WO2023024266A1

WO2023024266A1 - Coated sulfide solid electrolyte and preparation method therefor and use thereof

Info

Publication number: WO2023024266A1
Application number: PCT/CN2021/129082
Authority: WO
Inventors: 岳敏; 陈杰; 杨凯; 王倩; 钱超
Original assignee: 深圳市研一新材料有限责任公司
Priority date: 2021-08-27
Filing date: 2021-11-05
Publication date: 2023-03-02
Also published as: CN113745651B; CN113745651A

Abstract

The present invention relates to the field of solid batteries, and specifically to a coated sulfide solid electrolyte and a preparation method therefor and the use thereof. Provided is a coated sulfide solid electrolyte, which is a coated sulfide solid electrolyte having an oxide solid electrolyte layer covering the surfaces of sulfide solid electrolyte particles. A specific oxide solid electrolyte is coated on the surface of a sulfide solid electrolyte to obtain the coated sulfide solid electrolyte. The oxide solid electrolyte layer thereof has a relatively high ion conductivity and a high chemical stability, and is insensitive to moisture in the air, and has a good electrochemical stability and inhibits the formation of space charges when mixed with high voltage anode materials, which successfully solves the problems of poor water stability of sulfide solid electrolytes and the mismatch of electrochemical windows when sulfide solid electrolytes are mixed with anode materials.

Description

一种包覆型硫化物固态电解质及其制备方法和应用A kind of coated sulfide solid electrolyte and its preparation method and application

技术领域technical field

本发明涉及固态电池领域，具体涉及一种包覆型硫化物固态电解质及其制备方法和应用。The invention relates to the field of solid-state batteries, in particular to a coated sulfide solid-state electrolyte and a preparation method and application thereof.

背景技术Background technique

伴随着便携式移动电子设备的快速发展、新能源汽车的普及应用以及智能电网的建设，人们对于高效储能设备的需求愈加强烈。锂离子电池凭借着能量密度高、无记忆效应、工作电压高、循环寿命长的优点，已经成为现有储能设备中的主力。目前，商业化的锂离子电池使用的是酯类或醚类有机液态电解液，这类电解液在使用过程中易挥发、易分解、容易发生泄露等，严重影响电池的使用寿命，同时，有机电解液在电化学循环过程中容易与电极材料发生副反应，产生胀气，存在着火***等安全隐患。另外，为了获得高能量密度，采用金属锂作为锂离子电池负极材料具有应用前景，但是，在充放电过程中，金属锂在液态电解质中容易生长锂枝晶，锂枝晶可能会穿刺隔膜并导致短路、着火、甚至***。With the rapid development of portable mobile electronic devices, the popularization and application of new energy vehicles and the construction of smart grids, people's demand for high-efficiency energy storage devices is becoming stronger and stronger. With the advantages of high energy density, no memory effect, high working voltage and long cycle life, lithium-ion batteries have become the main force of existing energy storage devices. At present, commercial lithium-ion batteries use ester or ether organic liquid electrolytes, which are volatile, easy to decompose, and prone to leakage during use, which seriously affects the service life of the battery. At the same time, organic The electrolyte is prone to side reactions with the electrode materials during the electrochemical cycle, resulting in flatulence, fire and explosion and other safety hazards. In addition, in order to obtain high energy density, the use of metal lithium as the anode material of lithium-ion batteries has application prospects. However, during the charging and discharging process, metal lithium is prone to grow lithium dendrites in the liquid electrolyte, and lithium dendrites may puncture the separator and cause short circuit, catch fire, or even explode.

相比于液态电解质，固态电解质具有不发挥、不易燃、无腐蚀、机械强度大等优点，避免了传统液态锂离子电池中的电解液泄露、电极短路等现象，降低了电池组对于温度的敏感性，由于固态电解质机械强度大，可以有效地阻挡锂枝晶生长，在使用过程中具有极高的安全性。Compared with liquid electrolytes, solid electrolytes have the advantages of non-combustibility, non-flammability, non-corrosion, and high mechanical strength, which avoids electrolyte leakage and electrode short circuits in traditional liquid lithium-ion batteries, and reduces the sensitivity of the battery pack to temperature. Due to the high mechanical strength of the solid-state electrolyte, it can effectively prevent the growth of lithium dendrites, and has extremely high safety during use.

目前，固态电解质主要包括氧化物、硫化物、聚合物固态电解质，其中，氧化物固态电解质对环境不敏感，耐水耐氧性能优异，具有较稳定的物理化学性质，但电导率较低。聚合物固态电解质由极性高分子和金属盐络合形成，具有良好的成膜性，可弯曲和高安全性能，但电导率较低，锂离子的迁移数较小，机械性能较差。硫化物固态电解质具有媲美于液态电解质溶液的离子电导率，锂离子迁移数接近于1，电解质与电极材料浸润性好，适用于高能量密度储能器件，成为发展全固态电池中非常有希望的技术路线之一。At present, solid electrolytes mainly include oxides, sulfides, and polymer solid electrolytes. Among them, oxide solid electrolytes are not sensitive to the environment, have excellent water and oxygen resistance, and have relatively stable physical and chemical properties, but low conductivity. Polymer solid electrolyte is formed by the complexation of polar polymers and metal salts. It has good film-forming properties, flexibility and high safety performance, but has low conductivity, small migration number of lithium ions, and poor mechanical properties. The sulfide solid electrolyte has an ionic conductivity comparable to that of a liquid electrolyte solution, the lithium ion migration number is close to 1, and the electrolyte and electrode materials have good wettability. It is suitable for high energy density energy storage devices and has become a very promising candidate for the development of all-solid-state batteries. One of the technical routes.

然而，硫化物固态电解质对水、氧尤其敏感，在制备与使用过程中对环境的要求极为苛刻，严重限制了它的规模化应用，另外，硫化物固态电解质与高压正极材料的电化学窗口不匹配，往往在界面处产生较大的阻抗及多种分解产物，形成空间电荷层；此外，硫化物与金属锂负极接触时发生反应，生成导离子性较差的物质，不利于锂离子的迁移，硫化物固态电解质面临的这些问题极大地影响全固态电池的性能。However, sulfide solid-state electrolytes are particularly sensitive to water and oxygen, and the environmental requirements during preparation and use are extremely harsh, which severely limits its large-scale application. In addition, the electrochemical window of sulfide solid-state electrolytes and high-voltage cathode materials is not good. Matching, often produces a large impedance and a variety of decomposition products at the interface, forming a space charge layer; in addition, when the sulfide contacts with the lithium metal negative electrode, it reacts to form a substance with poor ion conductivity, which is not conducive to the migration of lithium ions , these problems faced by sulfide solid-state electrolytes greatly affect the performance of all-solid-state batteries.

中国专利CN111864256A公开了一种硫化物固态电解质及全固态锂二次电池，该发明的硫化物固态电解质是一种玻璃相与晶相均匀混合的玻璃陶瓷固态电解质，将Li ₂S、P ₂S ₅、M _xS ₂O ₃(M选自Na、K、Ba以及Ca中的一种或几种，1≤x≤2)按照比例混合，在150-450℃进行热处理，从而获得该发明的硫化物固态电解质。在全固态锂二次电池的制备过程中，正极膜片是通过将正极活性材料与该发明的硫化物固态电解质混合压制成层状得到。该工艺制备的硫化物固态电解质对水仍然较为敏感，且正极膜片中将硫化物固态电解质与高压正极活性材料直接混合，由于电化学窗口的不匹配，在电化学循环过程中，会发生较多的副反应；其次，正极膜片的制备需要在惰性气氛下进行，这大大增加了其制备成本，且不利于工业上大规模生产。 Chinese patent CN111864256A discloses a sulfide solid electrolyte and an all-solid lithium secondary battery. The sulfide solid electrolyte of the invention is a glass ceramic solid electrolyte in which a glass phase and a crystal phase are evenly mixed. Li ₂ S, P ₂ S _5. M _x S ₂ O ₃ (M is selected from one or more of Na, K, Ba and Ca, 1≤x≤2) are mixed in proportion, and heat-treated at 150-450°C to obtain the invention Sulfide solid electrolyte. In the preparation process of the all-solid-state lithium secondary battery, the cathode membrane is obtained by mixing and pressing the cathode active material and the sulfide solid electrolyte of the invention into layers. The sulfide solid electrolyte prepared by this process is still relatively sensitive to water, and the sulfide solid electrolyte is directly mixed with the high-voltage positive electrode active material in the positive electrode diaphragm. There are many side reactions; secondly, the preparation of the positive electrode membrane needs to be carried out under an inert atmosphere, which greatly increases its preparation cost and is not conducive to large-scale industrial production.

中国专利CN112203975A公开了一种硫化物固体电解质和电池，该发明涉及一种可用作锂二次电池等的固态电解质，其具有即使接触大气中的水分也能够抑制硫化氢气体产生的特性，其包含锂元素、磷元素、硫元素和卤素，并且具有硫银锗矿型结构的结晶相或者化合物。该工艺制备的硫化物固态电解质无法有效隔绝水分，在使用与存储过程中对水分仍然比较敏感，在湿度较低的环境中，仍产生大量硫化氢气体。使用该硫化物固态电解质组装电池时，无法有效抑制其与高压正极材料之间的界面问题。Chinese patent CN112203975A discloses a sulfide solid electrolyte and a battery. The invention relates to a solid electrolyte that can be used as a lithium secondary battery, etc., which has the property of suppressing the generation of hydrogen sulfide gas even when exposed to moisture in the atmosphere. A crystalline phase or compound containing lithium, phosphorus, sulfur and halogen, and having argentite structure. The sulfide solid electrolyte prepared by this process cannot effectively isolate moisture, and is still sensitive to moisture during use and storage, and still produces a large amount of hydrogen sulfide gas in an environment with low humidity. When a battery is assembled using the sulfide solid electrolyte, the interface problem between it and the high-voltage positive electrode material cannot be effectively suppressed.

中国专利CN111740152A公开了一种高性能的硫化物固态电解质及其制备方法，该发明提供一种具有高离子电导率和低电子电导率的高性能硫化物固态电解质，其中，通过将两种或者三种原料按照一定的摩尔比例混合，进行球磨和烧结，在这两个过程中在惰性气氛下进行，得到结构通式为(100-x)Li ₂P·xP ₂S ₅·yM的硫化物固态电解质，其中M为氧化锌、五氧化二磷、氟化锂、氯化锂。该发明通过往硫化物固态电解质中掺杂氧元素、氟元素或者氯元素来提升固态电解质的化学稳定性。但是，该工艺获得的硫化物固态电解质在使用与存储时对气氛要求仍然很高，氧含量不大于0.1ppm，水含量不大于0.1ppm，这样苛刻的低露点环境使得该硫化物固态电解质产业化困难。 Chinese patent CN111740152A discloses a high-performance sulfide solid-state electrolyte and its preparation method. The invention provides a high-performance sulfide solid-state electrolyte with high ionic conductivity and low electronic conductivity, wherein two or three The two raw materials are mixed according to a certain molar ratio, ball milled and sintered, and the two processes are carried out under an inert atmosphere to obtain a sulfide solid with the general structure of (100-x)Li ₂ P·xP ₂ S ₅ ·yM Electrolyte, wherein M is zinc oxide, phosphorus pentoxide, lithium fluoride, lithium chloride. The invention improves the chemical stability of the solid-state electrolyte by doping oxygen, fluorine or chlorine into the sulfide solid-state electrolyte. However, the sulfide solid electrolyte obtained by this process still has high requirements on the atmosphere during use and storage, the oxygen content is not more than 0.1ppm, and the water content is not more than 0.1ppm. Such a harsh low dew point environment makes the sulfide solid electrolyte industrialization difficulty.

中国专利CN111908437A公开了一种硫化物固态电解质的制备方法，该发明通过将Li ₂S、P ₂S ₅和卤化物的锂盐通过化学计量比混合、研磨、筛分，从而获得混合均匀的前驱体，然后将前驱体放置于微波设备中的陶瓷震动槽内震动翻转，在150-400℃下微波烧结10min-1h，冷却后得到含元素锂、磷、硫和卤素的硫银锗矿型固态电解质。该发明的硫化物固态电解质虽然有较高的离子电导率，但是，在空气中极其不稳定，限制了该固态电解质的实际应用。 Chinese patent CN111908437A discloses a preparation method of a sulfide solid electrolyte. The invention obtains a uniformly mixed precursor by mixing Li ₂ S, P ₂ S ₅ and lithium salts of halides through stoichiometric ratio, grinding and sieving Then place the precursor in the ceramic vibrating tank in the microwave equipment, vibrate and turn over, microwave sintering at 150-400°C for 10min-1h, and after cooling, obtain argentite-type solid state containing elements lithium, phosphorus, sulfur and halogen electrolyte. Although the sulfide solid electrolyte of the invention has high ion conductivity, it is extremely unstable in air, which limits the practical application of the solid electrolyte.

中国专利CN109509910A公开了一种复合型固态电解质及其制备方法，该发明通过在硫化物固态电解质表面复合非晶态氧化物固态电解质，从而改善硫化物固态电解质与电极材料之间的界面问题。该发明的复合型固态电解质并未解决硫化物固态电解质对湿度、氧气稳定性差的问题，而且在组装电池测试时，正极片制备过程中，无法避免正极材料与硫化物固态电解质的电压不匹配问题，严重影响循环稳定性。Chinese patent CN109509910A discloses a composite solid electrolyte and its preparation method. The invention improves the interface problem between the sulfide solid electrolyte and the electrode material by compounding the amorphous oxide solid electrolyte on the surface of the sulfide solid electrolyte. The composite solid electrolyte of the invention does not solve the problem of poor stability of the sulfide solid electrolyte to humidity and oxygen, and when the battery is assembled and tested, the voltage mismatch between the positive electrode material and the sulfide solid electrolyte cannot be avoided during the preparation of the positive electrode sheet. , seriously affecting the cycle stability.

发明内容Contents of the invention

发明要解决的问题：提高硫化物固态电解质对水稳定性，改善硫化物固态电解质与正极材料混合使用时电化学窗口的匹配度。The problem to be solved by the invention is to improve the stability of the sulfide solid electrolyte to water, and improve the matching degree of the electrochemical window when the sulfide solid electrolyte is mixed with positive electrode materials.

针对上述问题，本发明的目的之一是提供一种稳定性高的包覆型硫化物固态电解质,该包覆型硫化物固态电解质可以有效地提升硫化物固态电解质的对水稳定性以及与正负极材料混合使用时的电化学稳定性；本发明的目的之二是提供上述包覆型硫化物固态电解质的制备方法；本发明的目的之三是提供上述包覆型硫化物固态电解质在固态电池中的应用；本发明的目的之四是提供一种含有上述包覆型硫化物固态电解质的固态电池。In view of the above problems, one of the objects of the present invention is to provide a highly stable coated sulfide solid electrolyte, which can effectively improve the water stability of the sulfide solid electrolyte and the compatibility with normal electrolytes. Electrochemical stability when negative electrode materials are mixed and used; the second object of the present invention is to provide the preparation method of the above-mentioned coated sulfide solid electrolyte; the third object of the present invention is to provide the above-mentioned coated sulfide solid electrolyte in a solid state Application in batteries; the fourth object of the present invention is to provide a solid-state battery containing the above-mentioned coated sulfide solid-state electrolyte.

为了解决所述问题，本发明的技术方案如下：In order to solve the problem, the technical solution of the present invention is as follows:

一种包覆型硫化物固态电解质，其为氧化物固态电解质层包覆在硫化物固态电解质颗粒表面的包覆型硫化物固态电解质；A coated sulfide solid electrolyte, which is a coated sulfide solid electrolyte in which an oxide solid electrolyte layer is coated on the surface of sulfide solid electrolyte particles;

所述氧化物固态电解质为LiNb _xTa _1-xO ₃(0.15≤x≤0.85)型、LiPON型和 NASICON型中的至少一种。 The oxide solid electrolyte is at least one of LiNb _x Ta _1-x O ₃ (0.15≤x≤0.85) type, LiPON type and NASICON type.

优选的是，所述LiPON型为Li _3.3PO _3.9N _0.17，进一步优选地，所述NASICON型为Li _1.4Al _0.4Ti _1.6(PO ₄) ₃。 Preferably, the LiPON type is Li _3.3 PO _3.9 N _0.17 , and more preferably, the NASICON type is Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ .

