A low electronic conductivity anti-perovskite solid state electrolyte and a method of making the same

Abstract

The application discloses a low-electronic-conductivity anti-perovskite solid-state electrolyte and a preparation method thereof. The anti-perovskite solid-state electrolyte is a lithium-rich anti-perovskite solid-state electrolyte, and a chemical formula thereof is Li 2‑a+ b M a OH 1‑b X, Li 2+c‑a M a (OH) 1+c X or Li 2‑a+b+c M a O 1+b H 1+b‑ c X; or the anti-perovskite solid-state electrolyte is a sodium-rich anti-perovskite solid-state electrolyte, and a chemical formula thereof is Na 2‑a+b M a OH 1‑b X, Na 2+c‑a M a (OH) 1+c X or Na 2‑a+b+c M a O 1+b H 1+b‑c X. By reducing the content of H, or by introducing a Schottky defect, or by simultaneously reducing the content of H and introducing a Schottky defect, the electronic conductivity of the solid-state electrolyte is reduced, the lithium dendrite tolerance of the solid-state electrolyte is improved, and the cycle performance of a lithium symmetrical battery is improved, so that the cycle performance of a solid-state battery is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage batteries, and more particularly to an anti-perovskite solid electrolyte with low electronic conductivity and its preparation method. Background Technology

[0002] Under the policy background of "carbon peaking and carbon neutrality", energy storage batteries and renewable energy co-processing technologies are playing an increasingly important role. Traditional lithium-ion batteries contain flammable organic electrolytes, which can easily cause fires or explosions when the batteries are squeezed or punctured, threatening people's lives and property. Using inorganic solid electrolytes to replace the electrolytes to prepare all-solid-state batteries is considered one of the next-generation energy storage technologies.

[0003] Lithium-rich anti-perovskite (LiRAP) solid electrolytes exhibit high lithium-ion conductivity (up to 10). -3 S cm -1 LiRAP solid electrolytes, with their high lithium-ion conductivity (on orders of magnitude), wide electrochemical stability window, low preparation temperature, and low cost, are easy to mass-produce and have broad application prospects. However, LiRAP solid electrolytes with high lithium-ion conductivity are often prepared by vacuum methods, resulting in high material preparation costs and cumbersome processes. The lithium-ion conductivity of LiRAP solid electrolytes prepared at ambient pressure is an order of magnitude (~10⁻¹⁰) lower than that of LiRAP solid electrolytes prepared by vacuum methods. -4 S cm -1 On the other hand, the electronic conductivity of the solid electrolyte is closely related to the growth of lithium dendrites in the battery. High electronic conductivity will promote the growth of lithium dendrites, which can easily puncture the solid electrolyte and cause the solid battery to fail.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an anti-perovskite solid electrolyte with low electronic conductivity and its preparation method, in order to solve the problem that the high electronic conductivity of existing anti-perovskite solid electrolytes leads to poor cycle performance of solid-state batteries.

[0006] Reducing the electronic conductivity of solid-state electrolytes is of significant practical importance for improving the cycle performance of solid-state batteries. Since the electronic transport of materials is affected by the defect energy levels and band gap, the electronic conductivity of anti-perovskite solid-state electrolytes can be tuned by controlling the H content, Schottky defects (i.e., the simultaneous absence of lithium ion and halide ion sites), and the introduction of impurity atoms in H-containing anti-perovskite solid-state electrolytes.

[0007] Based on this, the present invention provides an anti-perovskite solid electrolyte with low electronic conductivity and a method for preparing the same. Specifically, by reducing the H content in the H-containing anti-perovskite solid electrolyte, or by introducing Schottky defects (i.e., the simultaneous absence of lithium ion and halide ion sites), or by reducing the hydrogen content in the H-containing anti-perovskite solid electrolyte while introducing Schottky defects, the electronic conductivity of the anti-perovskite solid electrolyte is reduced by two orders of magnitude.

[0008] Specifically, the technical solution of the present invention is as follows:

[0009] An anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, which reduces electronic conductivity by decreasing the H content. The chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2-a+ b M a OH 1-b X, such as Li 2.1 OH 0.9 Cl、Li 2.2 OH 0.8 Br, Li 2.1 OH 0.9 Br, etc.; introducing Schottky defects to reduce electronic conductivity, the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2+c-a M a (OH) 1+c X, such as Li 2.15 Na 0.05 (OH) 1.2 Cl 0.5 Br 0.5 Li 1.95 Al 0.05 (OH) 1.1 Br, Li 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 When the H content is simultaneously reduced and Schottky defects are introduced, the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2-a+b+c M a O 1+b H 1+b-c X, such as Li 2.1 Na 0.05 O 1.1 H 1.05 Br 0.9 (BH4) 0.1 Li 2.3 O 1.2 H 1.1Br, etc.; among which, the stoichiometric ratio calculation of Li should also take into account the valence state of M, X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4 and BO3, and at least one of X is a halogen; a = 0 to 1, b = 0 to 0.5, c = 0 to 0.5, M is selected from one or more of Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc and Y;

