A mixed anion halide-oxide solid-state electrolyte material, preparation method and application

Abstract

This invention discloses a halide oxide mixed anionic solid electrolyte material, its preparation method, and its application, including Cl... ‑ With O 2‑ A lithium-ion conductor with a mixed anionic framework and a high-valence metal Ta cation doping component, the chemical formula being Li 2+y Zr 1‑x Ta x Cl5O 0.5 Where 0.25 ≤ x ≤ 0.9, and y represents the valence state change caused by the introduction of doping elements, this invention constructs a halide-oxygen mixed anion framework by introducing oxygen anions into the halide lattice, and combines this with the charge compensation effect of high-valence metal ions to achieve synergistic regulation of the local structure and defect chemistry of the material. Under the synergistic effect of these two factors, the lithium-ion migration channels can be effectively broadened and the migration energy barrier reduced, thereby significantly improving the room-temperature ionic conductivity of the material. Compared with the undoped system, the ionic conductivity of the material of this invention is significantly improved, demonstrating excellent structural regulation effects.

Description

Technical Field

[0001] This invention belongs to the field of solid-state batteries and relates to a halide oxide mixed anion solid electrolyte material, its preparation method and application. Background Technology

[0002] Among various solid-state electrolyte systems, halide solid-state electrolytes are considered to have promising application prospects due to their high oxidation stability, good mechanical properties, and compatibility with high-voltage cathode materials. Currently, the preparation route for halide solid-state electrolytes is still mainly based on solid-state reactions, typically including ball milling, heat treatment, and high-temperature sintering to improve the crystallinity, density, and ion conductivity of the material. However, preparation processes relying on sintering or high-temperature heat treatment usually introduce high energy consumption, placing high demands on equipment conditions and process control, which is not conducive to reducing preparation costs and achieving large-scale production. At the same time, the high-temperature treatment process may also cause problems such as grain growth, uneven elemental distribution, or local compositional segregation, which will adversely affect the structural stability of the material and its interfacial compatibility with the electrode. In all-solid-state battery applications, these problems can easily lead to increased interfacial impedance, limiting the battery's rate performance and cycle stability.

[0003] Furthermore, existing technologies largely focus on controlling halide structures through metal cation doping or thermal treatment, while research on the design and control of anionic frameworks is relatively limited. In particular, there is a lack of systematic, repeatable, and scalable process-performance windows for achieving room-temperature lithium-ion conductivity that meets the requirements of all-solid-state battery assembly and operation without sintering or high-temperature thermal annealing by introducing oxygen anions into the halide lattice to construct a hybrid anionic structure and combining it with the charge regulation effect of high-valence metal ions to synergistically optimize the lithium-ion migration environment at the structural level.

[0004] Against this backdrop, how to construct a halide oxide solid electrolyte system with both structural stability and high ion conductivity through anion framework engineering, while avoiding high-temperature heat treatment and complex wet chemical processes, and achieving lithium-ion conductivity at room temperature that still meets the requirements for all-solid-state battery assembly and operation, and further simplifying the preparation process while taking into account the compatibility of the material and electrode interface, remains an important technical problem facing engineers in this field. Summary of the Invention

[0005] This invention addresses the problems of existing halide solid electrolytes, such as reliance on high-temperature sintering or thermal annealing, high energy consumption, complex processes, and difficulty in ensuring material structural stability under high-temperature conditions. It also avoids the drawbacks of wet chemical routes, such as difficulty in suppressing hydrolysis side reactions, high process costs, and significant environmental burden. The invention provides a halide oxide mixed anionic solid electrolyte material, its preparation method, and its applications.

