Biphasic halide solid-state electrolyte and preparation method and application in high-voltage, wide-temperature-range all-solid-state lithium battery

Abstract

This invention relates to a dual-phase symbiotic halide solid electrolyte, its preparation method, and its application in high-voltage, wide-temperature-range all-solid-state lithium batteries, belonging to the field of all-solid-state lithium battery technology. The electrolyte has a dual-phase symbiotic structure, with the general formula Li₂. a M m N n X b Where M and N include one or more metal cations, X is one or more of F, Cl, Br, I, N, O, and S, and a>0, 0 <m≤1,0<n≤1,b> The electrolyte comprises a dispersed nanocrystalline phase and a continuous amorphous phase, with chemical symbiosis at the interface between the two phases. Its preparation method is a one-step high-energy ball milling process, which is simple. This electrolyte exhibits high ionic conductivity (≥1.0 mS / cm at room temperature), ultra-high voltage stability (>4.8 V), and wide temperature range adaptability (-60°C to 55°C). All-solid-state lithium batteries assembled with this electrolyte demonstrate high specific capacity and ultra-long cycle stability under extreme conditions of 4.8V high voltage and high and low temperatures, showing promising commercial potential.

Description

Technical Field

[0001] This invention relates to lithium-ion battery materials, specifically to a method for preparing a two-phase symbiotic halide electrolyte and its application in all-solid-state lithium batteries, belonging to the field of all-solid-state lithium battery technology. Background Technology

[0002] With the rapid development of electric vehicles and other fields, higher demands are being placed on the energy density, safety, and environmental adaptability of lithium-ion batteries. All-solid-state lithium batteries, using non-flammable solid electrolytes, hold the promise of solving the safety hazards of traditional liquid electrolytes and achieving higher energy densities. The solid electrolyte is the core component of all-solid-state batteries; its ionic conductivity, electrochemical stability, and interfacial compatibility with the electrodes directly determine battery performance.

[0003] Currently, mainstream solid electrolytes include polymer, oxide, and sulfide systems, but each has significant drawbacks. Polymer electrolytes have low ionic conductivity at room temperature and poor high-temperature stability; oxide electrolytes have acceptable ionic conductivity but are brittle and have high interfacial impedance; sulfide electrolytes have high ionic conductivity but a narrow electrochemical window, are prone to reacting with high-voltage cathodes, and are unstable in air. Halide solid electrolytes have attracted attention due to their combination of high ionic conductivity, a moderate electrochemical stability window, and good deformability. However, single crystalline halide electrolytes exhibit severe ionic conductivity decay at low temperatures, while single amorphous halide electrolytes are prone to oxidative decomposition at high voltages, making it difficult to simultaneously meet the requirements of high-voltage, wide-temperature-range (especially low-temperature) applications.

[0004] Therefore, developing a solid electrolyte that combines high ionic conductivity, excellent high voltage stability, and wide temperature range performance is crucial for advancing the practical application of all-solid-state lithium batteries. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art and provide a solid electrolyte with a "dual-phase symbiotic" structure, its preparation method, and its application in high-voltage, wide-temperature-range all-solid-state batteries.

[0006] This electrolyte achieves a room-temperature ionic conductivity ≥1 mS / cm through a chemical symbiosis process, combining a nanocrystalline phase with high voltage stability with an amorphous phase possessing low-energy-barrier ion transport channels. This allows it to be compatible with a variety of commercially available cathode materials (such as LiCoO2 and LiNi). 0.8 Co 0.1 Mn 0.1 O2, etc.), with ultra-high voltage compatibility (up to 4.8 V vs. Li). + It also boasts excellent all-weather (-60°C to 55°C) performance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a two-phase co-existing halide solid electrolyte having the general structural formula Li a M m N n X b The electrolyte has a biphase coexisting structure, comprising a dispersed nanocrystalline phase and a continuous amorphous phase; wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La; N is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La; X is one or more of F, Cl, Br, I, N, O, and S; and a>0, 0 <m≤1,0<n≤1,b> 0; Preferably, the nanocrystalline phase is Li-MX phase, and the amorphous phase is Li-NX phase.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned dual-phase symbiotic halide solid electrolyte, which is synthesized in one step by high-energy ball milling, specifically including the following steps:

[0010] (1) Weigh the lithium source, M source and N source containing X according to the stoichiometric ratio of the general formula;

[0011] The lithium source containing X is selected from one or more of lithium oxide, lithium chloride, lithium hydroxide, lithium peroxide, lithium fluoride, lithium sulfide, and lithium nitride.

