Chemically and electrochemically reduced halide sodium fast ionic conductor material and applications thereof

Abstract

The application belongs to the technical field of batteries, and relates to a halide sodium fast ionic conductor material resistant to chemical and electrochemical reduction and application of the halide sodium fast ionic conductor material in a full-solid-state secondary sodium battery. The halide sodium fast ionic conductor material is doped with Na and / or Cl elements, and has a general formula of Na 1+x‑y A z M 1‑x M' x Cl 6‑m X m , wherein x, y, z and m satisfy 0 <= x <= 1, y-x < 1, 0 <= m <= 1, nz-y = m, y > 0, n is the valence of the element A, and z and m are not 0 at the same time. Compared with a conventional halide fast ionic conductor material, the material can widen a working voltage range of the full-solid-state secondary sodium battery, and significantly prolong a cycle life while improving an energy density of the battery.

Description

Technical Field

[0001] This invention belongs to the field of battery technology and relates to a halide sodium fast ion conductor material resistant to chemical and electrochemical reduction and its application in all-solid-state secondary sodium batteries. Background Technology

[0002] Compared to commercial sodium-ion batteries that use organic electrolytes, all-solid-state sodium batteries using solid-state electrolytes have received widespread attention from academia and industry due to their high safety. Among them, halide solid-state electrolytes have high room-temperature ionic conductivity and high voltage resistance (4.2 V vs. Na / Na). + The characteristics of sodium-ion batteries allow them to be matched with high-voltage, high-energy-density ternary layered cathode materials to improve battery energy density, showing great commercial potential. However, the metal cations (ligand centers) that make up halide solid electrolytes are easily reduced chemically and / or electrochemically, which limits the lifespan and capacity of all-solid-state sodium batteries. Therefore, developing a fast-ion conductor material of sodium that is resistant to chemical and electrochemical reduction to improve the lifespan and electrochemical performance of all-solid-state sodium batteries will greatly promote the commercialization of all-solid-state sodium batteries. Summary of the Invention

[0003] In view of this, the present invention provides a halide sodium fast ion conductor material resistant to chemical and electrochemical reduction and its application in an all-solid-state secondary sodium battery.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A sodium halide fast ion conductor material resistant to chemical and electrochemical reduction, wherein the sodium halide fast ion conductor material is doped with Na-site and / or Cl-site elements, with the general formula Na 1+x-y A z M 1-x M' x Cl 6-m X m In the formula, x, y, z and m satisfy 0 ≤ x≤ 1, yx<1, 0 ≤ m≤ 1, nz-y = m, y>0, n is the valence of element A, and z and m are not both 0.

[0005] Furthermore, When the material is doped only at the Na site, it yields a structure with the formula Na. 1+x-y A z M 1-x M' x Cl6, 0 ≤ x ≤ 1, y < 1 + x, y = nz, y > 0, where n is the valence of element A; When the material is doped only at the Cl site, the structure Na is obtained. 1+x-y M 1-x M' xCl 6-m X m ,0 ≤ x ≤ 1,0 <m ≤1，y+m="0，y">0; When the material is co-doped at Na and Cl sites, it yields a structure with the formula Na. 1+x-y A z M 1-x M' x Cl 6-m X m , 0 ≤ x ≤ 1, y < 1+x, 0 <m ≤ 1，nz-y="m，y">0, n is the valence of element A.

[0006] The Na-site dopant is a metallic element with electronegativity less than M and M' and a valence greater than +1; the Cl-site dopant is a non-metallic element with electronegativity less than Cl and a valence less than -1.

[0007] A is one or more of Mg, Ca, Sr, and Y; X is one or a combination of S and Se.

[0008] M is either Ta or Nb, and M' is either Zr or Hf.

[0009] The preparation method of the above-mentioned halide materials is as follows: Based on the chemical formula of the target product, the raw materials are ball-milled at a speed of 400-600 rpm for 10-30 hours according to the stoichiometric ratio to obtain the halide material.

[0010] Among them, the sodium element selected in the raw materials is NaCl, Na2S, or Na2Se; The A-site elements are selected from MgCl2, MgS, CaCl, CaS, SrCl2, and YCl. The X-position elements are selected from LiNa2S, Na2Se, SeS2, MgS, and CaS; The M-site elements were selected as TaCl5 and NbCl5. The element selected for the M' position is HfCl4 or ZrCl4; The Cl-position element is provided by the chloride-containing salt of the above elements.