[0006] To achieve the above objectives, this invention employs a halide oxide solid electrolyte material and its preparation method that can be directly applied to all-solid-state lithium-ion batteries without sintering or high-temperature heat treatment. By constructing a halogen-oxygen mixed anion framework involving oxygen anions and combining it with the charge regulation effect of high-valence metal ions, the lithium-ion migration environment is optimized at the structural level. While reducing preparation energy consumption and process complexity, the material possesses lithium-ion conductivity at room temperature that meets the assembly and operation requirements of all-solid-state batteries, and can form a stable interfacial contact with electrode materials. The technical solution is as follows: A halide oxide mixed anion solid electrolyte material, comprising Cl... - With O 2- A lithium-ion conductor with a mixed anionic framework and a high-valence metal Ta cation doping component, the chemical formula being Li 2+y Zr 1-x Ta x Cl5O 0.5 , where 0.25 ≤ x≤0.9, and y is the valence state change caused by the introduction of doping elements.

[0007] Furthermore, the value of x is in the range of 0.5 ≤ x ≤ 0.9.

[0008] Furthermore, the halide oxide mixed anionic solid electrolyte material includes an amorphous phase with a volume fraction of ≥50%.

[0009] Furthermore, when the mole fraction x of Ta is 0.5, 0.75, or 0.9, the lithium-ion conductivity of the halide oxide mixed anionic solid electrolyte material at room temperature is not less than 3 mS / cm. -1 7 mS cm -1 9 mS cm -1 .

[0010] Furthermore, the halide oxide mixed anionic solid electrolyte material exhibits a flux density of not less than 1.5 mS / cm at room temperature. -1 The lithium-ion conductivity.

[0011] A method for preparing a halide oxide mixed anionic solid electrolyte material includes the following steps: Oxygen source, lithium source, and metal halide precursors were selected, with ZrCl4 and TaCl5 as metal halide precursors and LiCl as the lithium source. Oxygen source, lithium source, and metal halide precursor were loaded into a ball mill container and subjected to high-energy mechanical ball milling under an inert atmosphere. The oxygen source and lithium source induced Cl through a mechanochemical reaction during ball milling. - With O 2-Anions rearrange and form an amorphous dominant structure. After the reaction is completed, a halide oxide solid electrolyte material with amorphous state is obtained.

[0012] Furthermore, the amount of LiCl added is higher than the amount of chlorine source required to meet the stoichiometry, so as to form a lithium-rich environment; LiCl participates in framework construction as a chlorine source and as an excess lithium source, which is used to regulate the lithium vacancy concentration and improve ionic conductivity.

[0013] Furthermore, the oxygen source is one or more of Li2O, LiOH, and Li2O2. When the oxygen source is Li2O or LiOH, the molar ratio of LiCl, Li2O / LiOH, ZrCl4, and TaCl5 satisfies: Li2O / LiOH:LiCl:ZrCl4:TaCl5 = 0.5: (5 - 5x - 4 (1 - x)): (1-x): x, 0.25 ≤ x ≤ 0.9; when the oxygen source is Li2O2, the molar ratio of LiCl, Li2O / LiOH, ZrCl4, and TaCl5 satisfies: Li2O2:LiCl:ZrCl4:TaCl5 = 0.25: (5 - 5x - 4 (1 - x)): (1-x): x, 0.25 ≤ x ≤ 0.9.

[0014] Furthermore, the inert atmosphere is argon, the ball milling speed is 400–500 rpm, and the ball milling time is 24–48 h.

[0015] The application of the halide oxide mixed anion solid electrolyte material in an all-solid-state lithium-ion battery, wherein the all-solid-state lithium-ion battery includes a composite positive electrode layer, a halide oxide solid electrolyte layer, a sulfide intermediate layer, and a negative electrode side metal layer stacked together. The composite positive electrode layer includes a positive electrode active material, the halide oxide mixed anion solid electrolyte material, and a conductive agent. The halide oxide solid electrolyte layer includes the halide oxide mixed anion solid electrolyte material. The sulfide intermediate layer is used to form a more stable ion transport and contact interface with the negative electrode side. The negative electrode side metal layer includes an indium metal foil and a lithium source metal layer.

