follows. First, the modifying interlayer was placed between the LLZT-2LWO pellet and Li foil to improve contact and stability. Second, on the cathode side, a small amount of liquid electrolyte (1:3 molar of LiTFSI and sulfolane (TMS) solution) was applied to obtain a good interface contact. All procedures were carried out in an argon- filled glove box with H2O and O2 levels <0.1 ppm to minimize the effects of moisture and oxygen. The components were then assembled in a CR2025 coin cell for testing.

[0184] Two such full cell solid-state lithium metal batteries were constructed with different cathode loadings. The first battery (Example 1#) had a cathode with a nickel-cobalt-manganese (NCM) loading of 3 mg/cm², while the second battery (Example 1*) had a higher NCM loading of 21 mg/cm². The higher loading is considered to be relatively high and may result in increased capacity and energy density of the battery. The performance of both batteries was evaluated through a series of tests, as further explained below.

[0185] Each of the full cell solid-state lithium metal batteries underwent a rate performance test to evaluate their ability to deliver power at different rates of discharge or charge. The battery’s 1 discharge or charge rate is expressed as its C-rate, which is the ratio of the current at which the battery is discharged or charged, relative to its rated capacity. During the test, the battery underwent a series of charge and discharge cycles at different C-rates (0.2C, 0.4C, 0.8C, 1C, and 0.2C again). The voltage and specific capacity of the battery were measured during the test to evaluate its performance and stability. Specific capacity refers to the amount of energy that can be stored per unit mass or volume of the battery, and is an important metric for battery performance.

[0186] The full cell solid-state lithium metal battery with an NCM cathode loading of 3 mg/cm² (Example 1#) was tested for its rate performance and cycling stability. The battery discharged 177.7, 165.4, 145.1, and 133.8 mAh/g at 0.2C, 0.4C, 0.8C, and 1.0C, respectively, showing good performance. The specific capacity and Columbic efficiency percentages were plotted as a function of cycle number and C-rate on FIG. 17. The voltage as a function of the specific capacity and C- rate was plotted on FIG. 18. Another test was conducted at 0.5C for 200 cycles, and the results were plotted on FIG. 19 and FIG. 20. The battery maintained a specific capacity of 133.7 mAh/g (0.35 mAh/cm²) at the end of the 200 cycles without obvious capacity decay (80% capacity retention). The cycling tests were conducted at 0.5C in the voltage range of 2.8 to 4.5V.

[0187] Results from the full cell solid-state lithium metal battery with an NCM cathode loading of 21 mg/cm² (Example 1*) are additionally presented herein. The battery’s specific capacity and Columbic efficiency were plotted on a graph, which is shown in FIG. 21. After 50 cycles, the battery delivered a discharge capacity of 3.16 mAh/cm² at a current density of 0.45 mA/cm². To visualize the relationship between voltage, specific capacity, and cycle number, a graph was created and is reproduced in FIG. 22. The long-term cycling tests were conducted at 0.45 mA/cm² in a voltage range of 2.8 to 4.5V. Further, a Nyquist plot was generated to examine interfacial resistance in the battery. The Nyquist plot, shown in FIG. 23, displays an interfacial resistance of about 304 Q cm².

[0188] All testing of the symmetric and full cell solid-state lithium metal batteries was conducted using a Neware battery test system (NEWARE CT-4008, Shenzhen, China). The Neware CT-4008 is a high-precision battery testing instrument capable of testing a wide range of battery chemistries and formats.

[0189] Example 2 (0.5 wt%DCA) - Example 2 is identical to Example 1, except that the solution used during the preparation step contained 0.5 wt% D(+)-10-Camphorsulfonic acid (DCA), instead of 1.0 wt% DCA as in Example 1. Nyquist plots were generated for the modifying interlayer at different temperatures and plotted on the same graph. The graph is presented in FIG. 24. By comparing the Nyquist plot for Example 1 with 1.0 wt% DCA (FIG. 13) with that for Example 2 with 0.5 wt% DCA (FIG. 24), it can be observed that the modifying layer made from the solution of Example 1 had less real impedance, particularly at lower temperatures, than the modifying layer made from the solution of Example 2.