[0011] Application of the aforementioned chemically and electrochemically resistant sodium halide fast ion conductor material, wherein the sodium halide fast ion conductor material is used as a conductive agent and / or electrolyte in a battery.

[0012] An all-solid-state secondary sodium battery includes a positive electrode, a negative electrode, and an all-solid-state electrolyte between the positive and negative electrodes, wherein the positive electrode and / or the electrolyte contains the aforementioned halide sodium fast ion conductor material that is resistant to chemical and electrochemical reduction.

[0013] The positive electrode material includes a positive electrode active material and a conductive agent; wherein the conductive agent includes a conductor and an ion-conducting aid, and the sodium halide fast ion conductor material can be used as an ion-conducting aid.

[0014] The positive electrode also includes a positive electrode active material, wherein the positive electrode active material is Na3V2(PO4)3, Na3V2(PO4)2F3, NaCrO2, or NaNi. 0.5 Mn 0.5 O2, NaCu 0.12 Ni 0.22 Fe 0.33 Mn 0.33 O2, Na 0.85 Mn 0.5 Ni 0.4 Fe 0.1 O2, NaMn 1 / 3 Ni 1 / 3 Fe 1 / 3O2.

[0015] The electrolyte material is the aforementioned sodium halide fast ion conductor material, NaTaCl6, or Na2O2:MCl. y (M = Hf, Zr, Ta, Nb), Na 3-x Y 1-x Zr x Cl6 (0≤ x ≤1), Na2ZrCl6, Na 0.5 ZrCl4F 0.5 Na2S:ZrCl4, NaAlCl 4- 2x O x (0 ≤ x ≤ 0.5), one or more of Na3PS4.

[0016] The negative electrode also includes a negative electrode active material, which may be a sodium metal sheet, a sodium metal alloy, hard carbon, an oxide negative electrode, or an organic negative electrode.

[0017] A method for preparing the all-solid-state secondary sodium battery involves stacking a positive electrode, an all-solid-state electrolyte, and a negative electrode, or a negative electrode, an all-solid-state electrolyte, and a positive electrode, to form an integrated all-solid-state secondary sodium battery with a sandwich structure.

[0018] Compared with the prior art, the beneficial effects of this invention are mainly reflected in: This invention achieves electronegativity-differentiated cation and / or anion substitution in halide electrolyte materials by doping Na and / or Cl sites with different elements. This allows for the control of the electron cloud density and effective charge number around the central cation in the halide electrolyte, thereby improving the reduction resistance of the halide material and broadening the voltage window of traditional halide electrolytes (2.6 – 4.2 V vs Na / Na). + This inhibits its own resistance to reduction and its chemical reaction with the positive electrode, thereby improving the energy density and cycle performance of the all-solid-state secondary sodium battery. Attached Figure Description

[0019] Figure 1 The XRD pattern of NaTaCl6.

[0020] Figure 2 Cyclic voltammetry curves for the NaTaCl6+VGCF|Na3PS4|Na2Sn all-solid-state battery.

[0021] Figure 3 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 Cyclic performance of O2+NaTaCl6|Na3PS4|Na2Sn all-solid-state battery.

[0022] Figure 4 for Na 1.2 TaCl 5.8 S 0.2 XRD patterns.

[0023] Figure 5 for Na 1.2 TaCl 5.8 S 0.2 Cross-sectional morphology under 500 MPa pressure.

[0024] Figure 6 for Na 1.2 TaCl 5.8 S 0.2 Cyclic voltammetry curves of +VGCF|Na3PS4|Na2Sn all-solid-state batteries.

[0025] Figure 7 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2+Na 1.2 TaCl 5.8 S 0.2 Cycle performance of Na3PS4|Na2Sn all-solid-state batteries.

[0026] Figure 8 for Na 0.6 Mg 0.2 XRD pattern of TaCl6.

[0027] Figure 9 for Na 0.6 Mg 0.2 Cyclic voltammetry curves of the TaCl6+VGCF|Na3PS4|Na2Sn all-solid-state battery.

[0028] Figure 10 NaCu 0.12 Ni 0.22 Fe 0.33 Mn 0.33 O2+.

