Amorphous solid-state electrolyte material, method for preparing the same, and use thereof

Abstract

This invention provides an amorphous solid electrolyte material, comprising: an amorphous matrix based on a disordered arrangement of polyhedra and an ion-conducting substance; wherein the polyhedra in the amorphous matrix are composed of at least one cation and at least one halide anion or oxygen-containing anion; the ion-conducting substance comprises at least one of the following: Li + Na + K + Cu + Ag + This invention also provides a method for preparing an amorphous solid electrolyte material and its application in an all-solid-state alkali metal battery.

Description

Technical Field

[0001] This invention relates to the field of solid electrolyte materials, and more particularly to amorphous solid electrolyte materials, their preparation methods, and their applications in all-solid-state alkali metal batteries. Background Technology

[0002] Compared to traditional liquid electrolyte alkali metal ion batteries, all-solid-state alkali metal batteries offer advantages such as high safety, high energy density, and long cycle life, and are considered one of the key technologies for revolutionizing electrochemical energy storage. Currently, the key to developing all-solid-state alkali metal batteries lies in preparing solid electrolyte materials that are stable to the alkali metal anode, have high room-temperature ionic conductivity, low migration activation energy, and a wide electrochemical window. Summary of the Invention

[0003] In view of this, the main objective of the present invention is to provide an amorphous solid electrolyte material, a method for preparing the same, and its application in all-solid-state alkali metal batteries, in order to at least partially solve one of the aforementioned technical problems.

[0004] As one aspect of the present invention, an amorphous solid electrolyte material is provided, comprising: an amorphous matrix based on a disordered arrangement of polyhedra and an ion-conducting substance;

[0005] The polyhedra in the amorphous matrix are composed of at least one cation and at least one halide anion or oxygen-containing anion.

[0006] Ion-conducting substances include at least one of the following: Li + Na + K + Cu + Ag + .

[0007] According to an embodiment of the present invention, an amorphous-nanocrystalline composite solid electrolyte material is prepared when the molar ratio of the chemical formula in the polyhedron of the amorphous matrix to the chemical formula in the ion-conducting material is greater than 1.

[0008] According to an embodiment of the present invention, an amorphous matrix based on the disordered arrangement of polyhedra forms an amorphous glassy network structure by the polyhedra sharing vertices / edges / faces and being randomly dispersed among themselves.

[0009] Amorphous glassy network structures are used for ion conduction in ion-conducting materials.

[0010] According to an embodiment of the present invention, the amorphous matrix based on the disordered arrangement of polyhedra includes octahedrons;

[0011] Among them, the chemical elements corresponding to the cations in the octahedron include at least one of the following: Ga, Fe, Nb, Ta, P;

[0012] The anions in an octahedron include at least one of the following: F - Cl - ,Br - I - O 2- OH - O2 2- .

[0013] According to an embodiment of the present invention, the amorphous solid electrolyte material has an ionic conductivity >1.0 mS / cm. -1 .

[0014] As another aspect of the present invention, a method for preparing an amorphous solid electrolyte material is also provided, comprising:

[0015] A precursor mixture formed by a first metal compound and a second metal or non-metal compound is ball-milled with ball milling beads at room temperature under an inert atmosphere to obtain an amorphous solid electrolyte material.

[0016] The first metal compound is composed of an ion-conducting substance and a halide anion or an oxygen-containing anion.

[0017] The second metal or nonmetal compound is composed of a metal or nonmetal cation and a halide anion or an oxoanion.

[0018] According to an embodiment of the present invention, the mass ratio of the precursor mixture to the milling beads is 1:(40-50); preferably 1:45.

[0019] According to an embodiment of the present invention, the rotational speed of the ball mill is 400-450 rpm; preferably 450 rpm.

[0020] According to an embodiment of the present invention, the ball milling time is 20 to 120 hours; preferably 80 to 120 hours.

[0021] As another aspect of the present invention, the application of an amorphous solid electrolyte material in an all-solid-state alkali metal battery is also provided. Attached Figure Description

[0022] Figure 1 A schematic cross-sectional view of an all-solid-state lithium metal symmetric battery obtained from an amorphous solid electrolyte material according to an embodiment of the present invention is shown.

[0023] Figure 2 A schematic cross-sectional view of an all-solid-state lithium metal full battery obtained from an amorphous solid electrolyte material according to an embodiment of the present invention is shown.

[0024] Figure 3 The X-ray diffraction pattern of the amorphous solid electrolyte material according to Embodiment T1 of the present invention is shown;

[0025] Figure 4 The X-ray diffraction patterns of the amorphous solid electrolyte materials according to embodiments T2 to T4 of the present invention are shown.

[0026] Figure 5 The X-ray diffraction patterns of the amorphous solid electrolyte materials according to embodiments T5-T6 of the present invention are shown.