[0016] In summary, the advantages of this invention are: This invention introduces oxygen anions into the halide lattice to construct a halide-oxygen mixed anionic framework, and combines this with the charge compensation effect of high-valence metal ions to achieve synergistic control over the local structure and defect chemistry of the material. On the one hand, the introduction of oxygen can change the chemical environment of the anionic framework, improving the tunability of the structure; on the other hand, the addition of high-valence metal ions helps to induce the formation of lithium vacancies and regulate the carrier concentration. The synergistic effect of these two factors effectively broadens the lithium-ion migration channels and lowers the migration barrier, thereby significantly improving the room-temperature ionic conductivity of the material. Compared with the undoped system, the ionic conductivity of the material of this invention is significantly improved, demonstrating excellent structure control.

[0017] This invention enables the construction of halide oxide solid electrolyte structures through high-energy ball milling, allowing the resulting materials to possess lithium-ion conductivity without sintering or high-temperature thermal annealing, and enabling them to be directly used in the assembly and operation of all-solid-state lithium batteries.

[0018] The halide oxide solid electrolyte prepared by this invention exhibits good lithium-ion conductivity at room temperature and can form stable contact with the positive electrode material and the lithium metal negative electrode, which helps to reduce interface impedance and support stable battery operation.

[0019] This invention omits the sintering and annealing steps, effectively reducing the energy consumption caused by high-temperature processes, while also lowering equipment requirements and process complexity, which is beneficial to improving the engineering feasibility and large-scale production potential of material preparation. Attached Figure Description

[0020] Figure 1 The X-ray diffraction patterns of the doped and undoped halide oxide solid electrolyte materials of the present invention are shown.

[0021] Figure 2 The Fourier transform infrared spectra of the Li–O and Li–Cl related vibrational regions in the doped and undoped halide oxide solid electrolyte materials of the present invention are shown.

[0022] Figure 3 The Nyquist plots show the AC impedance spectra of the doped and undoped halide oxide solid electrolyte materials of this invention.

[0023] Figure 4 This is a graph showing the relationship between the molar fraction of Ta doping and the room-temperature ionic conductivity of the halide oxide solid electrolyte material of the present invention.

[0024] Figure 5 This is a charge-discharge curve of the first cycle of the full battery consisting of a composite positive electrode, a halide solid electrolyte, a sulfide solid electrolyte interlayer, and a Li–In negative electrode, according to the present invention.

[0025] Figure 6This is a graph showing the cycle performance and capacity retention of the all-solid-state battery of the present invention at room temperature and 0.5 C.

[0026] Figure 7 This is a graph showing the rate performance and coulombic efficiency of the all-solid-state battery of this invention. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0028] Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with conventional techniques or conditions described in the literature in this field and the techniques or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products. The source, trade name, and, where necessary, composition of the reagents used shall be indicated upon their first appearance; thereafter, unless otherwise specified, the same information shall apply to the same reagents used.

[0029] Example: A halide oxide mixed anionic solid electrolyte material, comprising Cl - With O 2- A lithium-ion conductor with a mixed anionic framework and a high-valence metal Ta cation doped component.

[0030] The chemical formula of the halide oxide mixed anionic solid electrolyte material is Li 2+y Zr 1-x Ta x Cl5O 0.5 Where 0.25≤ x≤ 0.9, preferably, the value of x is in the range of 0.5 ≤ x ≤ 0.9, and y is the valence state change caused by the introduction of doping elements.

[0031] Preferably, when the mole fraction x of Ta is 0.5, 0.75, or 0.9, the lithium-ion conductivity of the halide oxide mixed anionic solid electrolyte material at room temperature is not less than 3 mS / cm. -1 7 mS cm -1 9 mS cm -1 .

[0032] The halide oxide mixed anionic solid electrolyte material includes an amorphous phase with a volume fraction of ≥50%.

[0033] The halide oxide mixed anionic solid electrolyte material exhibits a conductivity of not less than 1.5 mS / cm at room temperature. -1 The lithium-ion conductivity.