[0012] The M source is selected from one or more of magnesium chloride, calcium chloride, ferric chloride, strontium chloride, aluminum chloride, zirconium chloride, hafnium chloride, scandium chloride, indium chloride, tantalum chloride, niobium chloride, yttrium chloride, and lanthanum chloride;

[0013] The N source is selected from one or two of aluminum chloride and indium chloride;

[0014] (2) Under the protection of an inert atmosphere, the raw materials weighed in step (1) are mixed evenly and then subjected to high-energy ball milling; the ball milling speed is 400-600 rpm, the ball milling time is 20-50h, and the ball-to-material ratio is 1:30-1:50.

[0015] (3) After ball milling, the biphase symbiotic halide solid electrolyte powder is obtained.

[0016] Thirdly, the present invention provides an application of a dual-phase symbiotic halide solid electrolyte in a high-voltage, wide-temperature-range all-solid-state lithium battery. The all-solid-state lithium battery comprises a positive electrode, a negative electrode, a solid electrolyte layer located between the positive and negative electrodes, and a protective layer. The solid electrolyte layer comprises the aforementioned dual-phase symbiotic halide solid electrolyte or a dual-phase symbiotic halide solid electrolyte prepared by the aforementioned method.

[0017] Advantages and beneficial effects of the present invention:

[0018] The biphase symbiotic halide solid electrolyte provided by this invention exhibits high ionic conductivity, ultra-high voltage stability, and excellent all-weather performance. Its room temperature ionic conductivity is ≥1 mS / cm, and its low activation energy is beneficial for low-temperature operation; its electrochemical stability window exceeds 4.8 V, making it directly compatible with LiCoO2 and LiNi. 0.8 Co 0.1 Mn 0.1 High-voltage oxide cathodes such as O2 are used. All-solid-state lithium batteries assembled with these cathodes exhibit excellent cycle stability in an extreme temperature range of -60°C to 55°C. In particular, they can maintain 100% capacity retention for more than 120 cycles under the dual extreme conditions of -60°C and 4.8 V. At the same time, they show a cycle retention of more than 91% at 4.6 V and long life characteristics at high rates.

[0019] This invention achieves the controllable synthesis of a chemically coexisting structure of nanocrystalline and amorphous phases in one step using a high-energy ball milling method. The ball milling process is simple and efficient, requiring no complex post-processing and facilitating large-scale production. The unique dual-phase coexisting structure forms a near-seamless interface by in-situ embedding high-voltage stable nanocrystals into a highly ion-conducting amorphous matrix, effectively reducing the phase boundary impedance of traditional composite materials and achieving a synergistic enhancement effect of "1+1>2".

[0020] The raw materials used in this invention are widely available and inexpensive, and the preparation process has good repeatability. The resulting electrolyte is compatible with a variety of commercially available high-voltage cathode materials, demonstrating broad application prospects. This invention not only provides a novel material design approach and feasible technical solution for developing high-performance halide solid-state electrolytes, but also lays a solid material foundation for realizing next-generation all-solid-state lithium batteries with high energy density, high safety, and all-weather applicability. Attached Figure Description

[0021] Figure 1 The X-ray diffraction (XRD) pattern of the biphase symbiotic halide solid electrolyte prepared in Example 1 of this invention.

[0022] Figure 2 This is a high-resolution transmission electron microscope (HR-TEM) image of the biphase symbiotic halide solid electrolyte prepared in Example 1 of the present invention.

[0023] Figure 3 The graph shows the cycle performance of the all-solid-state lithium battery assembled in Embodiment 1 of the present invention at high voltage (4.8 V).

[0024] Figure 4The graph shows the cycle performance of the all-solid-state lithium battery assembled in Example 1 of this invention at high temperature (55 °C).

[0025] Figure 5 The graph shows the cycle performance of the all-solid-state lithium battery assembled in Example 1 of this invention at low temperature (-60 °C).