[0010] Alternatively, the anti-perovskite solid electrolyte is a sodium-rich anti-perovskite solid electrolyte, which reduces electronic conductivity by lowering the H content. The chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2-a+b M a OH 1-b X, such as Na 2.1 OH 0.9 Cl, Na 2.2 OH 0.8 Br, Na 2.1 OH 0.9 Br et al.; Schottky defects are introduced to reduce electronic conductivity; the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2+c-a M a (OH) 1+c X, such as Na 2.15 Na 0.05 (OH) 1.2 Cl 0.5 Br 0.5 Na 1.95 Al 0.05 (OH) 1.1 Br, Na 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 When the H content is simultaneously reduced and Schottky defects are introduced, the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2-a+b+c M a O 1+b H 1+b-c X, such as Na 2.1 Na 0.05 O 1.1 H 1.05 Br 0.9 (BH4) 0.1 Na 2.3 O 1.2 H 1.1Br, etc.; among which, the stoichiometric ratio calculation of Na should also take into account the valence state of M, wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4 and BO3, and at least one of X is a halogen; a = 0 to 1, b = 0 to 0.5, c = 0 to 0.5, and M is selected from one or more of Li, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc and Y.

[0011] When the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, the preparation method of the lithium-rich anti-perovskite solid electrolyte includes the following steps:

[0012] Under a predetermined dry environment, using LiOH, Li2O, and LiX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the lithium-rich anti-perovskite solid electrolyte.

[0013] Optionally, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0014] Optionally, the predetermined heating rate is 1–100°C / minute, more specifically 1–20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.; the preset temperature is 260–1000°C, more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.; and the heat preservation time is 0.01–120 hours, more specifically 24–72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0015] Optionally, the LiX is selected from one or more of LiF, LiCl, LiBr, LiI, LiBF4, LiBH4, LiNH2, LiNO2, LiNO3, Li2SO4, and Li3BO3.

[0016] Optionally, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3;

[0017] When the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3;

[0018] When the dopant is MX, MX is selected from one or more of NaF, KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3; or, selected from NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following; or, one or more selected from NaBr, KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3; or one or more of NaI, KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3.

[0019] When the anti-perovskite solid electrolyte is a sodium-rich anti-perovskite solid electrolyte, the preparation method of the sodium-rich anti-perovskite solid electrolyte includes the following steps:

[0020] Under a predetermined dry environment, using NaOH, Na2O, and NaX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed sodium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the sodium-rich anti-perovskite solid electrolyte.

[0021] Optionally, the NaX is selected from one or more of NaF, NaCl, NaBr, NaI, NaBF4, NaBH4, NaNH2, NaNO2, NaNO3, Na2SO4, and Na3BO3.

[0022] Optionally, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3;

[0023] When the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3;

[0024] When the dopant is MX, MX is selected from one or more of KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3; or, it is selected from KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following; or, one or more selected from KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3; KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3.

[0025] Optionally, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0026] Optionally, the predetermined heating rate is 1–100°C / minute, more specifically 1–20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.; the preset temperature is 260–1000°C, more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.; and the heat preservation time is 0.01–120 hours, more specifically 24–72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0027] Optionally, the cooling method is natural cooling, programmed cooling (0.1-20°C / minute), or rapid cooling.

[0028] Beneficial effects: This invention can satisfy the general formula Li by reducing the H content in H-containing anti-perovskite solid electrolytes.2-a+b M a OH 1-b X or Na 2-a+b M a OH 1-b X effectively reduces the electronic conductivity of LiRAP and NaRAP solid electrolytes, improves the lithium dendrite tolerance of solid electrolytes and the cycle performance of lithium symmetric batteries, which is beneficial to improving the cycle performance of solid batteries.

[0029] This invention can also achieve the desired result by introducing Schottky defects into the anti-perovskite solid electrolyte, satisfying the general formula Li 2+c-a M a (OH) 1+c X or Na 2+c-a M a (OH) 1+c X effectively reduces the electronic conductivity of LiRAP and NaRAP solid electrolytes, improves the lithium dendrite tolerance of solid electrolytes and the cycle performance of lithium symmetric batteries, which is beneficial to improving the cycle performance of solid batteries.

[0030] This invention can also satisfy the general formula Li by reducing the H content in the H-containing anti-perovskite solid electrolyte and introducing Schottky defects. 2-a+b+c M a O 1+b H 1+b-c X or Na 2-a+b+c M a O 1+b H 1+b-c X effectively reduces the electronic conductivity of LiRAP and NaRAP solid electrolytes, improves the lithium dendrite tolerance of solid electrolytes and the cycle performance of lithium symmetric batteries, which is beneficial to improving the cycle performance of solid batteries. Attached Figure Description

[0031] Figure 1 XRD patterns of LiRAP solid electrolytes with different H contents.

[0032] Figure 2 DC polarization current curves for LiRAP solid electrolytes with different H contents.

[0033] Figure 3 Electrochemical impedance spectroscopy of LiRAP solid electrolytes with different H contents.

[0034] Figure 4 The critical current density is given for LiRAP solid electrolytes with different H contents.

[0035] Figure 5 The cycling performance of lithium-symmetric batteries with LiRAP solid electrolytes of different H contents.

[0036] Figure 6 DC polarization current curves of LiRAP solid electrolytes with different Schottky defect concentrations.

[0037] Figure 7 The cycling performance of lithium-symmetric batteries with LiRAP solid electrolytes having different Schottky defect contents.