[0034] A method for preparing a halide oxide mixed anionic solid electrolyte material includes the following steps: Oxygen source, lithium source, and metal halide precursors were selected. Zirconium chloride (ZrCl4) and tantalum pentachloride (TaCl5) were used as metal halide precursors; lithium chloride (LiCl) was used as the lithium source; and one or more of lithium oxide (Li2O), lithium hydroxide (LiOH), and lithium peroxide (Li2O2) were used as the oxygen source.

[0035] The amount of LiCl added is higher than the amount of chlorine source required to meet the stoichiometry, so as to form a lithium-rich environment; LiCl not only serves as a chlorine source, but also as an excess lithium source to participate in framework construction, thereby regulating lithium vacancy concentration and improving ionic conductivity. When the oxygen source is Li2O or LiOH, the molar ratio of LiCl, Li2O / LiOH, ZrCl4 and TaCl5 satisfies: Li2O / LiOH:LiCl:ZrCl4:TaCl5 = 0.5 : (5 - 5x - 4 (1 - x)) : (1-x) : x, 0.25 ≤ x≤ 0.9; When the oxygen source is Li2O2, the molar ratio of LiCl, Li2O / LiOH, ZrCl4 and TaCl5 satisfies: Li2O2:LiCl:ZrCl4:TaCl5 = 0.25 : (5 - 5x - 4 (1 - x)) : (1-x) : x, 0.25 ≤ x≤ 0.9.

[0036] The molar ratios of oxygen source, lithium source, and metal halide precursor are the same. Preferably, when x=0.5, Li2O / LiOH:LiCl:ZrCl4:TaCl5 = 0.5:0.5:0.5:0.5.

[0037] Oxygen source, lithium source and metal halide precursor are loaded into a ball mill container and subjected to high-energy mechanical ball milling under an inert atmosphere. After ball milling, halide oxide solid electrolyte material is obtained.

[0038] Oxygen and lithium sources induce Cl through a mechanochemical reaction during ball milling. - With O 2- Anions rearrange and form an amorphous dominant structure, and after the reaction is completed, a halide oxide solid electrolyte material with amorphous state is obtained.

[0039] Under the continuous mechanical energy of high-energy mechanical ball milling, oxygen source, lithium source and metal halide precursor are fully mixed and induced to undergo solid-phase reaction to obtain halide oxide solid electrolyte material. The halide oxide solid electrolyte material can be directly used for the assembly and electrochemical performance testing of all-solid-state lithium batteries without further sintering or high-temperature thermal annealing treatment.

[0040] An inert atmosphere is preferably an argon atmosphere to reduce side reactions caused by the contact of raw materials with air and moisture.

[0041] The ball mill container is a sealed ball mill jar with a 100 mL zirconia liner; The grinding balls are made of zirconium oxide (ZrO2), and the diameter of the grinding balls includes at least two of the following: 12 mm, 10 mm, 8 mm, and 5 mm; the ball-to-material ratio is 80:1 – 120:1; the grinding speed is 400–500 rpm; and the grinding time is 24–48 h.

[0042] The high-energy mechanical ball mill uses alternating forward and reverse rotation, with a forward rotation time of 15 minutes, a reverse rotation time of 15 minutes, and a 15-minute interval between the forward and reverse rotation.

[0043] Under an inert atmosphere, the raw materials are subjected to a mechanochemical reaction that induces anion rearrangement and forms an amorphous dominant structure. After the reaction is completed, a halide oxide solid electrolyte material with amorphous state is obtained.

[0044] The halide oxide solid electrolyte material was tested by X-ray diffraction (XRD). The XRD showed broadened diffraction peaks / diffuse diffraction characteristics, indicating that it is mainly amorphous / quasi-amorphous; and no obvious precursor characteristic peaks were observed.

[0045] The ionic conductivity of the halide oxide solid electrolyte material, as measured by AC impedance spectroscopy, is approximately 3.5 mS / cm at room temperature. -1 (Ta=0.5). The results show that the ion conductivity of the material can be effectively improved by tantalum doping.

