Lithium-based solid electrolyte material

Abstract

A solid electrolyte material useful in a solid state battery including a semi-solid state flow battery is provided. The resulting solid state battery may have improved cycle capability and increased cycle life. The lithium-based solid electrolyte material may include a lithium-based solid electrolyte material including Li < 3 + x > A < x > B < 2-x > Si < 2 > PO < 12-d > Cd, where A is a trivalent metal, B is a transition metal, C is a halogen or sulfur, x is from 0.01 to 0.5, and d is from 0 to 12. In an optional embodiment, the present invention provides a composite solid electrolyte comprising a lithium-based solid electrolyte material comprising Li < 3 + x > A < x > B < 2-x > Si < 2 > PO < 12-d > Cd, where A is a trivalent metal, B is a transition metal, C is a halogen or sulfur, x is from 0.01 to 0.5, and d is from 0 to 12, a polymer solid electrolyte, and an inorganic salt.

Description

Related applications

[0001] The following non-provisional patent application claims priority to U.S. Provisional Patent Application No. 63 / 430,206, filed on December 5, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present invention relates to solid electrolyte materials, in particular composite solid electrolyte materials that can be incorporated into solid-state batteries. Background Art

[0003] Lithium and lithium-ion secondary or rechargeable batteries have been used in certain applications such as cellular phones, camcorders, and laptop computers, and even more recently, in higher power applications such as electric vehicles, hybrid electric vehicles, eVTOLs, and other air mobility applications. In these applications, it is preferred that the secondary battery have the highest possible specific capacity, but still provide safe operating conditions and good cycling capabilities so that the high specific capacity is maintained during subsequent recharge and discharge cycles.

[0004] Although there are various configurations for secondary batteries, each configuration includes a positive electrode (or cathode), a negative electrode (or anode), a separator separating the cathode and anode, and an electrolyte in electrochemical communication with the cathode and anode. For a secondary lithium battery, when the secondary battery is discharged, that is, when used for its specific application, lithium ions are transferred from the anode to the cathode through the electrolyte. During the discharge process, electrons are collected from the anode and transferred to the cathode through an external circuit. When the secondary battery is charging or recharging, lithium ions are transferred from the cathode to the anode through the electrolyte.

[0005] A new lithium-ion cell or battery pack is typically initially in a discharged state. During the first charge of a lithium-ion battery, lithium moves from the cathode material to the anode active material. The lithium that moves from the cathode to the anode reacts with the electrolyte material at the surface of the graphite anode, resulting in the formation of a passivation film on the anode. The passivation film formed on the graphite anode is a solid electrolyte interface (SEI). Upon subsequent discharge, the lithium consumed by the formation of the SEI does not return to the cathode. This causes the lithium-ion battery to have a smaller capacity than the initial charge capacity because some of the lithium has been consumed by the formation of the SEI. The partial consumption of available lithium in the first cycle reduces the capacity of the lithium-ion battery. This phenomenon is known as irreversible capacity and is known to consume approximately 10% to over 20% of the capacity of a lithium-ion battery. Therefore, after the initial charge of a lithium-ion battery, the lithium-ion battery loses approximately 10% to over 20% of its capacity.

[0006] Many lithium-ion batteries utilize liquid electrolytes. Liquid electrolytes can have battery leakage issues, thermal runaway issues, and the possibility of side reactions in addition to conventional battery reactions, leading to safety issues and problems. To avoid these concerns and problems, it has been proposed to utilize all-solid-state batteries, in which the liquid electrolyte is replaced by a solid electrolyte or a composite solid electrolyte. However, compared to batteries using liquid electrolytes, batteries including solid electrolytes or composite solid electrolytes generally have a smaller discharge capacity.

[0007] Therefore, it is desirable to provide a solid-state battery with high charge and discharge capacity and energy density. Summary of the Invention

[0008] The present invention provides a solid electrolyte material that can be used in solid-state batteries. The solid-state battery may include a semi-solid flow battery. The resulting solid-state battery may have improved cycle capability and increased cycle life. The lithium-based solid electrolyte material may include a lithium-ion battery. 3+x A x B 2-x Si2PO 12-d C d A lithium-based solid electrolyte material, wherein A is a trivalent metal, B is a transition metal, C is a halogen or sulfur, x is 0.01 to 0.5, and d is 0 to 12.

