Modified electrolyte and preparation method thereof, electrode material and battery

Abstract

The invention provides a modified electrolyte and a preparation method thereof, an electrode material and a battery. The modified electrolyte comprises a basic electrolyte and metal particles attached to the surface of the basic electrolyte; the materials of the metal particles comprise one or more of a nickel element, a copper element, a tin element, an iron element, a cobalt element and a precious metal element. According to the modified electrolyte provided by the invention, the specific solid electrolyte is used as the basic electrolyte, the surface of the basic electrolyte is modified by using the metal particles, the electronic conductivity of the modified electrolyte is effectively improved through cooperation of the solid electrolyte and the metal particles, and the positive electrode material containing the modified electrolyte can improve effective transmission of ions and electrons at the same time; the battery with the positive electrode material has low interface impedance and good electrochemical performance.

Description

Technical Field

[0001] The present application relates to the technical field of battery materials, and in particular to a modified electrolyte and a preparation method thereof, an electrode material and a battery. Background Art

[0002] Whether in the era of fossil energy or the era of new energy, electric energy is a key form of energy. The storage and application of electric energy are essential for efficient operation in the energy field. As a key device for energy storage, batteries play a vital role in both energy supply and consumption. On the supply side, various energy sources are converted into electric energy and stored in large battery systems to achieve optimal allocation of grid resources; on the consumer side, batteries, especially in mobile application scenarios, not only bring convenience to life, but also gradually reduce dependence on traditional fossil fuels. Therefore, the development of battery technology will have a profound impact on the adjustment of the energy structure. Solid-state batteries are highly expected by people due to their high safety and energy density, but interfacial impedance has always limited the development of solid-state batteries. Since solid electrolytes cannot penetrate into the pores of the positive electrode material like liquid electrolytes, solid-state batteries have higher interfacial impedance.

[0003] Traditionally, the interfacial impedance of solid-state batteries is reduced by adding a certain amount of solid electrolyte during the positive electrode mixing process. Although the solid electrolyte can build a lithium ion transmission channel in the positive electrode, the solid electrolyte itself has a low electronic conductivity and can easily block the conduction of electrons in the positive electrode, reducing electronic conductivity and causing battery performance to deteriorate. Summary of the invention

[0004] Based on this, it is necessary to provide a modified electrolyte with higher electronic conductivity and a preparation method thereof, an electrode material and a battery.

[0005] The present application discloses a modified electrolyte, comprising: a basic electrolyte and metal particles attached to the surface of the basic electrolyte;

[0006] The basic electrolyte has a general chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr 2- s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤t≤1, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W;

[0007] The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

[0008] In one embodiment, the average particle size of the metal particles is 0.01 μm to 10 μm.

[0009] In one embodiment, the mass ratio of the base electrolyte to the metal particles is (10-2000000):1.

[0010] Furthermore, the present application also provides a method for preparing a modified electrolyte, comprising the following steps:

[0011] Providing a basic electrolyte, and performing an activation treatment on the basic electrolyte to prepare an activated product;

[0012] Chemically plating metal particles on the surface of the activated product;

[0013] The basic electrolyte has a general chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr 2- s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12 One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W;

[0014] The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

[0015] In one embodiment, the steps of preparing the activated product include:

[0016] The basic electrolyte is placed in an activation solution for activation treatment.

[0017] In one embodiment, one or more of the following conditions are met:

[0018] (1) The activation solution comprises 1 g / L to 15 g / L of a first metal salt, 0 g / L to 120 g / L of a first complexing agent, 0 g / L to 14 g / L of a stabilizer, 0 g / L to 0.3 g / L of a protective agent, 0 g / L to 30 g / L of a first reducing agent, and 0 g / L to 8 g / L of a buffer;

[0019] (2) The pH value of the activation solution is 9.5-10.5;

[0020] (3) The ratio of the basic electrolyte to the activation solution is (80-120) g: (80-120) ml;

[0021] (4) The activation treatment time is 0.5 min to 8 min.

[0022] In one embodiment, the step of chemically plating metal particles on the surface of the activated product comprises:

[0023] The activated product is placed in a plating solution for chemical plating.

