Modified electrolyte and preparation method therefor, electrode material, and battery

Abstract

The present application provides a modified electrolyte and a preparation method therefor, 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 material of the metal particles comprises 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 present application, a specific solid electrolyte is used as the basic electrolyte, the surface of the basic electrolyte is modified with the metal particles, the electronic conductivity of the modified electrolyte is effectively improved by means of cooperation of the basic electrolyte and the metal particles, and the positive electrode material containing the modified electrolyte can simultaneously improve the effective transmission of ions and electrons, such that the battery having the positive electrode material has both low interface impedance and good electrochemical performance.

Description

Modified electrolyte, preparation method thereof, electrode material and battery TECHNICAL FIELD

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

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

[0003] Traditionally, a certain amount of solid-state electrolyte is added during the mixing process of the positive electrode to reduce the interface impedance of the solid-state battery. Although the solid-state electrolyte can construct a lithium ion transmission channel in the positive electrode, the solid-state electrolyte has low electronic conductivity, which easily blocks the conduction of electrons in the positive electrode, reduces the electronic conductivity, and leads to a decrease in battery performance. SUMMARY

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

[0005] The modified electrolyte provided by the present application comprises a base electrolyte and metal particles attached to the surface of the base electrolyte.

[0006] The chemical formula of the base electrolyte comprises 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 La3Zr 2-j Ej O 12 One or more of the following, 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 materials of the metal particles include one or more of the following elements: nickel, copper, tin, iron, cobalt, and precious metals.

[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, this application also provides a method for preparing a modified electrolyte, comprising the following steps:

[0011] A basic electrolyte is provided, and the basic electrolyte is activated to prepare an activated product;

[0012] The surface of the activated product is then chemically plated with metal particles.

[0013] The general chemical formula of the basic electrolyte includes 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 La3Zr 2-j E j O 12 One or more of the following, 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 materials of the metal particles include one or more of the following elements: nickel, copper, tin, iron, cobalt, and precious metals.

[0015] In one embodiment, the step of preparing the activated product includes:

[0016] The base electrolyte is placed in an activation liquid for activation treatment.

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

[0018] (1) the composition of the activation liquid includes 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 liquid is 9.5 to 10.5;

[0020] (3) the ratio of the base electrolyte to the activation liquid 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 electroless plating metal particles on the surface of the activation product includes:

[0023] The activation product is placed in a plating liquid for electroless plating.

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

[0025] (1) the composition of the plating liquid includes 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 activation product to the plating liquid is (1-20) g:(80-120) ml;

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

[0028] (4) the electroless plating time is 1 min to 10 min.

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

[0030] The application also provides a battery comprising a positive electrode, a negative electrode, and a solid-state electrolyte disposed 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 by the application effectively improves the electronic conductivity of the modified electrolyte by using a solid electrolyte with a specific composition as a base electrolyte and modifying the surface of the base electrolyte with metal particles. The positive electrode material containing the modified electrolyte can effectively transport ions and electrons, and the battery with the positive electrode material has low interface impedance and good electrochemical performance. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0033] Fig. 1a is a scanning electron microscope image of a LATP (Li 1.3 Al 0.3 Ti 1.7 Fig. 1b is a scanning electron microscope image of a modified electrolyte prepared from the LATP (Li 1.3 Al 0.3 Ti 1.7 Fig. 1c is a scanning electron microscope image of a modified electrolyte prepared from the LATP (Li 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 accompanying drawings. The preferred embodiments of the present application are shown 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 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 commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application and are not intended to limit the present application.

[0036] The term "and / or" used herein is selected from two or more related listed items, and also includes any and all combinations of related listed items, including any two related listed items, any more related listed items, or all related listed items. For example, "A and / or B" includes three parallel schemes of A, B and "combination of A and B".

[0037] In this document, "one or more" means any one of the listed items independently or any combination of the listed items. Similarly, "one or more" and the like, where used in the specification, mean "one or more, but not exclusively" unless otherwise indicated.