[0190] The ionic conductivity of the modifying interlayer was measured to evaluate its ability to facilitate ion transport between the lithium metal anode and the solid-state electrolyte. The measurements were conducted at two different temperatures, 30°C and 60°C. The ionic conductivity was found to be high, with a value of 6.92 x IO^-4 S/cm at 30°C and 14.96 x IO^-4 S/cm at 60°C. These high values indicate that the modifying interlayer is effective in promoting ion transport, which can enhance battery performance and stability.

[0191] To evaluate the effectiveness of the modifying interlayer of Example 2, a symmetric cell solid-state lithium metal battery was constructed, using the same assembly method described for Example 1. The critical current density of the battery was then tested to determine the maximum current density it could handle without degradation or damage. The test results showed that the critical current density of the battery with the modifying interlayer was about 4.6 mA/cm², which is significantly higher than the critical current density of the battery without the modifying interlayer (see Comparative Example 2 below). This suggests that the modifying interlayer effectively suppresses dendrite formation and enables high current density operation of the battery. A graph plotting the voltage and current density as a function of time during the critical current density test is presented in FIG. 25, demonstrating the stable performance of the battery under high current density conditions.

[0192] Example 3 (0.25wt% DCA) - Example 3 was conducted to investigate the effect of a lower concentration of D(+)-10-Camphorsulfonic acid (DCA) in the modifying interlayer solution. Similar to Examples 1 and 2, Example 3 involved the preparation of a modifying interlayer solution, but with a reduced amount of DCA (0.25 wt%). This variation in concentration was intended to explore the impact of DCA concentration on the performance of the modifying interlayer.

[0193] The ionic conductivity of the modifying interlayer was measured at 30°C using electrochemical impedance spectroscopy. The ionic conductivity was found to be 6.02 x 10^-4 S/cm, which is a relatively high value for solid-state lithium metal batteries. In comparison to previous examples, this value is slightly lower than the ionic conductivity obtained in Example 1 (1.0 wt% DCA, 6.14 x 10^-4 S/cm), but still falls within the same order of magnitude.

[0194] Example 4 (2.0 wt% DCA) - Example 4 is the same as Example 1, except that the solution made during the solution preparation step included 2.0 wt% of D(+)-10-Camphorsulfonic acid (DCA) instead of 1.0 wt% DCA as in Example 1.

[0195] The ionic conductivity of the modifying interlayer was measured for Examples 1-4. At 30°C, the ionic conductivity was measured to be 6.15 x 10^-4 S/cm for Example 1 (1.0 wt% DCA), 6.92 xlO^-4 S/cm for Example 2 (0.5 wt% DCA), 6.02 x 10^-4 S/cm for Example 3 (0.25 wt% DCA), and 5.58 x 10^-4 S/cm for Example 4 (2 wt% DCA). A graph comparing the ionic conductivities of the modifying interlayers of Examples 1-4 at 30°C is reproduced in FIG. 26. Notably, the graph shows that ionic conductivity is the highest when the DCA content is 0.5 wt%, and ionic conductivity generally decreases as the DCA content deviates from this concentration.

[0196] Example 5 (1 wt% DCA with etched solid-state electrolyte) - Example 1 is the same as Example 1 (with lwt% DCA), except that the solid-state electrolyte was etched with a 2 molar HC1 solution for 1 minute to form a porous surface (instead of the smooth surface formed by SiC polishing) (“etch”). FIG. 29 reproduces an SEM cross-sectional view of the etched solid-state electrolyte (before the modifying interlayer was formed). As shown, the pores extend to a depth of about 13 pm from a surface of the solid-state electrolyte.

[0197] The symmetric cell solid-state lithium metal battery formed from the modifying interlayer (with 1 wt% DCA) and the solid-state electrolyte (etched) of Example 5 exhibited a critical current density (CCD) of 2.8 mA/cm² at 25°C. Compared to Example 5 (CCD of 2.8 mA/cm²), the increased CCD of Example 1 (CCD of 4.0 mA/cm²) is likely due to the increased contact area between the SiC polished solid-state electrolyte (Example 1) compared to the etched solid-state electrolyte (Example 5). Since the modifying interlayer is cured before being positioned between the lithium-containing electrolyte (lithium metal) and the solid-state electrolyte, the modifying interlayer is unable to effectively occupy the pores in the etched surface of Example 5. Also, Example 5 comprised an interfacial resistance of 216 Q cm². This further reinforces the idea that the UV cured interlayer has better contact with the solid-state electrolyte when the solid-state electrolyte is polished and/or non-porous.