[0038] Figure 8 DC polarization current curves of LiRAP to simultaneously reduce H content and introduce Schottky defects. Detailed Implementation

[0039] This invention provides an anti-perovskite solid electrolyte with low electronic conductivity and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] This invention provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2-a+b M a OH 1-b X; wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4, and BO3, and at least one of X is a halogen (such as at least one of F, Cl, Br, and I); a = 0–1, b = 0–0.5, c = 0–0.5, and M is selected from one or more of Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc, and Y. For example, the lithium-rich anti-perovskite solid electrolyte is Li. 2.1 OH 0.9 Cl、Li 2.2 OH 0.8 Br, Li 2.1 OH 0.9 Br, etc.

[0041] This embodiment effectively reduces the electronic conductivity of the LiRAP solid electrolyte by decreasing the H content in the H-containing anti-perovskite solid electrolyte. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the LiRAP solid electrolyte, improving the lithium dendrite tolerance of the LiRAP solid electrolyte and the cycle performance of the lithium symmetric battery, thus contributing to improved cycle performance of the solid-state battery. Simultaneously, controlling the H content can effectively increase the ionic conductivity of the LiRAP solid electrolyte.

[0042] This invention provides a method for preparing the lithium-rich anti-perovskite solid electrolyte as described above, wherein the preparation method includes the following steps:

[0043] Under a predetermined dry environment, using LiOH, Li2O, and LiX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the lithium-rich anti-perovskite solid electrolyte.

[0044] Currently, controlling the hydrogen content in H-containing anti-perovskite solid electrolytes without affecting their phase stability is a challenge in this field. Georg Schwering et al. (ChemPhysChem 2003, 4, 343) and Ah-Young Song et al. (Adv. Energy Mater. 2018, 8, 1700971) used a hexane solution of n-butyllithium to perform a hydrogen replacement reaction with LiRAP solid electrolytes to control the hydrogen content. However, this method easily leads to the decomposition of LiRAP SE, impairing its electrochemical performance. In this embodiment, the method uses Li₂O to replace part of the LiOH raw material, achieving effective control of the hydrogen content in LiRAP SE. Furthermore, the controlled hydrogen content has no impact on the material's stability.

[0045] This embodiment describes a preparation method that effectively reduces the electronic conductivity of the LiRAP solid-state electrolyte by decreasing the H content in the H-containing anti-perovskite solid-state electrolyte. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the LiRAP solid-state electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid-state electrolyte and the cycle performance of the lithium-symmetric battery, thus contributing to improved cycle performance of the solid-state battery. Simultaneously, controlling the H content can effectively increase the ionic conductivity of the LiRAP solid-state electrolyte. This preparation method has advantages such as simple preparation, low cost, high efficiency, and suitability for large-scale production, providing a new technical solution for the preparation of low-cost solid-state batteries.

[0046] In one embodiment, the prepared lithium-rich anti-perovskite solid electrolyte is in the form of particles with a particle size of 10 nm to 200 μm.

[0047] In one embodiment, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0048] In one embodiment, the predetermined heating rate is 1 to 100°C / minute, more specifically 1 to 20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.

[0049] In one embodiment, the preset temperature is 260–1000°C, and more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.

[0050] In one embodiment, the heat preservation time is 0.01 to 120 hours, and more specifically 24 to 72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0051] In one embodiment, the cooling method can be natural cooling, programmed cooling (0.1–20°C / minute, such as 1°C / minute), or rapid cooling. Rapid cooling refers to directly placing the object from a temperature above room temperature under room temperature, liquid nitrogen, or liquid helium conditions for cooling.

[0052] In one embodiment, the LiX is selected from one or more of LiF, LiCl, LiBr, LiI, LiBF4, LiBH4, LiNH2, LiNO2, LiNO3, Li2SO4, and Li3BO3, but is not limited thereto.

[0053] In one embodiment, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3, but is not limited thereto.

[0054] In one embodiment, when the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3, but is not limited thereto.

[0055] In one embodiment, when the dopant is MX, the MX is selected from one or more of NaF, KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3, but is not limited thereto; or, it is selected from NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following, but not limited to: or, one or more of the following: NaBr, KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3, but not limited to: or, one or more of the following: NaI, KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3, but not limited to:

[0056] This invention provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2+c-a M a (OH) 1+c X; wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4, and BO3, and at least one of X is a halogen (such as at least one of F, Cl, Br, and I); a = 0–1, b = 0–0.5, c = 0–0.5, and M is selected from one or more of Li, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc, and Y. For example, the lithium-rich anti-perovskite solid electrolyte is Li 2.15 Na 0.05 (OH) 1.2 Cl 0.5 Br 0.5 Li 1.95 Al 0.05 (OH) 1.1 Br, Li 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 wait.

[0057] This embodiment effectively reduces the electronic conductivity of the LiRAP solid-state electrolyte by introducing Schottky defects. Lower electronic conductivity effectively suppresses the growth of lithium dendrites along the LiRAP solid-state electrolyte, improving the lithium dendrite tolerance of the LiRAP solid-state electrolyte and the cycle performance of the lithium-symmetric battery, thus contributing to improved cycle performance of the solid-state battery. Simultaneously, introducing Schottky defects can effectively improve the ionic conductivity of the LiRAP solid-state electrolyte.