优选的是，所述硫化物固态电解质为(1+x)Li ₂S·xP ₂S ₅(0＜x＜1)型、Li _6-yPS _5-yX _1+y(X＝Cl、Br、I，0≤y≤0.6)型和Li _11-zM _2-zP _1+zS ₁₂(M＝Ge、Sn、Si，0.5≤z≤1.5)型中的至少一种。 Preferably, the sulfide solid electrolyte is (1+x) Li ₂ S·xP ₂ S ₅ (0<x<1) type, Li _6-y PS _5-y X _1+y (X=Cl, At least one of Br, I, 0≤y≤0.6) type and Li _11-z M _2-z P _1+z S ₁₂ (M=Ge, Sn, Si, 0.5≤z≤1.5) type.

优选的是，所述硫化物固态电解质颗粒的D _N50粒径为0.50-30.00μm，优选为0.50-3.00μm；优选地，所述包覆型硫化物固态电解质的D _N50粒径为0.53-3.08μm。 Preferably, the _DN 50 particle size of the sulfide solid electrolyte particles is 0.50-30.00 μm, preferably 0.50-3.00 μm; preferably, the _DN 50 particle size of the coated sulfide solid electrolyte is 0.53 -3.08 μm.

优选的是，所述氧化物固态电解质层的厚度为8.00-100.00nm，优选为8.50-99.60nm。Preferably, the oxide solid electrolyte layer has a thickness of 8.00-100.00 nm, preferably 8.50-99.60 nm.

优选的是，所述包覆型硫化物固态电解质的初始离子电导率为0.35-9.2mS/cm，优选地，所述硫化物固态电解质初始离子电导率为0.68-10.8mS/cm。Preferably, the initial ion conductivity of the coated sulfide solid electrolyte is 0.35-9.2 mS/cm, preferably, the initial ion conductivity of the sulfide solid electrolyte is 0.68-10.8 mS/cm.

本发明还提供上述包覆型硫化物固态电解质的制备方法，包括如下步骤：The present invention also provides a preparation method for the above-mentioned coated sulfide solid electrolyte, comprising the following steps:

(1)将硫化物固态电解质原料进行球磨，依次经压片、烧结、研磨和筛分得到硫化物固态电解质颗粒，其中，所述球磨和烧结均在惰性条件下进行；(1) Ball milling the sulfide solid electrolyte raw material, followed by pressing, sintering, grinding and sieving to obtain sulfide solid electrolyte particles, wherein the ball milling and sintering are all carried out under inert conditions;

(2)在硫化物固态电解质颗粒的表面采用湿法包覆法或物理气相沉积法制备氧化物固态电解质层，得到包覆型硫化物固态电解质。(2) An oxide solid electrolyte layer is prepared on the surface of the sulfide solid electrolyte particles by a wet coating method or a physical vapor deposition method to obtain a coated sulfide solid electrolyte.

优选的是，上述制备方法中，步骤(1)所述压片的压力为100-1000MPa，优选地，所述烧结温度为350-600℃，进一步优选地，所述烧结时间为2-15h。Preferably, in the above preparation method, the pressing pressure of the tablet in step (1) is 100-1000 MPa, preferably, the sintering temperature is 350-600° C., further preferably, the sintering time is 2-15 h.

优选的是，上述制备方法，步骤(2)所述湿法包覆法包括如下步骤：Preferably, the above-mentioned preparation method, the wet coating method described in step (2) comprises the following steps:

(A)在惰性氛围下，将包含锂、乙醇钽和乙醇铌的氧化物固态电解质原料溶于醇中得到前驱体溶液,优选地，所述醇为无水乙醇；(A) under an inert atmosphere, dissolve the oxide solid electrolyte raw material comprising lithium, tantalum ethoxide and niobium ethoxide in alcohol to obtain a precursor solution, preferably, the alcohol is absolute ethanol;

(B)将步骤(A)制得前驱体溶液喷覆到硫化物固态电解质颗粒表面，在惰性氛围下预烧结，然后在纯氧氛围中烧结得到包覆型硫化物固态电解质。(B) spraying the precursor solution prepared in step (A) onto the surface of the sulfide solid electrolyte particles, pre-sintering in an inert atmosphere, and then sintering in a pure oxygen atmosphere to obtain a coated sulfide solid electrolyte.

优选的是，上述制备方法，步骤(B)所述喷覆速率为5-15g/min，优选地，所述喷覆时间为1-5min，进一步优选地，所述烧结温度为200-600℃，更进一步优选地，烧结时间为1-3h。Preferably, in the above preparation method, the spraying rate in step (B) is 5-15g/min, preferably, the spraying time is 1-5min, further preferably, the sintering temperature is 200-600°C , More preferably, the sintering time is 1-3h.

优选的是，上述制备方法，所述物理气相沉积法为磁控溅射法、原子层沉积法和真空蒸镀法中的一种，优选为磁控溅射法。Preferably, in the above preparation method, the physical vapor deposition method is one of magnetron sputtering, atomic layer deposition and vacuum evaporation, preferably magnetron sputtering.

优选的是，上述制备方法，所述磁控溅射法包括如下步骤：Preferably, above-mentioned preparation method, described magnetron sputtering method comprises the steps:

(a)将氧化物固态电解质与粘结剂研磨、压片制成靶材；(a) Grinding and pressing the oxide solid electrolyte and binder to make a target;

(b)打开磁控溅射设备，安装靶材和基片，将腔体真空抽到1.0×10 ^-4-10.0×10 ^-4Pa，调节气压和溅射功率，通入惰性气体进行溅射。 (b) Turn on the magnetron sputtering equipment, install the target and substrate, vacuum the cavity to 1.0×10 ^-4 -10.0×10 ^-4 Pa, adjust the air pressure and sputtering power, and inject inert gas for sputtering .

优选的是，上述制备方法，步骤(b)所述溅射功率为50-400W,优选为100-300W；优选地，所述溅射时间为100-300min；溅射气压为2.5×10 ^-1-9.0×10 ^-1Pa。 Preferably, in the above preparation method, the sputtering power in step (b) is 50-400W, preferably 100-300W; preferably, the sputtering time is 100-300min; the sputtering pressure is 2.5×10 ^-1 -9.0×10 ^-1 Pa.

本发明还提供上述包覆型硫化物固态电解质或上述制备方法制得的包覆型硫化物固态电解质在固态电池中的应用。The present invention also provides the application of the above coated sulfide solid electrolyte or the coated sulfide solid electrolyte prepared by the above preparation method in a solid state battery.

本发明还提供一种固态电池，包括正极、固态电解质和负极，其中，所述正极、固态电解质和负极中的至少一种包含上述包覆型硫化物固态电解质或利用上述制备方法制得的包覆型硫化物固态电解质。The present invention also provides a solid-state battery, including a positive electrode, a solid electrolyte, and a negative electrode, wherein at least one of the positive electrode, solid electrolyte, and negative electrode includes the above-mentioned coated sulfide solid electrolyte or the coated sulfide prepared by the above-mentioned preparation method. Coated sulfide solid electrolyte.

本发明的有益效果：Beneficial effects of the present invention:

本发明通过将特定的氧化物固态电解质包覆在硫化物固态电解质表面得到包覆型硫化物固态电解质，其氧化物固态电解质层具有相对较高的离子电导率，介于10 ^-4-10 ^-2S/cm，具有高的化学稳定性，对空气中的水分不敏感，与高压正极材料配混时的电化学稳定好，抑制了空间电荷的形成，从而成功地解决了硫化物固态电解质对水稳定性差和硫化物固态电解质与正极材料混合使用时电化学窗口不匹配的问题。在制备本发明包覆型硫化物固态电解质的过程中，严密地控制烧结温度等工艺条件，显著提升了包覆型硫化物固态电解质的化学稳定性，使得工业化大规模生产成为可能。另一方面，本发明包覆型硫化物固态电解质与高压正极材料更加适配，所制备的固态电池的电化学性能更加优异，安全性能更高。 In the present invention, a coated sulfide solid electrolyte is obtained by coating a specific oxide solid electrolyte on the surface of the sulfide solid electrolyte, and the oxide solid electrolyte layer has a relatively high ion conductivity, between 10 ^-4 -10 ^{- 2} S/cm, has high chemical stability, is insensitive to moisture in the air, and has good electrochemical stability when mixed with high-voltage cathode materials, which inhibits the formation of space charges, thus successfully solving the problem of sulfide solid electrolytes. Poor water stability and electrochemical window mismatch problems when sulfide solid electrolytes are mixed with cathode materials. In the process of preparing the coated sulfide solid electrolyte of the present invention, the process conditions such as sintering temperature are strictly controlled, which significantly improves the chemical stability of the coated sulfide solid electrolyte, making industrial large-scale production possible. On the other hand, the coated sulfide solid electrolyte of the present invention is more compatible with high-voltage positive electrode materials, and the prepared solid-state battery has more excellent electrochemical performance and higher safety performance.

附图说明Description of drawings

图1是本发明实施例的包覆型硫化物固态电解质的示意图；Fig. 1 is the schematic diagram of the coated sulfide solid state electrolyte of the embodiment of the present invention;

图2是本发明实施例的固态电池的示意图。Fig. 2 is a schematic diagram of a solid-state battery according to an embodiment of the present invention.

图中标记说明如下：A-硫化物固态电解质、B-包覆型硫化物固态电解质，C-正极、D-负极、E-固态电解质。The markings in the figure are explained as follows: A-sulfide solid electrolyte, B-coated sulfide solid electrolyte, C-positive electrode, D-negative electrode, E-solid electrolyte.

具体实施方式Detailed ways

为使本发明实施例的目的、技术方案和技术效果更加清楚，对本发明实施例中的技术方案进行清楚、完整地描述。以下所描述的实施例是本发明一部分实施例，而不是全部的实施例。结合本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本发明保护的范围。In order to make the purpose, technical solutions and technical effects of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. The embodiments described below are some, not all, embodiments of the present invention. In combination with the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

在本发明的描述中，使用了-表示了数值范围的情况下，它们包含两方的端点，单位是共通的。例如，硫化物固态电解质的粒径为0.5-30.0μm表示固态电解质的粒径为0.5μm及以上且在30.0μm及以下。In the description of the present invention, when - is used to indicate a numerical range, both endpoints are included, and the unit is common. For example, the particle size of the sulfide solid electrolyte is 0.5-30.0 μm means that the particle size of the solid electrolyte is 0.5 μm or more and 30.0 μm or less.

在本发明的描述中，“至少一种”是指一种或者多种，“多种”是指两种或两种以上。例如，“a、b、或c中的一种或几种”，或，“a、b、和c中的至少一种”，均可以表示：a、b、c、a-b(即a和b)、a-c、b-c、或a-b-c，其中a、b、c分别可以是单个，也可以是多个。In the description of the present invention, "at least one" means one or more, and "multiple" means two or more. For example, "one or more of a, b, or c", or, "at least one of a, b, and c" can mean: a, b, c, a-b (that is, a and b ), a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

在本发明的描述中，“D _N50粒径”是指样品的累积粒度数量分布百分数达到50％时所对应的粒径。 In the description of the present invention, " _DN 50 particle size" refers to the particle size corresponding to when the cumulative particle size number distribution percentage of the sample reaches 50%.

需要理解的是，本发明实施例中所提到的相关成分的质量不仅仅可以指代各组分的具体含量，也可以表示各组分间质量的比例关系，因此，只要是按照本发明实施例相关组分的含量按比例放大或缩小均在本发明公开的范围之内。具体地，本发明实施例中所述的重量可以是μg、mg、g、kg等化工领域公知的质量单位。It should be understood that the quality of the relevant components mentioned in the examples of the present invention can not only refer to the specific content of each component, but also represent the proportional relationship between the mass of each component. Therefore, as long as it is implemented according to the present invention The proportional expansion or reduction of the content of the relevant components of the example is within the scope of the disclosure of the present invention. Specifically, the weight described in the embodiments of the present invention may be μg, mg, g, kg and other well-known mass units in the chemical industry.

另外，除非上下文另外明确地使用，否则词的单数形式的表达应被理解为包含该词的复数形式。术语“包括”或“具有”旨在指定特征、数量、步骤、操作、元件、部分或者其组合的存在，但不用于排除存在或可能添加一个或多个其它特征、数量、步骤、操作、元件、部分或者其组合。Also, expressions in the singular of a word should be understood to include the plural of the word unless the context clearly uses otherwise. The term "comprising" or "having" is intended to specify the presence of a feature, number, step, operation, element, part or combination thereof, but is not intended to exclude the presence or possible addition of one or more other features, numbers, steps, operations, elements , part or a combination thereof.

为了更好地理解上述技术方案，下面对本发明作进一步的详细说明。In order to better understand the above technical solutions, the present invention will be further described in detail below.

本发明提供了一种包覆型硫化物固态电解质，其为氧化物固态电解质层包覆在硫化物固态电解质颗粒表面的包覆型硫化物固态电解质；The invention provides a coated sulfide solid electrolyte, which is a coated sulfide solid electrolyte with an oxide solid electrolyte layer coated on the surface of sulfide solid electrolyte particles;

所述氧化物固态电解质为LiNb _xTa _1-xO ₃(0.15≤x≤0.85)、LiPON型和NASICON型中的至少一种。 The oxide solid electrolyte is at least one of LiNb _x Ta _1-x O ₃ (0.15≤x≤0.85), LiPON type and NASICON type.

在本发明的一个优选实施方式中，所述LiPON型为Li _3.3PO _3.9N _0.17，优选地，所述NASICON型为Li _1.4Al _0.4Ti _1.6(PO ₄) ₃。 In a preferred embodiment of the present invention, the LiPON type is Li _3.3 PO _3.9 N _0.17 , preferably, the NASICON type is Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ .

上述硫化物固态电解质在空气中极其不稳定，遇水会产生硫化氢，极大地影响使用的安全性能；并且，硫化物固态电解质与高压正极材料存在电压不适配的问题，会产生空间电荷，使得界面处发生一系列副反应，增大了界面阻抗，严重影响固态电池的电化学性能。通过在硫化物固态电解质表面包覆LiNb _xTa _(1-x)O ₃(0.15≤x≤0.85)型、LiPON型和NASICON型中的至少一种氧化物固态电解质层，如图1所示，一方面增加了硫化物固态电解质对水的稳定性能，显著抑制了硫化物固态电解质在存储与使用过程中硫化氢气体的产生；另一方面，氧化物固态电解质层的包覆又起到隔绝高压正极材料与硫化物固态电解质的直接接触，抑制了硫化物固态电解质与高压正极间的空间电荷的形成。对于包覆层的选择，既要考虑到对水氧稳定性的因素，也要考虑到离子电导率的大小。其中，LiNb _xTa _(1-x)O ₃由于铌元素与钽元素的协同作用，无论在离子电导率还是在对水氧稳定性方面均优于LiNbO ₃和LiTaO ₃。Li _3.3PO _3.9N _0.17具有更高的离子电导率和更好的机械性能，化学性质和电化学性质稳定，并且可以同LiCoO ₂、LiMnO ₄等正极以及金属锂、锂合金等负极相匹配。Li _1.4Al _0.4Ti _1.6(PO ₄) ₃不仅有高的离子电导率，而且对水氧具有良好的化学稳定性，这些特点使得Li _1.4Al _0.4Ti _1.6(PO ₄) ₃可以作为硫化物固态电解质的包覆层。 The above-mentioned sulfide solid electrolyte is extremely unstable in the air, and hydrogen sulfide will be generated when it meets water, which greatly affects the safety performance of use; moreover, there is a problem of voltage mismatch between the sulfide solid electrolyte and the high-voltage positive electrode material, which will generate space charge. A series of side reactions occur at the interface, which increases the interface impedance and seriously affects the electrochemical performance of the solid-state battery. By coating the surface of the sulfide solid electrolyte with at least one oxide solid electrolyte layer among LiNb _x Ta _(1-x) O ₃ (0.15≤x≤0.85) type, LiPON type and NASICON type, as shown in Figure 1, On the one hand, the stability of the sulfide solid electrolyte to water is increased, which significantly suppresses the generation of hydrogen sulfide gas during storage and use of the sulfide solid electrolyte; The direct contact between the positive electrode material and the sulfide solid electrolyte suppresses the formation of space charges between the sulfide solid electrolyte and the high-voltage positive electrode. For the selection of the cladding layer, not only the factors of stability to water and oxygen, but also the size of the ion conductivity should be taken into consideration. Among them, LiNb _x Ta _(1-x) O ₃ is superior to LiNbO ₃ and LiTaO ₃ in terms of ionic conductivity and stability to water and oxygen due to the synergistic effect of niobium and tantalum. Li _3.3 PO _3.9 N _0.17 has higher ionic conductivity and better mechanical properties, stable chemical and electrochemical properties, and can be matched with positive electrodes such as LiCoO ₂ and LiMnO ₄ and negative electrodes such as metal lithium and lithium alloys. Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ not only has high ionic conductivity, but also has good chemical stability to water and oxygen, these characteristics make Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ can be used as a sulfide solid electrolyte of the cladding.