[0198] Comparative Examples [0199] Comparative Example 1 (No DCA) - Comparative Example 1 (CE 1) was prepared following the same steps as Example 1, except that the solution used in the electrospinning step did not contain any weight percentage of D(+)- 10-Camphorsulfonic acid (DCA) or any other sulfonic acid. An SEM image of the resulting electrospun polymer nanofibers was obtained and is presented in FIG. 27. The image shows that the diameter of the electrospun polymer nanofibers ranges from 100 nm to 200 nm, without the presence of any sulfonic acid, much greater than the diameter of the electrospun polymer nanofibers spun in the presence of sulfonic acid. Comparing the SEM images of Example 1 (with DCA) in FIG. 7 and Comparative Example 1 (without sulfonic acid) in FIG. 27 reveals that the presence of DCA in the electrospinning solution leads to smaller diameter electrospun polymer nanofibers compared to the nanofibers electrospun without any sulfonic acid. Additionally, the electrospun polymer nanofibers produced with DCA exhibit fewer nodules compared to the nanofibers electrospun without any sulfonic acid.

[0200] A symmetric cell solid-state lithium metal battery was constructed with a modifying interlayer prepared without DCA. The critical current density of the battery was measured at 25°C and found to be 3.6 mA/cm² This value is lower than the critical current densities obtained for Examples 1-4, which all contained a modifying interlayer made with DCA. These results suggest that modifying interlayers containing DCA not only help achieve good interfacial contact between Li and the solid-state electrolyte but also actively suppress dendrite formation.

[0201] Comparative Example 2 (No Modifying Interlayer) - Comparative Example 2 (CE 2) was a symmetric cell solid-state lithium metal battery without a modifying interlayer. The symmetric cell was assembled as follows. Au was sputtered onto the primary surfaces of an LLZT-2LWO pellet for 5 minutes. The LLZT-2LWO pellet was then transferred to an argon-filled glove box. A piece of lithium metal foil was placed at the center of one of the primary surfaces of the LLZT- 2LW0 pellet and heated to 250-300°C on a hot plate. The molten lithium was spread on the primary surface of the LLZT-2LWO pellet. Second, on the cathode side, a small amount of liquid electrolyte (1:3 molar of LiTFSI and sulfolane (TMS) solution) was applied to obtain a good interface contact. The components were then assembled in a CR2025 coin cell for testing.

[0202] The symmetric cell solid-state lithium metal battery without the modifying interlayer exhibited a critical current density of only 0.9 mA/cm² at 25°C. Furthermore, a full cell solid-state lithium metal battery with an NCM loading of 21 mg/cm² at the cathode was constructed without the modifying interlayer and subjected to a rate performance test. However, the battery failed during the second cycle. The voltage as a function of specific capacity and cycle number was plotted and the resulting graph is reproduced in FIG. 28.

[0203] Thermally cured VEC modifying interlayer

[0204] Table 1 presents properties of symmetric cells assembled for Examples 1-2 and 5-7 and Comparative Example 2. Table 2 presents properties of full, non-symmetric cells assembled for Examples 1*, 6*, and 7* and Comparative Example 2. Examples 1*, 6*, and 7* correspond to Examples 1 , 6, and 7, respectively, other than the use of the NCM cathode and the liquid electrolyte solution between the NCM cathode and the solid-state electrolyte. As used in this section and Tables 1 -2, “vinyl” refers to the modifying layer made by thermally curing the modifying reaction mixture including VEC along with the electrospun polymers while “methacrylate” refers to the modifying layer made by UV curing the modifying reaction mixture including PEGMEMA and the electrospun polymers. As used in this section and Tables 1-2, “SiC” refers to solid-state electrolytes that were polished using 1200 grit SiC as described herein, and “etch” refers to solid- state electrolytes that were etched with a 2 molar HC1 solution for 1 minute (“etch”).