[0024] In one embodiment, one or more of the following conditions are met:

[0025] (1) The plating solution comprises 4 g / L to 18 g / L of a second metal salt, 2 g / L to 40 g / L of a second reducing agent, and 5 g / L to 80 g / L of a second complexing agent;

[0026] (2) The ratio of the activated product to the plating solution is (1-20) g: (80-120) ml;

[0027] (3) The temperature of the chemical plating is 40°C to 70°C;

[0028] (4) The chemical plating time is 1 min to 10 min.

[0029] Furthermore, the present application also provides an electrode material, including the modified electrolyte as described above or the modified electrolyte prepared by the preparation method as described above.

[0030] The present application also provides a battery, comprising a positive electrode, a negative electrode and a solid electrolyte arranged between the positive electrode and the negative electrode, wherein the positive electrode material comprises the electrode material as described above.

[0031] The modified electrolyte provided in the present application utilizes a solid electrolyte of a specific composition as a base electrolyte and uses metal particles to modify its surface. The combination of the two effectively improves the electronic conductivity of the modified electrolyte. The positive electrode material containing the above-mentioned modified electrolyte can simultaneously improve the effective transmission of ions and electrons, so that the battery with the above-mentioned positive electrode material has both low interfacial impedance and good electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 a is LATP(Li 1.3 Al 0.3 Ti 1.7 (PO4)3) SEM image of solid electrolyte before nickel plating, Figure 1 b is LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) Scanning electron micrograph of the modified electrolyte prepared after nickel plating of the solid electrolyte. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0036] The term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, wherein the any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items. For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B".

[0037] In this article, unless otherwise specified, "one or more" means any one of the listed items or any combination of the listed items. Similarly, "one or more" and other expressions that mean "one or more" are also understood in the same way unless otherwise specified.

[0038] In this document, "further", "further", "particularly", "for example", "such as", "example", "for example", etc. are used for descriptive purposes, indicating that the previous and subsequent technical solutions are related in terms of the content covered, but should not be understood as limiting the previous technical solution, nor can they be understood as limiting the scope of protection of this document. In this document, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0039] Herein, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If multiple "optional" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" item is independent of each other. In this application, descriptions such as "optionally contain", "optionally include", etc. mean "contain or not contain". "Optional component X" means that component X exists or does not exist, or means that component X is contained or not contained.

[0040] In this document, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0041] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] Herein, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​within the numerical interval is considered to be continuous and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when a numerical interval only refers to integers within the numerical interval, including the two endpoint integers of the numerical range, and each integer between the two endpoints, is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0043] Herein, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments herein, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments herein, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0044] In this article, if there are multiple steps involved in the method flow, unless there is a clear different description in this article, there is no strict order restriction for the execution of these steps, and they can be executed in other orders than described. Moreover, any step can include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn, alternating or simultaneously with other steps or parts of sub-steps or stages of other steps.

[0045] The present application discloses a modified electrolyte, comprising: a basic electrolyte and metal particles attached to the surface of the basic electrolyte;

[0046] The basic electrolyte has a general chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr 2-s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W;

[0047] The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

[0048] In a specific example, the average particle size of the metal particles is 0.01 μm to 10 μm.

[0049] Specifically, the average particle size of the metal particles can be, but is not limited to, 0.01 μm, 0.03 μm, 0.05 μm, 0.07 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm. In a specific example, the mass ratio of the base electrolyte to the metal particles is (10-2000000):1.

[0050] Specifically, the mass ratio of the base electrolyte and the metal particles can be, but is not limited to, 10:1, 20:1, 30:1, 50:1, 80:1, 90:1, 100:1, 300:1, 500:1, 800:1, 1000:1, 2000:1, 3000:1, 5000:1, 6000:1, 7000:1, 8000:1, 10000:1, 30000:1, 50000:1, 60000:1, 70000:1, 80000:1, 100000:1, 30000:1, 500000:1, 60000:1, 70000:1, 800000:1, 1000000:1, 1500000:1 or 2000000:1.