[0027] Figure 6 The room-temperature electrochemical impedance spectroscopy spectra of the solid electrolytes according to Examples T1 to T17 of the present invention are shown.

[0028] Figure 7 The electrochemical performance curves of an all-solid-state lithium metal symmetric battery obtained based on the amorphous-nanocrystalline composite solid electrolyte material obtained in Example T3 of the present invention are shown.

[0029] Figure 8 The electrochemical performance curves of an all-solid-state lithium metal full battery obtained based on the amorphous-nanocrystalline composite solid electrolyte material obtained in Example T3 of the present invention are shown.

[0030] [Explanation of Labels in the Attached Image]

[0031] 10 - All-solid-state lithium metal symmetric battery; 101 - Symmetric electrode layer; 102 - Insulation layer; 103 - Solid electrolyte particles; 20 - All-solid-state lithium metal full battery; 201 - Positive electrode active material layer; 202 - Negative electrode layer; 203 - Positive electrode active material particles. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0033] Related studies have shown that a series of oxide types (such as La) 0.5 Li 0.5 TiO3, Li7La3Zr2O 12 Na-β-Al2O3, Na3Zr2Si2PO 12 ), sulfide type (e.g., Li6PS5Cl6, Li 10 GeP2S 12 Li 9.5 Si 1.74 P 1.44 S 11.7 Cl 0.3Na3PS4, Na 10 SnP2S 12 ) and halide-type crystalline ceramic materials (such as: Li3YCl6, Li3ErCl6, Li3InCl6, Li3ScCl6, Li2ZrCl6, Na2ZrCl6), sulfide-type glass-ceramic composite materials (such as: Li 3.2 P 0.8 Sn 0.2 Solid electrolytes, including S4, amorphous oxide materials (LiPON), and sulfide glass materials (such as Li2S-P2S5 and Na2S-P2S5), exhibit room-temperature ionic conductivity as high as 10. -4 ~10 -2 S cm -1 The room-temperature ionic conductivity is very close to or even exceeds that of organic liquid electrolytes. However, the large-scale practical application of all-solid-state alkali metal batteries is still limited by problems such as rapid interface deterioration and catastrophic battery failures caused by the penetration growth of alkali metal dendrites along grain boundaries in crystalline ceramic solid electrolytes.

[0034] Compared with crystalline solid electrolyte materials, amorphous solid electrolyte materials have the following advantages:

[0035] (1) Amorphous solid electrolyte materials have a large free volume, a defect-rich disordered lattice, and an isotropic ion conduction path through an open glass network, which is therefore expected to achieve ultrafast ion transport.

[0036] (2) Amorphous solid electrolyte materials are easy to manufacture into various shapes / sizes, including thin and dense films, without the need for complex sintering processes, making the industrial application of all-solid-state batteries cost-effective.

[0037] (3) There are no high-resistance grain boundaries in amorphous solid electrolyte materials, which is expected to achieve uniform deposition and extraction of alkali metal ions. At the same time, there will be no problem of alkali metal dendrites growing along the grain boundaries. They can form and maintain a tight solid-solid contact in the composite cathode, build a continuous ion transport network, and thus achieve stable cycling of all-solid alkali metal full cells.

[0038] Although oxide-type amorphous solid electrolyte materials LiPON and Li2S-P2S5-based sulfide and oxysulfide-type amorphous and derived glass-ceramic composite solid electrolyte materials have been extensively studied in all-solid-state lithium metal batteries, their inherent physicochemical properties limit their application in large-scale all-solid-state batteries, resulting in a significant challenge of low ionic conductivity (10⁻¹⁰). -6 ~10 -4 Scm -1Challenges include interface incompatibility, poor cycle stability, low energy density, and difficulties in replicating battery assembly processes. Therefore, halide-based amorphous solid-state electrolyte materials, possessing the advantages of both sulfide plasticity and oxide's wide electrochemical window and strong stability, hold promise as new alternatives. The aim is to simultaneously achieve high ionic conductivity at room temperature, high interfacial stability, and tight electrode / electrolyte solid-solid contact, thereby realizing highly stable and safe all-solid-state alkali metal batteries. However, no relevant research reports have been published yet; therefore, developing an amorphous solid-state electrolyte material is a technical challenge that urgently needs to be addressed by those skilled in the art.

[0039] Based on this, the present invention provides an amorphous solid electrolyte material, its preparation method, and its application in all-solid-state alkali metal batteries. Based on an A... a MX b The materials (a≥1, b≥4) were analyzed and studied to provide an amorphous matrix that can be used as a medium for rapid conduction of monovalent ions, thereby achieving a room temperature ionic conductivity as high as 5.86–6.88 mS / cm. -1 Amorphous solid electrolyte materials.