[0058] This invention provides a method for preparing the lithium-rich anti-perovskite solid electrolyte as described above, wherein the preparation method includes the following steps:

[0059] Under a predetermined dry environment, using LiOH and LiX as raw materials and MOH or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the chemical formula of the designed lithium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the lithium-rich anti-perovskite solid electrolyte.

[0060] This embodiment employs a method where the molar number of LiOH is greater than the molar number of LiX, creating a Li-X site defect in the crystal, thereby successfully introducing Schottky defects into the LiRAP solid-state electrolyte. Furthermore, the introduction of Schottky defects improves the phase purity of the solid-state electrolyte. This preparation method, by introducing Schottky defects, effectively reduces the electronic conductivity of the LiRAP solid-state electrolyte. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the LiRAP solid-state electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid-state electrolyte and the cycle performance of lithium-symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, the introduction of Schottky defects effectively enhances the ionic conductivity of the LiRAP solid-state electrolyte. This preparation method has advantages such as simple preparation, low cost, high efficiency, and suitability for large-scale production, providing a new technical solution for the preparation of low-cost solid-state batteries.

[0061] In one embodiment, the prepared lithium-rich anti-perovskite solid electrolyte is in the form of particles with a particle size of 10 nm to 200 μm.

[0062] In one embodiment, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0063] In one embodiment, the predetermined heating rate is 1 to 100°C / minute, more specifically 1 to 20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.

[0064] In one embodiment, the preset temperature is 260–1000°C, and more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.

[0065] In one embodiment, the heat preservation time is 0.01 to 120 hours, and more specifically 24 to 72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0066] In one embodiment, the cooling method can be natural cooling, programmed cooling (0.1–20°C / minute, such as 1°C / minute), or rapid cooling. Rapid cooling refers to directly placing the object from a temperature above room temperature to room temperature, liquid nitrogen, or liquid helium conditions for cooling.

[0067] In one embodiment, the LiX is selected from one or more of LiF, LiCl, LiBr, LiI, LiBF4, LiBH4, LiNH2, LiNO2, LiNO3, Li2SO4, and Li3BO3, but is not limited thereto.

[0068] In one embodiment, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3, but is not limited thereto.

[0069] In one embodiment, when the dopant is MX, the MX is selected from one or more of NaF, KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3, but is not limited thereto; or, it is selected from NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following, but not limited to: or, one or more of the following: NaBr, KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3, but not limited to: or, one or more of the following: NaI, KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3, but not limited to:

[0070] This invention provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2-a+b+c M a O 1+b H 1+b-c X; wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4, and BO3, and at least one of X is a halogen (such as at least one of F, Cl, Br, and I); a = 0–1, b = 0–0.5, c = 0–0.5, and M is selected from one or more of Li, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc, and Y. For example, the lithium-rich anti-perovskite solid electrolyte is Li 2.1 Na 0.05 O 1.1 H 1.05 Br 0.9 (BH4) 0.1 Li 2.3 O 1.2 H 1.1 Br, etc.

[0071] This embodiment effectively reduces the electronic conductivity of the LiRAP solid-state electrolyte by simultaneously reducing the H content and introducing Schottky defects. The lower electronic conductivity effectively suppresses the growth of lithium dendrites along the LiRAP solid-state electrolyte, improving the lithium dendrite tolerance of the LiRAP solid-state electrolyte and the cycle performance of the lithium-symmetric battery, thus contributing to improved cycle performance of the solid-state battery. Simultaneously, reducing the H content and introducing Schottky defects effectively improves the ionic conductivity of the LiRAP solid-state electrolyte.

[0072] This invention provides a method for preparing the lithium-rich anti-perovskite solid electrolyte as described above, wherein the preparation method includes the following steps:

[0073] Under a predetermined dry environment, using LiOH, Li2O, and LiX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the sodium-rich anti-perovskite solid electrolyte.

[0074] This embodiment uses a method where the molar number of LiOH is greater than the molar number of LiX, creating a Li-X site defect in the crystal, thereby successfully introducing Schottky defects into the LiRAP solid electrolyte. Simultaneously, replacing LiOH with a certain molar number of Li₂O reduces the H content in the product. This preparation method effectively lowers the electronic conductivity of the LiRAP solid electrolyte by reducing H content and simultaneously introducing Schottky defects. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the LiRAP solid electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid electrolyte and the cycle performance of lithium-symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Furthermore, reducing H content and introducing Schottky defects effectively improves the ionic conductivity of the LiRAP solid electrolyte. This preparation method has advantages such as simple preparation, low cost, high efficiency, and suitability for large-scale production, providing a new technical solution for preparing low-cost solid-state batteries.

[0075] In one embodiment, the prepared lithium-rich anti-perovskite solid electrolyte is in the form of particles with a particle size of 10 nm to 200 μm.

[0076] In one embodiment, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0077] In one embodiment, the predetermined heating rate is 1 to 100°C / minute, more specifically 1 to 20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.

[0078] In one embodiment, the preset temperature is 260–1000°C, and more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.

[0079] In one embodiment, the heat preservation time is 0.01 to 120 hours, more specifically 24 to 72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0080] In one embodiment, the cooling method can be natural cooling, programmed cooling (0.1–20°C / minute, such as 1°C / minute), or rapid cooling. Rapid cooling refers to directly placing the object from a temperature above room temperature to room temperature, liquid nitrogen, or liquid helium conditions for cooling.