[0009] In an optional embodiment, the present invention provides a composite solid electrolyte comprising a lithium-based solid electrolyte material, a polymer solid electrolyte and an inorganic salt, wherein the lithium-based solid electrolyte material comprises Li 3+x A x B 2-x Si2PO 12- d C d , wherein A is a trivalent metal, B is a transition metal, C is a halogen or sulfur, x is 0.01 to 0.5, and d is 0 to 12. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagram showing a solid-state battery according to the present invention.

[0011] Figure 2 This is a powder X-ray diffraction pattern of the solid electrolyte of Example 1.

[0012] Figure 3 This is a powder X-ray diffraction pattern of the solid electrolyte of Example 2.

[0013] Figure 4 This is a graph showing the cycle performance of various button batteries using the composite solid electrolyte of Example 2.

[0014] Figure 5This is a powder X-ray diffraction pattern of the solid electrolyte of Example 3.

[0015] Figure 6 This is a graph showing the cycle performance of various button batteries using the composite solid electrolyte of Example 3. DETAILED DESCRIPTION

[0016] The foregoing and other aspects of the present invention will now be described in more detail with respect to the description and methods provided herein. It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0017] The terms used in the description of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used in the description of the embodiments of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, as used herein, "and / or" refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0018] When referring to a measurable value such as the amount of a compound, dosage, time, temperature, etc., the term "about" as used herein is intended to encompass variations of 20%, 10%, 5%, 1%, 0.5% or even 0.1% of the specified amount. Unless otherwise defined, all terms (including technical and scientific terms used in the specification) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0019] As used herein, the terms “comprise,” “comprising,” “include,” “includes,” and “including” specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0020] As used herein, the term "consisting essentially of" (and grammatical variations thereof), when applied to the compositions and methods of the present invention, means that the composition / method may include additional components so long as the additional components do not materially alter the composition / method. The term "materially altered," when applied to a composition / method, means that the effectiveness of the composition / method is increased or decreased by at least about 20% or more.

[0021] All patents, patent applications, and publications mentioned herein are incorporated by reference in their entirety. In the event of a conflict in terminology, the present specification controls.

[0022] Figure 1 is a diagram illustrating a solid-state battery 10 of the present invention. The solid-state battery may include an anode 12, a cathode 14, and a lithium-based solid electrolyte 16 according to the present invention. The solid-state battery may include a semi-solid-state flow mode. The solid-state battery may also include an anode current collector 20 and a cathode current collector 22.

[0023] Lithium-based solid electrolytes can have a NASICON-type crystal structure and can have a rhombohedral or monoclinic structure. Lithium offers advantages over sodium because it has the lowest standard reduction potential (-3.07V), which results in a high battery nominal voltage. In addition, lithium-based anodes and cathodes will form more stable and reversible batteries compared to sodium-based compounds.

[0024] Specifically, the lithium-based solid electrolyte may include Li 3+x A x B 2-x Si2PO 12-d C d , wherein A is a trivalent metal, B is a transition metal, C is a halogen, x is 0.01 to 0.5, and d is 0 to 12. The trivalent metal may be selected from Sc, Y, La, Cr, Al, Fe, V, Cr, In, Ga, and Lu. The transition metal may be selected from Ti, Ge, Ta, Zr, Sn, Fe, V, Hf, Nb, Sb, and As. When d is greater than 0 and d may be 0.05 to 0.1, exemplary halogens may include chlorine, fluorine, bromine, and iodine. C may also be sulfur.

[0025] Specific lithium-based solid electrolyte materials may include Li 3.4 Zr 1.6 Sc 0.4 Si2PO 12 、Li 3.25 Zr 1.75 Sc 0.25 Si2PO 12 、Li 3.4 Zr 1.6 Sc 0.4 Si2PO 11.95 Cl 0.05 、Li 3.4 Zr 1.6 Sc 0.4 Si2PO 11.9 Cl 0.1 、Li 3.25 Zr 1.75 Sc 0.25 Si2PO 11.95 Cl 0.05 、Li 3.25 Zr 1.75 Sc 0.25Si2PO 11.9 Cl 0.1 He Li 3.1 Zr 1.9 Sc 0.1 SiPO 12 .