[0040] The following illustrative examples illustrate amorphous solid electrolyte materials, their preparation methods, and their applications in all-solid-state alkali metal batteries. It should be noted that these examples are merely specific embodiments of the present invention and do not limit the scope of protection of the present invention.

[0041] As one aspect of the present invention, an amorphous solid electrolyte material is provided, comprising: an amorphous matrix based on a disordered arrangement of polyhedra and an ion-conducting substance;

[0042] The polyhedra in the amorphous matrix are composed of at least one cation and at least one halide anion or oxygen-containing anion.

[0043] Ion-conducting substances include at least one of the following: Li + Na + K + Cu + Ag + .

[0044] According to embodiments of the present invention, the cation may include at least one of the following: Ga 3+ Fe 3+ Zr 4+ 、Nb 5+ Ta 5+ P 5 + Halogen anions or oxyanions may include at least one of the following: F - Cl - ,Br - I- O 2- OH - O2 2- .

[0045] According to embodiments of the present invention, the amorphous solid electrolyte material has a glassy network of an amorphous matrix and an ion-conducting substance. The amorphous matrix comprises multiple randomly arranged polyhedra, a large number of charge carriers, and abundant site defects. It exhibits high room-temperature ionic conductivity. The amorphous matrix does not show any diffraction peak signals in X-ray diffraction measurements using copper Kα rays.

[0046] It should be noted that amorphous solid electrolyte materials do not contain sulfur. Sulfur-free amorphous solid electrolyte materials do not produce toxic hydrogen sulfide when exposed to the atmosphere, thus exhibiting excellent safety in their preparation, storage, and application.

[0047] According to an embodiment of the present invention, an amorphous-nanocrystalline composite solid electrolyte material is prepared when the molar ratio of the chemical formula in the polyhedron of the amorphous matrix to the chemical formula in the ion-conducting material is greater than 1. The amorphous-nanocrystalline composite solid electrolyte material has an amorphous-nanocrystalline transition interface.

[0048] It should be noted that, in X-ray diffraction measurements using copper Kα rays, the amorphous-nanocrystalline composite solid electrolyte material exhibits intrinsic diffraction peak signals of the raw material AX, where AX includes at least one of the following: LiF, LiCl, LiBr, LiI, Li₂O, LiOH, Li₂O₂, NaF, NaCl, NaBr, NaI, Na₂O, NaOH, Na₂O₂, KF, KCl, KBr, KI, CuCl, CuBr, CuI, AgF, AgCl, AgBr, AgI. Furthermore, in high-resolution transmission electron microscopy imaging, the amorphous-nanocrystalline composite solid electrolyte material displays a distinct transition region between the amorphous matrix and the nanocrystalline interface.

[0049] According to an embodiment of the present invention, an amorphous glassy network structure is formed by the random arrangement of polyhedra and the polyhedra sharing vertices / edges / faces and randomly dispersing them.

[0050] Amorphous glassy network structures are used for ion conduction in ion-conducting materials.

[0051] It should be noted that since amorphous glassy network structures can be constructed from randomly distributed shared vertex / edge / face octahedra, they possess large free volumes, defect-rich disordered lattices, and isotropic ion conduction pathways. The abundant defects and disordered lattice allow for the configuration of a large number of monovalent cations as mobile charge carriers. Within the large free volume, the concentration of non-mobile cations that hinder ion conduction is relatively low. This means that monovalent cations have abundant low / high energy sites, migration transition state sites, and migration initiation / final state sites, while providing a large available space for ion conduction. Furthermore, the electrostatic interactions between halide anions and oxygen-containing anions and monovalent cations are small. As a result, the room-temperature ionic conductivity of amorphous solid electrolyte materials can be increased.

[0052] According to embodiments of the present invention, the polyhedra in an amorphous matrix based on the disordered arrangement of polyhedra include octahedrons;

[0053] Among them, the chemical elements corresponding to the cations in the octahedron include at least one of the following: Ga, Fe, Nb, Ta, P;

[0054] The anions in an octahedron include at least one of the following: F - Cl - ,Br - I - O 2- OH - O2 2- .

[0055] For example, the general chemical formula for amorphous solid electrolyte materials can be represented as: A a MX b And satisfying a≥1, b≥4. The octahedron MX6 in the amorphous matrix can be composed of at least one cation selected from Ga, Fe, Nb, Ta, and P, and a cation selected from F. - Cl - ,Br - I - O 2- OH - O2 2- It is composed of at least one anion. Ion-conducting substance A includes at least one of the following: Li + Na + K + Cu + Ag + .

[0056] Preferably, the ion-conducting material A can be Li + Na + Due to its small ionic radius, it can be dispersed in large quantities in amorphous matrices and achieve rapid conduction.

[0057] According to embodiments of the present invention, the amorphous solid electrolyte material has an ionic conductivity >1.0 mS / cm. -1 .