[0081] In one embodiment, the LiX is selected from one or more of LiF, LiCl, LiBr, LiI, LiBF4, LiBH4, LiNH2, LiNO2, LiNO3, Li2SO4, and Li3BO3, but is not limited thereto.

[0082] In one embodiment, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3, but is not limited thereto.

[0083] In one embodiment, when the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3, but is not limited thereto.

[0084] In one embodiment, when the dopant is MX, the MX is selected from one or more of NaF, KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3, but is not limited thereto; or, it is selected from NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following, but not limited to: or, one or more of the following: NaBr, KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3, but not limited to: or, one or more of the following: NaI, KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3, but not limited to:

[0085] This invention provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a sodium-rich anti-perovskite solid electrolyte, which reduces electronic conductivity by lowering the H content. The chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2-a+b M a OH 1-b X, such as Na 2.1 OH 0.9 Cl, Na 2.2 OH 0.8 Br, Na 2.1 OH 0.9 Br et al.; Schottky defects are introduced to reduce electronic conductivity; the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2+c-aM a (OH) 1+c X, such as Na 2.15 Na 0.05 (OH) 1.2 Cl 0.5 Br 0.5 Na 1.95 Al 0.05 (OH) 1.1 Br, Na 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 When the H content is simultaneously reduced and Schottky defects are introduced, the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na. 2-a+b+c M a O 1+b H 1+b-c X, such as Na 2.1 Na 0.05 O 1.1 H 1.05 Br 0.9 (BH4) 0.1 Na 2.3 O 1.2 H 1.1 Br, etc.; among which, the stoichiometric ratio calculation of Na should also take into account the valence state of M, wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4 and BO3, and at least one of X is a halogen; a = 0 to 1, b = 0 to 0.5, c = 0 to 0.5, and M is selected from one or more of Li, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc and Y.

[0086] This embodiment can satisfy the general formula Na by reducing the H content in the H-containing anti-perovskite solid electrolyte. 2-a+ b M a OH 1-b X effectively reduces the electronic conductivity of the NaRAP solid electrolyte. Lower electronic conductivity effectively suppresses the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the solid electrolyte and the cycle performance of lithium-symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, reducing the H content effectively increases the ionic conductivity of the NaRAP solid electrolyte.

[0087] This embodiment can also achieve the desired result by introducing Schottky defects into the anti-perovskite solid electrolyte, satisfying the general formula Na. 2+c- a M a (OH) 1+cX effectively reduces the electronic conductivity of the NaRAP solid electrolyte. Lower electronic conductivity effectively suppresses the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the solid electrolyte and the cycle performance of lithium-symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, introducing Schottky defects can effectively improve the ionic conductivity of the NaRAP solid electrolyte.

[0088] This embodiment can also reduce the H content in the H-containing anti-perovskite solid electrolyte and introduce Schottky defects to satisfy the general formula Na. 2-a+b+c M a O 1+b H 1+b-c X effectively reduces the electronic conductivity of the NaRAP solid electrolyte. Lower electronic conductivity effectively suppresses the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the solid electrolyte and the cycle performance of lithium-symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, reducing the H content and introducing Schottky defects effectively improves the ionic conductivity of the NaRAP solid electrolyte.

[0089] When the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na 2-a+b M a OH 1-b X or Na 2-a+b+c M a O 1+b H 1+b-c At time X, the preparation method of the sodium-rich anti-perovskite solid electrolyte includes the following steps:

[0090] Under a predetermined dry environment, using NaOH, Na2O, and NaX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed sodium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the sodium-rich anti-perovskite solid electrolyte.

[0091] In this embodiment, Na₂O can be used to replace part of the NaOH raw material, effectively controlling the H content in NaRAP SE without affecting the stability of the material. This preparation method effectively reduces the electronic conductivity of the NaRAP solid electrolyte by lowering the H content in the H-containing anti-perovskite solid electrolyte. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid electrolyte and the cycle performance of lithium symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, reducing the H content effectively increases the ionic conductivity of the NaRAP solid electrolyte.

[0092] In this embodiment, the molar number of NaOH can be greater than that of NaX, creating a Na-X position deficiency in the crystal and successfully introducing Schottky defects into the NaRAP solid electrolyte. Simultaneously, replacing NaOH with a certain molar number of Na₂O reduces the H content in the product. This preparation method effectively lowers the electronic conductivity of the NaRAP solid electrolyte by reducing the H content and simultaneously introducing Schottky defects. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid electrolyte and the cycle performance of lithium symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Furthermore, reducing the H content and simultaneously introducing Schottky defects effectively improves the ionic conductivity of the NaRAP solid electrolyte.

[0093] The preparation method described in this embodiment has the advantages of simple preparation, low cost, high efficiency, and suitability for large-scale production, providing a new technical solution for the preparation of low-cost solid-state batteries.

[0094] When the chemical formula of the sodium-rich anti-perovskite solid electrolyte is Na 2+c-a M a (OH) 1+c At time X, the preparation method of the sodium-rich anti-perovskite solid electrolyte includes the following steps:

[0095] Under a predetermined dry environment, using NaOH and NaX as raw materials and MOH or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed sodium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the sodium-rich anti-perovskite solid electrolyte.