[0046] To verify the practical application capability of the halide oxide solid electrolyte material prepared in Example 1, an all-solid-state lithium battery was constructed without sintering or high-temperature thermal annealing of the electrolyte material. All assembly steps were completed under an inert atmosphere, preferably an argon atmosphere, and in-mold layer-by-layer pressing assembly was performed using a pressing mold with an inner diameter of 10 mm and a PEEK inner liner.

[0047] The all-solid-state lithium-ion battery includes a composite positive electrode layer, a halide oxide solid electrolyte layer, a sulfide intermediate layer, and a negative electrode side metal layer (including a LiIn interface layer and a lithium source layer) stacked together. The composite positive electrode layer includes a positive electrode active material, a solid electrolyte, and a conductive agent. The halide oxide solid electrolyte layer includes a halide oxide solid electrolyte material. The sulfide intermediate layer is used to form a more stable ion transport and contact interface with the negative electrode side. The negative electrode side metal layer includes an indium (In) metal foil and a lithium source metal layer, and preferably further includes a lithium source layer supported by a copper current collector to achieve stable alloying and assembly consistency.

[0048] The positive electrode layer is a composite positive electrode layer, which includes NCM811, halide oxide solid electrolyte material and conductive agent VGCF, and the mass ratio of NCM811: solid electrolyte: VGCF is 6:3.5:0.5. The composite positive electrode layer is prepared by high-speed vibratory ball milling, and the mixing parameters are 1200 rpm and 1 min.

[0049] The all-solid-state lithium-ion battery is assembled using an in-mold layer-by-layer pressing method. Assembly takes place in a pressing mold with an inner diameter of 10 mm and a PEEK inner liner, and includes the following steps: Construction of the electrolyte layer: Approximately 70 mg of the halide oxide solid electrolyte powder obtained in Example 1 was placed in a Φ10 mm mold. An axial load equivalent to 1 t was applied using a press and held for 1 min to form a dense electrolyte layer with a diameter of approximately 10 mm. The resulting electrolyte layer exhibits good mechanical integrity and can serve as the main ion-conducting layer in an all-solid-state battery.

[0050] Weigh 70-90 mg of halide oxide solid electrolyte material and place it in the tableting mold. Apply an axial load equivalent to 0.5-2t and hold the pressure for 0.5-5 min to form a solid electrolyte layer. Preparation of composite cathode: The following components were weighed: NCM811 positive electrode active material, halide oxide solid electrolyte prepared in Example 1, and vapor-grown carbon fiber (VGCF) in a mass ratio of 6:3.5:0.5. They were rapidly mixed and dispersed using a high-speed vibratory ball mill at 1200 rpm for 1 min to obtain composite positive electrode powder. Approximately 7 mg of the composite positive electrode was uniformly spread on one side of the electrolyte layer and pressed for 1 min using a press with an axial load equivalent to 1 t to enhance interfacial contact and reduce interfacial impedance.

[0051] Add 7-10 mg of composite cathode powder to one side of the solid electrolyte layer, apply an axial load equivalent to 0.5-2t and hold for 0.5-5 min to form a tight contact interface between the cathode layer and the solid electrolyte layer. Intermediate layer introduction: Approximately 50 mg of Li6PS5Cl solid electrolyte was deposited on the other side of the electrolyte layer as an interfacial buffer layer, and an axial load equivalent to 3 t was applied for 1 min using a press. This intermediate layer can improve the interfacial compatibility between the metal layer / lithium source layer on the negative electrode side of the halide oxide electrolyte and help suppress interfacial side reactions; Add 40-60 mg of Li6PS5Cl powder to the other side of the solid electrolyte layer, apply an axial load equivalent to 1-3t and hold for 0.5-5 min to form the sulfide solid electrolyte intermediate layer.

[0052] In step (1), the amount of halide oxide solid electrolyte material used is 80 mg, the axial load is equivalent to 1t and the pressure is maintained for 1 min; in step (2), the amount of composite cathode powder used is 7 mg, the axial load is equivalent to 1t and the pressure is maintained for 1 min; in step (3), the amount of Li6PS5Cl powder used is 40 mg, the axial load is equivalent to 3t and the pressure is maintained for 1 min.