[0029] Na 0.6 Mg 0.2 Cycle performance of TaCl6|NaTaCl6|Na3PS4|Na3Sb all-solid-state batteries; Figure 11 NaCa 0.1 TaCl 5.8 S 0.2 XRD patterns.

[0030] Figure 12 NaCa 0.1 TaCl 5.8 S 0.2 Cyclic voltammetry curves of +VGCF|Na3PS4|Na2Sn all-solid-state batteries.

[0031] Figure 13 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2+.

[0032] NaCa 0.1 TaCl 5.8 S 0.2 |NaCa 0.1 TaCl 5.8 S 0.2 Cycle performance of Na3PS4|Na3Sb all-solid-state batteries.

[0033] Figure 14 for Na 1.3 Mg 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 XRD patterns.

[0034] Figure 15 for Na 1.3 Mg 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 Cyclic voltammetry curves of +VGCF|Na3PS4|Na2Sn all-solid-state batteries.

[0035] Figure 16 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2+.

[0036] Na 1.3 Mg 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 |Na 1.3 Mg 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 Cycle performance of Na3PS4|Na3Sb all-solid-state batteries.

[0037] Figure 17 for Na 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 XRD patterns.

[0038] Figure 18 for Na 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 +.

[0039] Cyclic voltammetry curves of VGCF|Na3PS4|Na2Sn all-solid-state batteries.

[0040] Figure 19 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2+.

[0041] Na 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 Cyclic performance of NaTaCl6|Na3PS4|Na3Sb all-solid-state batteries.

[0042] Figure 20 NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2|Na 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 Cycle performance of Na3PS4|Na3Sb all-solid-state batteries. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to specific examples. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0044] This invention replaces halide fast-ion conductor materials with heteroelement doping, which reduces the effective charge of the redox center cation, thereby enhancing its resistance to chemical and electrochemical reduction. Sodium halide materials, resistant to chemical and electrochemical reduction, can achieve reduction-resistant properties. Applying them to halide-based all-solid-state batteries addresses the bottleneck in existing halide-based all-solid-state batteries where the halide electrolyte is easily reduced and decomposes, leading to short battery life, limited capacity, and hindering the development and application of halide-based all-solid-state batteries.

[0045] Comparative Example 1 Materials preparation and characterization In a protective atmosphere, NaCl and TaCl5 were taken and fed into a zirconia ball mill jar at a molar ratio of 1:1. The ball mill speed was set to 600 rpm and the effective ball milling time was 40 hours. The powder obtained after ball milling was then ground to obtain the halide material NaTaCl6.

[0046] Depend on Figure 1 The XRD pattern of the prepared material showed that the electrolyte contained both amorphous and NaTaCl6 crystalline components. The sodium ion conductivity of the material, measured by AC impedance spectroscopy, was 0.4 mS / cm. –1 .

[0047] Electrochemical window testing In a protective atmosphere, the halide material NaTaCl6 prepared in this embodiment was mixed with the conductive agent VGCF (vapor-grown carbon fiber) at a mass ratio of 7:3 and thoroughly ground to obtain the positive electrode powder. 80 mg of Na3PS4 was weighed and placed into a mold with a diameter of 10 mm, and molded under a pressure of 500 MPa. 10 mg of the prepared positive electrode powder was weighed and evenly spread onto one side of the Na3PS4, and molded under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and molded under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mV s. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.6 to 4.2 V vs Na. + / Na ( Figure 2 ).

[0048] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 was mixed with NaTaCl6 prepared in this embodiment and conductive additive VGCF at a mass ratio of 5:5:0.5 to form a positive electrode powder. 80 mg of Na3PS4 was weighed and placed into a mold with a diameter of 10 mm and shaped under a pressure of 500 MPa. 10 mg of positive electrode powder was weighed and evenly spread on one side of Na3PS4 and shaped under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery.

[0049] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.6 – 4.2 V vs Na), + / Na) under the cycle. For example Figure 3 As shown, the all-solid-state battery only achieved 104 mAh g in its first cycle. -1 The specific capacity was only 30 mAh g after 200 cycles. -1 That is, the capacity retention rate is only 29%.