[0058] For example, when the molecular formula of the amorphous solid electrolyte material is LiTaCl6 (AX = LiCl, MX = TaCl5, a = 1, b = 6), the ionic conductivity at room temperature (25℃) is 5.86 mS / cm after electrochemical impedance spectroscopy. -1 When the molecular formula of the amorphous-nanocrystalline composite solid electrolyte material is Li₂TaCl₇ (AX = LiCl, MX = TaCl₅, a = 2, b = 7), the ionic conductivity at room temperature (25℃) is 6.88 mS / cm, as determined by electrochemical impedance spectroscopy. -1 When the molecular formula of the amorphous-nanocrystalline composite solid electrolyte material is Li4TaCl9 (AX = LiCl, MX = TaCl5, a = 4, b = 9), the ionic conductivity at room temperature (25℃) is 3.59 mS / cm after electrochemical impedance spectroscopy. -1 .

[0059] Among them, Li4TaCl9 and LiTaCl6 have different local microstructures, and Li4TaCl9 contains an amorphous-nanocrystalline transition interface.

[0060] According to some embodiments of the present invention, the amorphous-nanocrystalline composite solid electrolyte material has an ionic conductivity of 1.0–3.5 mS / cm. -1 However, it is not limited to this.

[0061] For example, when the molecular formula of the amorphous-nanocrystalline composite solid electrolyte material is Na3TaCl8 (AX = NaCl, MX = TaCl5, a = 3, b = 8), the ionic conductivity at room temperature (25℃) is 2.98 mS / cm after electrochemical impedance spectroscopy. -1 When the molecular formula of the amorphous-nanocrystalline composite solid electrolyte material is Na4TaCl9 (AX = NaCl, MX = TaCl5, a = 4, b = 9), the ionic conductivity at room temperature (25℃) is 3.21 mS / cm after electrochemical impedance spectroscopy. -1 .

[0062] It should be noted that amorphous solid-state electrolyte materials exhibit ultra-high room-temperature ionic conductivity due to their amorphous matrix based on the disordered arrangement of polyhedra. In particular, amorphous-nanocrystalline composite solid-state electrolyte materials, with their amorphous-nanocrystalline transition interface exhibiting localized lattice distortion and lack, provide abundant point defects for monovalent cation conduction. Furthermore, combined with the advantages of the aforementioned amorphous matrix, rapid ion conduction can still be achieved. In addition, the abundant nanocrystalline particles surrounding the amorphous matrix in amorphous-nanocrystalline composite solid-state electrolyte materials can stabilize the lithium metal interface. As a result, amorphous-nanocrystalline composite solid-state electrolyte materials are compatible with lithium metal anodes. They can even be simultaneously compatible with commercially available lithium metal anodes and high-voltage lithium nickel manganese oxide (NMC532) cathode materials.

[0063] As another aspect of the present invention, a method for preparing an amorphous solid electrolyte material is also provided.

[0064] According to an embodiment of the present invention, the preparation method of the amorphous solid electrolyte material includes:

[0065] A precursor mixture formed by a first metal compound and a second metal or non-metal compound is ball-milled with ball milling beads at room temperature under an inert atmosphere to obtain an amorphous solid electrolyte material.

[0066] The first metal compound is composed of an ion-conducting substance and a halide anion or an oxoanion; the second metal or non-metal compound is composed of a metal or non-metal cation and a halide anion or an oxoanion.

[0067] According to embodiments of the present invention, a precursor mixture can be obtained by mixing a first metal compound and a second metal or non-metal compound according to a predetermined molar ratio of the chemical formulas in the first metal compound and the second metal or non-metal compound. The predetermined molar ratio of the chemical formulas in the first metal compound and the second metal or non-metal compound can be determined based on the target composition of the amorphous solid electrolyte material.

[0068] It should be noted that, in order to offset possible compositional changes and precursor mixture losses during the synthesis process, the raw materials can be manually ground and premixed according to the predetermined molar ratio of the first metal compound to the second metal or non-metal compound to obtain a premixed precursor powder. This powder is then subjected to a solid-phase chemical reaction through mechanical ball milling in a mixing device such as a high-energy planetary ball mill to obtain an amorphous solid electrolyte material.

[0069] According to an embodiment of the present invention, the mass ratio of the precursor mixture to the milling beads is 1:(40-50); preferably 1:45.

[0070] According to an embodiment of the present invention, the rotational speed of the ball mill is 400-450 rpm; preferably 450 rpm.

[0071] According to an embodiment of the present invention, the ball milling time is 20 to 120 hours; preferably 80 to 120 hours.