[0053] Negative side construction and encapsulation voltage holding: On the side of the sulfide solid electrolyte intermediate layer away from the solid electrolyte layer, an In metal foil with a thickness of 20 μm and a LiCu metal sheet with a thickness of 10 μm are sequentially bonded together. A torque of 20 N·m is applied using a torque wrench for compression and encapsulation. The compressed state is maintained for 12 h for alloying treatment to complete the alloying interface stabilization treatment and further enhance the interface bonding stability between the functional layers.

[0054] Constant current charge-discharge tests were conducted at room temperature (25 °C): 2 cycles were activated at a 0.1 C rate, followed by cycling at a 0.5 C rate; the cutoff voltage was set to 2.18 - 3.68 V (vs. Li). + / LiIn); NCM811 has a nominal specific capacity of 180 mAh g based on active material. -1 .

[0055] Test Results and Analysis: First-cycle charge-discharge curves and coulombic efficiency like Figure 5 As shown, the all-solid-state lithium battery can achieve a reversible charge-discharge process within the voltage window, and under 0.1C rate conditions, the first discharge specific capacity is 168 mAh g. -1 The first-cycle coulombic efficiency was 87.04%. This result indicates that even without sintering or thermal annealing of the halide oxide electrolyte, the battery system can still form an effective ion transport and interfacial reaction pathway, achieving a high first-cycle reversible capacity output and possessing the foundation for reversible electrochemical reactions.

[0056] Cyclic stability like Figure 6 As shown, when cycled at 0.5 C rate at room temperature, the battery capacity exhibits good stability with cycling, and the coulombic efficiency remains at a high level overall. Within the cycle range shown, the capacity retention rate reaches 96.42%, indicating that by using the halide oxide solid electrolyte combined with the sulfide interlayer and In / LiCu alloy interface stabilization strategy, superior cycle stability and repeatable operation can be achieved without high-temperature treatment.

[0057] Ratio performance like Figure 7 As shown, this all-solid-state lithium-ion battery can achieve continuous charge-discharge processes at different rates, exhibiting a regular response of decreasing capacity with increasing rate and recovering capacity after rate recovery. Specifically, at the 0.1 C stage, the battery's discharge specific capacity is approximately 160 mAh g⁻¹. -1 The level (of which the first-cycle 0.1C discharge specific capacity is 168 mAh g) -1 When the rate of discharge is increased to 0.3 C, the discharge specific capacity is approximately 120 mAh g. -1 When the rate of discharge is further increased to 0.5 C, the discharge specific capacity is approximately 90 mAh g. -1 Under 1 C conditions, the discharge specific capacity is approximately 40 mAh g. -1 Under 2C conditions, the discharge specific capacity is approximately 20 mAh g. -1 Subsequently, when the rate is restored to 0.3 C, the discharge specific capacity can be restored to approximately 120 mAh g⁻¹. -1 It remains around 105 mAh·g in subsequent cycles, and decreases slowly in subsequent cycles but still remains at 105 mAh·g. -1 The above indicates that the system possesses a certain degree of rate adaptability and rate recovery capability; simultaneously, Figure 2 The coulombic efficiency shown remains at a high level overall, reflecting that the battery system still has good reversibility and stable operation capability during different rate switching processes.

[0058] To verify the effect of different tantalum contents on the ion conduction performance of halide oxide solid electrolyte materials, experimental examples were prepared. Based on the preparation method described in Example 1, halide oxide solid electrolyte materials with different doping amounts were prepared by adjusting the amount of tantalum pentachloride (TaCl5).