[0050] Example 1 Materials preparation and characterization In a protective atmosphere, NaCl, Na₂S, and TaCl₅ were added in a molar ratio of 4:1:5 and placed in a zirconia ball mill jar. The ball mill speed was set to 600 rpm, and the effective ball milling time was 25 hours. The resulting powder was then ground to obtain the halide material Na. 1.2 TaCl 5.8 S 0.2 (See) Figure 4 and Figure 5 ).

[0051] Depend on Figure 4 The XRD pattern of the prepared material shows that it consists of NaTaCl6 crystalline form and amorphous components. The cross-sectional morphology of the prepared material under 500 MPa pressure is as follows. Figure 5 As shown, the results indicate that the electrolyte can be densified by cold pressing at room temperature and assembled into an all-solid-state sodium battery. The sodium-ion conductivity of the material was measured to be 3.8 mS / cm using AC impedance spectroscopy. –1 .

[0052] Electrochemical window testing In a protective atmosphere, the halide material Na prepared in this embodiment is... 1.2 TaCl 5.8 S 0.2 The Na3PS4 was mixed with VGCF (vapor-grown carbon fiber) at a mass ratio of 7:3 and thoroughly ground to form the cathode powder. 80 mg of Na3PS4 was weighed and placed into a 10 mm diameter mold, and shaped under a pressure of 500 MPa. 10 mg of the prepared cathode powder was weighed and evenly spread onto one side of the Na3PS4, and shaped under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mV s. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.3 to 4.2 V vs Na. + / Na ( Figure 6 ).

[0053] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and Na prepared in this embodiment 1.2 TaCl 5.8 S 0.2 The conductive additive VGCF was mixed evenly in a mass ratio of 5:5:0.5 to form the positive electrode powder; 80 mg of Na3PS4 was weighed and placed into a mold with a diameter of 10 mm, and shaped under a pressure of 500 MPa; 10 mg of positive electrode powder was weighed and evenly spread on one side of Na3PS4, and shaped under a pressure of 500 MPa; finally, 20 mg of Na2Sn was placed on the other side of Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery.

[0054] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.3 – 4.2 V vs Na), + / Na) under the cycle. For example Figure 7 As shown, the all-solid-state battery can deliver 125 mAh g. -1 It has a high specific capacity and a capacity retention rate of 89% after 300 cycles, with a coulomb efficiency of over 99%.

[0055] Example 2 Materials preparation and characterization In a protective atmosphere, NaCl, MgCl2, and TaCl5 were added in a molar ratio of 3:1:5 and placed in a zirconia ball mill jar. The ball mill speed was set to 550 rpm, and the effective ball milling time was 20 hours. The resulting powder was then ground to obtain the halide material Na. 0.6 Mg 0.2 TaCl6.

[0056] Depend on Figure 8 The XRD pattern of the prepared material showed that the electrolyte contained both amorphous and NaTaCl6 crystalline components. The sodium ion conductivity of the material, measured by AC impedance spectroscopy, was 3.0 mS / cm. –1 .

[0057] Electrochemical window testing In a protective atmosphere, the halide material Na prepared in this embodiment is... 0.6 Mg 0.2 TaCl6 and VGCF (vapor-grown carbon fiber) were mixed at a mass ratio of 7:3 and thoroughly ground to prepare the cathode powder. 80 mg of Na3PS4 was weighed and placed into a 10 mm diameter mold, and shaped under a pressure of 500 MPa. 10 mg of the prepared cathode powder was weighed and evenly spread onto one side of the Na3PS4, and shaped under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mV s. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.4 to 4.2 V vs Na / Na. + ( Figure 9 ).

[0058] All-solid-state secondary battery fabrication In a protective atmosphere, NaCu 0.12 Ni 0.22 Fe 0.33 Mn 0.33 O2 and Na prepared in this embodiment 0.6 Mg 0.2 TaCl6 and conductive additive VGCF were mixed evenly in a mass ratio of 5:5:0.5 to form the positive electrode powder. 100 mg of NaTaCl6 was weighed and placed into a mold with a diameter of 10 mm, and shaped under a pressure of 500 MPa. 30 mg of Na3PS4 was weighed and placed on one side of NaTaCl6, and shaped under a pressure of 500 MPa. 10 mg of the positive electrode powder prepared above was weighed and evenly spread on the other side of NaTaCl6, and shaped under a pressure of 500 MPa. Finally, 30 mg of Na3Sb was placed on one side of Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery.