[0072] According to embodiments of the present invention, the first metal compound AX includes at least one of the following: LiF, LiCl, LiBr, LiI, Li2O, LiOH, Li2O2, NaF, NaCl, NaBr, NaI, Na2O, NaOH, Na2O2, KF, KCl, KBr, KI, CuCl, CuBr, CuI, AgF, AgCl, AgBr, AgI. The second metal or nonmetal compound includes at least one of the following: GaF3, GaCl3, GaBr3, GaI3, Ga(OH)3, FeF3, FeCl3, Fe(OH)3, ZrF4, ZrCl4, ZrBr4, Zr(OH)4, NbF5, NbCl5, NbBr5, NbI5, Nb(OH)5, TaF5, TaCl5, TaBr5, TaI5, Ta(OH)5, PCl5, PBr5. The inert atmosphere may include nitrogen or argon.

[0073] As another aspect of the present invention, the application of an amorphous solid electrolyte material in an all-solid-state alkali metal battery is also provided.

[0074] According to an embodiment of the present invention, an all-solid-state lithium metal symmetric battery is provided, comprising: lithium metal as a symmetric electrode layer and an insulating layer. The insulating layer is formed between the symmetric electrode layers. The insulating layer contains an amorphous-nanocrystalline composite solid electrolyte material or an amorphous solid electrolyte material.

[0075] According to embodiments of the present invention, a stable all-solid-state lithium metal symmetric battery with lithium deposition / deposition can be formed by using an amorphous-nanocrystalline composite solid electrolyte material or an amorphous solid electrolyte material. This all-solid-state lithium metal symmetric battery has a low polarization voltage and a long cycle life.

[0076] Figure 1 A schematic cross-sectional view of an all-solid-state lithium metal symmetric battery obtained from an amorphous solid electrolyte material according to an embodiment of the present invention is shown.

[0077] like Figure 1As shown, the all-solid-state lithium metal symmetric battery 10 includes: a lithium metal symmetric electrode layer 101 and an insulating layer 102. The insulating layer 102 is formed between the symmetric electrode layers 101. The symmetric electrode layer 101 may include lithium metal negative electrode discs. The diameter of the symmetric electrode layer 101 can be 6–8 mm, smaller than the diameter of the insulating layer 102 (8–10 mm), ensuring that the lithium metal will not stretch under pressure, causing a short circuit. The thickness of the symmetric electrode layer 101 can be 100–500 μm. The thickness of the insulating layer 102 can be 50–500 μm. The insulating layer 102 contains solid electrolyte particles 103, the main component of which includes amorphous solid electrolyte materials. It should be noted that the main component of the solid electrolyte particles 103 can also be an amorphous-nanocrystalline composite solid electrolyte material. The all-solid-state lithium metal symmetric battery 10 can be coin-shaped, square, button-shaped, or flat.

[0078] According to embodiments of the present invention, an all-solid-state lithium metal full battery is also provided, comprising: a positive electrode active material layer, a negative electrode layer, and an insulating layer. The insulating layer is formed between the positive electrode active material layer and the negative electrode layer. At least one of the positive electrode active material layer or the insulating layer contains an amorphous-nanocrystalline composite solid electrolyte material or an amorphous solid electrolyte material.

[0079] According to embodiments of the present invention, a high-output all-solid-state lithium metal full cell can be fabricated by using an amorphous-nanocrystalline composite solid-state electrolyte material or an amorphous solid-state electrolyte material; this all-solid-state lithium metal full cell possesses a high initial coulombic efficiency. All-solid-state batteries based on amorphous-nanocrystalline composite solid-state electrolyte materials or amorphous solid-state electrolyte materials exhibit stable cycle performance.

[0080] Figure 2 A schematic cross-sectional view of an all-solid-state lithium metal full battery obtained from an amorphous solid electrolyte material according to an embodiment of the present invention is shown.

[0081] like Figure 2 As shown, the all-solid-state lithium metal full battery 20 includes: a positive electrode active material layer 201, an insulating layer 102, and a negative electrode layer 202.

[0082] The insulating layer 102 is formed between the positive electrode active material layer 201 and the negative electrode layer 202. The negative electrode layer 202 contains compounds or elements capable of reversibly storing and releasing lithium ions, such as, but not limited to, graphite, coke, carbon fiber, graphene, silicon, silicon oxide, tin, lithium-tin alloy (Li-Sn), lithium-silicon alloy (Li-Si), and metallic elements. From an energy density perspective, the negative electrode layer 202 is preferably lithium metal with the chemical formula Li. The diameter of the negative electrode layer 202 can be 6–8 mm, smaller than the diameter of the insulating layer 102 (8–10 mm), ensuring that the lithium metal will not stretch under pressure, causing a short circuit in the battery. The thickness of the negative electrode layer 202 can be less than 100–500 μm.

[0083] The thickness of the insulating layer 102 can be 50–500 μm. The insulating layer 102 contains solid electrolyte particles 103, the main components of which include amorphous solid electrolyte materials. It should be noted that the main components of the solid electrolyte particles 103 can also be amorphous-nanocrystalline composite solid electrolyte materials.