[0051] Furthermore, the present application also provides a method for preparing a modified electrolyte, comprising the following steps:

[0052] Providing a basic electrolyte, performing an activation treatment on the basic electrolyte, and preparing an activated product;

[0053] chemically plating metal particles on the surface of the activated product;

[0054] The basic electrolyte has a general chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr2-s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12 One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W;

[0055] The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

[0056] In a specific example, the step of preparing the activated product includes: placing the basic electrolyte in an activation solution for activation treatment.

[0057] In a specific example, the composition of the activation solution includes 1g / L~15g / L of a first metal salt, 0g / L~120g / L of a first complexing agent, 0g / L~14g / L of a stabilizer, 0g / L~0.3g / L of a protective agent, 0g / L~30g / L of a first reducing agent, and 0g / L~8g / L of a buffer.

[0058] It can be understood that the composition of the activation solution includes 1g / L to 15g / L of the first metal salt and 1g / L to 8g / L of a buffer. Further, the buffer can be, but is not limited to, one or both of sodium citrate and lactic acid.

[0059] The composition of the activation solution may also include 1g / L~15g / L of the first metal salt, 40g / L~120g / L of the first complexing agent, 0.5g / L~14g / L of the stabilizer, 0.001g / L~0.3g / L of the protective agent, and 6g / L~30g / L of the first reducing agent. The first complexing agent may include, but is not limited to, ammonia water, and further, the mass percentage of ammonia water is 17%~28%. The stabilizer may include, but is not limited to, amylopectin (cas number is 9037-22-3), and further, the amylopectin is soluble amylopectin. The protective agent may include, but is not limited to, polyethylene glycol. The first reducing agent may include, but is not limited to, potassium sodium tartrate.

[0060] In a specific example, the pH value of the activation solution is 9.5-10.5. The pH value of the activation solution can be but is not limited to 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.1, 10.2, 10.3, 10.4 or 10.5. Preferably, the pH value of the activation solution is adjusted to 10 using triethylamine.

[0061] In a specific example, the ratio of the base electrolyte to the activation solution is (80~120)g: (80~120)ml.

[0062] Further, the ratio of the basic electrolyte to the activation solution is (80-120) g: 100 ml. Specifically, the ratio of the basic electrolyte to the activation solution can be, but is not limited to, 80 g: 100 ml, 90 g: 100 ml, 100 g: 100 ml, 110 g: 100 ml or 120 g: 100 ml.

[0063] In a specific example, the activation treatment time is 0.5 min to 8 min. Further, the activation treatment time can be but is not limited to 0.5 min, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min or 8 min.

[0064] Further, the basic electrolyte is activated in an activation solution under magnetic stirring at 1000 r / min to 3000 r / min.

[0065] In a specific example, the step of chemically plating metal particles on the surface of the activated product includes: placing the activated product in a plating solution for chemical plating.

[0066] In a specific example, the composition of the plating solution includes 4 g / L to 18 g / L of the second metal salt, 2 g / L to 40 g / L of the second reducing agent, and 5 g / L to 80 g / L of the second complexing agent.

[0067] Further, the second reducing agent may be, but is not limited to, sodium hypophosphite. Further, the second complexing agent may be, but is not limited to, one or more of citrate, ethylenediaminetetraacetate, lactate and chloride, and specifically, the second complexing agent may be, but is not limited to, one or two of sodium citrate, disodium ethylenediaminetetraacetate and ammonium chloride.

[0068] In a specific example, the first metal salt and the second metal salt each independently include one or more of silver nitrate, copper sulfate, copper chloride, nickel acetate, nickel nitrate, nickel sulfate and nickel chloride.

[0069] Furthermore, the first metal salt may be silver nitrate and may be, but is not limited to, nickel acetate; the second metal salt may be, but is not limited to, one or more of copper sulfate, copper chloride, nickel acetate, nickel nitrate, nickel sulfate and nickel chloride.

[0070] In a specific example, the ratio of the activated product to the plating solution is (1~20)g: (80~120)ml.

[0071] Further, the ratio of the activated product to the plating solution is (1-20) g: 100 ml. Specifically, the ratio of the activated product to the plating solution can be, but is not limited to, 1 g: 100 ml, 5 g: 100 ml, 10 g: 100 ml, 15 g: 100 ml or 20 g: 100 ml.

[0072] In a specific example, the temperature of chemical plating is 40°C~70°C. Further, the temperature of chemical plating can be but is not limited to 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C.