[0059] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at 60 °C and a 0.5 C rate (2.4 – 4.2 V vs Na / Na), + After 1300 cycles, it still has 115 mAh g. –1 Specifically, the capacity retention rate was 79.2%. Figure 10 ).

[0060] Example 3 Materials preparation and characterization In a protective atmosphere, NaCl, CaCl2, Na2S, and TaCl5 were added in a molar ratio of 6:1:2:10 and placed in a zirconia ball mill jar. The ball mill speed was set to 520 rpm, and the effective ball milling time was 27 hours. The resulting powder was then ground to obtain the halide material NaCa. 0.1 TaCl 5.8 S 0.2 .

[0061] Depend on Figure 11 The XRD pattern of the prepared material showed that it consisted of NaTaCl6 crystalline and amorphous components. The sodium ion conductivity of the material, measured by AC impedance spectroscopy, was 2.4 mS / cm. –1 .

[0062] Electrochemical window testing In a protective atmosphere, the halide material NaCa prepared in this embodiment is... 0.1 TaCl 5.8 S 0.2 The Na3PS4 was mixed with VGCF at a mass ratio of 7:3 and thoroughly ground to obtain the positive electrode powder. 80 mg of Na3PS4 was weighed and placed into a 10 mm diameter mold, and shaped under a pressure of 500 MPa. 10 mg of the prepared positive electrode powder was weighed and evenly spread onto one side of the Na3PS4, and shaped under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mV s. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.2 to 4.2 V vs Na. + / Na ( Figure 12 ).

[0063] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and the NaCa prepared in this embodiment 0.1 TaCl 5.8 S 0.2 The conductive additive acetylene black was mixed evenly at a mass ratio of 5:5:0.5 to form the positive electrode powder; 100 mg of the NaCa prepared in this example was weighed out. 0.1 TaCl 5.8 S 0.2 Place it into a mold with a diameter of 10 mm and shape it under a pressure of 500 MPa; weigh 30 mg of Na3PS4 and add it to NaMg. 0.1 TaCl 5.8 S 0.2 One side was formed under a pressure of 500 MPa; 10 mg of positive electrode powder was weighed and evenly spread onto NaCa. 0.1 TaCl 5.8 S 0.2 On the other side, it was molded under a pressure of 500 MPa; finally, 30 mg of Na3Sb was placed on one side of Na3PS4 and molded under a pressure of 500 MPa to obtain an all-solid-state battery.

[0064] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.2 – 4.2 V vs Na / Na), + The next loop. (e.g.) Figure 13 As shown, the all-solid-state battery can deliver 123 mAh g. -1 It has a high specific capacity and a capacity retention rate of 84.22% after 200 cycles, with a coulomb efficiency of over 99%.

[0065] Example 4 Materials preparation and characterization In a protective atmosphere, NaCl, SrCl2, Na2S, ZrCl4, and TaCl5 were added in a molar ratio of 9:1:2:3:7 and placed in a zirconia ball mill jar. The ball mill speed was set to 540 rpm, and the effective ball milling time was 28 hours. The resulting powder was then ground to obtain the halide material Na. 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 .

[0066] Depend on Figure 14 The XRD pattern of the prepared material showed that it consisted of NaTaCl6 crystalline and amorphous components. The sodium ion conductivity of the material, measured by AC impedance spectroscopy, was 1.6 mS / cm. –1 .

[0067] Electrochemical window testing In a protective atmosphere, the halide material Na prepared in this embodiment is... 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 The Na3PS4 was mixed with VGCF at a mass ratio of 7:3 and thoroughly ground to obtain the positive electrode powder. 80 mg of Na3PS4 was weighed and placed into a 10 mm diameter mold, and shaped under a pressure of 500 MPa. 10 mg of the prepared positive electrode powder was weighed and evenly spread onto one side of the Na3PS4, and shaped under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mVs. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.5 to 4.2 V vs Na / Na. + ( Figure 15 ).