[0096] In this embodiment, the molar number of NaOH is greater than that of NaX, creating a Na-X site defect in the crystal, thereby successfully introducing Schottky defects into the NaRAP solid electrolyte. Furthermore, the introduction of Schottky defects improves the phase purity of the solid electrolyte. This preparation method effectively reduces the electronic conductivity of the NaRAP solid electrolyte by introducing Schottky defects. Lower electronic conductivity effectively inhibits the growth of lithium dendrites along the NaRAP solid electrolyte, improving the lithium dendrite tolerance of the anti-perovskite solid electrolyte and the cycle performance of lithium symmetric batteries, thus contributing to improved cycle performance of solid-state batteries. Simultaneously, the introduction of Schottky defects effectively improves the ionic conductivity of the NaRAP solid electrolyte. This preparation method has advantages such as simple preparation, low cost, high efficiency, and suitability for large-scale production, providing a new technical solution for the preparation of low-cost solid-state batteries.

[0097] In one embodiment, the NaX is selected from one or more of NaF, NaCl, NaBr, NaI, NaBF4, NaBH4, NaNH2, NaNO2, NaNO3, Na2SO4, and Na3BO3.

[0098] In one embodiment, when the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3, and Y(OH)3;

[0099] When the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3;

[0100] When the dopant is MX, the MX is selected from one or more of KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3; or, it is selected from KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following; or, one or more of the following selected from KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3; or one or more of the following selected from KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3.

[0101] In one embodiment, the predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees.

[0102] In one embodiment, the predetermined heating rate is 1–100°C / minute, more specifically 1–20°C / minute, such as 3°C / minute, 5°C / minute, 10°C / minute, 20°C / minute, etc.; the preset temperature is 260–1000°C, more specifically 500–700°C, such as 500°C, 600°C, 700°C, etc.; and the heat preservation time is 0.01–120 hours, more specifically 24–72 hours, such as 24 hours, 48 ​​hours, 72 hours, etc.

[0103] In one embodiment, the cooling method is natural cooling, programmed cooling (0.1–20°C / minute), or rapid cooling.

[0104] The present invention will be further described below through specific embodiments.

[0105] Example 1

[0106] This embodiment provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2.2 OH 0.8 Br.

[0107] This embodiment Li 2.2 OH 0.8 The preparation method of Br solid electrolyte includes the following steps:

[0108] In an environment with a relative humidity of less than 30%, LiOH, Li₂O, and LiBr were used as raw materials. According to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte, the raw materials were ball-milled and mixed. The resulting mixture was placed in a container and then transferred to a high-temperature furnace. It was heated to 700°C at a heating rate of 5°C / min and held at that temperature for 24 hours. After natural cooling, the resulting solid was crushed and ground to obtain the Li₂O. 2.2 OH 0.8 Br solid electrolyte.

[0109] This embodiment reduces the H content in the H-containing anti-perovskite solid electrolyte, and the adjustment of the H content has no impact on the stability of the material. Figure 1 These are, respectively, existing Li2OHBr solid electrolyte and Li in this embodiment. 2.2 OH 0.8 XRD of Br solid electrolyte, from Figure 1 It can be seen that adjusting the H content has no effect on the crystal stability of the material.

[0110] Example 2

[0111] This embodiment provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2.1 OH 0.9 Br.

[0112] This embodiment Li 2.1 OH 0.9 The preparation method of Br solid electrolyte includes the following steps:

[0113] In an environment with a relative humidity of less than 30%, LiOH, Li₂O, and LiBr were used as raw materials. According to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte, the raw materials were ball-milled and mixed. The resulting mixture was placed in a container and then transferred to a high-temperature furnace. It was heated to 700°C at a heating rate of 5°C / min and held at that temperature for 24 hours. After natural cooling, the resulting solid was crushed and ground to obtain the Li₂O. 2.1 OH 0.9 Br solid electrolyte.

[0114] This embodiment effectively reduces the electronic conductivity of the anti-perovskite solid electrolyte by reducing the H content in the H-containing anti-perovskite solid electrolyte. Figure 2 These are, respectively, existing Li2OHBr solid electrolyte and Li in this embodiment. 2.1 OH 0.9 Electronic conductivity test data of Br solid electrolyte, from Figure 2It can be seen that the electronic conductivity of the anti-perovskite solid electrolyte in this embodiment can reach as low as 10. -9 S cm -1 This represents an order of magnitude reduction in electronic conductivity compared to existing anti-perovskite solid electrolytes, see [reference needed]. Figure 2 As shown.

[0115] This embodiment effectively reduces the AC impedance of the anti-perovskite solid electrolyte by reducing the H content in the H-containing anti-perovskite solid electrolyte. Figure 3 These are, respectively, existing Li2OHBr solid electrolyte and Li in this embodiment. 2.1 OH 0.9 Electrochemical impedance spectroscopy of Br solid electrolyte, from Figure 3 It can be seen that reducing the H content in this embodiment can lower the AC impedance of the anti-perovskite solid electrolyte by approximately 1.7 times. This indicates that adjusting the H content has a positive effect on improving the lithium-ion conductivity of H-containing LiRAP solid electrolytes and provides guidance for the design of solid electrolytes.