在本发明的一个优选实施方式中，在上述包覆型硫化物固态电解质中，所述硫化物固态电解质为(1+x)Li ₂S·xP ₂S ₅(0＜x＜1)型、Li _6-yPS _5-yX _1+y(X＝Cl、Br、I，0≤y≤0.6)型和Li _11-zM _2-zP _1+zS ₁₂(M＝Ge、Sn、Si，0.5≤z≤1.5)型中的至少一种。 In a preferred embodiment of the present invention, in the above-mentioned coated sulfide solid electrolyte, the sulfide solid electrolyte is (1+x)Li ₂ S·xP ₂ S ₅ (0<x<1) type, Li _6-y PS _5-y X _1+y (X=Cl, Br, I, 0≤y≤0.6) type and Li _11-z M _2-z P _1+z S ₁₂ (M=Ge, Sn, At least one of Si, 0.5≤z≤1.5) type.

在本发明的一个优选实施方式中，在上述包覆型硫化物固态电解质中，所述硫化物固态电解质颗粒的D _N50粒径为0.50-30.00μm，优选地，所述硫化物固态电解质颗粒的D _N50粒径为0.50-3.00μm，所述包覆型硫化物固态电解质的D _N50粒径为0.53-3.08μm。为了保证在正极制备过程中，使得包覆型硫化物固态电解质与正极活性材料充分接触，所述硫化物固态电解质颗粒的D _N50粒径优选控制在0.50-3.00μm。在包覆型硫化物固态电解质与正负极活性材料混合形成浆料时，包覆型硫化物固态电解质更倾向于在正负极活性材料颗粒间进行填充，这要求硫化物固态电解质的颗粒粒径不易过大。另外，粒径过大时，则颗粒之间的接触面积小，孔隙大，导致界面电阻大。粒径过低时，则不利于工艺制备，工序复杂。 In a preferred embodiment of the present invention, in the above-mentioned coated sulfide solid electrolyte, the D _N 50 particle size of the sulfide solid electrolyte particles is 0.50-30.00 μm, preferably, the sulfide solid electrolyte particles The _DN 50 particle size of the coated sulfide solid electrolyte is 0.50-3.00 μm, and the _DN 50 particle size of the coated sulfide solid electrolyte is 0.53-3.08 μm. In order to ensure that the coated sulfide solid electrolyte is in full contact with the positive electrode active material during the preparation of the positive electrode, the _DN 50 particle size of the sulfide solid electrolyte particles is preferably controlled at 0.50-3.00 μm. When the coated sulfide solid electrolyte is mixed with the positive and negative active materials to form a slurry, the coated sulfide solid electrolyte is more likely to be filled between the positive and negative active material particles, which requires the particle size of the sulfide solid electrolyte The diameter is not easy to be too large. In addition, when the particle size is too large, the contact area between particles is small and the pores are large, resulting in large interface resistance. When the particle size is too low, it is not conducive to the process preparation, and the process is complicated.

在本发明的一个优选实施方式中，在上述包覆型硫化物固态电解质中，所述氧化物固态电解质层的厚度为8.00-100.00nm，优选为8.50-99.60nm，所述氧化物固态电解质层的厚度过薄时则影响对水氧的稳定性，影响使用的安全性能，还会导致氧化物电解质层容易破碎；过厚时则显著降低整体的固态电解质的离子电导率，影响离子传输性能，不利于循环性能；另外由于氧化物固态电解质相比于硫化物固态电解质的电导率低，为了避免包覆氧化物固态电解质层对硫化物固态电解质电导率产生较大的影响，氧化物固态电解质包覆层不易过厚或者过薄。In a preferred embodiment of the present invention, in the above-mentioned coated sulfide solid electrolyte, the oxide solid electrolyte layer has a thickness of 8.00-100.00 nm, preferably 8.50-99.60 nm, and the oxide solid electrolyte layer When the thickness is too thin, it will affect the stability of water and oxygen, affect the safety performance of use, and cause the oxide electrolyte layer to be easily broken; when it is too thick, it will significantly reduce the ionic conductivity of the overall solid electrolyte, affecting ion transport performance. It is not conducive to the cycle performance; in addition, because the conductivity of the oxide solid electrolyte is lower than that of the sulfide solid electrolyte, in order to avoid the coating of the oxide solid electrolyte layer from having a greater impact on the conductivity of the sulfide solid electrolyte, the oxide solid electrolyte package The coating is not easy to be too thick or too thin.

在本发明的一个优选实施方式中，在上述包覆型硫化物固态电解质中，所述包覆型硫化物固态电解质的初始离子电导率为0.35-9.2mS/cm，优选地，所述硫化物固态电解质的电导率为0.68-10.8mS/cm。In a preferred embodiment of the present invention, in the above-mentioned coated sulfide solid electrolyte, the initial ion conductivity of the coated sulfide solid electrolyte is 0.35-9.2mS/cm, preferably, the sulfide The conductivity of the solid electrolyte is 0.68-10.8 mS/cm.

本发明还提供了上述包覆型硫化物固态电解质的制备方法，包括如下步骤：The present invention also provides a preparation method for the above-mentioned coated sulfide solid electrolyte, comprising the following steps:

(1)将硫化物固态电解质原料进行球磨，压片、烧结、研磨和筛分得到硫化物固态电解质颗粒，其中，球磨和烧结均在惰性氛围下进行；(1) Ball milling the sulfide solid electrolyte raw material, pressing, sintering, grinding and sieving to obtain sulfide solid electrolyte particles, wherein the ball milling and sintering are all carried out under an inert atmosphere;

步骤(1)中所述硫化物固态电解质原料包括金属硫化物、金属卤化物、P ₂S ₅中的一种或两种以上，其中金属硫化物包括Li ₂S、GeS ₂、SiS ₂、SnS ₂中的一种或两种以上，金属卤化物包括LiCl、LiBr和LiI中的一种或两种以上。具体地，按照硫化物固态电解质的化学计量比称取各原料组分，无需某个过量。 The sulfide solid-state electrolyte raw material in step (1) includes one or more of metal sulfide, metal halide, and P ₂ S ₅ , wherein the metal sulfide includes Li ₂ S, GeS ₂ , SiS ₂ , SnS One or more of ₂ , the metal halides include one or more of LiCl, LiBr and LiI. Specifically, each raw material component is weighed according to the stoichiometric ratio of the sulfide solid electrolyte, without a certain excess.

在本发明的一个优选实施方式中，上述制备方法中，步骤(1)所述压片的压力为100-1000MPa，所述烧结在惰性氛围下，温度为350-600℃下烧结烧结2-15h，其中，升/降温速度为2-5℃/min。压片时压力过低，则难以压制成型，过高则可能对模具造成损伤。烧结时烧结温度过高，烧结时间过长，则固态电解质会融化，杂质相会增多；烧结温度过低，烧结时间过短，则反应不充分。In a preferred embodiment of the present invention, in the above preparation method, the pressure of the tablet pressing in step (1) is 100-1000 MPa, and the sintering is carried out under an inert atmosphere at a temperature of 350-600° C. for 2-15 hours. , wherein the temperature rising/falling rate is 2-5°C/min. If the pressure is too low during tablet compression, it will be difficult to form the tablet, and if it is too high, the mold may be damaged. If the sintering temperature is too high and the sintering time is too long, the solid electrolyte will melt and the impurity phase will increase; if the sintering temperature is too low and the sintering time is too short, the reaction will be insufficient.

在本发明的一个优选实施方式中，上述制备方法中，步骤(2)所述湿法包覆法包括如下步骤：In a preferred embodiment of the present invention, in the above-mentioned preparation method, the wet coating method described in step (2) includes the following steps:

(A)在惰性氛围下，将包含锂、乙醇钽和乙醇铌的氧化物固态电解质原料溶于醇中得到前驱体溶液；(A) under an inert atmosphere, dissolve the oxide solid electrolyte raw material comprising lithium, tantalum ethoxide and niobium ethoxide in alcohol to obtain a precursor solution;

(B)将步骤(A)制得前驱体溶液喷覆到硫化物固态电解质颗粒表面，在惰性氛围下预烧结，然后在纯氧氛围中烧结得到包覆层硫化物固态电解质。(B) spraying the precursor solution obtained in step (A) onto the surface of the sulfide solid electrolyte particles, pre-sintering in an inert atmosphere, and then sintering in a pure oxygen atmosphere to obtain a coating layer sulfide solid electrolyte.

上述湿法包覆法中，步骤(A)中氧化物固态电解质的原料选用金属锂、乙醇铌与乙醇钽，考虑到合成产物的纯度，金属锂优选为电池级金属锂，纯度不低于99.6％。在惰性气氛下，将金属锂溶解在醇中，待金属锂完全溶解后，再加入乙醇钽和乙醇铌的混合物，形成前驱体溶液。使用醇作为反应溶剂，一方面，考虑到醇的成本较低；另一方面，硫化物固态电解质与醇可以稳定存在，在包覆过程中不会发生副反应。考虑到醇的毒性与沸点，优选为无水乙醇。In the above wet coating method, metal lithium, niobium ethoxide and tantalum ethoxide are selected as raw materials for the oxide solid electrolyte in step (A). Considering the purity of the synthesized product, the metal lithium is preferably battery-grade metal lithium with a purity of not less than 99.6 %. Under an inert atmosphere, metal lithium is dissolved in alcohol, and after the metal lithium is completely dissolved, a mixture of tantalum ethoxide and niobium ethoxide is added to form a precursor solution. Using alcohol as a reaction solvent, on the one hand, considering the lower cost of alcohol; on the other hand, the sulfide solid electrolyte and alcohol can exist stably, and no side reactions will occur during the coating process. Considering the toxicity and boiling point of alcohol, absolute ethanol is preferred.

在本发明的一个优选实施方式中，上述湿法包覆法中，步骤(B)所述喷覆速率为5-15g/min，优选地，所述喷覆时间为1-5min，进一步优选地，喷覆后还包括将硫化物固态电解质进行干燥和筛分，其中干燥温度为80℃。经过发明人研究发现，喷覆速率和喷覆时间与氧化物固态电解质层的厚度存在正相关的关系，通过调控这两个参数，可以控制氧化物固态电解质层厚度。In a preferred embodiment of the present invention, in the above-mentioned wet coating method, the spraying rate in step (B) is 5-15g/min, preferably, the spraying time is 1-5min, further preferably , after spraying, it also includes drying and sieving the sulfide solid electrolyte, wherein the drying temperature is 80°C. The inventors have found through research that there is a positive correlation between the spraying rate and the spraying time and the thickness of the oxide solid electrolyte layer, and the thickness of the oxide solid electrolyte layer can be controlled by adjusting these two parameters.

在本发明的一个优选实施方式中，上述湿法包覆法中，步骤(B)中的预烧结是在惰性气氛下，在120℃保持2小时，其中升温速率为5℃/min；然后进行烧结，通入纯度99.99％的氧气，将温度升高至200-600℃，优选为500-600℃，保持恒温1-3h，其中升温速率为5℃/min，待烧结结束后，获得包覆型硫化物固态电解质。关于整个烧结过程，先在惰性气氛下进行预烧结，目的是为了先在硫化物固态电解质表面形成致密层，然后再升高温度，在纯氧中进行烧结，除去表面的有机基团。In a preferred embodiment of the present invention, in the above-mentioned wet coating method, the pre-sintering in step (B) is under an inert atmosphere, kept at 120°C for 2 hours, and the heating rate is 5°C/min; then Sintering, feed oxygen with a purity of 99.99%, raise the temperature to 200-600°C, preferably 500-600°C, keep the temperature at a constant temperature for 1-3h, and the heating rate is 5°C/min. After the sintering is completed, the coating is obtained type sulfide solid electrolyte. Regarding the whole sintering process, pre-sintering is carried out under an inert atmosphere. The purpose is to form a dense layer on the surface of the sulfide solid electrolyte, and then raise the temperature and sinter in pure oxygen to remove the organic groups on the surface.

在本发明的一个优选实施方式中，上述制备方法中，所述物理气相沉积法为磁控溅射法、原子层沉积法或真空蒸镀法中的一种，优选为磁控溅射法。In a preferred embodiment of the present invention, in the above preparation method, the physical vapor deposition method is one of magnetron sputtering, atomic layer deposition or vacuum evaporation, preferably magnetron sputtering.

在本发明的一个优选实施方式中，上述制备方法中，所述磁控溅射法包括如下步骤：In a preferred embodiment of the present invention, in the above preparation method, the magnetron sputtering method includes the following steps:

(b)打开磁控溅射设备，安装靶材和基片，将腔体真空抽到1.0×10 ^-4-4×10 ^-4Pa，调节气压和溅射功率，通入惰性气体进行溅射。 (b) Turn on the magnetron sputtering equipment, install the target and substrate, vacuum the cavity to 1.0×10 ^-4 -4×10 ^-4 Pa, adjust the air pressure and sputtering power, and inject inert gas for sputtering .

在本发明的一个优选实施方式中，上述磁控溅射法中，步骤(b)所述溅射功率为50-400W,优选为100-300W；所述溅射时间为100-300min；溅射气压为2.5×10 ^-1-9.0×10 ^-1Pa。 In a preferred embodiment of the present invention, in the above-mentioned magnetron sputtering method, the sputtering power in step (b) is 50-400W, preferably 100-300W; the sputtering time is 100-300min; The air pressure is 2.5×10 ^-1 -9.0×10 ^-1 Pa.

本发明还提供一种固态电池，包括正极极片、固态电解质和负极极片，其中，所述正极极片、固态电解质和负极极片中的至少一种包含上述包覆型硫化物固态电解质或上述制备方法制得的包覆型硫化物固态电解质。The present invention also provides a solid-state battery, including a positive pole piece, a solid electrolyte and a negative pole piece, wherein at least one of the positive pole piece, the solid electrolyte and the negative pole piece comprises the above-mentioned coated sulfide solid electrolyte or The coated sulfide solid electrolyte prepared by the above preparation method.

在本发明的一个优选实施方式中，上述固态电池中，所述正极极片通过以下步骤制备得到：在露点-30℃的环境下，按照一定的比例称取导电剂、粘结剂、正极活性材料和包覆型硫化物固态电解质，加入到有机溶剂中，研磨并混合均匀，得到正极活性浆料；将正极活性浆料均匀涂覆于正极集流体表面形成正极活性层，干燥后进行辊压、裁剪得到正极极片。在制备过程中添加一定量的包覆型固态电解质，这样的作用是使得锂离子可以在正极中进行有效的传导，同时，包覆型固态电解质的添加量对固态电池的总体电化学性能有一定的影响。In a preferred embodiment of the present invention, in the above-mentioned solid-state battery, the positive electrode piece is prepared by the following steps: under the environment of dew point -30°C, weigh the conductive agent, binder, positive electrode active The material and the coated sulfide solid electrolyte are added to the organic solvent, ground and mixed uniformly to obtain the positive active slurry; the positive active slurry is evenly coated on the surface of the positive current collector to form a positive active layer, and then rolled after drying , Cut to get the positive pole piece. A certain amount of coated solid electrolyte is added in the preparation process, so that lithium ions can be effectively conducted in the positive electrode. At the same time, the amount of coated solid electrolyte has a certain effect on the overall electrochemical performance of the solid-state battery. Impact.