[0073] In a specific example, the time for chemical plating is 1 min to 10 min. Further, the time for chemical plating can be but is not limited to 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0074] Furthermore, the activated product is electrolessly plated in a plating solution under magnetic stirring at 200 r / min to 3000 r / min. It is understandable that after the step of electrolessly plating metal particles on the surface of the activated product, washing and drying steps are also included.

[0075] Furthermore, the washing step includes washing with deionized water and anhydrous ethanol in sequence.

[0076] Furthermore, the drying step includes drying at a temperature of 70° C. to 90° C. for 10 hours to 14 hours.

[0077] Furthermore, the present application also provides an electrode material, including the modified electrolyte as described above or the modified electrolyte prepared by the preparation method as described above.

[0078] It can be understood that the electrode material also includes an active substance, a conductive additive and a binder. Further, the electrode material includes an active substance, a conductive additive, a binder and a modified electrolyte in a mass ratio of (80-100): (1-5): (2-8): (1-3).

[0079] The present application also provides a battery, comprising a positive electrode, a negative electrode and a solid electrolyte arranged between the positive electrode and the negative electrode, wherein the positive electrode material comprises the electrode material as described above.

[0080] The modified electrolyte provided in the present application uses a specific solid electrolyte as the base electrolyte and uses metal particles to modify the surface of the solid electrolyte. The combination of the two effectively improves the electronic conductivity of the modified electrolyte. The positive electrode material containing the above-mentioned modified electrolyte can simultaneously improve the effective transmission of ions and electrons, so that the battery with the above-mentioned positive electrode material has both low interfacial impedance and good electrochemical performance.

[0081] The present application is further described in detail below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance given in the present application, and can also be based on the experimental manuals or conventional conditions in the art, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0082] In the following specific embodiments, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument test accuracy or operation accuracy are allowed. "Normal temperature" refers to 25°C; "normal pressure" refers to 100KPa or 101KPa.

[0083] The solid electrolyte LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) is homemade, and the specific preparation method is as follows:

[0084] 1. Ball milling: Add isopropyl alcohol and agate balls to an agate ball mill, mix the raw material powders of lithium source (Li2CO3), aluminum source (Al2O3), titanium source (TiO2) and phosphoric acid source (NH4H2PO4) according to the stoichiometric ratio of the chemical formula, and then perform forward and reverse ball milling at 400 rpm for 6 hours.

[0085] 2. Vacuum drying: vacuum dry the milled slurry at 80°C for 3 hours until completely dry.

[0086] 3. Calcination: The dried powder was placed in an alumina crucible and calcined at 900°C for 6 hours.

[0087] 4. Secondary ball milling: The calcined powder block is again ball milled at 250 rpm for 6 hours.

[0088] 5. Mixing PVA: Mix the ball-milled powder with polyvinyl alcohol (PVA) in proportion and stir evenly in an agate mortar to form a block.

[0089] 6. Drying and molding: After the mixture is dried under vacuum at 80°C for 1 hour, it is ground into powder and collected.

[0090] 7. Tablet pressing: weigh 0.8 g of powder and use a pressure of 10 MPa to tablet for 1 minute. Repeat the operation to obtain multiple pieces of preliminary samples.

[0091] 8. Heat treatment: Place each of the above-mentioned primary samples in a crucible covered with alumina (Al2O3) mother powder, heat to 1200℃ in 5 hours, and keep warm for 40 minutes to obtain LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) Solid electrolyte.

[0092] Example 1

[0093] This embodiment provides a modified electrolyte and a preparation method thereof, wherein the preparation method comprises the following steps:

[0094] (1) Activation: 100g of LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) The solid electrolyte is placed in 100 ml of activation solution containing 6 g / L sodium citrate, 2 g / L nickel acetate, and 10 ml / L lactic acid. The pH is adjusted to 10 with triethylamine, and the activation time is 1 min with magnetic stirring at 2000 r / min. The activation product is taken out for later use;

[0095] (2) Chemical nickel plating: put 10g of the activated product into 100ml of chemical plating solution, which contains a mixed aqueous solution of 13g / L nickel sulfate, 30g / L sodium hypophosphite, 40g / L sodium citrate and 30g / L ammonium chloride. 50℃, 2000r / min magnetic stirring for 5min, that is, the chemical nickel plating time is 5min, then take it out;

[0096] (3) Place the nickel-plated product in a Buchner funnel and rinse it with deionized water for 5 times; rinse it with anhydrous ethanol for 3 times and drain it;

[0097] (4) The washed product was placed in a vacuum drying oven and vacuum dried at 80°C for 12 hours to obtain the final product.