[0026] In one embodiment, the solid electrolyte can be a composite solid electrolyte and includes the above-mentioned lithium-based solid electrolyte material, a polymer solid electrolyte and an inorganic salt. Exemplary polymer solid electrolytes can include polyethylene oxide (PEO), polysiloxane (PSO), polypropylene carbonate (PPC), polyethylene carbonate (PEC), polyvinyl chloride (PVC), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyvinylidene fluoride or polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polymethyl methacrylate (PMMA), n-hydroxysuccinimide (NHD), polypropylene glycol (PPG), polydimethylsiloxane (PDMS), polypropylene carbonate (PPC), polycaprolactone (PCL), polytrimethylene carbonate (PTMC) and polyethyleneimine (PEI) or polymer ionic liquid (PIL). Exemplary inorganic salts may include lithium bis(trifluoromethanesulfonyl)imide (LiTFSi), lithium bis(fluorosulfonyl)imide (LiFSi), lithium hexafluorophosphate (LiPF 6) 、Lithium perchlorate (LiCLO4), lithium tetrafluoroborate (LiBF 4) , lithium sulfate (Li2SO4), trifluoromethyl (CF3), lithium hexafluoroarsenate (LiAsF6), lithium bis(oxalato)borate (LiBOB) and lithium difluoro(oxalato)borate (LiDFOB). The lithium-based solid electrolyte can be formed or synthesized using a known solution method, comprising dissolving a stoichiometric amount of precursors in a solvent such as water or ethanol or a mixture thereof. The dissolved precursors can then be mixed, followed by solvent evaporation and calcination at a temperature of 500°C to 1100°C.

[0027] The obtained solid electrolyte or composite solid electrolyte may have -3 S / cm to 10 -5 High ionic conductivity in the S / cm range.

[0028] The anode of a solid-state battery can be formed from a host material capable of absorbing and desorbing lithium in an electrochemical system, where stable lithium metal powder is dispersed in the host material. For example, when the battery (especially the anode) is recharged, the lithium present in the anode can be inserted into the host material, form an alloy with the host material or be absorbed by the host material. The host material can include materials capable of absorbing and desorbing lithium in an electrochemical system, such as carbonaceous materials; materials containing Si, Sn, tin and silicon oxides or composite tin and / or silicon alloys or intermetallic compounds; transition metal oxides, such as cobalt oxide; lithium metal nitrides, such as Li 3-x Co x N, where 0 < x < 0.5; and lithium metal oxides, such as Li4Ti5O 12 .

[0029] The cathode can be formed from an active material, which is typically combined with a carbonaceous material and a binder polymer. The active material used in the cathode can preferably be a material that can be lithiated at a useful voltage (e.g., 2.0 to 5.0 V relative to lithium). Preferably, non-lithiated materials such as MnO2, V2O5 or MoS2, certain transition metal phosphates, certain transition metal fluorides, sulfur or mixtures thereof can be used as the active material. However, lithiated materials such as LiMn2O4, LiMn 1.5 Ni 0.5 O4, LiMPO4 (M = Fe, Co, Ni), LiMO2 (M = Co, Mn, Fe, Ni), LiNi with x + y + z x Mn y Co z O2 = 1 and LiNi with x + y + z x Co y Al z O2 = 1 can be used. Non-lithiated active materials can be selected because they generally have a higher voltage platform, better safety, lower voltage cost and wider selection than lithiated active materials in such a configuration, and can therefore provide increased power compared to secondary batteries using only lithiated active materials. In addition, since the anode includes lithium as discussed below, the cathode does not have to include a lithiated material for secondary battery operation. The amount of active material provided in the cathode can preferably be sufficient to accept the removable lithium present in the anode.

[0030] In one embodiment, the printable lithium composition can be deposited or applied to the active anode material on the current collector, i.e., forming a pre-lithiated anode. As disclosed in U.S. Application No. 17 / 324,499 and U.S. Serial No. 18 / 205,712, filed concurrently with the present application on June 5, 2023 (the disclosures of which are incorporated by reference in their entirety), the printable lithium composition may include lithium metal powder, a polymer binder, a rheology modifier, and may further include a solvent. The polymer binder may be compatible with the lithium metal powder. The rheology modifier may be compatible with the lithium metal powder and the polymer binder. The solvent may be compatible with the lithium metal powder and the polymer binder. The lithium metal powder may be in the form of a finely divided powder. The average particle size of the lithium metal powder is typically less than about 80 microns, typically less than about 40 microns, and sometimes less than about 20 microns. The lithium metal powder may be a low pyrophoric stable lithium metal powder (SLMP) available from Livent USA Corp. The current collector material may be foil, mesh or foam, as well as conventional metals such as copper or nickel. Application can be by spraying, extrusion, coating, printing, painting, and dipping, and is described in US Patent Application Nos. 16 / 359,707 and 16 / 359,723.