上述正极活性材料包括钴酸锂、锰酸锂、磷酸铁锂、三元材料和LiNi _aCo _bMn _1-a-bM _cO ₂(0.3≤a≤0.75，0.2≤b≤0.3，0≤c≤0.1；M为Ti、Mg、Al、V、Cr、Zr、Ba、La、Ce、Sn)中的至少一种。该发明所提供的固态电池的容量主要由正极活性物质的量来贡献的，其在正极活性层的质量占比对正极的充放电容量存在显著的影响。可以通过优化正极活性材料的添加量，来优化整体固态电池的电化学性能。 The above positive electrode active materials include lithium cobaltate, lithium manganate, lithium iron phosphate, ternary materials and LiNi _a Co _b Mn _1-ab M _c O ₂ (0.3≤a≤0.75, 0.2≤b≤0.3, 0≤c≤ 0.1; M is at least one of Ti, Mg, Al, V, Cr, Zr, Ba, La, Ce, Sn). The capacity of the solid-state battery provided by the invention is mainly contributed by the amount of positive electrode active material, and its mass proportion in the positive electrode active layer has a significant impact on the charge and discharge capacity of the positive electrode. The electrochemical performance of the overall solid-state battery can be optimized by optimizing the amount of positive active material added.

上述正极集流体选自铝箔、涂炭铝箔、泡沫铝箔、泡沫镍的至少一种，优选为涂炭铝箔。这是因为正极在充放电过程中处于相对较高的电位，而负极处于低电位，在充电过程中集流体容易发生氧化，而涂炭铝箔的表面有一层致密的氧化铝，可以抵抗该氧化作用，而不能选用铜箔等易在高压下氧化的金属。The positive current collector is selected from at least one of aluminum foil, carbon-coated aluminum foil, foamed aluminum foil, and foamed nickel, preferably carbon-coated aluminum foil. This is because the positive electrode is at a relatively high potential during charging and discharging, while the negative electrode is at a low potential. The current collector is prone to oxidation during the charging process, and the surface of the carbon-coated aluminum foil has a layer of dense alumina, which can resist this oxidation. Metals that are easily oxidized under high pressure such as copper foil cannot be used.

上述导电剂选自SuperP、乙炔黑、科琴黑、炭黑、碳纳米管、石墨烯和碳纤维的至少一种。导电剂的添加起到加强正极整体电子电导率的作用，不作为容量贡献的来源。因此，导电剂的添加量一定程度上会影响正极整体容量，导电剂的添加量太低，则电子导电通道过少，不利于大电流充放电；导电剂的添加量太高又会降低正极活性物质的相对含量，影响电池容量，通过优化导电剂在正极活性层的质量占比，以获得最优的电化学性能。The conductive agent is at least one selected from SuperP, acetylene black, Ketjen black, carbon black, carbon nanotubes, graphene and carbon fibers. The addition of the conductive agent plays a role in enhancing the overall electronic conductivity of the positive electrode, not as a source of capacity contribution. Therefore, the amount of conductive agent added will affect the overall capacity of the positive electrode to a certain extent. If the amount of conductive agent added is too low, there will be too few electronic conduction channels, which is not conducive to high-current charging and discharging; if the added amount of conductive agent is too high, the activity of the positive electrode will be reduced. The relative content of substances affects the battery capacity, and the optimal electrochemical performance can be obtained by optimizing the mass proportion of the conductive agent in the positive active layer.

上述粘结剂选自聚偏氟乙烯、聚四氟乙烯、CMC、SBR、NBR、PVC、Polysiloxane、SEBS和SBS中的至少一种。粘结剂的添加量太低，则难以起到稳定电极结构的作用；粘结剂的添加量太高又会引起电阻的升高，导致导电剂或正极活性物质的相对含量降低及所得正极导电性能的下降。The above binder is selected from at least one of polyvinylidene fluoride, polytetrafluoroethylene, CMC, SBR, NBR, PVC, Polysiloxane, SEBS and SBS. If the amount of binder added is too low, it will be difficult to stabilize the electrode structure; if the amount of binder added is too high, it will cause an increase in resistance, resulting in a decrease in the relative content of the conductive agent or positive electrode active material and a decrease in the resulting positive electrode conductivity. performance degradation.

上述有机溶剂选自N-甲基吡咯烷酮、碳酸二甲酯、乙酸乙酯、无水乙醇、丙酮、碳酸二乙酯和丙酸甲酯中的至少一种。这些有机溶剂对正极活性物质、导电剂、粘结剂、包覆型硫化物固态电解质是不发生反应的，并且汽化温度较低。The organic solvent is at least one selected from N-methylpyrrolidone, dimethyl carbonate, ethyl acetate, absolute ethanol, acetone, diethyl carbonate and methyl propionate. These organic solvents do not react to positive electrode active materials, conductive agents, binders, and coated sulfide solid electrolytes, and have a relatively low vaporization temperature.

在本发明的一个优选实施方式中，上述固态电池中，所述固态电解质片通过以下方法制备：将包覆型硫化物固态电解质在压力100MPa-1000MPa下进行压片得到。由于固态电解质片过厚会导致锂离子传输速率慢，因此固态电解质应尽可能做的更薄。In a preferred embodiment of the present invention, in the above-mentioned solid-state battery, the solid-state electrolyte sheet is prepared by the following method: compressing the coated sulfide solid-state electrolyte under a pressure of 100MPa-1000MPa. Since the solid electrolyte sheet is too thick, the lithium ion transmission rate will be slow, so the solid electrolyte should be made as thin as possible.

另外，本发明的固态电池负极优选地可以为锂金属片、铟片、锂-铟合金、铝箔、锡箔、锂铝合金或锂硅合金中的一种，或者通过下述方法制备获得负极：在露点-30℃的环境下，按照一定的比例称取导电剂、粘结剂、负极活性材料和包覆型硫化物固态电解质，加入到有机溶剂中，研磨并混合均匀，得到负极活性浆料；将负极活性浆料均匀涂覆于负极集流体表面形成负极活性层，干燥后进行辊压、裁剪得到负极。In addition, the negative electrode of the solid-state battery of the present invention can preferably be one of lithium metal sheet, indium sheet, lithium-indium alloy, aluminum foil, tin foil, lithium aluminum alloy or lithium silicon alloy, or the negative electrode can be prepared by the following method: In an environment with a dew point of -30°C, weigh the conductive agent, binder, negative electrode active material and coated sulfide solid electrolyte according to a certain proportion, add them to the organic solvent, grind and mix evenly to obtain the negative electrode active slurry; The negative electrode active slurry is uniformly coated on the surface of the negative electrode current collector to form a negative electrode active layer, and after drying, the negative electrode is obtained by rolling and cutting.

上述负极活性材料包含硅碳、钛酸锂或石墨中的一种，且上述负极集流体选自铜箔、不锈钢箔中的一种。The anode active material includes one of silicon carbon, lithium titanate or graphite, and the anode current collector is selected from one of copper foil and stainless steel foil.

在本发明的一个优选实施方式中，上述固态电池通过下述方法制备：将正极极片、固态电解质片和负极依序层叠并施加500MPa-1000MPa的压力进行冷压得到固态电池。In a preferred embodiment of the present invention, the above-mentioned solid-state battery is prepared by the following method: the positive electrode sheet, the solid-state electrolyte sheet and the negative electrode are sequentially laminated and subjected to cold pressing under a pressure of 500MPa-1000MPa to obtain a solid-state battery.

在本发明的一个优选实施方式中，上述固态电池包括但不限于扣式电池、平板电池、圆柱电池和软包电池中的一种。In a preferred embodiment of the present invention, the solid-state battery includes but is not limited to one of a button battery, a flat battery, a cylindrical battery and a pouch battery.

本发明中使用的原料或试剂均购自市场主流厂家，未注明生产厂商者或者未注明浓度者，均为可以常规获取的分析纯级的原料或试剂，只要能起到预期的作用，并无特别限制。本实施例中使用的仪器设备均购自市场主要厂家，只要能起到预期的作用，并无特别限定。本实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。The raw materials or reagents used in the present invention are all purchased from mainstream manufacturers in the market, and those who do not indicate the manufacturer or the concentration are all analytically pure grade raw materials or reagents that can be routinely obtained. As long as they can play the expected role, There are no particular restrictions. The instruments and equipment used in this example are all purchased from major manufacturers in the market, and there are no special limitations as long as they can play the expected role. If no specific technique or condition is indicated in this example, the technique or condition described in the literature in this field or the product manual shall be followed.

仪器：instrument:

磁控溅射仪，购自沈阳景逸研科技术有限公司，型号：高真空多功能磁控溅射设备(101A-1B)。The magnetron sputtering apparatus was purchased from Shenyang Jingyi Research Technology Co., Ltd., model: high vacuum multifunctional magnetron sputtering equipment (101A-1B).

激光粒度分析仪，购自珠海真理光学仪器有限公司，型号：LT3600。Laser particle size analyzer, purchased from Zhuhai Zhenzhen Optical Instrument Co., Ltd., model: LT3600.

三温区管式炉，购自上海翰军实验设备有限公司,型号：HTF-1200III。The tube furnace with three temperature zones was purchased from Shanghai Hanjun Experimental Equipment Co., Ltd., model: HTF-1200III.

等静压机，购买于合肥科晶材料技术有限公司，型号：YLJ-CIP-15；压片模具购买于合肥科晶材料技术有限公司，型号：Die-SP20；电导率测试套件，购买于合肥科晶材料技术有限公司，型号：EQ-PSC。The isostatic press was purchased from Hefei Kejing Material Technology Co., Ltd., model: YLJ-CIP-15; the tableting die was purchased from Hefei Kejing Material Technology Co., Ltd., model: Die-SP20; the conductivity test kit was purchased from Hefei Kejing Material Technology Co., Ltd., model: EQ-PSC.

高能球磨机，购自长沙市德科仪器设备有限公司，型号为DECO-PBM-V-0.4L。A high-energy ball mill was purchased from Changsha Deco Instrument Equipment Co., Ltd., model DECO-PBM-V-0.4L.

BTS-5V10mA电池检测设备，购自深圳新威尔电子有限公司。BTS-5V10mA battery testing equipment was purchased from Shenzhen Newwell Electronics Co., Ltd.

透射电子显微镜，购自德国蔡司(Zeiss)。A transmission electron microscope was purchased from Zeiss, Germany.

能量色散X射线荧光光谱仪，购自日立公司。Energy dispersive X-ray fluorescence spectrometer was purchased from Hitachi.

试剂：Reagent:

Li ₂S、GeS ₂、SiS ₂、SnS ₂、LiCl、LiBr、LiI、P ₂S ₅均购买于上海阿拉丁生化科技股份有限公司。 Li ₂ S, GeS ₂ , SiS ₂ , SnS ₂ , LiCl, LiBr, LiI, P ₂ S ₅ were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

Li _1.4Al _0.4Ti _1.6(PO ₄) ₃购买于合肥科晶技术材料有限公司。 Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ was purchased from Hefei Kejing Technology Materials Co., Ltd.

以下，利用实施例、对比例更具体说明本发明，但本发明的技术范围不限定于这些示例。需要说明的是，只要不是特别地记载，那么本发明中使用的全部的百分率、份、比率基于质量。Hereinafter, although an Example and a comparative example demonstrate this invention more concretely, the technical scope of this invention is not limited to these examples. In addition, all percentages, parts, and ratios used in the present invention are based on mass unless otherwise specified.

实施例1Example 1

(一)Li ₆PS ₅Cl(LPSC)硫化物固态电解质颗粒的制备 (1) Preparation of Li ₆ PS ₅ Cl (LPSC) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅、LiCl按摩尔比例5：1：2进行充分混合，得到混合粉末6.0g。使用直径10mm的氧化锆球进行球磨，球磨转速设置为300rpm，球磨时间为30小时，球料质量比为40:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, fully mix Li ₂ S, P ₂ S ₅ , and LiCl in a molar ratio of 5:1:2 to obtain 6.0 g of mixed powder. Zirconia balls with a diameter of 10 mm were used for ball milling, the ball milling speed was set at 300 rpm, the ball milling time was 30 hours, and the ball-to-material mass ratio was 40:1. The ball-milled powder is ground in a mortar to make the powder fine.

2.将步骤1得到的粉料倒入压片模具中，利用等静压机进行压片，压力保持为200MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder obtained in step 1 into a tableting mold, and use an isostatic press to perform tableting with a pressure of 200 MPa and a holding time of 1 min to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中，以升/降温速度5℃/min，升温至550℃进行烧结，保温烧结时间为10h，在升降温和保温的过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere, heat up to 550°C for sintering at a temperature rising/falling rate of 5°C/min, and hold for 10 hours. During the heat preservation process, the flow rate of argon was 1.0 L/min.

4.烧结结束后，将烧结后收集到的Li ₆PS ₅Cl块体在手套箱中进行充分研磨，使用孔径为30μm的筛网进行筛分，得到粉末状的Li ₆PS ₅Cl硫化物固态电解质颗粒。用激光粒度分析仪测得粒径D _N50为0.5μm。 4. After sintering, fully grind the Li ₆ PS ₅ Cl block collected after sintering in a glove box, and sieve it with a sieve with a pore size of 30 μm to obtain a powdery Li ₆ PS ₅ Cl sulfide solid Electrolyte particles. The particle size D _N 50 measured by a laser particle size analyzer is 0.5 μm.

(二)包覆型硫化物固态电解质LiNb _0.5Ta _0.5O ₃-LPSC的制备 (2) Preparation of coated sulfide solid electrolyte LiNb _0.5 Ta _0.5 O ₃ -LPSC

1.在氩气氛围下，将14.0mmol(0.0972g)的锂金属溶于45.68g无水乙醇中，再混合7.0mmol(2.8438g)乙醇钽和7.0mmol(2.2275g)乙醇铌，得到前驱体溶液。1. Under an argon atmosphere, dissolve 14.0mmol (0.0972g) of lithium metal in 45.68g of absolute ethanol, and then mix 7.0mmol (2.8438g) of tantalum ethoxide and 7.0mmol (2.2275g) of niobium ethoxide to obtain a precursor solution.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li ₆PS ₅Cl硫化物固态电解质颗粒的表面，喷覆速率为5g/min，喷覆时间为1.5min。 2. Spray the above precursor solution evenly on the surface of the Li ₆ PS ₅ Cl sulfide solid electrolyte particles prepared in step (1), the spraying rate is 5g/min, and the spraying time is 1.5min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到粉末状的内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiNb _0.5Ta _0.5O ₃包覆层的包覆型硫化物固态电解质LiNb _0.5Ta _0.5O ₃-LPSC。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then cool down naturally to room temperature to obtain powdery coated sulfide solid electrolyte LiNb _0.5 Ta _0.5 O ₃ -LPSC with Li ₆ PS ₅ Cl sulfide solid electrolyte inside and LiNb _0.5 Ta _0.5 O ₃ coating layer on the surface.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为10.5nm，用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为0.53μm。 The thickness of the oxide solid electrolyte layer was measured by transmission electron microscope TEM to be 10.5 nm, and the particle size of the coated sulfide solid electrolyte _DN 50 was measured by a laser particle size analyzer to be 0.53 μm.

实施例2Example 2

(一)Li ₃PS ₄(LPS)硫化物固态电解质颗粒的制备 (1) Preparation of Li ₃ PS ₄ (LPS) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅按摩尔比例3：1得到混合粉末6g，使用10mm的氧化锆球进行球磨，球磨转速设置为400rpm，球磨时间为14h，球料质量比为60:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, mix Li ₂ S and P ₂ S ₅ in a molar ratio of 3:1 to obtain 6g of mixed powder, and use 10mm zirconia balls for ball milling. The ball milling speed is set to 400rpm, and the ball milling time is 14h, the mass ratio of ball to material is 60:1. The ball-milled powder is ground in a mortar to make the powder fine.

2.将该粉料倒入压片模具中，利用等静压机进行压片，压力保持200MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder into a tableting mold, and use an isostatic press to perform tableting with a pressure of 200 MPa and a holding time of 1 min to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中升温至350℃进行烧结，其中升/降温速度均为2℃/min，保温时间为2h，在整个升降温过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere and raise the temperature to 350°C for sintering, the temperature rising/falling speed is 2°C/min, and the holding time is 2h. The flow rate of argon gas during the cooling process was 1.0 L/min.