[0205] Example 6 (1 wt%DCA with polished solid-state electrolyte) - Example 6 comprised a SiC polished electrolyte prepared identically to Example 1, and the solution made during the solution preparation step included 1.0 wt% of D(+)-10-Camphorsulfonic acid (DC A) identically to Example 1. However, the modifying reaction mixture for Example 6 included vinylethylenecarbonate (VEC) instead of PEGMEMA as the crosslinkable monomer or prepolymer in Example 1, and the modifying reaction mixture for Example 6 included 0.5 wt% of 2,2’-azobis(2-methylpropionitrile) (AIBN) based on the weight of VEC, as a thermal initiator, instead of the HMPP photoinitiator in Example 1. 20 pL of the modifying reaction mixture was added dropwise to the electrospun polymer. After waiting 30 minutes, the electrospun polymer including the absorbed modifying reaction mixture was positioned between the SiC polished electrolyte and a sheet of lithium metal foil. The modifying interlayer was formed by heating the lithium metal foil, SiC polished electrolyte, and electrospun polymer including the absorbed modifying reaction mixture assembly at 70°C for 2 hours to cure the modifying reaction mixture. [0206] The symmetric cell solid-state lithium metal battery formed from the modifying interlayer (with 1 wt% DCA, vinyl cross-linker functionality) and the solid-state electrolyte (SiC polished) of Example 6 exhibited a critical current density (CCD) of 4.0 mA/cm² at 25°C. As such, Example 6 (thermally cured vinyl cross-linker functionality) achieved the same CCD as Example 1 (UV cured meth acrylate cross-linker functionality), indicating that both cross-linker functionalities can perform equally well when used in combination with SiC polished solid-state electrolyte. Also, Example 6 comprised an interfacial resistance of 388 cm².

[0207] Example 7 (1 wt% DC A with etched solid-state electrolyte) - Example 7 is identical to Example 6 (comprising the same modifying interlayer composition) except that the solid-state electrolyte was etched (porous surface) in Example 7 instead of the solid-state electrolyte being SiC polished (smooth surface).

[0208] The symmetric cell solid-state lithium metal battery formed from the modifying interlayer (with 1 wt% DCA, vinyl cross-linker functionality) and the solid-state electrolyte (etched) of Example 7 exhibited a critical current density (CCD) of 5.1 mA/cm² at 25°C. Compared to Example 6 (thermally cured modifying layer with SiC polished solid-state electrolyte), the combination of the thermally cured modifying layer with the porous surface resulting from etching the solid-state electrolyte increases the CCD from 4.0 mA/cm² to 5.1 mA/cm². It is believed that the increase in CCD is the result of a portion of the modifying interlayer being positioned in pores of the porous surface of the solid-state electrolyte, which increases a contact area between the modifying interlayer and the solid-state electrolyte (compared to a solid-state electrolyte with a smooth surface). Unlike the UV-cured modifying interlayer (Example 5), a portion of the thermally cured modifying interlayer can be positioned in the pores of the etched solid-state electrolyte because the precursor (electrospun polymer and/or absorbed modifying reaction mixture) is in contact with and/or can flow into the pores before being cured. Indeed, Example 7 (thermally cured and etched solid-state electrolyte, 5.1 mA/cm²) has a much higher CCD than Example 5 (UV-cured electrolyte and etched solid-state electrolyte, 2.8 mA/cm²). Also, Example 7 comprised an interfacial resistance of 202 Q cm². Of the Examples presented in Table 1, Example 7 has the lowest reported interfacial resistance, which is consistent with the interpretation that a portion of the thermally cured modifying interlayer is positioned in pores of the porous surface of the solid- state electrolyte.

