Chloride solid electrolyte capable of being rapidly synthesized and preparation method and application thereof

Abstract

This invention discloses a rapidly synthesizable chloride solid electrolyte, its preparation method, and its applications. The chloride solid electrolyte of this invention contains anions, cations, and water of crystallization, wherein the anions include Cl... ‑ and at least one of the following ions: F ‑ OH ‑ O 2‑ CO3 2‑ S 2‑ SO4 2‑ PO4 3‑ N 3‑ NO3 3‑ The cation includes Zr. 4+ Li + and at least one of the following ions: H + Ca 2+ Cu 2+ Fe 2+ Mg 2+ Zn 2+ Na + Al 3+ Zr 4+ Fe 3+ Co 2+ Ba 2+ Mn 2+ This invention prepares the chloride solid electrolyte by introducing crystalline hydrates, which improves the lithium-ion conductivity of the chloride solid electrolyte, broadens the electrochemical stability window and the thermodynamic stability potential of the electrolyte, enabling the cathode / electrolyte interface to stably transport lithium ions under high voltage (4.5 V), making it more suitable for high-capacity, high-voltage all-solid-state batteries.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, specifically relating to a class of rapidly synthesizable chloride solid electrolytes, their preparation methods, and applications. Background Technology

[0002] As a key next-generation energy storage technology, all-solid-state batteries, with their high safety and high energy density potential, are expected to drive revolutionary development in fields such as electric vehicles, portable electronics, and energy storage systems. In the commercialization of all-solid-state batteries, the selection and optimization of solid-state electrolyte materials is one of the core challenges. Currently, commonly used inorganic solid-state electrolytes are mainly divided into three categories: oxides, sulfides, and halides. While oxide electrolytes possess excellent oxidation stability, their processing performance is poor and their interfacial impedance is high. Sulfide electrolytes, although possessing high ionic conductivity and good mechanical deformability, have a narrow electrochemical stability window, making them difficult to directly integrate with high-voltage layered oxide cathodes. In contrast, halide solid-state electrolytes combine the advantages of oxide and sulfide electrolytes, possessing both high ionic conductivity and high voltage stability and good flexibility, thus attracting increasing attention. Since its inception in the 1930s, halide solid-state electrolyte systems have gradually expanded from compositions with limited conductivity to include Li... a M b X c A rich family of materials including (M = Y, Sc, In, Zr, etc., X = Cl, Br) and UCl3-type structural analogs. Among them, Zr-based chloride electrolytes have become a research focus due to their advantages in both cost and conductivity.

[0003] In terms of synthesis methods, ball milling is considered an important means to promote the development of chloride solid-state electrolytes due to its simplicity and ease of scale-up. However, to achieve high ionic conductivity, traditional processes often require high-energy ball milling lasting tens of hours to form a distorted, aperiodic structure conducive to ion migration. This lengthy process is not only energy-intensive and inefficient, but also severely restricts its large-scale production and economic feasibility. Although methods such as hydration, annealing, and ammonia-assisted synthesis have been developed as supplementary methods, significantly shortening the synthesis time while ensuring performance remains a key challenge to be overcome in this field. Therefore, developing a synthesis strategy that balances high performance and ultra-short preparation time for chloride electrolyte systems is not only of urgent practical significance for promoting the industrialization of all-solid-state batteries, but also provides an important research direction for a deeper understanding of structure-performance relationships and the exploration of novel rapid ion transport mechanisms. Overcoming the bottleneck of rapid synthesis technology will directly help reduce production costs, improve manufacturing efficiency, and accelerate the transition of all-solid-state batteries from the laboratory to large-scale applications. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A type of chloride solid electrolyte, wherein the chloride solid electrolyte contains anions, cations and water of crystallization, wherein, The anion includes Cl. - and at least one of the following ions: F - OH - O 2- CO3 2- S 2- SO4 2- PO4 3- N 3- NO3 3- ; The cation includes Zr. 4+ Li + and at least one of the following ions: H + Ca 2+ Cu 2+ Fe 2+ Mg 2+ Zn 2+ Na + Al 3+ Zr 4+ Fe 3+ Co 2+ Ba 2+ Mn 2+ .