[0038] In this document, "further", "furthermore", "in particular", "for example", "for instance", "such as", "for example", "for instance", and the like are used for descriptive purposes only, and should not be construed as limiting the preceding technical solution, nor should it be construed as limiting the scope of protection in this document. In this document, 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] In this document, "optionally", "optional", "optional" means optional, that is, selected from "yes" or "no" two parallel schemes. If there are multiple "optional" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction, each "optional" is independent of each other. In this application, "optionally contains", "optionally contains" and the like, means "contains or does not contain". "Optional component X" means that component X exists or does not exist, or means that it contains or does not contain the component X.

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

[0041] In this document, the technical features described in an open manner include both the closed technical solution consisting of the listed features and the open technical solution containing the listed features.

[0042] In this document, when referring to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of selectable values ​​within a numerical interval is considered continuous, and includes the two endpoints (i.e., the minimum and maximum values) of the numerical interval, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, and other numerical interval types.

[0043] In this document, the terms "room temperature" or "normal temperature" generally refer to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments of this document, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this document, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0044] In this document, for methods involving multiple steps, unless otherwise explicitly stated herein, there is no strict order constraint on the execution of these steps; they may be executed in any order other than those described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times, and their execution order is not necessarily sequential, but may be executed in turn, alternately, or simultaneously with other steps or parts of the sub-steps or stages of other steps.

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

[0046] Among them, the general chemical formula of the basic electrolyte includes 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 La3Zr 2-j E j O 12one or more of Al, Ge, and D comprises one or more of Nb, Ta, Te, and W, 0

[0047] The material of the metal particles includes one or more of a nickel element, a copper element, a tin element, an iron element, a cobalt element, and a noble metal element.

[0048] In one 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 one specific example, the mass ratio of the base electrolyte and 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] Further, the present application also provides a preparation method of the modified electrolyte, comprising the following steps:

[0052] providing a base electrolyte, activating the base electrolyte to prepare an activated product;

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

[0054] The chemical formula of the base electrolyte comprises 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)3and Li 7-2n-2j D n La3Zr 2-j E j O 12 one or more of Ti, Al, (PO4)3, Li, D, La3Zr, E, O, 0≤t≤2, 0≤q≤2 / 3, 0≤s≤2, 0≤m≤2, 0≤n≤3, 0≤j≤2, D includes one or both of Ge and Al, E includes one or more of Nb, Ta, Te and W;

[0055] The material of the metal particles includes one or more of a nickel element, a copper element, a tin element, an iron element, a cobalt element and a noble metal element.

[0056] In one specific example, the step of preparing the activation product includes: placing the base electrolyte in an activation liquid for activation treatment.

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

[0058] Understandably, the composition of the activation liquid includes 1g / L-15g / L of the first metal salt and 1g / L-8g / L of the buffering agent. Further, the buffering agent can be but is not limited to one or both of sodium citrate and lactic acid.

[0059] The composition of the activation liquid can further 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 can be but is not limited to including ammonia water, further, the mass percentage of the ammonia water is 17%-28%. The stabilizer can be but is not limited to including a branched amylose (cas number 9037-22-3), further, the branched amylose is soluble branched amylose. The protective agent can be but is not limited to including polyethylene glycol. The first reducing agent can be but is not limited to including potassium sodium tartrate.

[0060] In one specific example, the pH value of the activation solution is 9.5-10.5, which 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 one 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 base electrolyte to the activation solution is (80-120) g:100 ml. Specifically, the ratio of the base 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 one specific example, the activation treatment time is 0.5 min-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 base electrolyte is activated in the activation solution under magnetic stirring at 1000 r / min-3000 r / min.

[0065] In one specific example, the step of electroless plating metal particles on the surface of the activation product comprises: placing the activation product in a plating solution for electroless plating.

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

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

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

[0069] Further, the first metal salt can be but is not limited to nickel acetate; the second metal salt can 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 one specific example, the ratio of the activation product to the plating solution is (1-20) g:(80-120) ml.

[0071] Further, the ratio of the activation product to the plating solution is (1-20) g: 100 ml. Specifically, the ratio of the activation 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 one specific example, the temperature of the electroless plating is 40℃-70℃, further, the temperature of the electroless plating can be but is not limited to 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃ or 70℃.

[0073] In one specific example, the time of the electroless plating is 1 min-10 min, further, the time of the electroless 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] Further, the activation product is electrolessly plated in the plating solution under magnetic stirring at 200 r / min-3000 r / min. Understandably, the step of electrolessly plating metal particles on the surface of the activation product further comprises a step of washing and drying.