4.烧结结束后，将烧结后收集到的LPS块体在手套箱中研磨，使用孔径为30μm的筛网得到粉末状的LPS硫化物固态电解质。利用激光粒度分析仪测得粒径D _N50为3.0μm。 4. After sintering, grind the LPS block collected after sintering in a glove box, and use a sieve with a pore size of 30 μm to obtain a powdered LPS sulfide solid electrolyte. The particle size D _N 50 measured by a laser particle size analyzer was 3.0 μm.

(二)包覆型硫化物固态电解质LiNb _0.15Ta _0.85O ₃-LPS制备 (2) Preparation of coated sulfide solid electrolyte LiNb _0.15 Ta _0.85 O ₃ -LPS

1.在氩气氛围下，将14.0mmol(0.0972g)的锂金属溶于45.68g无水乙醇中，再混合11.9mmol(4.834g)乙醇钽和2.1mmol(0.668g)乙醇铌，得到前驱体溶液。1. Under an argon atmosphere, dissolve 14.0mmol (0.0972g) of lithium metal in 45.68g of absolute ethanol, and then mix 11.9mmol (4.834g) of tantalum ethoxide and 2.1mmol (0.668g) of niobium ethoxide to obtain a precursor solution.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li ₃PS ₄硫化物固态电解质颗粒的表面，喷覆速率为10g/min，喷覆时间为2.6min。 2. Spray the above precursor solution evenly on the surface of the Li ₃ PS ₄ sulfide solid electrolyte particles prepared in step (1), the spraying rate is 10g/min, and the spraying time is 2.6min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到粉末状的内部为Li ₃PS ₄硫化物固态电解质而表面为LiNb _0.15Ta _0.85O ₃包覆层的包覆型硫化物固态电解质LiNb _0.15Ta _0.85O ₃-LPS。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then cool down naturally to room temperature to obtain powdery coated sulfide solid electrolyte LiNb _0.15 Ta _0.85 O ₃ -LPS with Li ₃ PS ₄ sulfide solid electrolyte inside and LiNb _0.15 Ta _0.85 O ₃ coating layer on the surface.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为38.6nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为3.08μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 38.6 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 3.08 μm.

实施例3Example 3

(一)Li ₁₀GeP ₂S ₁₂(LGPS)硫化物固态电解质颗粒的制备 (1) Preparation of Li ₁₀ GeP ₂ S ₁₂ (LGPS) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅和GeS ₂按摩尔比例5：1：1得到混合粉末6g，使用10mm的氧化锆球进行球磨，球磨转速设置为450rpm，球磨时间为14h，球料质量比为60:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, mix Li ₂ S, P ₂ S ₅ and GeS ₂ in a molar ratio of 5:1:1 to obtain 6g of mixed powder, and use 10mm zirconia balls for ball milling. The ball milling speed is set to 450rpm, the ball milling time is 14h, and the mass ratio of ball to material is 60:1. The ball-milled powder is ground in a mortar to make the powder fine.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中升温至550℃进行烧结，其升温方式为5℃/min升高至500℃，然后以2℃/min升高至550℃，保温时间为8h，降温速率为5℃/min，在整个升降温过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere and raise the temperature to 550°C for sintering. The heating method is 5°C/min to 500°C, and then 2°C/min Raise to 550°C, the holding time is 8h, the cooling rate is 5°C/min, and the flow rate of argon is 1.0L/min during the whole heating and cooling process.

4.烧结结束后，将烧结后收集到的LGPS块体在手套箱中研磨，使用孔径为30μm的筛网得到粉末状的LGPS硫化物固态电解质。利用激光粒度分析仪测得D _N50粒径为1.0μm。 4. After sintering, grind the LGPS block collected after sintering in a glove box, and use a sieve with a pore size of 30 μm to obtain a powdered LGPS sulfide solid electrolyte. The _DN 50 particle size measured by a laser particle size analyzer is 1.0 μm.

(二)包覆型硫化物固态电解质LiNb _0.85Ta _0.15O ₃-LGPS的制备 (2) Preparation of coated sulfide solid electrolyte LiNb _0.85 Ta _0.15 O ₃ -LGPS

1.在氩气氛围下，将14.0mmol(0.0972g)的锂金属溶于45.68g无水乙醇中，再混合2.1mmol(0.853g)乙醇钽和11.9mmol(3.787g)乙醇铌，得到前驱体溶液。1. Under an argon atmosphere, dissolve 14.0mmol (0.0972g) of lithium metal in 45.68g of absolute ethanol, and then mix 2.1mmol (0.853g) of tantalum ethoxide and 11.9mmol (3.787g) of niobium ethoxide to obtain a precursor solution.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li ₁₀GeP ₂S ₁₂硫化物固态电解质颗粒的表面，喷覆速率为6g/min，喷覆时间为1min。 2. Spray the above precursor solution evenly on the surface of the Li ₁₀ GeP ₂ S ₁₂ sulfide solid electrolyte particles prepared in step (1), the spraying rate is 6g/min, and the spraying time is 1min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5 ℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到粉末状的内部为Li ₁₀GeP ₂S ₁₂硫化物固态电解质而表面为LiNb _0.85Ta _0.15O ₃包覆层的包覆型硫化物固态电解质LiNb _0.85Ta _0.15O ₃-LGPS。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then naturally cool down to room temperature to obtain a powdery coated sulfide solid electrolyte LiNb _0.85 Ta _0.15 O ₃ -LGPS with a Li ₁₀ GeP ₂ S ₁₂ sulfide solid electrolyte inside and a LiNb _0.85 Ta _0.15 O ₃ coating on the surface .

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为8.5nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为1.01μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 8.5 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 1.01 μm.

实施例4Example 4

(一)Li _5.5PS _4.5Br _1.5(LPSB)硫化物固态电解质颗粒的制备 (1) Preparation of Li _5.5 PS _4.5 Br _1.5 (LPSB) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅、LiBr按摩尔比例4：1：3进行充分混合，得到混合粉末6.0g。使用直径10mm的氧化锆球进行球磨，球磨转速设置为300rpm，球磨时间为20小时，球料质量比为30:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, Li ₂ S, P ₂ S ₅ , and LiBr were thoroughly mixed in a molar ratio of 4:1:3 to obtain 6.0 g of mixed powder. Zirconia balls with a diameter of 10 mm were used for ball milling, the ball milling speed was set at 300 rpm, the ball milling time was 20 hours, and the mass ratio of balls to materials was 30:1. The ball-milled powder is ground in a mortar to make the powder fine.

2.将步骤1得到的粉料倒入压片模具中，利用等静压机进行压片，压力保持为350MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder obtained in step 1 into a tableting mold, and use an isostatic press to perform tableting with a pressure of 350 MPa and a holding time of 1 min to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中升温至450℃进行烧结，其中升/降温速度均为3℃/min，保温时间为10h，在整个升降温过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere and raise the temperature to 450°C for sintering. The flow rate of argon gas during the cooling process was 1.0 L/min.

4.烧结结束后，将烧结后收集到的LPSB块体在手套箱中研磨，使用孔径为30μm的筛网得到粉末状的LPSB硫化物固态电解质。利用激光粒度分析仪测得D _N50粒径为1.5μm。 4. After sintering, grind the LPSB block collected after sintering in a glove box, and use a sieve with a pore size of 30 μm to obtain a powdered LPSB sulfide solid electrolyte. The _DN 50 particle size measured by a laser particle size analyzer is 1.5 μm.

(二)包覆型硫化物固态电解质LiNb _0.25Ta _0.75O ₃-LPSB的制备 (2) Preparation of coated sulfide solid electrolyte LiNb _0.25 Ta _0.75 O ₃ -LPSB

1.在氩气氛围下，将14.0mmol(0.0972g)的锂金属溶于45.68g无水乙醇中，再混合10.5mmol(4.265g)乙醇钽和3.5mmol(1.114g)乙醇铌，得到前驱体溶液。1. Under an argon atmosphere, dissolve 14.0mmol (0.0972g) of lithium metal in 45.68g of absolute ethanol, and then mix 10.5mmol (4.265g) of tantalum ethoxide and 3.5mmol (1.114g) of niobium ethoxide to obtain a precursor solution.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li _5.5PS _4.5Br _1.5硫化物固态电解质颗粒的表面，喷覆速率为15g/min，喷覆时间为3min。 2. Spray the above precursor solution evenly on the surface of the Li _5.5 PS _4.5 Br _1.5 sulfide solid electrolyte particles prepared in step (1), the spraying rate is 15g/min, and the spraying time is 3min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5 ℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至600℃，再在纯氧氛围下在600℃保温烧结3h。然后自然降温至室温，得到粉末状的内部为Li _5.5PS _4.5Br硫化物固态电解质而表面为LiNb _0.25Ta _0.75O ₃包覆层的包覆型硫化物固态电解质LiNb _0.25Ta _0.75O ₃-LPSB。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 600°C at a heating rate of 5°C/min, and then sintered at 600°C for 3 hours in a pure oxygen atmosphere. Then cool down naturally to room temperature to obtain a powdery coated sulfide solid electrolyte LiNb _0.25 Ta _0.75 O ₃ -LPSB with a Li _5.5 PS _4.5 Br sulfide solid electrolyte inside and a LiNb _0.25 Ta _0.75 O ₃ coating on the surface.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为68.7nm。用激光粒度分析仪测得包覆型硫化物固态电解质粒径D _N50为1.63μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 68.7 nm. The particle size D _N 50 of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 1.63 μm.

实施例5Example 5

(一)Li _10.5Sn _1.5P _1.5S ₁₂(LSPS)硫化物固态电解质颗粒的制备 (1) Preparation of Li _10.5 Sn _1.5 P _1.5 S ₁₂ (LSPS) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅、SnS ₂按摩尔比例5.25：0.75：1.5进行充分混合，得到混合粉末6.0g。使用直径10mm的氧化锆球进行球磨，球磨转速设置为450rpm，球磨时间为15小时，球料质量比为10:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, Li ₂ S, P ₂ S ₅ , and SnS ₂ were thoroughly mixed in a molar ratio of 5.25:0.75:1.5 to obtain 6.0 g of mixed powder. Zirconia balls with a diameter of 10 mm were used for ball milling, the ball milling speed was set at 450 rpm, the ball milling time was 15 hours, and the ball-to-material mass ratio was 10:1. The ball-milled powder is ground in a mortar to make the powder fine.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中升温至400℃进行烧结，其中升/降温速度均为3.5℃/min，保温时间为15h，在整个升降温过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere and heat it up to 400°C for sintering, the temperature rising/falling speed is 3.5°C/min, and the holding time is 15h. The flow rate of argon gas during the cooling process was 1.0 L/min.

4.烧结结束后，将烧结后收集到的LSPS块体在手套箱中研磨，使用孔径为30μm的筛网得到粉末状的LSPS硫化物固态电解质。利用激光粒度分析仪测得D _N50粒径为1.5μm。 4. After sintering, grind the LSPS block collected after sintering in a glove box, and use a sieve with a pore size of 30 μm to obtain a powdered LSPS sulfide solid electrolyte. The _DN 50 particle size measured by a laser particle size analyzer is 1.5 μm.

(二)包覆型硫化物固态电解质LiNb _0.75Ta _0.25O ₃-LSPS的制备 (2) Preparation of coated sulfide solid electrolyte LiNb _0.75 Ta _0.25 O ₃ -LSPS

1.在氩气氛围下，将14.0mmol(0.0972g)的锂金属溶于45.68g无水乙醇中，再混合3.5mmol(1.422g)乙醇钽和10.5mmol(3.341g)乙醇铌，得到前驱体溶液。1. Under an argon atmosphere, dissolve 14.0mmol (0.0972g) of lithium metal in 45.68g of absolute ethanol, and then mix 3.5mmol (1.422g) of tantalum ethoxide and 10.5mmol (3.341g) of niobium ethoxide to obtain a precursor solution.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li _10.5Sn _1.5P _1.5S ₁₂硫化物固态电解质颗粒的表面，喷覆速率为6g/min，喷覆时间为5min。 2. Spray the above precursor solution evenly on the surface of the Li _10.5 Sn _1.5 P _1.5 S ₁₂ sulfide solid electrolyte particles prepared in step (1), the spraying rate is 6g/min, and the spraying time is 5min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5 ℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到粉末状的内部为Li _10.5Sn _1.5P _1.5S ₁₂硫化物固态电解质而表面为LiNb _0.75Ta _0.25O ₃包覆层的包覆型硫化物固态电解质LiNb _0.75Ta _0.25O ₃-LSPS。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then naturally cool down to room temperature to obtain a powdery coated sulfide solid electrolyte LiNb _0.75 Ta _0.25 O ₃ with a Li _10.5 Sn _1.5 P _1.5 S ₁₂ sulfide solid electrolyte inside and a LiNb _0.75 Ta _0.25 O ₃ coating on the surface -LSPS.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为50.6nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为1.60μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 50.6 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 1.60 μm.

实施例6Example 6

(一)Li _9.5Si _0.5P _2.5S ₁₂(LSiPS)硫化物固态电解质颗粒的制备 (1) Preparation of Li _9.5 Si _0.5 P _2.5 S ₁₂ (LSiPS) sulfide solid electrolyte particles

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅、SiS ₂按摩尔比例9.5：2.5：1.0进行充分混合，得到混合粉末6.0g。使用直径10mm的氧化锆球进行球磨，球磨转速设置为450rpm，球磨时间为10小时，球料质量比为10:1。将球磨后的粉料在研钵中进行研磨使得粉料变得细腻。 1. In a glove box under an argon atmosphere, Li ₂ S, P ₂ S ₅ , and SiS ₂ were thoroughly mixed in a molar ratio of 9.5:2.5:1.0 to obtain 6.0 g of mixed powder. Zirconia balls with a diameter of 10 mm were used for ball milling, the ball milling speed was set at 450 rpm, the ball milling time was 10 hours, and the ball-to-material mass ratio was 10:1. The ball-milled powder is ground in a mortar to make the powder fine.

2.将步骤1得到的粉料倒入压片模具中，利用等静压机进行压片，压力保持为300MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder obtained in step 1 into a tableting mold, and use an isostatic press to perform tableting with a pressure of 300 MPa and a holding time of 1 min to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中升温至450℃进行烧结，其中升/降温速度均为4℃/min，保温时间为12h，在整个升降温过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere and heat it up to 450°C for sintering, the temperature rising/falling speed is 4°C/min, and the holding time is 12h. The flow rate of argon gas during the cooling process was 1.0 L/min.

4.烧结结束后，将烧结后收集到的LSiPS块体在手套箱中研磨，使用孔径为30μm的筛网得到粉末状的LSiPS硫化物固态电解质。利用激光粒度分析仪测得D _N50粒径为1.25μm。 4. After sintering, grind the LSiPS block collected after sintering in a glove box, and use a sieve with a pore size of 30 μm to obtain a powdered LSiPS sulfide solid electrolyte. The _DN 50 particle size measured by a laser particle size analyzer is 1.25 μm.

(二)包覆型硫化物固态电解质LATP-LSiPS的制备(2) Preparation of coated sulfide solid electrolyte LATP-LSiPS

1.靶材的制备：取15g的Li _1.4Al _0.4Ti _1.6(PO ₄) ₃固态电解质粉末与1％的粘结剂(PVA)进行研磨，使之混合均匀，利用压片机以300kg/cm ²的压力将粉末压在直径为50mm的铜模具中，制成厚度为2.5mm的铜背靶材。 1. Preparation of target material: Grind 15g of Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ solid electrolyte powder and 1% binder (PVA) to make them evenly mixed, and use a tablet press at 300kg/cm The pressure of ² presses the powder into a copper mold with a diameter of 50mm to make a copper back target with a thickness of 2.5mm.