[0068] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and Na prepared in this embodiment 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 Acetylene black was mixed evenly at a mass ratio of 5:5:0.5 to form the positive electrode powder; 100 mg of Na prepared in this example was weighed out. 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 Place it into a mold with a diameter of 10 mm and mold it under a pressure of 500 MPa; weigh 30 mg of Na3PS4 and place it into Na 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 One side of the cathode was formed under a pressure of 500 MPa; 10 mg of positive electrode powder was weighed and evenly spread onto the Na... 1.3 Sr 0.1 Zr 0.3 Ta 0.7 Cl 5.8 S 0.2 On the other side, it was molded under a pressure of 500 MPa; finally, 30 mg of Na3Sb was placed on one side of Na3PS4 and molded under a pressure of 500 MPa to obtain an all-solid-state battery.

[0069] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.5 – 4.2 V vs Na / Na), + The next loop. (e.g.) Figure 16 As shown, the all-solid-state battery can deliver 117.5 mAh g. -1 It has a high specific capacity and a capacity retention rate of 81% after 100 cycles, with a coulomb efficiency of over 99%.

[0070] Example 5 Materials preparation and characterization In a protective atmosphere, NaCl, YCl3, Na2S, HfCl4, and NbCl5 were respectively added in a molar ratio of 9:1:2:4:6 and placed in a zirconia ball mill jar. The ball mill speed was set to 560 rpm, and the effective ball milling time was 29 hours. Subsequently, the powder obtained after ball milling was ground to obtain the halide material Na. 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 .

[0071] Figure 17 The XRD pattern of the prepared material shows that it consists of NaTaCl6 crystalline and amorphous components. The sodium ion conductivity of the material, measured by AC impedance spectroscopy, is 1.3 mS / cm. –1 .

[0072] Electrochemical window testing In a protective atmosphere, the halide material Na prepared in this embodiment is... 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 The Na3PS4 was mixed with conductive agent VGCF at a mass ratio of 7:3 and thoroughly ground to form the positive electrode powder. 80 mg of Na3PS4 was weighed and placed into a mold with a diameter of 10 mm, and molded under a pressure of 500 MPa. 10 mg of the prepared positive electrode powder was weighed and evenly spread onto one side of the Na3PS4, and molded under a pressure of 500 MPa. Finally, 20 mg of Na2Sn was placed on the other side of the Na3PS4 and molded under a pressure of 500 MPa to obtain an all-solid-state battery. Cyclic voltammetry was performed using a charge-discharge meter (Wuhan LAND) with a scan rate set to 0.1 mV s. –1 The voltage range was scanned from 1.0 to 5.0 V, yielding a voltage window of 2.1 to 4.2 V vs Na / Na. + ( Figure 18 ).

[0073] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and Na prepared in this embodiment 1.3 Y 0.1 Hf 0.3 Nb 0.7 Cl 5.8 S 0.2 The conductive additive acetylene black was mixed evenly in a mass ratio of 5:5:0.5 to form the positive electrode powder. 100 mg of NaTaCl6 was weighed and placed into a mold with a diameter of 10 mm, and shaped under a pressure of 500 MPa. 30 mg of Na3PS4 was weighed and placed on one side of NaTaCl6, and shaped under a pressure of 500 MPa. 10 mg of positive electrode powder was weighed and evenly spread on the other side of NaTaCl6, and shaped under a pressure of 500 MPa. Finally, 30 mg of Na3Sb was placed on one side of Na3PS4 and shaped under a pressure of 500 MPa to obtain an all-solid-state battery.

[0074] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.1 – 4.2 V vs Na), + / Na) under the cycle. For example Figure 19 As shown, the all-solid-state battery can deliver 128 mAh g. -1 It has a high specific capacity and a capacity retention rate of 93.4% after 200 cycles, with a coulomb efficiency of over 99%.

[0075] Example 6 Materials preparation and characterization In a protective atmosphere, NaCl, YCl3, Na2S, HfCl4, and NbCl5 were respectively added in a molar ratio of 9:1:2:4:6 and placed in a zirconia ball mill jar. The ball mill speed was set to 560 rpm, and the effective ball milling time was 29 hours. Subsequently, the powder obtained after ball milling was ground to obtain the halide material Na. 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 .