[0116] Figure 4 These are, respectively, existing Li2OHBr solid electrolyte and Li in this embodiment. 2.1 OH 0.9 The critical current density of Br solid electrolyte, from Figure 4 It can be seen that the critical current density of the anti-perovskite solid electrolyte after regulation in this embodiment is increased by 0.1 mA·cm⁻¹. -2 This is mainly because reducing the H content decreases the electronic conductivity of the material, thus inhibiting the growth of lithium dendrites along the grain boundaries of the solid electrolyte.

[0117] Figure 5 These are, respectively, existing Li2OHBr solid electrolyte and Li in this embodiment. 2.1 OH 0.9 The cycling performance of Br solid electrolyte lithium symmetric batteries, from Figure 5 It can be seen that after the H content is reduced in this embodiment, the polarization voltage of the lithium symmetric battery decreases, which is due to the increase in lithium-ion conductivity. The number of cycles increases, which is mainly due to the improvement effect brought about by the decrease in electronic conductivity.

[0118] Example 3

[0119] This embodiment provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 .

[0120] This embodiment Li 2.1O 1.1 H 1.1 Cl 0.5 Br 0.5 The preparation method of solid electrolyte includes the following steps:

[0121] In an environment with relative humidity less than 30%, LiOH, LiCl, and LiBr were used as raw materials. According to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte, the raw materials were ball-milled and mixed. The resulting mixture was placed in a container and then transferred to a high-temperature furnace. It was heated to 600°C at a heating rate of 5°C / min and held at that temperature for 48 hours. After natural cooling, the resulting solid was crushed and ground to obtain the Li... 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 Solid electrolyte.

[0122] Figure 6 They are the existing Li2OHCl 0.5 Br 0.5 Solid electrolyte and Li in this embodiment 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 Electronic conductivity test data of solid electrolytes, from Figure 6 It can be seen that Li2OHCl 0.5 Br 0.5 After adding Schottky defects, the chemical formula becomes Li 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 The electronic conductivity of the solid electrolyte decreased significantly to 1% of its original value.

[0123] Figure 7 They are the existing Li2OHCl 0.5 Br 0.5 Solid electrolyte and Li in this embodiment 2.1 O 1.1 H 1.1 Cl 0.5 Br 0.5 The cycle performance of lithium-symmetric batteries with solid electrolytes, from Figure 7 It can be seen that Li2OHCl 0.5 Br 0.5The addition of Schottky defects significantly improves lithium cycle performance, noticeably delaying the number of short-circuit cycles caused by lithium dendrite formation. Therefore, the reduction in electronic conductivity by Schottky defects significantly enhances the suppression of lithium dendrite formation. Furthermore, Schottky defects increase the ionic conductivity of the material, significantly reducing the polarization voltage.

[0124] Example 4

[0125] This embodiment provides an anti-perovskite solid electrolyte, wherein the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2.3 O 1.2 H 1.1 Br.

[0126] Li in this embodiment 2.3 O 1.2 H 1.1 The preparation method of Br solid electrolyte includes the following steps:

[0127] In an environment with relative humidity less than 30%, LiOH, Li₂O, and LiBr were used as raw materials. According to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte, the raw materials were ball-milled and mixed. The resulting mixture was placed in a container and then transferred to a high-temperature furnace. It was heated to 500°C at a heating rate of 10°C / min and held at that temperature for 72 hours. After natural cooling, the resulting solid was crushed and ground to obtain the Li₂O. 2.3 O 1.2 H 1.1 Br solid electrolyte.

[0128] Figure 8 These are, respectively, an existing Li₂OHBr solid electrolyte and a Li₂OHBr electrolyte of this embodiment that simultaneously contains 20% Schottky defects and a 10% reduction in H content. 2.3 O 1.2 H 1.1 Electronic conductivity test data of Br solid electrolyte, from Figure 8 It can be seen that the electronic conductivity of the anti-perovskite solid electrolyte in this embodiment can reach as low as 10. -10 S cm -1 This is two orders of magnitude lower than the reference sample. From Figure 8 It is known that by reducing the H content in the H-containing anti-perovskite solid electrolyte and introducing Schottky defects, the electronic conductivity of the LiRAP solid electrolyte can be effectively reduced.

[0129] In summary, this invention provides a low electronic conductivity anti-perovskite solid electrolyte and its preparation method. This invention can effectively reduce the electronic conductivity of LiRAP and NaRAP solid electrolytes by decreasing the H content in the H-containing anti-perovskite solid electrolyte, thereby improving the lithium dendrite tolerance of the solid electrolyte and the cycle performance of lithium symmetric batteries, which is beneficial for improving the cycle performance of solid-state batteries.

[0130] This invention can also effectively reduce the electronic conductivity of LiRAP and NaRAP solid electrolytes by introducing Schottky defects into the anti-perovskite solid electrolyte, thereby improving the lithium dendrite tolerance of the solid electrolyte and the cycle performance of lithium symmetric batteries, which is beneficial to improving the cycle performance of solid batteries.

[0131] This invention can also effectively reduce the electronic conductivity of LiRAP and NaRAP solid electrolytes by reducing the H content in H-containing anti-perovskite solid electrolytes and introducing Schottky defects, thereby improving the lithium dendrite tolerance of solid electrolytes and the cycle performance of lithium symmetric batteries, which is beneficial to improving the cycle performance of solid batteries.