2.包覆层的制备：采用射频磁控溅射法，磁控溅射的参数为：腔室真空度为1.0×10 ^-4Pa，工作气氛为氩气，靶间距为7cm，气体流量为35sccm，工作压强为0.25Pa，溅射时间为100min，溅射功率为100W，衬底温度为室温，在Li _9.5Si _0.5P _2.5S ₁₂(LSiPS)硫化物固态电解质表面构建Li _1.4Al _0.4Ti _1.6(PO ₄) ₃(LATP)包覆层，得到包覆型硫化物固态电解质LATP-LSiPS。 2. Preparation of cladding layer: adopt radio frequency magnetron sputtering method, the parameters of magnetron sputtering are: chamber vacuum degree is 1.0×10 ^-4 Pa, working atmosphere is argon, target distance is 7cm, gas flow rate is 35sccm, working pressure 0.25Pa, sputtering time 100min, sputtering power 100W, substrate temperature at room temperature, build Li _1.4 Al _0.4 Ti _1.6 on the surface of Li _9.5 Si _0.5 P _2.5 S ₁₂ (LSiPS) sulfide solid electrolyte (PO ₄ ) ₃ (LATP) cladding layer to obtain the cladding sulfide solid electrolyte LATP-LSiPS.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为9.8nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为1.28μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 9.8 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 1.28 μm.

实施例7Example 7

和实施例3中步骤(一)制备方法相同。Same as the preparation method of step (1) in Example 3.

(二)包覆型硫化物固态电解质LiPON-LGPS的制备(2) Preparation of coated sulfide solid electrolyte LiPON-LGPS

1.靶材的制备：取15g的Li ₃PO ₄与1％的粘结剂(PVA)进行研磨，使之混合均匀，利用压片机以300kg/cm ²的压力将粉末压在直径为50mm的铜模具中，制成厚度为2.5mm的铜背靶材。 1. Preparation of target material: Grind 15g of Li ₃ PO ₄ and 1% binder (PVA) to make them evenly mixed, and use a tablet press to press the powder on a surface with a diameter of 50mm at a pressure of 300kg/cm ² A copper back target with a thickness of 2.5 mm was made in a copper mold.

2.包覆层的制备：采用射频磁控溅射法，磁控溅射的参数为：腔室真空度为10.0×10 ^-4Pa，工作气氛为氮气：氩气＝3:1的氛围，靶间距为7cm，气体流量为35sccm，工作压强为0.9Pa，溅射时间为300min，溅射功率为300W，衬底温度为室温，在Li ₁₀GeP ₂S ₁₂(LGPS)硫化物固态电解质表面构建LiPON包覆层，得到包覆型硫化物固态电解质LiPON-LGPS。 2. Preparation of cladding layer: adopt radio frequency magnetron sputtering method, the parameters of magnetron sputtering are: the vacuum degree of the chamber is 10.0×10 ^-4 Pa, the working atmosphere is nitrogen: argon = 3:1 atmosphere, The target distance is 7cm, the gas flow rate is 35sccm, the working pressure is 0.9Pa, the sputtering time is 300min, the sputtering power is 300W, the substrate temperature is room temperature, and it is constructed on the surface of Li ₁₀ GeP ₂ S ₁₂ (LGPS) sulfide solid electrolyte LiPON coating layer, to obtain coated sulfide solid electrolyte LiPON-LGPS.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为95.3nm。利用能量色散X射线荧光光谱仪(测试条件)对氧化物固态电解质层进行元素成分含量测试，得到LiPON的分子式为Li _3.3PO _3.9N _0.17。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为1.25μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 95.3 nm. Energy dispersive X-ray fluorescence spectrometer (test conditions) was used to test the elemental composition content of the oxide solid electrolyte layer, and the molecular formula of LiPON was Li _3.3 PO _3.9 N _0.17 . The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 1.25 μm.

实施例8Example 8

1.在氩气氛围下的手套箱中，将Li ₂S、P ₂S ₅、LiCl按摩尔比例5：1：2进行充分混合，得到混合粉末6.0g。使用直径10mm的氧化锆球进行球磨，球磨转速设置为300rpm，球磨时间为30小时，球料质量比为40:1。将球磨后的粉料在研钵中进行研磨，使得粉料变得更细腻。 1. In a glove box under an argon atmosphere, fully mix Li ₂ S, P ₂ S ₅ , and LiCl in a molar ratio of 5:1:2 to obtain 6.0 g of mixed powder. Zirconia balls with a diameter of 10 mm were used for ball milling, the ball milling speed was set at 300 rpm, the ball milling time was 30 hours, and the ball-to-material mass ratio was 40:1. The ball-milled powder is ground in a mortar to make the powder finer.

2.将步骤1得到的粉料倒入压片模具中，利用等静压机进行压片，压力保持为100MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder obtained in step 1 into a tableting mold, and use an isostatic press to perform tableting, the pressure is kept at 100 MPa, and the holding time is 1 minute to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中，以升/降温速度3℃/min，升温至600℃进行烧结，保温烧结时间为6h，在升降温和保温的过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere, heat up to 600°C for sintering at a temperature rising/falling rate of 3°C/min, and hold for 6 hours. During the heat preservation process, the flow rate of argon was 1.0 L/min.

4.烧结结束后，将烧结后收集到的Li ₆PS ₅Cl块体在手套箱中进行充分研磨，使用孔径为30μm的筛网进行筛分，得到粉末状的Li ₆PS ₅Cl硫化物固态电解质颗粒。用激光粒度分析仪测得粒径D _N50为2.0μm。 4. After sintering, fully grind the Li ₆ PS ₅ Cl block collected after sintering in a glove box, and sieve it with a sieve with a pore size of 30 μm to obtain a powdery Li ₆ PS ₅ Cl sulfide solid Electrolyte particles. The particle size D _N 50 measured by a laser particle size analyzer is 2.0 μm.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li ₆PS ₅Cl硫化物固态电解质颗粒表面，喷覆速率为5g/min，喷覆时间为2min。 2. Spray the above precursor solution evenly on the surface of the Li ₆ PS ₅ Cl sulfide solid electrolyte particles prepared in step (1), the spraying rate is 5g/min, and the spraying time is 2min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至200℃，再在纯氧氛围下在200℃保温烧结2h。然后自然降温至室温，得到粉末状的内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiNb _0.5Ta _0.5O ₃包覆层的包覆型硫化物固态电解质LiNb _0.5Ta _0.5O ₃-LPSC。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 200°C at a heating rate of 5°C/min, and then sintered at 200°C for 2 hours in a pure oxygen atmosphere. Then cool down naturally to room temperature to obtain powdery coated sulfide solid electrolyte LiNb _0.5 Ta _0.5 O ₃ -LPSC with Li ₆ PS ₅ Cl sulfide solid electrolyte inside and LiNb _0.5 Ta _0.5 O ₃ coating layer on the surface.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为17.5nm，用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为2.04μm。 The thickness of the oxide solid electrolyte layer was measured to be 17.5 nm by transmission electron microscope TEM, and the particle size of the coated sulfide solid electrolyte _DN 50 was measured to be 2.04 μm by a laser particle size analyzer.

实施例9Example 9

2.将步骤1得到的粉料倒入压片模具中，利用等静压机进行压片，压力保持为1000MPa，保压时间1min，获得直径为16mm的圆片。2. Pour the powder obtained in step 1 into a tableting mold, and use an isostatic press to perform tableting. The pressure is maintained at 1000 MPa, and the holding time is 1 minute to obtain a disc with a diameter of 16 mm.

3.将该圆片移入坩埚中，并将坩埚放入氩气氛围的管式炉中，以升/降温速度3℃/min，升温至450℃进行烧结，保温烧结时间为15h，在升降温和保温的过程中氩气的流速为1.0L/min。3. Move the wafer into a crucible, put the crucible into a tube furnace with an argon atmosphere, heat up to 450°C for sintering at a temperature rising/falling rate of 3°C/min, and heat preservation and sintering time is 15h. During the heat preservation process, the flow rate of argon was 1.0 L/min.

4.烧结结束后，将烧结后收集到的Li ₆PS ₅Cl块体在手套箱中进行充分研磨，使用孔径为30μm的筛网进行筛分，得到粉末状的Li ₆PS ₅Cl硫化物固态电解质颗粒。用激光粒度分析仪测得粒径D _N50为2.8μm。 4. After sintering, fully grind the Li ₆ PS ₅ Cl block collected after sintering in a glove box, and sieve it with a sieve with a pore size of 30 μm to obtain a powdery Li ₆ PS ₅ Cl sulfide solid Electrolyte particles. The particle size D _N 50 measured by a laser particle size analyzer is 2.8 μm.

2.将上述前驱体溶液均匀喷覆在步骤(一)制备的Li ₆PS ₅Cl硫化物固态电解质颗粒表面，喷覆速率为15g/min，喷覆时间为5min。 2. Spray the above precursor solution evenly on the surface of the Li ₆ PS ₅ Cl sulfide solid electrolyte particles prepared in step (1), the spraying rate is 15g/min, and the spraying time is 5min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至400℃，再在纯氧氛围下在400℃保温烧结1h。然后自然降温至室温，得到粉末状的内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiNb _0.5Ta _0.5O ₃包覆层的包覆型硫化物固态电解质LiNb _0.5Ta _0.5O ₃-LPSC。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 400°C at a heating rate of 5°C/min, and then sintered at 400°C for 1 hour under pure oxygen atmosphere. Then cool down naturally to room temperature to obtain powdery coated sulfide solid electrolyte LiNb _0.5 Ta _0.5 O ₃ -LPSC with Li ₆ PS ₅ Cl sulfide solid electrolyte inside and LiNb _0.5 Ta _0.5 O ₃ coating layer on the surface.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为99.6nm，用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为3.0μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 99.6 nm, and the particle size of the coated sulfide solid electrolyte _DN 50 was measured to be 3.0 μm by a laser particle size analyzer.

对比例1Comparative example 1

制备Li ₆PS ₅Cl(LPSC)硫化物固态电解质颗粒，制备方法和实施例1中步骤(一)的制备方法相同。 The preparation method of Li ₆ PS ₅ Cl (LPSC) sulfide solid electrolyte particles is the same as the preparation method of step (1) in Example 1.

对比例2Comparative example 2

制备Li ₃PS ₄(LPS)硫化物固态电解质颗粒，制备方法和实施例2中步骤(一)制备方法相同。 To prepare Li ₃ PS ₄ (LPS) sulfide solid electrolyte particles, the preparation method is the same as the preparation method in step (1) in Example 2.

对比例3Comparative example 3

制备Li ₁₀GeP ₂S ₁₂(LGPS)硫化物固态电解质颗粒，制备方法和实施例3中步骤(一)的制备方法相同。 The preparation method of Li ₁₀ GeP ₂ S ₁₂ (LGPS) sulfide solid electrolyte particles is the same as the preparation method of step (1) in Example 3.

对比例4Comparative example 4

同实施例1中步骤(一)制备方法With step (one) preparation method in embodiment 1

(二)包覆型硫化物固态电解质LiNbO ₃-LPSC的制备 (2) Preparation of coated sulfide solid electrolyte LiNbO ₃ -LPSC

1.在氩气氛围下，将100mg的锂金属(14.0mmol)溶于45.68g的无水乙醇中，再混合4.455g乙醇铌(14.0mmol)得到前驱体溶液。1. Under an argon atmosphere, dissolve 100 mg of lithium metal (14.0 mmol) in 45.68 g of absolute ethanol, and then mix 4.455 g of niobium ethoxide (14.0 mmol) to obtain a precursor solution.

2.将前驱体溶液喷覆在Li ₆PS ₅Cl硫化物固态电解质表面，喷覆速率为5g/min，喷覆时间为1.5min。 2. Spray the precursor solution on the surface of the Li ₆ PS ₅ Cl sulfide solid electrolyte, the spraying rate is 5g/min, and the spraying time is 1.5min.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiNbO ₃包覆层的包覆型硫化物固态电解质粉末LNO-LPSC。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then the temperature was naturally lowered to room temperature, and the coated sulfide solid electrolyte powder LNO-LPSC with Li ₆ PS ₅ Cl sulfide solid electrolyte inside and LiNbO ₃ coating layer on the surface was obtained.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为11.5nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为0.55μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 11.5 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 0.55 μm.

对比例5Comparative example 5

同实施例1中步骤(一)制备方法。Same as step (1) preparation method in Example 1.

(二)包覆型硫化物固态电解质LiTaO ₃-LPSC的制备 (2) Preparation of coated sulfide solid electrolyte LiTaO ₃ -LPSC

1.在氩气氛围下，将100mg的锂金属(14.0mmol)溶于45.68g的无水乙醇中，再混合5.687g乙醇钽(14.0mmol)得到前驱体溶液。1. Under an argon atmosphere, dissolve 100 mg of lithium metal (14.0 mmol) in 45.68 g of absolute ethanol, and then mix 5.687 g of tantalum ethoxide (14.0 mmol) to obtain a precursor solution.

3.将喷覆后的固态电解质放置于管式炉中，在氩气氛围下以升温速度5℃/min升温至120℃，在120℃预烧结2h，然后将氩气氛围更换为纯氧气氛，以升温速度5℃/min升温至500℃，再在纯氧氛围下在500℃保温烧结3h。然后自然降温至室温，得到内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiTaO ₃包覆层的包覆型硫化物固态电解质粉末LTO-LPSC。 3. Place the sprayed solid electrolyte in a tube furnace, heat up to 120°C at a heating rate of 5°C/min in an argon atmosphere, pre-sinter at 120°C for 2 hours, and then replace the argon atmosphere with a pure oxygen atmosphere , the temperature was raised to 500°C at a heating rate of 5°C/min, and then sintered at 500°C for 3 hours in a pure oxygen atmosphere. Then the temperature was naturally lowered to room temperature, and the coated sulfide solid electrolyte powder LTO-LPSC with Li ₆ PS ₅ Cl sulfide solid electrolyte inside and LiTaO ₃ coating layer on the surface was obtained.

利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为12.0nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为0.54μm。 Using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 12.0 nm. The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 0.54 μm.

对比例6Comparative example 6

和实施例1中步骤(二)的区别在于，喷覆时间为0.5min；得到粉末状的内部为Li ₆PS ₅Cl硫化物固态电解质而表面为LiNb _0.5Ta _0.5O ₃包覆层的包覆型硫化物固态电解质LiNb _0.5Ta _0.5O ₃-LPSC；利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为3.4nm，用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为0.51μm。 The difference from step (2) in Example 1 is that the spraying time is 0.5min; the powdery interior is Li ₆ PS ₅ Cl sulfide solid electrolyte and the surface is coated with LiNb _0.5 Ta _0.5 O ₃ coating layer Type sulfide solid electrolyte LiNb _0.5 Ta _0.5 O ₃ -LPSC; using a transmission electron microscope TEM, the thickness of the oxide solid electrolyte layer was measured to be 3.4nm, and the coated sulfide solid electrolyte D was measured by a laser particle size analyzer. _{The N} 50 particle size is 0.51 μm.

对比例7Comparative example 7

同实施例2中步骤(一)制备方法。With step (1) preparation method in the embodiment 2.

和实施例2中步骤(二)的区别在于，喷覆速率为10g/min，喷覆时间为10min；得到粉末状的内部为Li ₃PS ₄硫化物固态电解质而表面为LiNb _0.15Ta _0.85O ₃包覆层的包覆型硫化物固态电解质LiNb _0.15Ta _0.85O ₃-LPS；利用透射电子显微镜TEM，测得所述氧化物固态电解质层的厚度为140.6nm。用激光粒度分析仪测得包覆型硫化物固态电解质D _N50粒径为3.26μm。 The difference from step (2) in Example 2 is that the spraying rate is 10g/min, and the spraying time is 10min; the obtained powdery interior is Li ₃ PS ₄ sulfide solid electrolyte and the surface is LiNb _0.15 Ta _0.85 O ₃ Coated sulfide solid electrolyte LiNb _0.15 Ta _0.85 O ₃ -LPS for the coating layer; the thickness of the oxide solid electrolyte layer was measured to be 140.6 nm by using a transmission electron microscope (TEM). The _DN 50 particle size of the coated sulfide solid electrolyte was measured by a laser particle size analyzer to be 3.26 μm.

实验例1Experimental example 1

按照如下方法测定实施例1-9和对比例1-7的初始离子电导率、干燥空气曝露后的离子电导率、硫化氢(H ₂S)的产生量。 The initial ion conductivity, the ion conductivity after exposure to dry air, and the amount of hydrogen sulfide (H ₂ S) produced in Examples 1-9 and Comparative Examples 1-7 were measured according to the following methods.