Table 1 : Properties of Examples 1 and 5-7 and Comparative Example 2

[0209] Table 2 presents properties of full, non-symmetric cells assembled for Examples 1*, 6*, and 7* and Comparative Example 2. Examples 1*, 6*, and 7* correspond to Examples 1, 6, and 7, respectively, other than the use of the NCM cathode and the liquid electrolyte solution between the NCM cathode and the solid-state electrolyte. Likewise, Comparative Example 2* corresponds to Comparative Example 2 other than the use of the NCM cathode and the liquid electrolyte solution between the NCM cathode and the solid-state electrolyte. As shown in Table 2, Examples 1*, 6*, and 7* comprised the NCM cathode with a loading of 21 mg/cm². Comparative Example 2* was also tested at a cathode loading of 21 mg/cm², but Comparative Example 2* short-circuited by the second cycle with the 21 mg/cm² cathode loading. As discussed above, Example 1* exhibited a capacity retention of 88% after 50 cycles at 0.45 mA/cm² and at 25°C. Also, as noted in Table 2, Example 1* exhibited a capacity retention of 96% after 100 cycles at 0.45 mA/cm² and at 25°C.

[0210] FIG. 32 shows the specific capacity (mAh/cm²) and Columbic efficiency (%) of Example 6* being cycled at 0.45 mA/cm² and at 25°C. The filled circles correspond to specific capacity measurements, and open circles correspond to Columbic efficiency measurements. As shown in Table 2 and FIG. 32, Example 6* exhibited a capacity retention of 86% after 67 cycles. However, Example 6* short circuited (SC) during cycle 68. FIG. 33 shows traces of cycle numbers 1, 25, 50, and 68. The curves for cycles 1, 25, and 50 look normal. However, as shown in the top curve (charging) for cycle 68, the cell was overcharged and short circuited.

[0211] FIG. 30 shows the specific capacity (mAh/cm²) and Columbic efficiency (%) of Example 7* being cycled at 0.45 mA/cm² and at 25°C. The filled circles correspond to specific capacity measurements, and open circles correspond to Columbic efficiency measurements. As shown in Table 2 and FIG. 32, Example 7* exhibited a capacity retention of 79% after 87 cycles and a capacity retention of 71% after 100 cycles. FIG. 31 shows traces of cycle numbers 1, 25, 50, 75, and 100.

Table 2: Properties of Examples 1*, 6*, and 7 and Comparative Example 2*

Claims

CLAIMS What is claimed is:

1. A solid-state lithium- containing battery comprising: an electrode; a solid-state electrolyte; and a modifying interlayer disposed between, and in direct contact with, the electrode and the solid-state electrolyte, the modifying interlayer comprising: a three-dimensional (3D) polymeric framework comprising (i) electrospun polymer nanofibers having a diameter within a range from 10 nm to 50 nm, (ii) a framework additive integrated into the electrospun polymer nanofibers, the framework additive comprising a sulfonic acid containing compound, and (iii) pores between the electrospun polymer nanofibers, a crosslinked polymer within the pores of the 3D polymeric framework, a crosslinking solvent within the pores of the 3D polymeric framework, and a lithium salt within the pores of the 3D polymeric framework.

2. The solid-state lithium-containing battery of claim 1, wherein the electrospun polymer nanofibers comprise one or more of poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride), polyurethane, polyacrylonitrile, poly(vinyl alcohol), poly(ethylene glycol), poly(methyl methacrylate), poly(acrylic acid), carboxymethyl cellulose, poly(ethylene oxide), poly(acrylonitrile-co-butadiene-co-styrene), or a polyimide.

3. The solid-state lithium-containing battery of claim 2, wherein the electrospun polymer nanofibers comprise poly (vinylidene fluoride-co-hexafluoropropylene).

4. The solid-state lithium-containing battery of claim 1, wherein the sulfonic acid containing compound comprises one or more of D(+)- 10-camphorsulfonic acid (DCA), DL-10- camphorsulfonic acid, L(-)-camphorsulfonic acid, benzenesulfonic acid, o-cresol-4-sulfonic acid, or 2-naphthalenesulfonic acid.

5. The solid-state lithium-containing battery of claim 4, wherein the sulfonic acid containing compound comprises D(+)-10-camphorsulfonic acid.

6. The solid-state lithium-containing battery of any one of claims 1-5, wherein the 3D polymeric network is substantially free of nodules of the electrospun polymer nanofibers.