[0031] The present invention is further described with reference to examples, but the present invention should not be limited to the following examples. Example Example 1 (Li 3.4 Zr 1.6 Sc 0.4 Si2PO 12 Synthesis of

[0032] Step 1: Prepare the following solutions separately. (a) 50 mL of 4 M HNO3 from original or concentrated HNO3 (70% or 15.8 M) was provided by adding 37.4 mL to 12.6 mL of HNO3 distilled water. (b) Si(C2H5O)4 was provided in 30 mL of distilled water and 20 mL of ethanol, and the pH was adjusted to 1 by adding 4 M HNO3 from (a). (c) Provide LiOH (50 mL) in 50 mL of distilled water (d) Provide ZrO(NO3)2·xH2O (100 mL) in 100 mL of distilled water (e) Provide Sc(NO3)3·xH2O (50 mL) in 50 mL of distilled water (f) Provide NH4H2PO4 (50 mL) in 50 mL of distilled water Step 2: Mix the four solutions (b) to (f) in a beaker at room temperature with stirring. A white precipitate or gel will form at this stage. Step 3: Slowly dry the gel at 100°C until a dry precursor is obtained. Step 4: Grind the dried precursor from step 3 using a mortar and pestle and calcine at 750-1150°C in argon for 12-24 hours. The powder X-ray diffraction pattern is Figure 2 Available in. Example 2

[0033] The same steps as in Example 1 were used to form Li 3.25 Zr 1.75 Sc 0.25 Si2PO 12 The powder X-ray diffraction pattern is Figure 3 Available in. Table 1 particles R (Ohm) t(cm) σ(S / cm) <![CDATA[Area (cm 2 )]]> 600mg 500 0.1755 2.6E-04 1.327 900mg 552 0.2225 3.0E-04 1.327 Conductivity calculation: σ=(1 / R)*(t / A) Table 1 shows that acceptable ionic conductivity can be achieved with the solid electrolyte of Example 2.

[0034] use Coin cells were formed with a printed lithium foil anode, LiFePO4 as cathode, and a composite solid electrolyte comprising the solid electrolyte of Example 2, PEO, and LLTZO. Conventional anode coin cells were also formed. The printed lithium foil anode had a thickness of 20 μm, and the commercial lithium foil anode had a thickness of 250 μm. Cycling was performed at 2.8 V to 3.8 V, 0.1 C to 0.1 CC. The solid state battery was at 45°C. Figure 4 The combination of a printable lithium foil or conventional anode was shown to perform essentially equivalently to the Example 2 solid electrolyte, where 20 μm The foil anode performs slightly better than the conventionally available 250 μm anodes. Example 3

[0035] The same steps as in Example 1 were used to form Li 3.1 Zr 1.9 Sc 0.1 Si2PO 12 The powder X-ray diffraction pattern is Figure 5 Available in. Table 2: particles R (Ohm) t(cm) σ(S / cm) <![CDATA[Area (cm 2 )]]> 600mg 1745 0.1626 7.0E-05 1.327 900mg 1273 0.2252 1.3E-04 1.327 Conductivity calculation: σ=(1 / R)*(t / A) Table 2 shows that acceptable ionic conductivity can be achieved with the solid electrolyte of Example 3.

[0036] use A coin cell was formed with a printable lithium foil anode, LiFePO4 as a cathode, and a composite solid electrolyte comprising the solid electrolyte of Example 3, PEO, and LLTZO. The printed lithium foil anode had a thickness of 20 μm, and conventionally available lithium foil anodes had thicknesses of 20 μm and 250 μm. The coin cells were cycled between 2.8 V and 3.8 V at 45°C with a constant current constant voltage corresponding to 0.1C and a current cutoff at 0.1C. Figure 6 It was shown that the combination of printed lithium foil or 20 μm or 250 μm conventionally available anodes performed essentially equivalently to the Example 3 solid electrolyte.

[0037] Although the present invention has been described and illustrated herein with reference to preferred embodiments and specific examples thereof, it will be apparent to those skilled in the art that other embodiments and examples may perform similar functions and / or achieve similar results. All such equivalent embodiments and examples are within the spirit and scope of the present invention.