[0005] According to an embodiment of the present invention, the chemical formula of the chloride solid electrolyte is shown in formula (I): ZrCl4· x Li a A· y M(Ⅰ) Where 0.2≤x≤1, 0.05≤y≤0.6; Li a A is one or more of Li3PO4, Li3N, Li2O, Li2S, LiCl, LiNO3, LiF, LiBr, and LiI; M is selected from crystalline hydrates, such as MnSO4·H2O, KAl(SO4)2·12H2O, CaSO4·2H2O, Zr(SO4)2·4H2O, CuSO4· nOne, two, or more of the following: H2O, FeSO4·7H2O, MgSO4·7H2O, ZnSO4·7H2O, Na2SO4·10H2O, LiOH·H2O, Na2CO3·10H2O, AlF3·3H2O, FeCl3·6H2O, CoCl3·6H2O, BaCl2·2H2O, CaCl2·2H2O, Co(NO3)2·6H2O, and Al(NO3)3·9H2O.

[0006] Preferably, 0.3 ≤ x ≤ 0.8, for example, 0.4, 0.5, 0.6, 0.7 or any two of the above values.

[0007] Preferably, 0.05≤y≤0.35, for example, 0.1, 0.15, 0.2, 0.25, 0.3 or any two of the above values.

[0008] According to an embodiment of the present invention, the chloride solid electrolyte is selected from at least one of ZrCl4·0.8Li2O·0.05(CaSO4·2H2O), ZrCl4·0.8Li2O·0.2(LiOH·H2O), ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O), ZrCl4·0.4Li3PO4·0.2(Zr(SO4)2·4H2O), ZrCl4·0.55Li3N·0.1(AlF3·3H2O), ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O), and ZrCl4·0.35Li3PO4·0.15Li3N·0.05(FeSO4·7H2O).

[0009] According to an embodiment of the present invention, the ionic conductivity of the chloride solid electrolyte is greater than 2 × 10⁻⁶. -4 S cm -1 The electrochemical window of the chloride solid electrolyte is 0–5 V (relative to Li). + / Li electrode) inside.

[0010] The present invention also provides a method for preparing the above-mentioned chloride solid electrolyte, the method comprising: weighing metal chloride, lithium salt and crystalline hydrate according to the stoichiometric ratio of the above-mentioned chloride solid electrolyte, mixing and grinding to obtain the chloride solid electrolyte.

[0011] Preferably, the molar ratio of the metal chloride, lithium salt, and crystalline hydrate is 1:x:y, where x and y have the meanings described above.

[0012] According to an embodiment of the present invention, the metal chloride is ZrCl4.

[0013] According to an embodiment of the present invention, the lithium salt is selected from Li a A is one, two or more of the following: Li3PO4, Li3N, Li2O, Li2S, LiCl, LiNO3, LiF, LiBr, and LiI.

[0014] According to an embodiment of the present invention, the crystalline hydrate is selected from MnSO4·H2O, KAl(SO4)2·12H2O, CaSO4·2H2O, Zr(SO4)2·4H2O, CuSO4· n One, two, or more of the following: H2O, FeSO4·7H2O, MgSO4·7H2O, ZnSO4·7H2O, Na2SO4·10H2O, LiOH·H2O, Na2CO3·10H2O, AlF3·3H2O, FeCl3·6H2O, CoCl3·6H2O, BaCl2·2H2O, CaCl2·2H2O, Co(NO3)2·6H2O, and Al(NO3)3·9H2O.

[0015] According to an embodiment of the invention, the grinding is ball milling. Preferably, the ball milling is performed in a ball mill known in the art.

[0016] According to an embodiment of the present invention, the ball milling conditions are as follows: the rotation speed is 300~1000 rpm, preferably 400~600 rpm; the time is 0.1~10 h, preferably 0.5~4 h.

[0017] According to an embodiment of the present invention, the preparation method is carried out in an inert gas atmosphere; for example, weighing, mixing, and ball milling are all carried out in an inert gas atmosphere. Preferably, the inert gas in the inert gas atmosphere is selected from gases known in the art, such as Ar. Further, the O2 content in the inert gas atmosphere is less than 0.1 ppm and the H2O content is less than 0.1 ppm.