7. The solid-state lithium-containing battery of any one of claims 1 -5, wherein the crosslinked polymer comprises a crosslinked polymer network comprising units of one or more of an ether- containing acrylate, an ether-containing methacrylates, an alkyl carbonate, or combinations thereof.

8. The solid-state lithium-containing battery of any one of claims 1 -5, wherein the crosslinked polymer network of the crosslinked polymer comprises a fluoroether additive.

9. The solid-state lithium-containing battery of claim 8, wherein the fluoroether additive comprises one or more of perfluoropolyether (PFPE), fluorinated ether of bis (2,2-difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3-hexafluoropropyl ether (THE), 1,3, 5 -trifluorobenzene (3FB), fluorobenzene (FB), or combinations thereof.

10. The solid-state lithium-containing battery of any one of claims 1-5, wherein the crosslinking solvent comprises one or more of fluoroethylene carbonate (FEC), vinylene carbonate (VC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), fluoroethylene sulfite (FES), difluoroethylene carbonate (DFEC), trifluoroethyl methyl carbonate (FEMC), or combinations thereof.

11. The solid-state lithium-containing battery of any one of claims 1-5, wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

12. The solid-state lithium-containing battery of any one of claims 1-5, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte, the modifying interlayer has an uncompressed thickness when not compressed between the electrode and the solid-state electrolyte, and a ratio of the uncompressed thickness to the compressed thickness is from 2 to 10.

13. The solid-state lithium-containing battery of any one of claims 1-5, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte that is from 2 pm to 20 pm.

14. The solid-state lithium-containing battery of any one of claims 1-5, wherein the modifying interlayer exhibits an ionic conductivity at 25°C within a range from 4.5 x 10'⁴ S/cm to 7.5 x 10'⁴ S/cm.

15. The solid-state lithium-containing battery of any one of claims 1-5, wherein the electrode is a lithium-containing anode, and the modifying interlayer is positioned between the lithium- containing anode and the solid-state electrolyte.

16. The solid-state lithium-containing battery of any one of claims 1-5, wherein the electrode includes lithium metal.

17. The solid-state lithium-containing battery of claim 16, further comprising: a second electrode comprising lithium metal, the solid-state electrolyte disposed between the electrode and the second electrode, wherein the solid-state lithium-containing battery is a symmetric cell solid-state lithium metal battery.

18. The solid-state lithium-containing battery of any one of claims 1-5, wherein the solid-state electrolyte comprises a lithium garnet ceramic.

19. The solid-state lithium-containing battery of claim 18, wherein the lithium garnet ceramic has a major phase according to at least one of the following formulas:

(i) Li₇-3aLa3Zr₂QaOi2, where Q = Al, Ga or Fe and 0 < a < 0.33;

(ii) Li?La3-bZr2MbOi2, where M = Bi or Y and 0 < b < 1; and (iii) Li?-cLa3Zr2-cNcOi2, with N = In, Si, Ge, Sn, V, W, Te, Nb, or Ta and 0 < c < 1.

20. The solid-state lithium- containing battery of claim 18, wherein the lithium garnet ceramic has a major phase according to the formula LiyLasZnOn.

21. The solid-state lithium-containing battery of claim 18, wherein the lithium garnet ceramic has a major phase of LLZO doped with one or more dopants.

22. The solid-state lithium-containing battery of claim 18, wherein the solid-state electrolyte is a composite that combines two or more ceramics.

23. The solid-state lithium-containing battery of any one of claims 1-5, further comprising: a cathode comprising one or more of lithium cobalt oxide (LiCoCh), lithium nickel oxide (LiNiCh), lithium manganese oxide represented by the formula Lii+xM -xC (wherein x is 0 to 0.33), Ni site-type lithium nickel oxide represented by the formula LiNii-xMxCh (wherein M is Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x is 0.01 to 0.3), and a lithium nickel cobalt manganese material represented by the formula LiNi_xCo_yMn i-x-yCh (wherein x is 0 to 1, y is 0 to 1, and x+y< 1); and a liquid electrolyte solution disposed between the cathode and the solid-state electrolyte, wherein the electrode is an anode, and the solid-state lithium-containing battery is a full cell solid-state lithium-containing battery.