(1)初始离子电导率测试(1) Initial ionic conductivity test

在用充分干燥后的氩气(露点-60℃以下)置换的手套箱内，将上述实施例1-9和对比例1-7中制得的产品放入压片模具中，利用等静压机进行压片，其中压力为200MPa，保压时间为1.5min，经脱模，获得固态电解质片。利用数显千分尺测量该固态电解质片的厚度。以直径为16mm的不锈钢圆片为阻塞电极，利用电导率测试套件对该固态电解质片进行封装，利用电化学工作站进行EIS测试。In a glove box replaced with fully dried argon (below dew point -60°C), the products prepared in the above-mentioned Examples 1-9 and Comparative Examples 1-7 were put into a tableting mold, and were pressed by isostatic pressing. The tablet was pressed by a machine, the pressure was 200MPa, and the pressure holding time was 1.5min. After demoulding, a solid electrolyte sheet was obtained. The thickness of the solid electrolyte sheet was measured with a digital display micrometer. A stainless steel disc with a diameter of 16 mm was used as the blocking electrode, and the solid electrolyte sheet was packaged with a conductivity test kit, and the EIS test was performed using an electrochemical workstation.

EIS测试方法如下：用交流阻抗法在1Hz至1MHz的频率范围内施加50mV的电压；用σ＝L/RS方程计算离子电导率σ，其中R是固态电解质片的总电阻，L是固态电解质片的厚度，S是固体电解质片的单表面的面积，测试结果如表1。The EIS test method is as follows: use the AC impedance method to apply a voltage of 50mV within the frequency range of 1Hz to 1MHz; use the σ=L/RS equation to calculate the ionic conductivity σ, where R is the total resistance of the solid electrolyte sheet, and L is the solid electrolyte sheet The thickness, S is the area of a single surface of the solid electrolyte sheet, the test results are shown in Table 1.

(2)干燥空气曝露后的离子电导率的测定(2) Determination of ionic conductivity after exposure to dry air

在用露点为-45℃的干燥空气置换的手套箱内，将上述实施例1-9和对比例1-7中制得的产品放置4h，然后，再次放入用充分干燥后的Ar气体(露点-60℃以下)置换的手套箱内，采用与初始离子电导率测试同样的测试方法，测定干燥空气曝露后的离子电导率，测试结果如表1。In a glove box replaced by dry air with a dew point of -45°C, the products prepared in Examples 1-9 and Comparative Examples 1-7 were placed for 4 hours, and then placed again with fully dried Ar gas ( dew point -60°C or less) in the glove box, the same test method as the initial ion conductivity test was used to measure the ion conductivity after exposure to dry air, and the test results are shown in Table 1.

(3)硫化氢(H ₂S)的产生量的测定 (3) Determination of the amount of hydrogen sulfide (H ₂ S) produced

在用露点为-60℃的干燥空气置换的手套箱内，称量上述实施例1-9和对比例1-7中制得的产品100mg，将其放置于体积为1755cm ³的干燥器中(温度为25℃，湿度为30％)，利用硫化氢检测仪(SK-800-H2S，东日瀛能制造)测量300秒后硫化氢的浓度，计算出硫化氢的容积，求出硫化氢的产生量，计算结果如表1。 In a glove box replaced by dry air with a dew point of -60°C, weigh 100 mg of the product obtained in the above Examples 1-9 and Comparative Examples 1-7, and place it in a desiccator with a volume of 1755 ^cm ( The temperature is 25°C, the humidity is 30%), and the concentration of hydrogen sulfide after 300 seconds is measured by a hydrogen sulfide detector (SK-800-H2S, manufactured by TORIYING), and the volume of hydrogen sulfide is calculated to obtain the volume of hydrogen sulfide. The calculation results are shown in Table 1.

表1实施例1-9和对比例1-7制得产品的性能指标The performance index of the product that table 1 embodiment 1-9 and comparative example 1-7 make

实验例2Experimental example 2

按下述方式评价实施例1-9和对比例1-7制备样品在固态锂电池中的应用性能，首先制备负极极片、固态电解质片和正极极片，然后制作固态电池，最后测试电池性能。Evaluate the application performance of the samples prepared in Examples 1-9 and Comparative Examples 1-7 in solid-state lithium batteries in the following manner, first prepare the negative electrode sheet, solid electrolyte sheet and positive electrode sheet, then make the solid-state battery, and finally test the battery performance .

(一)制备负极极片(1) Preparation of negative pole piece

1.金属锂负极极片：在真空手套箱中，裁取直径为12mm的金属锂负极圆片，该金属锂负极圆片是负极活性材料兼负极集流体。1. Lithium metal negative pole piece: In a vacuum glove box, cut a metal lithium negative pole disc with a diameter of 12mm, which is the negative active material and negative current collector.

2.锂-铟合金负极极片：在真空手套箱中，裁取直径为12mm的锂-铟合金负极圆片，该锂-铟合金负极圆片是负极活性材料兼负极集流体。2. Lithium-indium alloy negative pole piece: In a vacuum glove box, cut a lithium-indium alloy negative pole disc with a diameter of 12mm, which is the negative active material and negative current collector.

3.含包覆型硫化物固态电解质的负极极片3. Negative electrode sheet containing coated sulfide solid electrolyte

在露点-30℃的环境下，将导电剂(Super P)、粘结剂(PVDF)、负极活性物质(SiO/石墨(SiO质量比为10％))、实施例3制备的包覆型硫化物固态电解质按照质量比为0.5：0.5：7.5：1.5混合于N-甲基吡咯烷酮(NMP)溶剂中，制得负极活性浆料。将负极活性浆料涂布到铜箔上，在80℃真空干燥后进行辊压切片，得到直径12mm的负极极片，记为CE-S3。Under the environment of dew point -30 ℃, the conductive agent (Super P), binder (PVDF), negative electrode active material (SiO/graphite (SiO mass ratio is 10%)), the coated vulcanization prepared in Example 3 The solid-state electrolyte is mixed in N-methylpyrrolidone (NMP) solvent according to the mass ratio of 0.5:0.5:7.5:1.5 to prepare negative electrode active slurry. The negative electrode active slurry was coated on the copper foil, and after vacuum drying at 80°C, it was rolled and sliced to obtain a negative electrode sheet with a diameter of 12 mm, which was designated as CE-S3.

(二)固态电解质片的制备(2) Preparation of solid electrolyte sheets

分别将实施例1-9对比例1-7制得的样品放置于模具中，通过施加压力100MPa，制备成厚度为100μm、直径为16mm的固态电解质片，分别记为SSE-S1、SSE-S2、SSE-S3、SSE-S4、SSE-S5、SSE-S6、SSE-S7、SSE-S8、SSE-S9、SSE-C1、SSE-C2、SSE-C3、SSE-C4、SSE-C5、SSE-C6和SSE-C7。The samples prepared in Examples 1-9 and Comparative Examples 1-7 were respectively placed in a mold, and a solid electrolyte sheet with a thickness of 100 μm and a diameter of 16 mm was prepared by applying a pressure of 100 MPa, respectively denoted as SSE-S1 and SSE-S2 , SSE-S3, SSE-S4, SSE-S5, SSE-S6, SSE-S7, SSE-S8, SSE-S9, SSE-C1, SSE-C2, SSE-C3, SSE-C4, SSE-C5, SSE -C6 and SSE-C7.

(三)制备正极极片(3) Preparation of positive pole piece

在露点-30℃的环境下，分别称取1.5质量份实施例1-9和对比例1-7制备的样品，然后与0.5质量份导电剂(Super P)、0.5质量份粘结剂(PVDF)、7.5质量份正极活性材料(钴酸锂)一起加入到有机溶剂N-甲基吡咯烷酮(NMP)中，研磨并混合均匀，得到正极活性浆料。将正极活性浆料均匀涂覆于正极集流体涂炭铝箔表面，形成正极活性层，在80℃真空干燥后进行辊压，裁剪得到直径为10mm的正极极片，分别记为PE-S1、PE-S2、PE-S3、PE-S4、PE-S5、PE-S6、PE-S7、PE-S8、PE-S9、PE-C1、PE-C2、PE-C3、PE-C4、PE-C5、PE-C6和PE-C7。In an environment with a dew point of -30°C, weigh 1.5 parts by mass of the samples prepared in Examples 1-9 and Comparative Examples 1-7, and then mix them with 0.5 parts by mass of conductive agent (Super P), 0.5 parts by mass of binder (PVDF ), 7.5 parts by mass of the positive electrode active material (lithium cobaltate) were added together in the organic solvent N-methylpyrrolidone (NMP), ground and mixed uniformly to obtain the positive electrode active slurry. The positive electrode active slurry was evenly coated on the surface of the positive electrode current collector carbon-coated aluminum foil to form the positive electrode active layer. After vacuum drying at 80°C, it was rolled and cut to obtain positive electrode pieces with a diameter of 10mm, which were respectively recorded as PE-S1, PE- S2, PE-S3, PE-S4, PE-S5, PE-S6, PE-S7, PE-S8, PE-S9, PE-C1, PE-C2, PE-C3, PE-C4, PE-C5, PE-C6 and PE-C7.

(四)组装固态电池：(4) Assembling solid-state batteries:

分别选取上述制备的正极极片、固态电解质片、负极极片依序层叠并施加500MPa的压力进行冷压得到固态电池，电池示意图如图2所示，记为BA-S1、BA-S2、BA-S3、BA-S4、BA-S5、BA-S6、BA-S7、BA-S8、BA-S9、BA-C1、BA-C2、BA-C3、BA-C4、BA-C5、BA-C6和BA-C7，将组装好的电池按下述方法进行电池测试，其中，正极极片、固态电解质片和负极极片组合方式如表2所示，测试结果如表3。Select the positive electrode sheet, solid electrolyte sheet, and negative electrode sheet prepared above to be stacked in sequence and apply a pressure of 500 MPa to cold press to obtain a solid-state battery. The schematic diagram of the battery is shown in Figure 2, which is marked as BA-S1, BA-S2, and BA -S3, BA-S4, BA-S5, BA-S6, BA-S7, BA-S8, BA-S9, BA-C1, BA-C2, BA-C3, BA-C4, BA-C5, BA-C6 and BA-C7, the assembled battery was tested according to the following method, wherein the combination of positive electrode sheet, solid electrolyte sheet and negative electrode sheet is shown in Table 2, and the test results are shown in Table 3.

1.首次充放电性能1. The first charge and discharge performance

在25℃下，使用BTS-5V10mA电池测试柜，将上述制备的固态电池以电流密度为0.2C恒流充电至4.5V，再在4.5V电压下恒压充电至截止电流0.02C，以0.2C放电至2.4V，得到首次循环充放电比容量。At 25°C, use the BTS-5V10mA battery test cabinet to charge the solid-state battery prepared above at a constant current density of 0.2C to 4.5V, and then charge at a constant voltage at 4.5V to a cut-off current of 0.02C. Discharge to 2.4V to obtain the first cycle charge and discharge specific capacity.

2.循环特性2. Cycle characteristics

在25℃下，使用BTS-5V10mA电池测试柜，将上述制备的固态电池进行活化后，按0.5C恒流恒压充至4.5V，截止电流0.02C，搁置5min，然后按0.5C恒流放电至2.4V，搁置5min。依此循环，充放电100次循环后，计算第100次循环的放电比容量。At 25°C, use the BTS-5V10mA battery test cabinet to activate the solid-state battery prepared above, charge it to 4.5V at a constant current and constant voltage of 0.5C, cut off the current at 0.02C, leave it for 5 minutes, and then discharge it at a constant current of 0.5C to 2.4V, hold for 5min. According to this cycle, after charging and discharging 100 cycles, calculate the discharge specific capacity of the 100th cycle.

3.倍率测试3. Magnification test

在25℃下，使用BTS-5V10mA电池测试柜，将上述制备的固态电池以0.2C恒流恒压充电至4.5V，截止电流0.02C，搁置5min，在25℃以0.2C放电至2.4V，记录电池的0.2C放电比容量，搁置5min。以0.2C恒流恒压充电至4.5V，截止电流0.02C，搁置5min，以1C放电至2.5V，记录1C放电比容量。然后，以0.2C恒流恒压充电至4.5V，截止电流0.02C，搁置5min，以3C放电至2.5V，记录3C放电比容量。最后，以0.2C恒流恒压充电至4.5V，截止电流0.02C，搁置5min，以5C放电至2.5V，记录5C放电比容量。At 25°C, use the BTS-5V10mA battery test cabinet to charge the solid-state battery prepared above to 4.5V at 0.2C constant current and constant voltage, with a cut-off current of 0.02C, leave it for 5 minutes, and discharge it at 0.2C to 2.4V at 25°C. Record the 0.2C discharge specific capacity of the battery and leave it for 5 minutes. Charge to 4.5V with 0.2C constant current and constant voltage, cut-off current 0.02C, leave for 5min, discharge to 2.5V with 1C, record 1C discharge specific capacity. Then, it was charged to 4.5V with 0.2C constant current and constant voltage, the cut-off current was 0.02C, left for 5min, and discharged to 2.5V at 3C, and the 3C discharge specific capacity was recorded. Finally, it was charged to 4.5V with 0.2C constant current and constant voltage, cut-off current was 0.02C, left for 5min, discharged to 2.5V at 5C, and the 5C discharge specific capacity was recorded.

表2固态电池的组装方式。Table 2 Assembly method of solid-state battery.

编号serial number	固态电解质solid electrolyte	正极极片Positive electrode	负极极片Negative pole piece
BA-S1BA-S1	SSE-S1SSE-S1	PE-S1PE-S1	锂金属lithium metal
BA-S2BA-S2	SSE-S2SSE-S2	PE-S2PE-S2	锂金属lithium metal
BA-S3BA-S3	SSE-S3SSE-S3	PE-S3PE-S3	CE-S3CE-S3
BA-S4BA-S4	SSE-S4SSE-S4	PE-S4PE-S4	锂-铟合金lithium-indium alloy
BA-S5BA-S5	SSE-S5SSE-S5	PE-S5PE-S5	锂金属lithium metal
BA-S6BA-S6	SSE-S6SSE-S6	PE-S6PE-S6	锂金属lithium metal
BA-S7BA-S7	SSE-S7SSE-S7	PE-S7PE-S7	锂金属lithium metal
BA-S8BA-S8	SSE-S8SSE-S8	PE-S8PE-S8	锂金属lithium metal
BA-S9BA-S9	SSE-S9SSE-S9	PE-S9PE-S9	锂金属lithium metal
BA-C1BA-C1	SSE-C1SSE-C1	PE-C1PE-C1	锂金属lithium metal
BA-C2BA-C2	SSE-C2SSE-C2	PE-C2PE-C2	锂金属lithium metal

BA-C3BA-C3	SSE-C3SSE-C3	PE-C3PE-C3	锂金属lithium metal
BA-C4BA-C4	SSE-C4SSE-C4	PE-C4PE-C4	锂金属lithium metal
BA-C5BA-C5	SSE-C5SSE-C5	PE-C5PE-C5	锂金属lithium metal
BA-C6BA-C6	SSE-C6SSE-C6	PE-C6PE-C6	锂金属lithium metal
BA-C7BA-C7	SSE-C7SSE-C7	PE-C7PE-C7	锂金属lithium metal

表3固态电池性能测试结果Table 3 Solid-state battery performance test results

关于实施例1-9中制备的包覆型硫化物固态电解质，与对比例1-3中未包覆的硫化物固态电解质相比而言，由表1可知，本发明包覆型硫化物固态电解质的硫化氢气体产生量远远低于未包覆的硫化物固态电解质，且在干燥空气中曝露4h后的离子电导率的衰减程度明显低于对比例1-3；由表3可知，电池测试结果表明，和含有未包覆的硫化物固态电解质电池相比，含有本发明包覆型硫化物固态电解质的电池，其首次循环充电比容量、首次循环放电比容量、循环100圈后的放电比容量和倍率性能显明增高。Regarding the coated sulfide solid electrolytes prepared in Examples 1-9, compared with the uncoated sulfide solid electrolytes in Comparative Examples 1-3, it can be seen from Table 1 that the coated sulfide solid electrolytes of the present invention The amount of hydrogen sulfide gas produced by the electrolyte is much lower than that of the uncoated sulfide solid electrolyte, and the attenuation of the ion conductivity after exposure to dry air for 4 hours is significantly lower than that of Comparative Examples 1-3; it can be seen from Table 3 that the battery The test results show that, compared with the uncoated sulfide solid electrolyte battery, the battery containing the coated sulfide solid electrolyte of the present invention has the first cycle charge specific capacity, the first cycle discharge specific capacity, and the discharge capacity after 100 cycles. The specific capacity and rate performance are significantly increased.