[0098] Example 2

[0099] The modified electrolyte provided in this embodiment has a preparation method different from that in Example 1 in that the activation time is 0.5 min.

[0100] Example 3

[0101] The modified electrolyte provided in this embodiment has a preparation method different from that in Embodiment 1 in that the activation time is 3 minutes.

[0102] Example 4

[0103] The modified electrolyte provided in this embodiment has a preparation method different from that in Embodiment 1 in that the activation time is 5 minutes.

[0104] Example 5

[0105] The modified electrolyte provided in this embodiment is prepared in a method different from that in Example 1 in that the chemical nickel plating time is 8 minutes.

[0106] Example 6

[0107] The modified electrolyte provided in this embodiment is prepared in a method different from that in Example 1 in that the chemical nickel plating time is 10 minutes.

[0108] Example 7

[0109] This embodiment provides a modified electrolyte and a preparation method thereof, wherein the preparation method comprises the following steps:

[0110] (1) Activation: 100g of LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) The solid electrolyte is placed in 100 ml of activation solution, which contains 10 g / L silver nitrate, 80 g / L 25% ammonia water, 10 g / L soluble amylopectin, 0.2 g / L polyethylene glycol, and 20 g / L potassium sodium tartrate. The pH is adjusted to 10 with triethylamine, and the activation time is 1 min with magnetic stirring at 2000 r / min. The activated product is taken out for use;

[0111] (2) Chemical copper plating: put 2g of the activated product into 100ml of chemical plating solution, which contains a mixed aqueous solution of 6g / L CuSO4, 4g / L sodium hypophosphite, 10g / L disodium ethylenediaminetetraacetate Na2 (EDTA) and 2mg / L ammonium chloride. Stir with magnetic force at 65℃, 500r / min for 5min, i.e. the chemical copper plating time is 5min, then take it out;

[0112] (3) Place the copper-plated product in a Buchner funnel and rinse it with deionized water for 5 times; rinse it with anhydrous ethanol for 3 times and drain it;

[0113] (4) The washed product was placed in a vacuum drying oven and vacuum dried at 80°C for 12 hours to obtain the final product.

[0114] Example 8

[0115] The modified electrolyte provided in this embodiment is prepared in a method different from that in Example 1 in that the base electrolyte is replaced by a solid electrolyte LLZO (Li7La3Zr2O 12 ), solid electrolyte LLZO (Li7La3Zr2O 12 ) is different from the basic electrolyte provided in Example 1 in that the raw material powder is replaced with a base electrolyte having the chemical formula Li7La3Zr2O 12 A lithium source (LiOH), a lanthanum source (La2O3) and a zirconium source (ZrO2) in a stoichiometric ratio.

[0116] Comparative Example 1

[0117] The modified electrolyte provided in this comparative example comprises the following steps: 100 g of LATP (Li 1.3 Al 0.3 Ti 1.7 The (PO4)3) solid electrolyte was immersed in deionized water for 6 minutes and then placed in a vacuum drying oven at 80°C for 12 hours.

[0118] Comparative Example 2

[0119] The modified electrolyte provided in this comparative example has a preparation method comprising the following steps: 100 g of LATP solid electrolyte and 1 g of nickel powder are ball-milled and mixed for 1 hour to obtain a mixed powder.

[0120] Test methods and results

[0121] like Figure 1 a shows the above LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) SEM image of solid electrolyte before nickel plating, such as Figure 1 b shows the LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) Scanning electron micrograph of the modified electrolyte prepared after nickel plating of the solid electrolyte.