[0018] The present invention also provides the application of the above-mentioned chloride solid electrolyte, preferably in the preparation of solid-state batteries.

[0019] The present invention also provides a composite cathode material, wherein the composite cathode material comprises the above-mentioned chloride solid electrolyte, cathode active material and conductive agent.

[0020] According to an embodiment of the present invention, the positive electrode active material is selected from LiFePO4, LiCoO2, LiNiO2, LiMn2O4, and LiNi 0.5 Mn 1.5 O4, Li 1.2 Ni 0.13 Co 0.13 Mn0.54 O4, Li 1.2 Ni 0.2 Mn 0.6 O4, LiNi 0.6 Co 0.2 Mn 0.2 O4, LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811), LiNi 0.9 Co 0.5 Mn 0.5 O4 and LiNi 0.92 Co 0.03 Mn 0.05 One, two, or more of the following: O2 (NCM92).

[0021] According to an embodiment of the present invention, the conductive agent is selected from one or more of Super-P, superconducting carbon black, acetylene black and Ketjen black.

[0022] According to an embodiment of the present invention, each 100 parts by weight of the composite cathode material comprises: 60-90 parts by weight of positive electrode active material Chloride solid electrolyte, 10-40 parts by weight Conductive agent: 0-6 parts by weight.

[0023] According to an embodiment of the present invention, the mass ratio of the positive electrode active material, the chloride solid electrolyte and the conductive agent is (60~90):(10~40):(0~6), preferably (70~80):(20~30):(0~2).

[0024] According to an exemplary embodiment of the present invention, the positive electrode active material in the composite positive electrode material is LiNi. 0.92 Co 0.03 Mn 0.05 O2, the chloride solid electrolyte is ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O), and the mass ratio of the positive electrode active material to the chloride solid electrolyte is 80:20.

[0025] The present invention also provides a method for preparing the above-mentioned composite cathode material, comprising the following steps: mixing the chloride solid electrolyte, the cathode active material and the conductive agent in the above mass ratio and then grinding or ball milling to obtain the mixture.

[0026] Preferably, grinding or ball milling can be performed using methods known in the art.

[0027] The present invention also provides an energy storage element comprising the above-mentioned chloride solid electrolyte and / or the above-mentioned composite cathode material.

[0028] Furthermore, the energy storage element is a solid-state battery.

[0029] The present invention also provides a solid-state battery, the solid-state battery comprising a positive electrode, a solid electrolyte, and a negative electrode; wherein, The positive electrode is selected from the composite positive electrode material; The solid electrolyte is selected from the above-mentioned chloride solid electrolyte, or a combination of the above-mentioned chloride solid electrolyte and sulfide solid electrolyte; The negative electrode is selected from one of the following: metallic Li, Li-In alloy, and Si.

[0030] Preferably, the mass ratio of chloride solid electrolyte to sulfide solid electrolyte is (3~5):(5~7).

[0031] According to an embodiment of the present invention, the sulfide solid electrolyte is preferably Li6PS5Cl or Li 5.5 PS 4.5 Cl 1.5 Li 5.3 PS 4.3 Cl 0.8 Br 0.7 Li3PS4, Li7P3S 11 .

[0032] The present invention also provides a method for preparing the above-mentioned solid-state battery, the method comprising: First, the solid electrolyte is pressed under pressure to form a solid electrolyte sheet. Then, the composite positive electrode material is placed on one side of the solid electrolyte sheet and pressed under pressure to form a positive electrode. The negative electrode material is placed on the other side of the solid electrolyte sheet and pressed under pressure to form a negative electrode. The solid battery is then assembled under pressure.

[0033] According to an embodiment of the present invention, the pressure pressing or pressure assembly in the present invention can be carried out using conditions known in the art, as long as the solid-state battery can be obtained.

[0034] According to an embodiment of the present invention, the solid-state battery is prepared under an inert gas atmosphere. Preferably, the inert gas atmosphere has the meaning described above.

[0035] According to an embodiment of the present invention, when the solid electrolyte is a composition of chloride solid electrolyte and sulfide solid electrolyte, the solid electrolyte sheet includes a chloride solid electrolyte layer obtained by pressing the chloride solid electrolyte and a sulfide solid electrolyte layer obtained by pressing the sulfide solid electrolyte, wherein the chloride solid electrolyte layer is in direct contact with the positive electrode and the sulfide solid electrolyte layer is in direct contact with the negative electrode.