因此，通过在本发明的特定硫化物固态电解质颗粒的表面包覆一层环境稳定性高的特定氧化物固态电解质,可以有效地阻隔环境水分与硫化物固态电解质的直接接触，大大地提升了硫化物固态电解质的电化学稳定性，改善与正极材料混合使用时电化学窗口不匹配的问题。Therefore, by coating a layer of specific oxide solid electrolyte with high environmental stability on the surface of the specific sulfide solid electrolyte particles of the present invention, it can effectively block the direct contact between environmental moisture and sulfide solid electrolyte, greatly improving the sulfide solid electrolyte. The electrochemical stability of solid-state electrolyte improves the electrochemical window mismatch problem when mixed with positive electrode materials.

关于实施例1-9中制备的包覆型硫化物固态电解质，与对比例4-5中的包覆LiNbO ₃或LiTaO ₃的包覆型硫化物固态电解质相比而言，由表1可知，本发明包覆型硫化物固态电解质的硫化氢气体产生量也远远低于包覆层为LiNbO ₃或LiTaO ₃的包覆型硫化物固态电解质，且在干燥空气中曝露4h后的离子电导率的衰减程度也明显低于对比例4-5；由表3可知，电池测试结果表明，和含有包覆层为LiNbO ₃或LiTaO ₃的包覆型硫化物固态电解质电池相比，含有本发明包覆型硫化物固态电解质的电池，其首次循环充电比容量、首次循环放电比容量、循环100圈后的放电比容量和倍率性能明显提升。 Regarding the coated sulfide solid electrolytes prepared in Examples 1-9, compared with the coated _LiNbO3 or _LiTaO3 coated sulfide solid electrolytes in Comparative Examples 4-5, it can be seen from Table 1 that, The amount of hydrogen sulfide gas produced by the coated sulfide solid electrolyte of the present invention is also far lower than that of the coated sulfide solid electrolyte with the coating layer being _LiNbO3 or _LiTaO3 , and the ion conductivity after 4h exposure in dry air The degree of attenuation is also significantly lower than that of Comparative Examples 4-5; as can be seen from Table 3, the battery test results show that, compared with the coated sulfide solid electrolyte battery containing the coating layer of LiNbO ₃ or LiTaO ₃ , the battery containing the coating of the present invention The battery with the coated sulfide solid electrolyte has significantly improved charge specific capacity for the first cycle, specific discharge capacity for the first cycle, discharge specific capacity after 100 cycles, and rate performance.

进一步证明，本发明中，通过钽元素与铌元素的协同作用，LiNb _xTa _1-xO ₃(0.15≤x≤0.85)在保证固态电解质对水氧稳定性均优于LiNbO ₃和LiTaO ₃，能够提升硫化物固态电解质的电化学稳定性，在提升电池的循环性能和倍率性能方面均显著优于LiNbO ₃和LiTaO ₃。 It is further proved that in the present invention, through the synergistic effect of tantalum and niobium, LiNb _x Ta _1-x O ₃ (0.15≤x≤0.85) is superior to LiNbO ₃ and LiTaO ₃ in ensuring the stability of the solid electrolyte to water and oxygen, It can improve the electrochemical stability of the sulfide solid electrolyte, and is significantly better than LiNbO ₃ and LiTaO ₃ in improving the cycle performance and rate performance of the battery.

关于对比例6中的硫化物固态电解质，与实施例1中制备的包覆型硫化物固态电解质对比而言，由表1可知，氧化物固态电解质层的厚度过低，低于本发明的优选范围，因此导致硫化氢气体产生量过大，在干燥空气中曝露4h后的离子电导率的衰减程度明显变大，这说明此时无法提高硫化物固态电解质的电化学稳定性；由表3可知，电池测试结果表明，包覆型硫化物固态电解质的氧化物固态电解质层的厚度过低，其首次循环充电比容量、首次循环放电比容量、循环100圈后的放电比容量和倍率性能显著降低。Regarding the sulfide solid electrolyte in Comparative Example 6, compared with the coated sulfide solid electrolyte prepared in Example 1, it can be seen from Table 1 that the thickness of the oxide solid electrolyte layer is too low, which is lower than the preferred thickness of the present invention. Therefore, the amount of hydrogen sulfide gas generated is too large, and the attenuation of ionic conductivity after 4 hours of exposure in dry air becomes significantly larger, which indicates that the electrochemical stability of the sulfide solid electrolyte cannot be improved at this time; it can be seen from Table 3 , the battery test results show that the thickness of the oxide solid electrolyte layer of the coated sulfide solid electrolyte is too low, and its first cycle charge specific capacity, first cycle discharge specific capacity, discharge specific capacity and rate performance after 100 cycles are significantly reduced .

关于对比例7中的硫化物固态电解质，与实施例2中制备的包覆型硫化物固态电解质对比而言，由表1可知，氧化物固态电解质层的厚度过厚，高于本发明的优选范围，虽然提高了硫化物固态电解质的电化学稳定性，但是，由表3可知，电池测试结果表明，包覆型硫化物固态电解质的氧化物固态电解质层的厚度过厚，其首次循环充电比容量、首次循环放电比容量、循环100圈后的放电比容量和倍率性能显著降低。这是由于氧化物固态电解质层的厚度过厚，氧化物固态电解质的离子电导率低于硫化物固态电解质，因而显著降低整体的固态电解质的离子电导率，导致内阻增大，影响离子传输性能,不利于循环性能,导致充放电比容量和循环性能降低，严重降低倍率放电性能。Regarding the sulfide solid electrolyte in Comparative Example 7, compared with the coated sulfide solid electrolyte prepared in Example 2, it can be seen from Table 1 that the thickness of the oxide solid electrolyte layer is too thick, which is higher than the preferred value of the present invention. range, although the electrochemical stability of the sulfide solid electrolyte is improved, but, as can be seen from Table 3, the battery test results show that the thickness of the oxide solid electrolyte layer of the coated sulfide solid electrolyte is too thick, and its first cycle charge ratio The capacity, the first cycle discharge specific capacity, the discharge specific capacity after 100 cycles and the rate performance are significantly reduced. This is because the thickness of the oxide solid electrolyte layer is too thick, and the ionic conductivity of the oxide solid electrolyte is lower than that of the sulfide solid electrolyte, thus significantly reducing the ionic conductivity of the overall solid electrolyte, resulting in an increase in internal resistance and affecting ion transport performance. , is not conducive to the cycle performance, resulting in a decrease in the charge-discharge specific capacity and cycle performance, and seriously reduces the rate discharge performance.

以上所述，仅是本发明实施的较佳实施例，并非对本发明做任何形式上的限制，凡在本发明的精神和原则之内所做的修改、等同替换和改进等，均需要包含在本发明的保护范围之内。The above is only a preferred embodiment for the implementation of the present invention, and does not limit the present invention in any form. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention need to be included in the within the protection scope of the present invention.

Claims

一种包覆型硫化物固态电解质，其特征在于，其为氧化物固态电解质层包覆在硫化物固态电解质颗粒表面的包覆型硫化物固态电解质；A coated sulfide solid electrolyte, characterized in that it is a coated sulfide solid electrolyte in which an oxide solid electrolyte layer is coated on the surface of sulfide solid electrolyte particles;

所述氧化物固态电解质为LiNb _xTa _1-xO ₃(0.15≤x≤0.85)型、LiPON型和NASICON型中的至少一种。 The oxide solid electrolyte is at least one of LiNb _x Ta _1-x O ₃ (0.15≤x≤0.85) type, LiPON type and NASICON type.
根据权利要求1所述包覆型硫化物固态电解质，其特征在于，所述LiPON型为Li _3.3PO _3.9N _0.17，进一步优选地，所述NASICON型为Li _1.4Al _0.4Ti _1.6(PO ₄) ₃。 The coated sulfide solid electrolyte according to claim 1, wherein the LiPON type is Li _3.3 PO _3.9 N _0.17 , and more preferably, the NASICON type is Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ .
根据权利要求1或2所述包覆型硫化物固态电解质，其特征在于，所述硫化物固态电解质为(1+x)Li ₂S·xP ₂S ₅(0＜x＜1)型、Li _6-yPS _5-yX _1+y(X＝Cl、Br、I，0≤y≤0.6)型和Li _11-zM _2-zP _1+zS ₁₂(M＝Ge、Sn、Si，0.5≤z≤1.5)型中的至少一种。 The coated sulfide solid electrolyte according to claim 1 or 2, characterized in that the sulfide solid electrolyte is (1+x) Li ₂ S·xP ₂ S ₅ (0<x<1) type, Li _6-y PS _5-y X _1+y (X=Cl, Br, I, 0≤y≤0.6) type and Li _11-z M _2-z P _1+z S ₁₂ (M=Ge, Sn, Si , 0.5≤z≤1.5) at least one type.
根据权利要求1-3中任一项所述包覆型硫化物固态电解质，其特征在于，所述硫化物固态电解质颗粒的D _N50粒径为0.50-30.00μm，优选地，所述硫化物固态电解质颗粒的D _N50粒径为0.50-3.00μm，所述包覆型硫化物固态电解质的D _N50粒径为0.53-3.08μm。 The coated sulfide solid electrolyte according to any one of claims 1-3, characterized in that, the D _N 50 particle size of the sulfide solid electrolyte particles is 0.50-30.00 μm, preferably, the sulfide The _DN 50 particle size of the solid electrolyte particles is 0.50-3.00 μm, and the _DN 50 particle size of the coated sulfide solid electrolyte is 0.53-3.08 μm.
根据权利要求1-4中任一项所述包覆型硫化物固态电解质，其特征在于，所述氧化物固态电解质层的厚度为8.00-100.00nm，优选为8.50-99.60nm。The coated sulfide solid electrolyte according to any one of claims 1-4, characterized in that the thickness of the oxide solid electrolyte layer is 8.00-100.00 nm, preferably 8.50-99.60 nm.
根据权利要求1-5中任一项所述包覆型硫化物固态电解质，其特征在于，所述包覆型硫化物固态电解质的初始离子电导率为0.35-9.2mS/cm，优选地，所述硫化物固态电解质初始离子电导率为0.68-10.8mS/cm。According to the coated sulfide solid electrolyte according to any one of claims 1-5, it is characterized in that the initial ion conductivity of the coated sulfide solid electrolyte is 0.35-9.2mS/cm, preferably, the The initial ion conductivity of the sulfide solid electrolyte is 0.68-10.8mS/cm.
权利要求1-6中任一项所述包覆型硫化物固态电解质的制备方法，其特征在于，包括如下步骤：The preparation method of the coated sulfide solid electrolyte according to any one of claims 1-6, characterized in that it comprises the steps of:

(1)将硫化物固态电解质原料进行球磨，依次经压片、烧结、研磨和筛分得到硫化物固态电解质颗粒，其中，所述球磨和烧结均在惰性条件下进行；(1) Ball milling the sulfide solid electrolyte raw material, followed by pressing, sintering, grinding and sieving to obtain sulfide solid electrolyte particles, wherein the ball milling and sintering are all carried out under inert conditions;

(2)在硫化物固态电解质颗粒的表面采用湿法包覆法或物理气相沉积法制备氧化物固态电解质层，得到包覆型硫化物固态电解质。(2) An oxide solid electrolyte layer is prepared on the surface of the sulfide solid electrolyte particles by a wet coating method or a physical vapor deposition method to obtain a coated sulfide solid electrolyte.
根据权利要求7所述制备方法，其特征在于，步骤(1)所述压片的压力为100-1000MPa，优选地，所述烧结温度为350-600℃，进一步优选地，所述烧结时间为2-15h。According to the preparation method according to claim 7, it is characterized in that, the pressure of the tablet pressing in step (1) is 100-1000MPa, preferably, the sintering temperature is 350-600°C, further preferably, the sintering time is 2-15h.
根据权利要求7或8所述制备方法，其特征在于，步骤(2)所述湿法包覆法包括如下步骤：According to the described preparation method of claim 7 or 8, it is characterized in that the wet coating method described in step (2) comprises the following steps:

(A)在惰性氛围下，将包含锂、乙醇钽和乙醇铌的氧化物固态电解质原料溶于醇中得到前驱体溶液，优选地，所述醇为无水乙醇；(A) under an inert atmosphere, dissolve the oxide solid electrolyte raw material comprising lithium, tantalum ethoxide and niobium ethoxide in alcohol to obtain a precursor solution, preferably, the alcohol is absolute ethanol;

(B)将步骤(A)制得前驱体溶液喷覆到硫化物固态电解质颗粒表面，在惰性氛围下预烧结，然后在纯氧氛围中烧结得到包覆型硫化物固态电解质。(B) spraying the precursor solution prepared in step (A) onto the surface of the sulfide solid electrolyte particles, pre-sintering in an inert atmosphere, and then sintering in a pure oxygen atmosphere to obtain a coated sulfide solid electrolyte.
根据权利要求9所述制备方法，其特征在于，步骤(B)所述喷覆速率为5-15g/min，优选地，所述喷覆时间为1-5min，进一步优选地，所述烧结温度为200-600℃，更进一步优选地，烧结时间为1-3h。The preparation method according to claim 9, characterized in that, the spraying rate in step (B) is 5-15g/min, preferably, the spraying time is 1-5min, further preferably, the sintering temperature 200-600°C, more preferably, the sintering time is 1-3h.
根据权利要求7或8所述制备方法，其特征在于，所述物理气相沉积法为磁控溅射法、原子层沉积法和真空蒸镀法中的一种，优选为磁控溅射法。The preparation method according to claim 7 or 8, wherein the physical vapor deposition method is one of magnetron sputtering, atomic layer deposition and vacuum evaporation, preferably magnetron sputtering.
根据权利要求11所述制备方法，其特征在于，所述磁控溅射法包括如下步骤：According to the described preparation method of claim 11, it is characterized in that the magnetron sputtering method comprises the steps of:

(a)将氧化物固态电解质与粘结剂研磨、压片制成靶材；(a) Grinding and pressing the oxide solid electrolyte and binder to make a target;

(b)打开磁控溅射设备，安装靶材和基片，将腔体真空抽到1.0×10 ^-4-10.0×10 ^-4Pa，调节气压和溅射功率，通入惰性气体进行溅射。 (b) Turn on the magnetron sputtering equipment, install the target and substrate, vacuum the cavity to 1.0×10 ^-4 -10.0×10 ^-4 Pa, adjust the air pressure and sputtering power, and inject inert gas for sputtering .
根据权利要求12所述制备方法，其特征在于，步骤(b)所述溅射功率为50-400W,优选为100-300W；优选地，所述溅射时间为100-300min；溅射气压为2.5×10 ^-1-9.0×10 ^-1Pa。 The preparation method according to claim 12, characterized in that, the sputtering power of step (b) is 50-400W, preferably 100-300W; preferably, the sputtering time is 100-300min; the sputtering pressure is 2.5×10 ^-1 -9.0×10 ^-1 Pa.
权利要求1-6中任一项所述的包覆型硫化物固态电解质或利用权利要求7-13中任一项所述制备方法制得的包覆型硫化物固态电解质在固态电池中的应用。Application of the coated sulfide solid electrolyte described in any one of claims 1-6 or the coated sulfide solid electrolyte prepared by the preparation method described in any one of claims 7-13 in solid-state batteries .
一种固态电池，其特征在于，包括正极、固态电解质和负极，其中，所述正极、固态电解质和负极中的至少一种包含权利要求1-6中任一项所述的包覆型硫化物固态电解质或利用权利要求7-13中任一项制备方法制得的包覆型硫化物固态电解质。A solid-state battery, characterized in that it includes a positive electrode, a solid electrolyte, and a negative electrode, wherein at least one of the positive electrode, solid electrolyte, and negative electrode comprises the coated sulfide according to any one of claims 1-6 A solid electrolyte or a coated sulfide solid electrolyte prepared by any one of the preparation methods in claims 7-13.