[0026] Figure 6 This is a graph showing the long-cycle performance of the all-solid-state lithium battery assembled in Embodiment 1 of the present invention at high rate (10 C).

[0027] Figure 7 Example 1 of the present invention and LiNi 0.8 Co 0.1 Mn 0.1 Cyclic performance of an all-solid-state lithium battery with O2 cathode matching under high voltage. Detailed Implementation

[0028] The following specific embodiments, in conjunction with the accompanying drawings, further illustrate the present invention. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from its spirit and essence are within the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0029] Example 1:

[0030] This embodiment provides a biphase symbiotic halide electrolyte Li2Ta 0.52 Al 0.8 Cl5O, the specific preparation method is as follows:

[0031] Weigh out the corresponding masses of lithium oxide, tantalum chloride, and aluminum chloride according to a molar ratio of 1:0.52:0.8, and mix the above raw materials evenly. In a glove box filled with argon, add the above raw materials to a zirconium dioxide ball mill jar and add zirconium dioxide grinding beads with a diameter of 5~10mm and a ball-to-material ratio of 1:50.

[0032] The raw materials were first ball-milled at a low speed of 150 r / min for 1 h to ensure uniform mixing, and then ball-milled at a high speed of 550 r / min for 32 h. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-1.

[0033] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0034] Example 2:

[0035] This embodiment provides a biphase symbiotic halide electrolyte Li2Ta 0.2 Al 0.8 Cl 3.4 O, the specific preparation method is as follows:

[0036] Weigh out the corresponding masses of lithium oxide, tantalum chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:50.

[0037] The raw materials were first ball-milled at a low speed of 150 r / min for 1 h to ensure uniform mixing, and then ball-milled at a high speed of 550 r / min for 32 h. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-2.

[0038] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0039] Example 3:

[0040] This embodiment provides a biphase symbiotic halide electrolyte Li2Zr 0.2 Al 0.8 Cl4O, the specific preparation method is as follows:

[0041] Weigh out the corresponding masses of lithium oxide, zirconium chloride, and aluminum chloride according to a molar ratio of 1:0.4:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0042] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-3.

[0043] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0044] Example 4:

[0045] This embodiment provides a biphase symbiotic halide electrolyte Li2In 0.2 Al 0.8 Cl3O, the specific preparation method is as follows:

[0046] Weigh out the corresponding masses of lithium oxide, indium chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0047] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a two-phase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-4.

[0048] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0049] Example 5:

[0050] This embodiment provides a biphase symbiotic halide electrolyte Li2Nb 0.2 Al 0.8 Cl 3.2 O, the specific preparation method is as follows:

[0051] Weigh out the corresponding masses of lithium oxide, niobium chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0052] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-5.

[0053] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0054] Example 6:

[0055] This embodiment provides a biphase symbiotic halide electrolyte Li2Y.0.2 Al 0.8 Cl3O, the specific preparation method is as follows:

[0056] Weigh out the corresponding masses of lithium oxide, yttrium chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5~10mm and a ball-to-material ratio of 1:40.

[0057] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-6.

[0058] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0059] Example 7:

[0060] This embodiment provides a biphase symbiotic halide electrolyte Li2Fe 0.2 Al 0.8 Cl3O, the specific preparation method is as follows:

[0061] Weigh out the corresponding masses of lithium oxide, ferric chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5~10mm and a ball-to-material ratio of 1:40.

[0062] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-7.

[0063] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0064] Example 8:

[0065] This embodiment provides a biphase symbiotic halide electrolyte Li2Zr 0.4 In 0.8 Cl 4.8O, the specific preparation method is as follows:

[0066] Weigh out the corresponding masses of lithium oxide, zirconium chloride, and indium chloride according to a molar ratio of 1:0.4:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0067] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-8.

[0068] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0069] Example 9:

[0070] This embodiment provides a biphase symbiotic halide electrolyte Li2Zr 0.2 In 0.8 Cl 3.2 O, the specific preparation method is as follows:

[0071] Weigh out the corresponding masses of lithium oxide, indium chloride, and aluminum chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0072] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a biphase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-9.