[0122] Battery preparation: The lithium iron phosphate solid button battery was used as the evaluation standard, wherein the mass ratio of the positive electrode composition was: active material lithium iron phosphate: conductive additive conductive carbon black: binder polyvinylidene fluoride: modified electrolyte of each embodiment or comparative example = 90:3:5:2; the electrolyte was LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) Solid electrolyte ceramic sheet, the negative electrode is metallic lithium. The above batteries were charged and discharged at a rate of 1C.

[0123] The internal resistance of the battery is directly read by the battery internal resistance meter.

[0124] Battery 100-week capacity retention rate Φ = ((1st week capacity - 100th week capacity) / 1st week capacity) × 100%.

[0125] The limitations of the metal particles in the modified electrolytes of the batteries of the above embodiments and comparative examples and the electrical properties of the batteries are summarized in Table 1 below.

[0126] Table 1

[0127]

[0128] It can be seen that Examples 1 to 8 use a specific solid electrolyte as the base electrolyte and then modify it by attaching specific modified metal particles to its surface, which can effectively improve the electrical properties of the solid-state battery containing this modified electrolyte, so that the battery with the above-mentioned positive electrode material has both lower interface impedance and good electrochemical performance.

[0129] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the specification and drawings may be used to interpret the scope of the claims.

Claims

1. A modified electrolyte, characterized in that include: A basic electrolyte and metal particles attached to the surface of the basic electrolyte; The basic electrolyte has a chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr 2-s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12 One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W; The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

2. The modified electrolyte according to claim 1, characterized in that The average particle size of the metal particles is 0.01 μm to 10 μm.

3. The modified electrolyte according to claim 1 or 2, characterized in that The mass ratio of the basic electrolyte to the metal particles is (10-2000000):

1.

4. A method for preparing a modified electrolyte, characterized in that: The following steps are involved: Providing a basic electrolyte, and performing an activation treatment on the basic electrolyte to prepare an activated product; Chemically plating metal particles on the surface of the activated product; The basic electrolyte has a chemical formula of Li 1+t Al t Ge 2-t (PO4)3、Li 3q La 2 / 3-q TiO3、LiZr 2-s Ti s (PO4)3、Li 1+m Al m Ti 2-m (PO4)3 and Li 7-2n-2j D n LqCy 2-j E j O 12 One or more of, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or two of Ge and Al, and E includes one or more of Nb, Ta, Te and W; The material of the metal particles includes one or more of nickel, copper, tin, iron, cobalt and precious metal elements.

5. The preparation method according to claim 4, characterized in that: The steps of preparing the activated product include: The basic electrolyte is placed in an activation solution for activation treatment.

6. The preparation method according to claim 5, characterized in that: One or more of the following conditions are met: (1) The activation solution comprises 1 g / L to 15 g / L of a first metal salt, 0 g / L to 120 g / L of a first complexing agent, 0 g / L to 14 g / L of a stabilizer, 0 g / L to 0.3 g / L of a protective agent, 0 g / L to 30 g / L of a first reducing agent, and 0 g / L to 8 g / L of a buffer; (2) The pH value of the activation solution is 9.5-10.5; (3) The ratio of the basic electrolyte to the activation solution is (80-120) g: (80-120) ml; (4) The activation treatment time is 0.5 min to 8 min.

7. The preparation method according to any one of claims 4 to 6, characterized in that: The step of chemically plating metal particles on the surface of the activated product comprises: The activated product is placed in a plating solution for chemical plating.

8. The preparation method according to claim 7, characterized in that: One or more of the following conditions are met: (1) The plating solution comprises 4 g / L to 18 g / L of a second metal salt, 2 g / L to 40 g / L of a second reducing agent, and 5 g / L to 80 g / L of a second complexing agent; (2) The ratio of the activated product to the plating solution is (1-20) g: (80-120) ml; (3) The temperature of the chemical plating is 40°C to 70°C; (4) The chemical plating time is 1 min to 10 min.

9. An electrode material, characterized in that: The invention comprises a modified electrolyte as described in any one of claims 1 to 3 or a modified electrolyte prepared by the preparation method as described in any one of claims 4 to 8.

10. A battery, characterized in that: It comprises a positive electrode, a negative electrode and a solid electrolyte arranged between the positive electrode and the negative electrode, and the positive electrode material comprises the electrode material as claimed in claim 9.

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