[0036] Beneficial effects This invention prepares the chloride solid electrolyte by introducing crystalline hydrates and adjusting the type and proportion of crystalline hydrates. This not only significantly shortens the synthesis time of the chloride solid electrolyte, but also improves the lithium-ion conductivity, broadens the electrochemical stability window and the thermodynamic stability potential of the electrolyte. This allows the cathode / electrolyte interface to stably transport lithium ions under high voltage (4.5 V), making it more suitable for high-capacity, high-voltage all-solid-state batteries.

[0037] This invention can not only improve the electrochemical stability window of solid electrolytes, but also enable stable operation at a high voltage of 4.5 V when matched with a high voltage cathode.

[0038] The raw materials used in this invention are inexpensive, easy to integrate with existing battery production processes, and easy to commercialize, showing great application prospects. Attached Figure Description

[0039] Figure 1 The results of scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM-EDS) analysis of the chloride solid electrolyte ZrCl4·0.8Li2O·0.05(CaSO4·2H2O) that can be rapidly synthesized in Example 1 of this invention are shown.

[0040] Figure 2 The electrochemical impedance spectroscopy (EIS) results are for the chloride solid electrolyte ZrCl4·0.8Li2O·0.05(CaSO4·2H2O) that can be rapidly synthesized in Example 1 of this invention.

[0041] Figure 3 The X-ray diffraction (XRD) results are for the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) that can be rapidly synthesized in Example 3 of this invention.

[0042] Figure 4 The results of scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM-EDS) analysis of the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) that can be rapidly synthesized in Example 3 of this invention are shown.

[0043] Figure 5 The electrochemical impedance spectroscopy (EIS) results are for the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) that can be rapidly synthesized in Example 3 of this invention.

[0044] Figure 6 The charge-discharge curves of the all-solid-state battery of the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) that can be rapidly synthesized in Example 3 of this invention are shown at 4.5V.

[0045] Figure 7 The X-ray energy dispersive spectroscopy (XRD) results are for the chloride solid electrolyte ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O) that can be rapidly synthesized in Example 6 of this invention.

[0046] Figure 8 The results of scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM-EDS) analysis of the chloride solid electrolyte ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O) that can be rapidly synthesized in Example 6 of this invention are shown.

[0047] Figure 9 The electrochemical impedance spectroscopy (EIS) results are for the chloride solid electrolyte ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O) that can be rapidly synthesized in Example 6 of this invention.

[0048] Figure 10 The results are obtained by electrochemical impedance spectroscopy (EIS) of the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.02(Zr(SO4)2·4H2O) in Comparative Example 1.

[0049] Figure 11 The charge-discharge curves of the all-solid-state battery of the chloride solid electrolyte ZrCl4·0.35Li3PO4·0.02(Zr(SO4)2·4H2O) in Comparative Example 1 are shown at 4.5V. Detailed Implementation

[0050] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0051] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0052] Example 1 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte ZrCl4·0.8Li2O·0.05(CaSO4·2H2O) I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh ZrCl4, Li2O, and CaSO4·2H2O in the appropriate molar ratio into a ball mill jar in a glove box. The grinding balls are made of zirconium oxide and have a diameter of 5 mm. Tighten the ball mill jar to create an inert argon atmosphere. Ball mill at 450 rpm for 3 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.8Li2O·0.05(CaSO4·2H2O).

[0053] II. Characterization of rapidly synthesizable chloride solid electrolytes Scanning electron microscope (SEM) images and X-ray energy dispersive spectroscopy (EDS) images of the rapidly synthesizable chloride solid electrolyte prepared in this embodiment are shown below. Figure 1 As shown, Zr, Ca, O, and Cl elements are uniformly distributed in the particles. In summary, this embodiment successfully yielded a rapidly synthesizable chloride solid electrolyte ZrCl4·0.8Li2O·0.05(CaSO4·2H2O).