[0059] In the experimental examples, other raw material ratios and ball milling process parameters remained unchanged, only the proportion of tantalum introduced was varied. The proportions of tantalum were set to 0.25, 0.5, 0.75, and 0.9, respectively. The resulting samples, after AC impedance spectroscopy, showed room temperature ionic conductivity of approximately 1.5 mS / cm. -1(Ta=0.25); 3.5 mS cm -1 (Ta=0.5); 7.5 mS cm -1 (Ta=0.75); 10.1 mScm -1 (Ta=0.9), samples with different tantalum contents were obtained; the relationship between samples with different tantalum contents and the room temperature ionic conductivity of halide oxide solid electrolyte materials is as follows: Figure 4 As shown, the AC impedance test results for samples with different tantalum contents are as follows: Figure 3 As shown, the X-ray diffraction (XRD) test results of samples with different tantalum contents are as follows. Figure 1 As shown, infrared spectroscopy tests were performed on samples with different tantalum contents. Figure 2 As shown.

[0060] To verify the effect of tantalum on the ion conduction performance of solid electrolyte materials, a comparative example was prepared. Based on the preparation method described in Example 1, the comparative example removed tantalum pentachloride (TaCl5) to prepare a tantalum-free halide oxide solid electrolyte material.

[0061] In the comparative example, a halide oxide solid electrolyte material was prepared according to the preparation method described in the examples, without the addition of tantalum pentachloride (TaCl5), while maintaining the same raw material ratios and ball milling process parameters. The resulting undoped tantalum sample was tested using AC impedance spectroscopy. Figure 3 As shown, the X-ray diffraction (XRD) test results of the undoped sample are as follows: Figure 1 As shown, infrared spectroscopy was performed on the undoped sample. Figure 2 As shown.

[0062] according to Figure 3 as well as Figure 4 It can be seen that the lithium-ion conductivity of the undoped sample at room temperature is approximately 0.5 mS / cm. -1 The lithium-ion conductivity of the material was significantly lower than that of the tantalum-doped sample. With increasing tantalum content, the lithium-ion conductivity of the material increased significantly. Impedance spectroscopy showed a marked decrease in the equivalent resistance (especially the bulk / grain boundary contribution in the high-frequency region), indicating that Ta doping effectively reduces ion conduction impedance, thereby improving room-temperature lithium-ion conductivity. This demonstrates that the introduction of tantalum can effectively modulate the material structure and improve ion migration characteristics.

[0063] according to Figure 1 It can be seen that, compared with the undoped sample, the diffraction peaks of the tantalum-doped sample show a certain degree of broadening. The introduction of tantalum modulates the crystal structure, possibly forming a structure with partially disordered characteristics, which is conducive to the migration of lithium ions.

[0064] Based on the infrared spectra of both doped and undoped samples, characteristic absorption peaks related to Li–O(Zr) and Li–Cl(Zr) can be observed in both types of samples; however, in the tantalum-doped sample, the positions of the corresponding characteristic peaks are shifted (e.g., the Li–O related peak is shifted from approximately 858.6 cm⁻¹). -1 It moved to approximately 851.3 cm in the vicinity. -1 The Li–Cl related peak is approximately 755 cm⁻¹. -1 It moved to approximately 653.7 cm in the vicinity. -1 The results indicate that tantalum doping alters the local coordination / bonding environment, suggesting that the mixed anionic framework and local structure are modulated. This change in local structure is consistent with the disordering trend reflected by XRD, further supporting the inference that "Ta doping can optimize the lithium-ion migration environment through structural modulation."

[0065] In summary, the experimental and comparative results show that, under the same mechanochemical process conditions, the introduction of Ta can significantly reduce impedance and improve room temperature lithium-ion conductivity. Combined with XRD broadening / dispersion and FTIR characteristic peak shift, it can be seen that Ta doping has a modulating effect on the local structure and disorder of halide oxides, which is beneficial to constructing a transport environment more suitable for lithium-ion migration.

[0066] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A halide oxide mixed anionic solid electrolyte material, characterized in that: Including Cl - With O 2- A lithium-ion conductor with a mixed anionic framework and a high-valence metal Ta cation doping component, the chemical formula being Li 2+y Zr 1-x Ta x Cl5O 0.5 , where 0.25 ≤ x ≤ 0.9, and y is the valence state change caused by the introduction of doping elements.