[0084] The positive electrode active material layer 201 contains positive electrode active material particles 203 and solid electrolyte particles 103. The thickness of the positive electrode active material layer 201 can be 5–100 μm. The mass ratio of the positive electrode active material particles 203 to the sum of the masses of the positive electrode active material particles 203 and the solid electrolyte particles 103 can be 40%–95%. The positive electrode active material particles 203 contain compounds capable of reversibly storing and releasing lithium ions, such as, but not limited to, transition metal oxides (lithium cobalt oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminum oxide, etc.), transition metal sulfides (antimony sulfide, bismuth sulfide, etc.), transition metal fluorides (iron fluoride, etc.), and organic electrode materials. The transition metal oxide can be a single-crystal lithium nickel manganese cobalt oxide material, and its chemical composition can be LiNi. 0.5 Mn 0.3 Co 0.2 O2.

[0085] It should be noted that at least one of the insulating layer 102 and the positive electrode active material layer 201 may contain a solid electrolyte other than an amorphous solid electrolyte material or an amorphous-nanocrystalline composite solid electrolyte material, for the purpose of improving ion conductivity and electrochemical stability. The other solid electrolyte may be oxide-type (including but not limited to La). 0.5 Li 0.5 TiO3, Li7La3Zr2O 12 ), sulfide type (including but not limited to Li6PS5Cl6, Li 10 GeP2S 12 Li 9.5 Si1.74 P 1.44 S 11.7 Cl 0.3 ) and halide-type crystalline ceramics (including but not limited to Li3YCl6, Li3InCl6, Li3ScCl6, Li2ZrCl6), sulfide-type glass-ceramic (including but not limited to Li 3.2 P 0.8 Sn 0.2 S4), amorphous oxides (including but not limited to LiPON), sulfide-type glasses (including but not limited to Li2S-P2S5), and organic polymer-type solid electrolytes (including but not limited to PEO-LiTFSI).

[0086] The positive electrode active material layer 201 also contains a binder and a conductive agent to improve the solid-solid contact and electronic conduction properties between particles. The binder includes, but is not limited to, polyvinylidene fluoride, bacterial cellulose, styrene-butadiene rubber, polymethyl methacrylate, polyvinyl alcohol, and polytetrafluoroethylene. Polytetrafluoroethylene is preferred. The conductive agent includes, but is not limited to, graphite, Ketjen black, acetylene black, polypyrrole, and carbon fiber. Carbon fiber is preferred.

[0087] The all-solid-state lithium metal full battery 20 can be coin-shaped, square, button-shaped, or flat.

[0088] The following detailed embodiments illustrate amorphous solid electrolyte materials, their preparation methods, and their applications in all-solid-state alkali metal batteries. It should be noted that these examples are merely specific embodiments of the present invention and do not limit the scope of protection of the present invention.

[0089] Example T1

[0090] Anhydrous lithium chloride and anhydrous tantalum chloride were mixed in a dry atmosphere protected by argon at a stoichiometric molar ratio of LiCl:TaCl5 = 1:1, and manually ground in an agate mortar for 10–30 min to obtain a homogeneous precursor mixture powder. The precursor mixture powder was then subjected to a mechanochemical reaction at 450 rpm for 120 h using a high-energy planetary ball mill. This yielded a solid electrolyte powder, i.e., an amorphous solid electrolyte material. The molecular formula of this amorphous solid electrolyte material is LiTaCl6.

[0091] Figure 3 The X-ray diffraction pattern of the amorphous solid electrolyte material according to Embodiment T1 of the present invention is shown. Figure 3 It can be seen that the ball-milled sample LiTaCl6 formed diffraction results that were completely different from those of the raw materials LiCl and TaCl5. That is, LiTaCl6 did not have any diffraction peaks, indicating the successful preparation of amorphous solid electrolyte materials.

[0092] Example T2

[0093] In this embodiment T2, while keeping other conditions unchanged from embodiment T1, the anhydrous lithium chloride and anhydrous tantalum chloride raw materials were mixed in a stoichiometric molar ratio of LiCl:TaCl5 = 2:1. The molecular formula of the prepared amorphous-nanocrystalline composite solid electrolyte material is Li2TaCl7.

[0094] Figure 4 X-ray diffraction patterns of amorphous solid electrolyte materials T2 to T4 according to embodiments of the present invention are shown. Figure 4 It can be seen that Li2TaCl7 formed diffraction peaks that are completely different from the raw material TaCl5 but perfectly matched the LiCl crystal phase, indicating the successful preparation of amorphous-nanocrystalline composite solid electrolyte material.

[0095] Example T3

[0096] In this embodiment T3, while keeping other conditions unchanged from embodiment T1, the anhydrous lithium chloride and anhydrous tantalum chloride raw materials were mixed in a stoichiometric molar ratio of LiCl:TaCl5 = 4:1. The molecular formula of the prepared amorphous-nanocrystalline composite solid electrolyte material is Li4TaCl9.