Claims

1. A lithium-based solid electrolyte material comprising Li 3+x A x B 2-x Si2PO 12-d C d ,in: A is a trivalent metal, B is a transition metal, C is a halogen or sulfur, x is 0.01 to 0.5, d is 0 to 12.

2. The lithium-based solid electrolyte material according to claim 1, wherein the trivalent metal is selected from Sc, Y, La, Cr, Al, Fe, V, Cr, In, Ga and Lu.

3. The lithium-based solid electrolyte material of claim 1, wherein the transition metal is selected from the group consisting of Ti, Ge, Ta, Zr, Sn, Fe, V, Hf, Nb, Sb and As.

4. The lithium-based solid electrolyte material according to claim 1, wherein the halogen is selected from chlorine, fluorine, bromine and iodine. The lithium-based solid electrolyte material according to claim 1 , wherein d is 0. The lithium-based solid electrolyte material according to claim 1 , wherein the material has a NASICON-type crystal structure. 7 . The lithium-based solid electrolyte material according to claim 1 , wherein the NASICON-type crystal structure is selected from a rhombohedral structure and a monoclinic structure. 8 . A composite solid electrolyte comprising the lithium-based solid electrolyte material according to claim 7 , a polymer solid electrolyte and an inorganic salt.

9. The composite electrolyte according to claim 8, wherein the polymer solid electrolyte is polyethylene oxide (PEO), polysiloxane (PSO), polypropylene carbonate (PPC), polyethylene carbonate (PEC), polyvinyl chloride (PVC), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyvinylidene fluoride or polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polymethyl methacrylate (PMMA), n-hydroxysuccinimide (NHD), polypropylene glycol (PPG), polydimethylsiloxane (PDMS), polypropylene carbonate (PPC), polycaprolactone (PCL), polytrimethylene carbonate (PTMC) and polyethyleneimine (PEI) or polymer ionic liquid (PIL).

10. The composite solid electrolyte of claim 9, wherein the inorganic salt is selected from lithium bis(trifluoromethanesulfonyl)imide (LiTFSi), lithium bis(fluorosulfonyl)imide (LiFSi), lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiCLO4), lithium tetrafluoroborate (LiBF4), lithium sulfate (Li2SO4), trifluoromethyl (CF3), lithium hexafluoroarsenate (LiAsF6), lithium bis(oxalato)borate (LiBOB) and lithium difluoro(oxalato)borate (LiDFOB). 11 . A solid-state battery comprising a cathode, an anode and the composite solid electrolyte according to claim 8 .

12. A composite solid electrolyte comprising a solid electrolyte material, a polymer solid electrolyte and an inorganic salt, wherein the solid electrolyte material is selected from Li 3.4 Zr 1.6 Sc 0.4 Si2PO 12 、Li 3.25 Zr 1.75 Sc 0.25 Si2PO 12 、Li 3.4 Zr 1.6 Sc 0.4 Si2PO 11.95 Cl 0.05 、Li 3.4 Zr 1.6 Sc 0.4 Si2PO 11.9 Cl 0.1 、Li 3.25 Zr 1.75 Sc 0.25 Si2PO 11.95 Cl 0.05 He Li 3.25 Zr 1.75 Sc 0.25 Si2PO 11.9 Cl 0.1 .

13. The composite electrolyte according to claim 12, wherein the polymer solid electrolyte is polyethylene oxide (PEO), polysiloxane (PSO), polypropylene carbonate (PPC), polyethylene carbonate (PEC), polyvinyl chloride (PVC), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyvinylidene fluoride or polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polymethyl methacrylate (PMMA), n-hydroxysuccinimide (NHD), polypropylene glycol (PPG), polydimethylsiloxane (PDMS), polypropylene carbonate (PPC), polycaprolactone (PCL), polytrimethylene carbonate (PTMC) and polyethyleneimine (PEI) or polymer ionic liquid (PIL).

14. The composite solid electrolyte according to claim 12, wherein The inorganic salt is selected from lithium bis(trifluoromethanesulfonyl)imide (LiTFSi), lithium bis(fluorosulfonyl)imide (LiFSi), lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiCLO4), lithium tetrafluoroborate (LiBF4), lithium sulfate (Li2SO4), trifluoromethyl (CF3), lithium hexafluoroarsenate (LiAs F6), lithium bis(oxalato)borate (LiBOB) and lithium difluoro(oxalato)borate (LiDFOB). 15 . A solid-state battery comprising a cathode, an anode and the composite solid electrolyte according to claim 12 .

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