[0132] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An anti-perovskite solid electrolyte, characterized in that, The anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, and the chemical formula of the lithium-rich anti-perovskite solid electrolyte is Li. 2-a+b M a OH 1-b X, Li 2+c-a M a (OH) 1+c X or Li 2-a+b+c M a O 1+b H 1+b-c X; wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4 and BO3, and at least one of X is a halogen; a = 0~1, b = 0~0.5, c = 0~0.5, and a is not 0, b is not 0, c is not 0; M is selected from one or more of Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc and Y; Alternatively, the anti-perovskite solid electrolyte is a sodium-rich anti-perovskite solid electrolyte with the chemical formula Na. 2-a+b M a OH 1-b X, Na 2+c-a M a (OH) 1+c X or Na 2-a+b+c M a O 1+b H 1+b-c X; wherein X is selected from one or more of halogens, BF4, BH4, NH2, NO2, NO3, SO4 and BO3, and at least one of X is a halogen; a = 0~1, b = 0~0.5, c = 0~0.5, and a is not 0, b is not 0, c is not 0, and M is selected from one or more of Li, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In, La, Sc and Y.

2. A method for preparing the anti-perovskite solid electrolyte according to claim 1, characterized in that, When the anti-perovskite solid electrolyte is a lithium-rich anti-perovskite solid electrolyte, the preparation method of the lithium-rich anti-perovskite solid electrolyte includes the following steps: Under a predetermined dry environment, using LiOH, Li2O, and LiX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are mixed according to the stoichiometric ratio of the designed lithium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the lithium-rich anti-perovskite solid electrolyte.

3. The method for preparing the anti-perovskite solid electrolyte according to claim 2, characterized in that, The predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees; the predetermined heating rate is 1~100℃ / minute, the preset temperature is 260~1000℃, and the heat preservation time is 0.01~120 hours.

4. The method for preparing the anti-perovskite solid electrolyte according to claim 2, characterized in that, The LiX is selected from one or more of LiF, LiCl, LiBr, LiI, LiBF4, LiBH4, LiNH2, LiNO2, LiNO3, Li2SO4 and Li3BO3.

5. The method for preparing the anti-perovskite solid electrolyte according to claim 2, characterized in that, When the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3 and Y(OH)3; When the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3; When the dopant is MX, MX is selected from one or more of NaF, KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3; or, selected from NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following; or, one or more selected from NaBr, KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3; or one or more of NaI, KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3.

6. A method for preparing the anti-perovskite solid electrolyte according to claim 1, characterized in that, When the anti-perovskite solid electrolyte is a sodium-rich anti-perovskite solid electrolyte, the preparation method of the sodium-rich anti-perovskite solid electrolyte includes the following steps: Under a predetermined dry environment, using NaOH, Na2O, and NaX as raw materials and MOH, MO, or MX as dopants, the raw materials and dopants are ball-milled and mixed according to the stoichiometric ratio of the designed sodium-rich anti-perovskite solid electrolyte. The resulting mixture is placed in a container and then transferred to a high-temperature furnace. It is heated to a preset temperature at a predetermined heating rate, held at that temperature for a period of time, and then cooled. The cooled solid is then crushed and ground to obtain the sodium-rich anti-perovskite solid electrolyte.

7. The method for preparing the anti-perovskite solid electrolyte according to claim 6, characterized in that, The NaX is selected from one or more of NaF, NaCl, NaBr, NaI, NaBF4, NaBH4, NaNH2, NaNO2, NaNO3, Na2SO4, and Na3BO3.

8. The method for preparing the anti-perovskite solid electrolyte according to claim 6, characterized in that, When the dopant is MOH, the MOH is selected from one or more of NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Ga(OH)3, In(OH)3, La(OH)3 and Y(OH)3; When the dopant is MO, the MO is selected from one or more of Na2O, K2O, Rb2O, Cs2O, BeO, MgO, CaO, SrO, BaO, Al2O3, Ga2O3, In2O3, La2O3, Sc2O3, and Y2O3; When the dopant is MX, MX is selected from one or more of KF, RbF, CsF, BeF2, MgF2, CaF2, SrF2, BaF2, AlF3, GaF3, InF3, LaF3, ScF3, and YF3; or, it is selected from KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, AlCl3, GaCl3, InCl3, LaCl3, ScCl3, and YCl3. One or more of the following; or, one or more selected from KBr, RbBr, CsBr, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, AlBr3, GaBr3, InBr3, LaBr3, ScBr3 and YBr3; KI, RbI, CsI, BeI2, MgI2, CaI2, SrI2, BaI2, AlI3, GaI3, InI3, LaI3, ScI3 and YI3.

9. The method for preparing the anti-perovskite solid electrolyte according to claim 6, characterized in that, The predetermined dry environment refers to an environment with a relative humidity of less than 30% or a dew point of less than -20 degrees; the predetermined heating rate is 1~100℃ / minute, the preset temperature is 260~1000℃, and the heat preservation time is 0.01~120 hours.

10. The method for preparing the anti-perovskite solid electrolyte according to claim 6, characterized in that, The cooling method is natural cooling, programmed cooling, or rapid cooling.

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