2. The halide oxide mixed anionic solid electrolyte material according to claim 1, characterized in that: The value of x is in the range of 0.5 ≤ x ≤ 0.

9.

3. The halide oxide mixed anionic solid electrolyte material according to claim 1, characterized in that: The halide oxide mixed anionic solid electrolyte material includes an amorphous phase with a volume fraction of ≥50%.

4. The halide oxide mixed anionic solid electrolyte material according to claim 1, characterized in that: When the mole fraction x of Ta is 0.5, 0.75, or 0.9, the lithium-ion conductivity of the halide oxide mixed anionic solid electrolyte material at room temperature is not less than 3 mS / cm. -1 7 mS cm -1 9 mS cm -1 .

5. The halide oxide mixed anionic solid electrolyte material according to claim 1, characterized in that: The halide oxide mixed anionic solid electrolyte material exhibits a strength of not less than 1.5 mS / cm at room temperature. -1 The lithium-ion conductivity.

6. A method for preparing a halide oxide mixed anionic solid electrolyte material, characterized in that: Includes the following steps: Oxygen source, lithium source, and metal halide precursors were selected, with ZrCl4 and TaCl5 as metal halide precursors and LiCl as the lithium source. Oxygen source, lithium source, and metal halide precursor were loaded into a ball mill container and subjected to high-energy mechanical ball milling under an inert atmosphere. The oxygen source and lithium source induced Cl through a mechanochemical reaction during ball milling. - With O 2- Anions rearrange and form an amorphous dominant structure. After the reaction is completed, a halide oxide solid electrolyte material with amorphous state is obtained.

7. The method for preparing a halide oxide mixed anionic solid electrolyte material according to claim 6, characterized in that: The amount of LiCl added is higher than the amount of chlorine source required to meet the stoichiometry, so as to form a lithium-rich environment; LiCl participates in framework construction as a chlorine source and as an excess lithium source, which is used to regulate the lithium vacancy concentration and improve ionic conductivity.

8. The method for preparing a halide oxide mixed anionic solid electrolyte material according to claim 7, characterized in that: The oxygen source is one or more of Li2O, LiOH, and Li2O2. When the oxygen source is Li2O or LiOH, the molar ratio of LiCl, Li2O / LiOH, ZrCl4, and TaCl5 satisfies: Li2O / LiOH:LiCl:ZrCl4:TaCl5 = 0.5 : (5 - 5x - 4 (1 - x)) : (1-x) : x, 0.25 ≤ x≤ 0.9; when the oxygen source is Li2O2, the molar ratio of LiCl, Li2O / LiOH, ZrCl4, and TaCl5 satisfies: Li2O2:LiCl:ZrCl4:TaCl5 = 0.25 : (5 - 5x - 4 (1 - x)) : (1-x) : x, 0.25 ≤ x≤ 0.

9.

9. The method for preparing a halide oxide mixed anionic solid electrolyte material according to claim 7, characterized in that: The inert atmosphere is argon, the ball milling speed is 400–500 rpm, and the ball milling time is 24–48 h.

10. The application of the halide oxide mixed anionic solid electrolyte material according to claims 1-5 in an all-solid-state lithium-ion battery, characterized in that: The all-solid-state lithium-ion battery comprises a composite positive electrode layer, a halide oxide solid electrolyte layer, a sulfide intermediate layer, and a negative electrode side metal layer stacked together. The composite positive electrode layer includes a positive electrode active material, the halide oxide mixed anion solid electrolyte material as described in claims 1-5, and a conductive agent. The halide oxide solid electrolyte layer includes the halide oxide mixed anion solid electrolyte material as described in claims 1-5. The sulfide intermediate layer is used to form a more stable ion transport and contact interface with the negative electrode side. The negative electrode side metal layer includes an indium metal foil and a lithium source metal layer.

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