[0054] III. Testing of Lithium-ion Conductivity The prepared electrolyte powder was placed in a 10 mm diameter polytetrafluoroethylene mold, and then an EIS test was performed after applying pressure of 450 MPa using a 10 mm diameter iron cylinder. The test results are as follows. Figure 2 As shown, the obtained ionic conductivity at room temperature is 5.1. 10 -4 S cm -1 .

[0055] Example 2 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte ZrCl4·0.8Li2O·0.2(LiOH·H2O) I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh ZrCl4, Li2O, and LiOH·H2O into a ball mill jar in the glove box, and tighten the jar to create an inert argon atmosphere. Ball mill at 450 rpm for 2 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.8Li2O·0.2(LiOH·H2O).

[0056] II. Testing of Lithium-ion Conductivity The test conditions were basically the same as in Example 1, and the obtained ionic conductivity at room temperature was 1.08. 10 -3 S cm -1 .

[0057] Example 3 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh the appropriate molar proportions of ZrCl4, Li3PO4, and Zr(SO4)2·4H2O into a ball mill jar in a glove box, tighten the jar, and ensure an inert argon atmosphere inside. Ball mill at 450 rpm for 2 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O).

[0058] II. Characterization of rapidly synthesizable chloride solid electrolytes X-ray diffraction (XRD) of the rapidly synthesizable chloride solid electrolyte prepared in this embodiment is as follows: Figure 3 As shown, the scanning electron microscope (SEM) image and X-ray energy dispersive spectroscopy (EDS) image are as follows. Figure 4 As shown, Zr, P, O, S, and Cl elements are uniformly distributed in the particles. In summary, this embodiment successfully obtained a rapidly synthesizable chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O).

[0059] III. Testing of Lithium-ion Conductivity The test conditions are basically the same as in Example 1, such as... Figure 5 As shown, the obtained ionic conductivity at room temperature is 4.17. 10 - 4 S cm -1 .

[0060] IV. Electrochemical Performance Testing 1. Preparation of a rapidly synthesizable chloride solid electrolyte composite cathode material: ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) The positive electrode material NCM92 and the rapidly synthesizable chloride solid electrolyte ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) were weighed at a mass ratio of 80:20, mixed in an agate mortar, and ground for 30 min to ensure uniform mixing, thus obtaining the composite positive electrode material.

[0061] 2. Assemble solid-state batteries: In a 10 mm diameter mold, 70 mg of Li6PS5Cl was first added and pressurized for 1 t, followed by 30 mg of ZrCl4·0.35Li3PO4·0.2(Zr(SO4)2·4H2O) and pressurized for another 1 t. Then, 8 mg of the composite cathode material was added to the positive electrode side (the side in contact with the chloride electrolyte) and pressurized for 3 t. Finally, a Li-In alloy was added to the negative electrode side (the side in contact with Li6PS5Cl) and pressurized for 1.5 t. The entire preparation process must be carried out in a glove box.

[0062] 3. Testing of all-solid-state batteries: The test temperature was 25 ℃, and the voltage range for the constant current charge-discharge test was 2.4~3.9 V. The charge-discharge curve of the all-solid-state battery at a charge-discharge rate of 0.1 C is shown below. Figure 6 As shown. The battery's discharge specific capacity at a 0.1 C rate is 206.2 mAh g. -1 .

[0063] Example 4 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte, ZrCl4·0.4Li3PO4·0.2(Zr(SO4)2·4H2O). I. Preparation of rapidly synthesizable chloride solid electrolytes The preparation steps are basically the same as in Example 3, except that different molar mass ratios are used.

[0064] II. Testing of Lithium-ion Conductivity The test conditions were basically the same as in Example 1, and the obtained ionic conductivity at room temperature was 5.7. 10 -4 S cm -1 .

[0065] Example 5 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte, ZrCl4·0.55Li3N·0.1(AlF3·3H2O). I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh ZrCl4, Li3N, and AlF3·3H2O into a ball mill jar in the glove box, and tighten the jar to create an inert argon atmosphere. Ball mill at 450 rpm for 3 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.55Li3N·0.1(AlF3·3H2O).

[0066] II. Testing of Lithium-ion Conductivity The test conditions were basically the same as in Example 1, and the obtained ionic conductivity at room temperature was 1.03. 10 -3 S cm -1 .