[0097] Depend on Figure 4 It can be seen that Li4TaCl9 formed diffraction peaks that were completely different from the raw material TaCl5 but perfectly matched the LiCl crystal phase, indicating the successful preparation of amorphous-nanocrystalline composite solid electrolyte material.

[0098] Example T4

[0099] In Example T4, while keeping other conditions unchanged from Example T1, the anhydrous lithium chloride and anhydrous tantalum chloride raw materials were mixed in a stoichiometric molar ratio of LiCl:TaCl5 = 7:1. The resulting amorphous-nanocrystalline composite solid electrolyte material has the molecular formula Li7TaCl5. 12 .

[0100] Depend on Figure 4 It can be seen that Li7TaCl 12 The formation of diffraction peaks that are completely different from the raw material TaCl5 but perfectly match the LiCl crystal phase indicates the successful preparation of amorphous-nanocrystalline composite solid electrolyte material.

[0101] Example T5

[0102] In this embodiment T5, while keeping other conditions unchanged from embodiment T1, the anhydrous sodium chloride and anhydrous tantalum chloride raw materials were mixed in a stoichiometric molar ratio of NaCl:TaCl5 = 3:1. The molecular formula of the prepared amorphous-nanocrystalline composite solid electrolyte material is Na3TaCl8.

[0103] Figure 5 X-ray diffraction patterns of amorphous solid electrolyte materials T5-T6 according to embodiments of the present invention are shown. Figure 5 It can be seen that Na3TaCl8 formed diffraction peaks that were completely different from the raw material TaCl5 but perfectly matched the NaCl crystal phase, indicating the successful preparation of amorphous-nanocrystalline composite solid electrolyte material.

[0104] Example T6

[0105] In this embodiment T6, while keeping other conditions unchanged from embodiment T1, the anhydrous sodium chloride and anhydrous tantalum chloride raw materials were mixed in a stoichiometric molar ratio of NaCl:TaCl5 = 4:1. The molecular formula of the prepared amorphous-nanocrystalline composite solid electrolyte material is Na4TaCl9.

[0106] Depend on Figure 5 It can be seen that Na4TaCl9 formed diffraction peaks that are completely different from the raw material TaCl5 but perfectly matched the NaCl crystal phase, indicating the successful preparation of amorphous-nanocrystalline composite solid electrolyte material.

[0107] Examples T7 to T17

[0108] In Examples T7 to T17, while keeping other conditions unchanged in Example T1, the ratio of AX to MX, or the material of AX, or the material of MX were changed before mixing, as shown in Table 1 below. The molecular formula of the prepared amorphous-nanocrystalline composite solid electrolyte material is shown in Table 1 below.

[0109] The materials prepared in Examples T1 to T17 above were subjected to performance tests:

[0110] Ionic conductivity test: 100 mg of each material (powder) obtained from each embodiment was fed into an MJP-Y type ordinary cylindrical mold (Φ10 mm). A pressure of 400-480 MPa was applied using a YLJ-15T-LD manual tablet press. After cold pressing for 3-5 minutes, the solid electrolyte cold-pressed tablets corresponding to the solid electrolyte powders of each embodiment were obtained. Subsequently, double-sided gold plating was performed on the solid electrolyte cold-pressed tablets corresponding to each embodiment using an SD-900M type ion sputtering instrument. The room temperature ionic conductivity was then tested using a Bio-logic VMP3 dual-channel electrochemical workstation. The test frequency was 7 MHz to 1 Hz, and the applied bias voltage was 50 mV.

[0111] Figure 6 Room temperature electrochemical impedance spectroscopy (EIC) spectra of solid electrolytes according to embodiments T1 to T17 of the present invention are shown. Among them, as... Figure 6 As shown in Table 1, the horizontal axis represents the real impedance, and the vertical axis represents the imaginary impedance. The test results are shown in Table 1 below.

[0112] Table 1. Results of Ion Conductivity Test

[0113]

[0114] Solid-state lithium metal symmetric battery deposition / deposition stability test: The solid electrolyte sheet corresponding to the material (powder) obtained in Example T3 was assembled into a CR-2032 type coin cell all-solid-state lithium metal symmetric battery by simultaneously attaching commercial lithium metal sheets (Φ8mm) to both sides as symmetric electrodes in an argon-filled dry atmosphere. After assembly, the battery was subjected to constant-current electrochemical testing at 30°C using a Shenzhen Xinwei battery tester. The applied current density in this test was 0.5 mA / cm². -2 The capacity is 1.0mAh cm⁻¹. -2 .