[0073] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0074] Example 10:

[0075] This embodiment provides a biphase symbiotic halide electrolyte Li2Ta 0.2 In 0.8 Cl 3.4 O, the specific preparation method is as follows:

[0076] Weigh out the corresponding masses of lithium oxide, tantalum chloride, and indium chloride according to a molar ratio of 1:0.2:0.8. Mix the above raw materials evenly; add the above raw materials to a zirconium dioxide ball mill jar in an argon-filled glove box, and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:40.

[0077] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 500 rpm for 24 hours. The final product was a two-phase co-existing halide solid electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-10.

[0078] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0079] Comparative Example 1

[0080] This comparative example provides an amorphous phase halide electrolyte Li₂TaCl₅O, and the specific preparation method is as follows:

[0081] Weigh out the appropriate amounts of lithium oxide and tantalum chloride at a molar ratio of 1:1. Mix the above raw materials thoroughly; in an argon-filled glove box, add the above raw materials to a zirconium dioxide ball mill jar and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:50.

[0082] The raw materials were first ball-milled at a low speed of 150 rpm for 1 hour to ensure uniform mixing, and then ball-milled at a high speed of 550 rpm for 32 hours. The final product was an amorphous halide electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was removed from the glove box and labeled SSE-11.

[0083] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0084] Comparative Example 2

[0085] This comparative example provides a crystalline halide electrolyte, LiAlCl4, and the specific preparation method is as follows:

[0086] Weigh out the appropriate amounts of lithium chloride and aluminum chloride according to a molar ratio of 1:1. Mix the above raw materials evenly; in an argon-filled glove box, add the above raw materials to a zirconium dioxide ball mill jar and add zirconium dioxide grinding beads with a diameter of 5-10 mm and a ball-to-material ratio of 1:50.

[0087] The raw materials were first ball-milled at a low speed of 150 r / min for 1 h to ensure uniform mixing, and then ball-milled at a high speed of 550 r / min for 32 h. The final product was a crystalline halide electrolyte powder sample with the corresponding chemical formula. After ball milling, the sample was heated to 300 °C at a heating rate of 2 °C / min in a glove box and calcined for 5 h. It was then allowed to cool naturally to room temperature, removed from the glove box, and labeled SSE-12.

[0088] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, a prepared halide solid electrolyte as the electrolyte, Li6PS5Cl as the protective layer, and Li-In alloy as the negative electrode.

[0089] Structural characterization

[0090] Characterization of SSE-1 obtained in Example 1: XRD pattern ( Figure 1 The image shows predominantly amorphous peaks in a bun-like shape, accompanied by weak LiAlCl4 crystalline phase diffraction peaks. HR-TEM image ( Figure 2 The images clearly show that LiAlCl4 nanocrystals with a size of 5-10 nm are uniformly dispersed in the amorphous matrix, and the two phase interfaces are fused without clear physical boundaries, confirming the "chemical symbiosis" structure.

[0091] All-solid-state battery assembly and performance testing

[0092] With LiCoO2 or LiNi 0.8 Co 0.1 Mn 0.1 O2 is the positive electrode active material. The solid electrolyte prepared in the above embodiment is used as the positive electrode composite electrolyte and the separator layer electrolyte. Li6PS5Cl is used as the negative electrode interface protection layer. Li-In alloy is used as the negative electrode. The battery is assembled into a 2032 type coin cell all-solid-state battery in an argon atmosphere glove box.

[0093] (1) Ionic conductivity test: 80-150 mg of electrolyte powder was compressed into tablets (10 mm in diameter, 300 MPa pressure) and tested using an electrochemical workstation via AC impedance spectroscopy. Ionic conductivity was calculated using the formula... Calculate, where: : Ionic conductivity of solid electrolytes; The thickness of a solid electrolyte sample is typically the distance between the two electrodes. The resistance of solid electrolytes can be measured by electrochemical methods such as AC impedance spectroscopy. : The effective contact area between the electrode and the solid electrolyte.

[0094] (2) Battery electrochemical performance test: Using a battery testing system, charge-discharge cycle test and rate performance test are performed at specified temperatures (-60°C, 25°C, 55°C) and voltage windows.

[0095] Test Results

[0096] Table 1: Room temperature ionic conductivity of electrolytes prepared in different embodiments and comparative examples, and corresponding cycle performance of all-solid-state batteries (LCO cathode, 3.0-4.6V, 0.5C, 25°C).