[0076] All-solid-state secondary battery fabrication In a protective atmosphere, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and conductive additive acetylene black are mixed evenly at a mass ratio of 5:0.5 to form the positive electrode powder; 100 mg of Na is weighed out. 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 Place it into a mold with a diameter of 10 mm and mold it under a pressure of 500 MPa; weigh 30 mg of Na3PS4 and place it into Na 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 One side of the cathode is formed under a pressure of 500 MPa; 10 mg of positive electrode powder is weighed and evenly spread onto the Na... 1.3 Y 0.1 Hf 0.4 Nb 0.6 Cl 5.8 S 0.2 On the other side, it was molded under a pressure of 500 MPa; finally, 30 mg of Na3Sb was placed on one side of Na3PS4 and molded under a pressure of 500 MPa to obtain an all-solid-state battery.

[0077] The all-solid-state secondary sodium battery obtained above was subjected to room temperature electrochemical performance testing. Using a charge-discharge apparatus (Wuhan LAND), at room temperature and a 0.2 C rate (2.1 – 4.2 V vs Na), + / Na) under the cycle. For example Figure 20 As shown, the all-solid-state battery can deliver 123 mAh g. -1 It has a high specific capacity and a capacity retention rate of 88.3% after 300 cycles, with a coulomb efficiency of over 99%.< / m> < / m>

Claims

1. A sodium halide fast ion conductor material resistant to chemical and electrochemical reduction, characterized in that: Na- and / or Cl-site doping in sodium halide fast ion conductor materials, with the general formula Na 1+x-y A z M 1-x M' x Cl 6-m X m In the formula, x, y, z and m satisfy 0 ≤ x ≤ 1, yx < 1, 0 ≤ m ≤ 1, nz-y = m, y>0, n is the valence of element A, and z and m are not both 0.

2. The halide sodium fast ion conductor material resistant to chemical and electrochemical reduction according to claim 1, characterized in that, The Na-site dopant is a metallic element with electronegativity less than M and M' and a valence greater than +1; the Cl-site dopant is a non-metallic element with electronegativity less than Cl and a valence less than -1.

3. The halide sodium fast ion conductor material resistant to chemical and electrochemical reduction according to claim 2, characterized in that, A is one or more of Mg, Ca, Sr, and Y; X is one or a combination of S and Se.

4. The halide sodium fast ion conductor material resistant to chemical and electrochemical reduction according to claim 1, characterized in that, M is either Ta or Nb, and M' is either Zr or Hf.

5. The application of the halide sodium fast ion conductor material resistant to chemical and electrochemical reduction as described in claim 1, characterized in that, The material is used as a conductive agent and / or electrolyte in batteries.

6. A fully solid-state secondary sodium battery, comprising a positive electrode, a negative electrode, and a fully solid-state electrolyte between the positive and negative electrodes, characterized in that, The positive electrode and / or electrolyte contains the fast ion conductor material of claim 1.

7. The all-solid-state secondary sodium battery according to claim 6, characterized in that: The positive electrode also includes a positive electrode active material, wherein the positive electrode active material is Na3V2(PO4)3, Na3V2(PO4)2F3, NaCrO2, or NaNi. 0.5 Mn 0.5 O2, NaCu 0.12 Ni 0.22 Fe 0.33 Mn 0.33 O2, Na 0.85 Mn 0.5 Ni 0.4 Fe 0.1 O2, NaMn 1 / 3 Ni 1 / 3 Fe 1 / 3 O2.

8. The all-solid-state secondary sodium battery according to claim 6, characterized in that: The electrolyte material is the sodium halide material resistant to chemical and electrochemical reduction as described in claim 1, NaTaCl6, or Na2O2:MCl. y (M = Hf, Zr, Ta, Nb), Na 3-x Y 1-x Zr x Cl6 (0≤ x ≤1), Na2ZrCl6, Na 0.5 ZrCl4F 0.5 Na2S:ZrCl4, NaAlCl 4-2x O x (0 ≤ x ≤ 0.5), one or more of Na3PS4.

9. The all-solid-state secondary sodium battery according to claim 6, characterized in that: The negative electrode also includes a negative electrode active material, which may be a sodium metal sheet, a sodium metal alloy, hard carbon, an oxide negative electrode, or an organic negative electrode.

10. A method for preparing the all-solid-state secondary sodium battery according to claim 5, characterized in that, An integrated all-solid-state secondary sodium battery with a sandwich structure is formed by stacking the positive electrode, all-solid-state electrolyte, and negative electrode in either the order of negative electrode, all-solid-state electrolyte, and positive electrode.

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