[0115] Figure 7 The electrochemical performance curves of an all-solid-state lithium metal symmetric battery based on the amorphous-nanocrystalline composite solid electrolyte material obtained in Example T3 of this invention are shown. The horizontal axis represents the test time, and the vertical axis represents the deposition / deposition potential.

[0116] like Figure 7 As shown, this all-solid-state lithium metal symmetric battery can form stable lithium deposition / deposition behavior, and it has a low polarization voltage and a long cycle life.

[0117] First Coulombic Efficiency Test of Solid-State Lithium Metal Full Cell: The solid electrolyte sheet corresponding to the material (powder) obtained in Example T3 was prepared into a solid-state lithium metal full cell by feeding it to the positive and negative electrodes in an argon-filled dry atmosphere. The positive electrode active material particles (NMC532): halide-based amorphous solid electrolyte (LiTaCl6): conductive additive carbon fiber (VGCF): binder (PTFE) were mixed in a mass ratio of 60:30:5:5 and manually ground in an agate mortar for 120 min to obtain a uniform composite positive electrode powder. Then, the composite positive electrode powder, negative electrode sheet (lithium sheet, Φ8mm), and amorphous-nanocrystalline composite solid electrolyte material were assembled into a CR-2032 coin cell solid-state lithium metal full cell. The obtained battery was charged and discharged at 30°C using a Shenzhen Xinwei Battery Tester with a charge and discharge voltage of 2.2-4.2V and a current density of 0.6C to test the first coulombic efficiency.

[0118] Figure 8 The electrochemical performance curves of an all-solid-state lithium metal full battery based on the amorphous-nanocrystalline composite solid electrolyte material obtained in Example T3 of this invention are shown. The horizontal axis represents areal capacity, and the vertical axis represents voltage.

[0119] like Figure 8 As shown, this all-solid-state lithium metal full cell exhibits high output characteristics and a high first-order coulombic efficiency.

[0120] According to embodiments of the present invention, the materials provided in each embodiment exhibit high room-temperature ionic conductivity due to the abundant free volume space, defects, and isotropic conduction paths of the amorphous matrix. Furthermore, due to the unique structure of the amorphous-nanocrystalline composite solid electrolyte material, stable operation of lithium metal batteries without a protective layer can be achieved; for example, stable deposition and desorption behavior can be maintained for 2700 hours, with a first-cycle coulombic efficiency as high as 87%.

[0121] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An amorphous solid electrolyte material, characterized in that, The amorphous solid electrolyte material includes: an amorphous matrix based on the disordered arrangement of polyhedra and an ion-conducting substance; The amorphous matrix based on the disordered arrangement of polyhedra forms an amorphous glassy network structure by sharing vertices / edges / faces and randomly dispersing these polyhedra. The amorphous matrix exhibits no diffraction peak signal in X-ray diffraction using copper Kα rays. Each polyhedron in the amorphous matrix is ​​composed of at least one cation and at least one halide anion or oxygen-containing anion. The polyhedra in the disordered arrangement of polyhedra include octahedrons, wherein the chemical element corresponding to the cation in the octahedron includes at least one of the following: Fe, Nb, Ta; and the anion in the octahedron includes at least one of the following: F. - Cl - ,Br - I - O 2- OH - ; The ion-conducting material includes Li + ; The amorphous solid electrolyte material includes an amorphous-nanocrystalline composite structure, which is used to stabilize the lithium metal interface. The amorphous-nanocrystalline composite structure has an amorphous-nanocrystalline transition interface, where local lattice distortion and loss exist, forming point defects that facilitate ion conduction.

2. The amorphous solid electrolyte material according to claim 1, wherein, The amorphous glassy network structure is used for ion conduction of the ion-conducting material.

3. The amorphous solid electrolyte material according to claim 1, wherein, The amorphous solid electrolyte material has an ionic conductivity >1.0 mS / cm. -1 .

4. A method for preparing an amorphous solid electrolyte material as described in any one of claims 1 to 3, characterized in that, include: A precursor mixture formed by a first metal compound and a second metal or non-metal compound is ball-milled with ball milling beads at room temperature under an inert atmosphere to obtain an amorphous solid electrolyte material. The first metal compound is composed of an ion-conducting substance and a halide anion or an oxo anion. The second metal or non-metal compound is composed of a metal or non-metal cation and the halide anion or oxy-containing anion; The precursor mixture and the ball milling beads are in a mass ratio of 1:(40~50), the ball milling speed is 400~450 rpm, and the ball milling time is 20~120h.

5. The preparation method according to claim 4, wherein, The mass ratio of the precursor mixture to the milling beads is 1:

45.

6. The preparation method according to claim 4, wherein, The ball mill rotates at a speed of 450 rpm.

7. The preparation method according to claim 4, wherein, The ball milling time is 80-120 hours.

8. The application of the amorphous solid electrolyte material according to any one of claims 1 to 3 in all-solid-state alkali metal batteries.

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