24. The solid-state lithium-containing battery of any one of claims 1-5, wherein the solid-state lithium-containing battery exhibits a critical current density at 25 °C of 3.5 mA/cm² or more.

25. The solid-state lithium-containing battery of claim 24, wherein the critical current density at 25°C is 4.5 mA/cm² or more.

26. The solid-state lithium-containing battery of any one of claims 1-5, wherein the solid-state lithium-containing battery exhibits a Coulombic efficiency that is greater than or equal to 90% for at least 50 cycles of charging and discharging at 0.5C and at 25°C.

27. The solid-state lithium-containing battery of any one of claims 1-5, wherein the solid-state lithium-containing battery exhibits a Coulombic efficiency that is greater than or equal to 90% for at least 200 cycles of charging and discharging at 0.5C and at 25°C.

28. The solid-state lithium-containing battery of any one of claims 1-5, wherein a capacity retention of the solid-state lithium-containing battery is about 80% or more after 50 cycles of charging and discharging at 0.5C and at 25°C.

29. The solid-state lithium-containing battery of any one of claims 1-5, wherein a capacity retention of the solid-state lithium-containing battery is about 90% or more after 100 cycles of charging and discharging at 0.5C and at 25°C.

30. The solid-state lithium-containing battery of any one of claims 1-5, wherein an interfacial resistance of the solid-state lithium-containing battery at 25°C is about 400 cm² or less.

31. The solid-state lithium-containing battery of claim 30, wherein the interfacial resistance of the solid-state lithium-containing battery at 25°C is about 250 cm² or less.

32. The solid-state lithium-containing battery of any one of claims 1-5, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.

33. A method of manufacturing a solid-state lithium-containing battery comprising: electrospinning a solution comprising a polymer and a framework additive into a three- dimensional (3D) polymeric framework comprising (i) electrospun polymer nanofibers comprising the polymer and the framework additive integrated into the electrospun polymer nanofibers and (ii) pores between the electrospun polymer nanofibers fibers; and contacting the 3D polymeric framework with a monomer reaction mixture, the monomer reaction mixture comprising (i) a crosslinkable monomer or prepolymer, (ii) a crosslinking solvent, and (iii) a lithium salt; reacting the crosslinkable monomer or prepolymer of the monomer reaction mixture to form a modifying interlayer comprising (i) the 3D polymeric framework, (ii) a crosslinked polymer within the pores of the 3D polymeric framework, (iii) a crosslinking solvent within the pores of the 3D polymeric framework, and (iv) a lithium salt within the pores of the 3D polymeric framework, wherein the framework additive comprises a sulfonic acid containing compound.

34. The method of claim 33, wherein the polymer comprises one or more of poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride), polyurethane, polyacrylonitrile, poly(vinyl alcohol), poly(ethylene glycol), poly(methyl methacrylate), poly(acrylic acid), carboxymethyl cellulose, poly(ethylene oxide), poly(acrylonitrile-co-butadiene-co-styrene), or a polyimide.

35. The method of claim 33, wherein a weight percentage of the framework additive in the solution is from 0.1 wt% to 3.0 wt%.

36. The method of claim 33, wherein the sulfonic acid containing compound comprises one or more of D(+)-10-camphorsulfonic acid (DCA), DL-10-camphorsulfonic acid, L(-)- camphorsulfonic acid, benzenesulfonic acid, o-cresol-4-sulfonic Acid, and 2-naphthalenesulfonic acid.

37. The method of claim 36, wherein the sulfonic acid containing compound comprises D(+)- 10-camphorsulfonic acid (DCA).

38. The method of claim 36, wherein the 3D polymeric framework exhibits an absorption capacity of the monomer reaction mixture is greater than or equal to 800%.

39. The method of any one of claims 33-38, wherein the crosslinkable monomer or prepolymer comprises one or more of a glycol-containing acrylate, a glycol-containing methacrylates, a vinyl carbonate, or combinations thereof.