[0067] Example 6 Preparation and performance testing of a rapidly synthesizable chloride solid electrolyte ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O) I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh ZrCl4, Li3PO4, and AlF3·3H2O in the appropriate molar ratio into a ball mill jar in a glove box, tighten the jar, and ensure an inert argon atmosphere inside. Ball mill at 450 rpm for 3 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O).

[0068] II. Characterization of rapidly synthesizable chloride solid electrolytes X-ray diffraction (XRD) of the rapidly synthesizable chloride solid electrolyte prepared in this embodiment is as follows: Figure 7 As shown, the scanning electron microscope (SEM) image and X-ray energy dispersive spectroscopy (EDS) image are as follows. Figure 8 As shown, Zr, Al, P, O, F, and Cl elements are uniformly distributed in the particles. In summary, this embodiment successfully yielded a rapidly synthesizable chloride solid electrolyte, ZrCl4·0.55Li3PO4·0.2(AlF3·3H2O).

[0069] III. Testing of Lithium-ion Conductivity The test conditions were basically the same as in Example 1, and the test results were as follows: Figure 9 As shown, the obtained ionic conductivity at room temperature is 1.13. 10 -3 S cm -1 .

[0070] Example 7 Preparation and performance testing of a rapidly synthesized chloride solid electrolyte ZrCl4·0.35Li3PO4·0.15Li3N·0.05(FeSO4·7H2O) I. Preparation of rapidly synthesizable chloride solid electrolytes Accurately weigh the appropriate molar proportions of ZrCl4, Li3PO4, Li3N, and FeSO4·7H2O into a ball mill jar in a glove box, tighten the jar, and ensure an inert argon atmosphere inside. Ball mill at 450 rpm for 4 h to obtain the rapidly synthesized solid electrolyte ZrCl4·0.35Li3PO4·0.15Li3N·0.05(FeSO4·7H2O).

[0071] II. Testing of Lithium-ion Conductivity The test conditions were basically the same as in Example 1, and the obtained ionic conductivity at room temperature was 3.5. 10 -4 S cm -1 .

[0072] Comparative Example 1 This comparative example refers to Example 3, except that the raw materials were prepared according to the molar ratio of ZrCl4·0.35Li3PO4·0.02(Zr(SO4)2·4H2O) for the solid electrolyte; the other conditions were the same as in Example 3.

[0073] II. Lithium-ion conductivity and full-cell performance testing The EIS testing conditions were basically the same as in Example 3, and the obtained ionic conductivity at room temperature was 1.15. 10 -4 S cm -1 ,like Figure 10 As shown; the assembly and testing conditions of the full battery are basically the same as in Example 3, and the charge-discharge curve of the battery at a 0.1 C rate is shown below. Figure 11 As shown, the discharge specific capacity is 185.8 mAh g. -1 .

[0074] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A type of chloride solid electrolyte, characterized in that, The chloride solid electrolyte contains anions, cations, and water of crystallization, wherein, The anion includes Cl. - and at least one of the following ions: F - OH - O 2- CO3 2- S 2- SO4 2- PO4 3- N 3- NO3 3- ; The cation includes Zr. 4+ Li + and at least one of the following ions: H + Ca 2+ Cu 2+ Fe 2+ Mg 2+ Zn 2+ Na + Al 3+ Zr 4+ Fe 3+ Co 2+ Ba 2+ Mn 2+ .

2. The chloride solid electrolyte according to claim 1, characterized in that, The chemical formula of the chloride solid electrolyte is shown in formula (Ⅰ): ZrCl4· x Li a A· y M(Ⅰ) Where 0.2≤x≤1, 0.05≤y≤0.6; Li a A is one or more of Li3PO4, Li3N, Li2O, Li2S, LiCl, LiNO3, LiF, LiBr, and LiI; M is selected from crystalline hydrates; the crystalline hydrates are MnSO4·H2O, KAl(SO4)2·12H2O, CaSO4·2H2O, Zr(SO4)2·4H2O, CuSO4· n One, two, or more of the following: H2O, FeSO4·7H2O, MgSO4·7H2O, ZnSO4·7H2O, Na2SO4·10H2O, LiOH·H2O, Na2CO3·10H2O, AlF3·3H2O, FeCl3·6H2O, CoCl3·6H2O, BaCl2·2H2O, CaCl2·2H2O, Co(NO3)2·6H2O, and Al(NO3)3·9H2O; The ionic conductivity of the chloride solid electrolyte is greater than 2 × 10⁻⁶. -4 S cm -1 The electrochemical window of the chloride solid electrolyte is within 0~5 V.