[0097] Table 1

[0098] Sample number Electrical conductivity (mS / cm) Capacity retention rate (%) SSE-1 2.5 94 SSE-2 2.0 91 SSE-3 1.5 89 SSE-4 1.2 88 SSE-5 1.1 86 SSE-6 1.2 88 SSE-7 1.6 89 SSE-8 1.5 88 SSE-9 1.3 87 SSE-10 1.4 85 SSE-11 3.6 60 SSE-12 <![CDATA[3.8×10 -4 ]]> 0

[0099] Comprehensive performance analysis (taking SSE-1 as an example):

[0100] High voltage performance ( Figure 3 ): Within the 3.0-4.8 V window, after 100 cycles at 0.5C, the capacity retention rate reaches 90.5%.

[0101] High temperature performance ( Figure 4 ): After 150 cycles at 55°C, 3.0-4.6 V window, and 3C rate, the capacity retention rate reaches 80.7%.

[0102] Low temperature performance ( Figure 5 ): It can be cycled 120 times at -60°C, 3.0-4.8 V window, and 0.1C rate with 100% capacity retention and stable operation for more than 1800 hours.

[0103] High-rate performance ( Figure 6 ): After 2000 cycles at 10C ultra-high rate, the capacity retention rate still reaches 81.7%.

[0104] Universality verification ( Figure 7 ): When matched with the NMC811 positive electrode, the capacity retention rate reaches 80.2% after 500 cycles at 1C in the 2.8-4.8V window.

[0105] The above results demonstrate that the dual-phase symbiotic halide solid electrolyte and its preparation method provided by this invention successfully solve the problem of performance imbalance in single-phase halide electrolytes, and provide a key electrolyte material solution for realizing high energy density, high safety, and all-weather applicable all-solid-state lithium batteries.

Claims

1. A dual cation halide solid state electrolyte, characterized in that, The general structural formula is Li a M m N n X b The electrolyte has a biphase coexisting structure, comprising a dispersed nanocrystalline phase and a continuous amorphous phase; wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La; N is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La; X is one or more of F, Cl, Br, I, N, O, and S; and a>0, 0 <m≤1,0<n≤1,b> 0.

2. The dual-phase, halide solid-state electrolyte of claim 1, wherein, The nanocrystalline phase is Li-MX phase, and the amorphous phase is Li-NX phase.

3. The method of producing a dual solid state electrolyte halide according to claim 1 or 2, characterized in that, The one-step synthesis using high-energy ball milling includes the following steps: (1) Weigh the lithium source, M source and N source containing X according to the stoichiometric ratio of the general formula; (2) Under the protection of an inert atmosphere, the raw materials weighed in step (1) are mixed evenly and then subjected to high-energy ball milling; the ball milling speed is 400-600 rpm, the ball milling time is 20-50h, and the ball-to-material ratio is 1:30-1:

50. (3) After ball milling, the biphase symbiotic halide solid electrolyte powder is obtained.

4. The method of making a dual-phase, halide solid-state electrolyte of claim 3, wherein, The lithium source containing X is selected from one or more of lithium oxide, lithium chloride, lithium hydroxide, lithium peroxide, lithium fluoride, lithium sulfide, and lithium nitride. The M source is selected from one or more of magnesium chloride, calcium chloride, ferric chloride, strontium chloride, aluminum chloride, zirconium chloride, hafnium chloride, scandium chloride, indium chloride, tantalum chloride, niobium chloride, yttrium chloride, and lanthanum chloride; The N source is selected from one or both of aluminum chloride and indium chloride.

5. The application of the dual-phase symbiotic halide solid electrolyte as described in claim 1 or 2, or the dual-phase symbiotic halide solid electrolyte prepared by the method described in claim 3 or 4, in high-voltage, wide-temperature-range all-solid-state lithium batteries.

6. Use according to claim 5, characterized in that, The all-solid-state lithium battery comprises a positive electrode, a negative electrode, a solid electrolyte layer located between the positive electrode and the negative electrode, and a protective layer. The solid electrolyte layer comprises the biphase symbiotic halide solid electrolyte as described in claim 1 or 2, or the biphase symbiotic halide solid electrolyte prepared by the method described in claim 3 or 4.

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