40. The method of any one of claims 33-38, wherein the crosslinkable monomer or prepolymer comprises one or more of diethylene glycol diacrylate (DEGDA), diethylene glycol dimethacrylate (DEGDMA), triethylene glycol diacrylate (TEGDA), triethylene glycol dimethacrylate (TEGDMA), tetraethylene glycol diacrylate (TTEGDA), glycidyl methacrylate, polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), polypropylene glycol diacrylate (PPGDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dianol diacrylate (DDA), dianol dimethacrylate (DDMA), ethoxylated trimethylolpropane triacrylate (ETPTA), acrylate-functionalized ethylene oxide, butanediol dimethacrylate, ethoxylated neopentyl glycol diacrylate (NPEOGDA), propoxylated neopentyl glycol diacrylate (NPPOGDA), trimethylol propane triacrylate (TMPTA), trimethylol propane trimethacrylate (TMPTMA), pentaerythritol triacrylate (PETA), ethoxylated propoxylated trimethylol propane triacrylate (TMPEOTA)/(TMPPOTA), propoxylated glyceryl triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate (THEICTA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPEPA), ditrimethylol propane tetraacrylate (DTMPTTA), diglycidyl ester, diallylsuberate, acrylamide, divinylbenzene, a poly(ethylene glycol methyl ether methacrylate) (PEGMEMA), or combinations thereof.

41. The method of any one of claims 33-38, wherein the crosslinkable monomer or prepolymer comprises vinylethylenecarbonate.

42. The method of any one of claims 33-38, wherein the crosslinking solvent comprises one or more of fluoroethylene carbonate (FEC), vinylene carbonate (VC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), fluoroethylene sulfite (FES), or combinations thereof.

43. The method of any one of claims 33-38, wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

44. The method of any one of claims 33-38, wherein the monomer reaction mixture further comprises a fluoroether additive.

45. The method of any one of claims 33-38, wherein the monomer reaction mixture further comprises one or more of the perfluoropolyether (PFPE), fluorinated ether of bis (2,2- difluoroethyl) ether (BDE), fluoroalkyl ether 2,2,2-trifluoroethyl-l,l,2,3,3,3-hexafluoropropyl ether (THE), 1,3,5-trifluorobenzene (3FB), fluorobenzene (FB), or combinations thereof.

46. The method of any one of claims 33-38, wherein the monomer reaction mixture further comprises a photoinitiator, and the reacting comprises impinging the crosslinkable monomer or prepolymer of the monomer reaction mixture with ultraviolet light.

47. The method of any one of claims 33-38, further comprising: and disposing the modifying interlayer between a lithium- containing electrode and a solid-state electrolyte.

48. The method of any one of claims 33-38, wherein the monomer reaction mixture further comprises a thermal initiator, and the reacting comprises heating the monomer reaction mixture.

49. The method of claim 48, further comprising, after the contacting and before the reacting, positioning the 3D polymeric framework and the monomer reaction mixture between a lithium- containing electrode and a solid-state electrolyte.

50. The method of claim 49, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.

51. The method of claim 47, 49, or 50, wherein the solid-state electrolyte comprises a lithium garnet ceramic.

52. The method of any one of claims 33-38, wherein the modifying interlayer has a compressed thickness when compressed between the electrode and the solid-state electrolyte, the modifying interlayer has an uncompressed thickness when not compressed between the electrode and the solid-state electrolyte, and a ratio of the uncompressed thickness to the compressed thickness is from 2 to 10.

53. The method of any one of claims 33-38, wherein the solid-state lithium- containing battery exhibits a critical current density at 25°C of 3.5 mA/cm² or more.

54. The method of any one of claims 33-38, wherein a capacity retention of the solid-state lithium-containing battery is about 80% or more after 50 cycles of charging and discharging at 0.5C and at 25°C.

55. The method of any one of claims 33-38, wherein a capacity retention of the solid-state lithium-containing battery is about 90% or more after 100 cycles of charging and discharging at 0.5C and at 25°C.

56. The method of any one of claims 33-38, wherein an interfacial resistance of the solid-state lithium-containing battery at 25°C is about 400 cm² or less.

57. The method of claim 56, wherein the interfacial resistance of the solid-state lithium- containing battery at 25°C is about 250 cm² or less.

58. The method of any one of claims 33-38, wherein the solid-state electrolyte comprises pores, and at least a portion of the modifying interlayer is positioned within the pores of the solid-state electrolyte.