3. The method for preparing the chloride solid electrolyte according to claim 1 or 2, characterized in that, The preparation method includes: weighing metal chloride, lithium salt and crystalline hydrate according to the stoichiometric ratio in the chloride solid electrolyte, mixing and grinding to obtain the chloride solid electrolyte.

4. The preparation method according to claim 3, characterized in that, The metal chloride is ZrCl4; The lithium salt is selected from Li a A is one, two or more of the following: Li3PO4, Li3N, Li2O, Li2S, LiCl, LiNO3, LiF, LiBr, and LiI; The crystalline hydrate is selected from MnSO4·H2O, KAl(SO4)2·12H2O, CaSO4·2H2O, Zr(SO4)2·4H2O, CuSO4· n One, two, or more of the following: H2O, FeSO4·7H2O, MgSO4·7H2O, ZnSO4·7H2O, Na2SO4·10H2O, LiOH·H2O, Na2CO3·10H2O, AlF3·3H2O, FeCl3·6H2O, CoCl3·6H2O, BaCl2·2H2O, CaCl2·2H2O, Co(NO3)2·6H2O, and Al(NO3)3·9H2O; The grinding process described is ball milling; the ball milling conditions are as follows: rotation speed 300~1000 rpm; time 0.1~10 h; The preparation method is carried out in an inert gas atmosphere.

5. The application of the chloride solid electrolyte according to claim 1 or 2 in the preparation of solid-state batteries.

6. A composite cathode material, characterized in that, The composite cathode material includes the chloride solid electrolyte, cathode active material, and conductive agent as described in claim 1 or 2; Preferably, the positive electrode active material is selected from LiFePO4, LiCoO2, LiNiO2, LiMn2O4, and LiNi 0.5 Mn 1.5 O4, Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O4, Li 1.2 Ni 0.2 Mn 0.6 O4, LiNi 0.6 Co 0.2 Mn 0.2 O4, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.9 Co 0.5 Mn 0.5 O4 and LiNi 0.92 Co 0.03 Mn 0.05 One, two, or more of the following: O2; Preferably, the conductive agent is selected from one or more of Super-P, superconducting carbon black, acetylene black and Ketjen black; Preferably, each 100 parts by weight of the composite cathode material comprises: 60-90 parts by weight of positive electrode active material 10-40 parts by weight of chloride solid electrolyte 0-6 parts by weight of conductive agent; Preferably, the mass ratio of the positive electrode active material, the chloride solid electrolyte, and the conductive agent is (60~90):(10~40):(0~6).

7. The method for preparing the composite cathode material according to claim 6, characterized in that it comprises the following steps: mixing the chloride solid electrolyte, the cathode active material and the conductive agent according to the mass ratio and then grinding or ball milling to obtain the composite cathode material.

8. An energy storage element comprising the chloride solid electrolyte of claim 1 or 2 and / or the composite cathode material of claim 6.

9. A solid-state battery, characterized in that, The solid-state battery includes a positive electrode, a solid electrolyte, and a negative electrode; wherein... The positive electrode is selected from the composite positive electrode material according to claim 7; The solid electrolyte is selected from the chloride solid electrolyte of claim 1 or 2, or a combination of the chloride solid electrolyte of claim 1 or 2 and the sulfide solid electrolyte. The negative electrode is selected from one of the following: metallic Li, Li-In alloy, and Si.

10. The method for preparing a solid-state battery according to claim 9, characterized in that, The method for preparing the solid-state battery includes: First, the solid electrolyte is pressed under pressure to form a solid electrolyte sheet. Then, the composite positive electrode material is placed on one side of the solid electrolyte sheet and pressed under pressure to form a positive electrode. The negative electrode material is placed on the other side of the solid electrolyte sheet and pressed under pressure to form a negative electrode. The solid battery is then assembled under pressure.

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