[0075] Further, the step of washing comprises washing with deionized water and anhydrous ethanol in sequence.

[0076] Further, the step of drying comprises drying at a temperature of 70℃-90℃ for 10 hours-14 hours.

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

[0078] Understandably, the electrode material further comprises an active material, a conductive additive and a binder. Further, the electrode material comprises the active material, the conductive additive, the binder and the modified electrolyte in a mass ratio of (80-100):(1-5):(2-8):(1-3).

[0079] The application also provides a battery, comprising a positive electrode, a negative electrode, and a solid-state 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 by the application is prepared by modifying the surface of a specific solid-state electrolyte as a base electrolyte with metal particles, which can effectively improve the electronic conductivity of the modified electrolyte. The positive electrode material containing the modified electrolyte can improve the effective transmission of ions and electrons, and the battery with the positive electrode material has low interface impedance and good electrochemical performance.

[0081] The application will be further described in detail below with reference to specific examples. It should be understood that the examples are only used to illustrate the application and not used to limit the scope of the application. In the following examples, the experimental methods without specific conditions are preferred to be referred to the instructions given in the application, and can also be referred to the experimental manuals or conventional conditions in the art, or the conditions suggested by the manufacturers, or the known experimental methods in the art.

[0082] In the following specific examples, the measurement parameters of the raw material components may have slight deviations within the weighing accuracy range if not otherwise specified. The temperature and time parameters allow acceptable deviations caused by the instrument testing accuracy or operation accuracy. "Normal temperature" refers to 25°C; "normal pressure" refers to 100 KPa or 101 KPa.

[0083] The solid electrolyte LATP (Li1.3Al0.3Ti1.7(PO4)3) provided in the following examples is self-made, and the specific preparation method is as follows: 1.3 Al 0.3 Ti 1.7 The specific preparation method is as follows:

[0084] 1. Ball milling: isopropanol and agate balls are added to a marumeu ball mill tank, and the raw material powders lithium source (Li2CO3), aluminum source (Al2O3), titanium source (TiO2), and phosphoric acid source (NH4H2PO4) are mixed according to the stoichiometric ratio of the chemical formula, and then ball milling at 400 rpm for 6 hours.

[0085] 2. Vacuum drying: the ball-milled powder slurry is vacuum dried at 80°C for 3 hours until completely dried.

[0086] 3. Calcination: the dried powder is 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: the ball-milled powder is mixed with polyvinyl alcohol (PVA) in a marumeu mortar according to the proportion, and stirred uniformly in the marumeu mortar to form a block.

[0089] 6. Dry molding: The mixture is vacuum dried at 80°C for 1 hour, then ground into powder and collected.

[0090] 7. Tabletting: 0.8 g of the powder is weighed and tabletted using a pressure of 10 MPa for 1 minute, and the operation is repeated to obtain a plurality of primary samples.

[0091] 8. Heat treatment: Each of the primary samples is placed in a crucible coated with alumina (Al2O3) mother powder, heated to 1200°C for 5 hours, and held for 40 minutes to obtain a LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) solid electrolyte.

[0092] Example 1

[0093] The present example provides a modified electrolyte and a preparation method thereof, wherein the preparation method comprises the following steps:

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

[0095] (2) Electroless nickel plating: 10 g of the activated product is placed in 100 ml of an electroless plating solution containing a mixed aqueous solution of 13 g / L of nickel sulfate, 30 g / L of sodium hypophosphite, 40 g / L of sodium citrate, and 30 g / L of ammonium chloride. The electroless nickel plating is performed by magnetic stirring at 50°C and 2000 r / min for 5 min. The product is taken out;

[0096] (3) The product after electroless nickel plating is placed in a Buchner funnel and washed with deionized water for 5 times, and then washed with anhydrous ethanol for 3 times and dried.

[0097] (4) The washed product is 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 the present example differs from that of Example 1 in that the activation time is 0.5 min.

[0100] Example 3

[0101] The modified electrolyte provided by the embodiment, the preparation method thereof is different from that of embodiment 1 in that the activation time is 3 min.

[0102] Example 4

[0103] The modified electrolyte provided by the embodiment, the preparation method thereof is different from that of embodiment 1 in that the activation time is 5 min.

[0104] Example 5

[0105] The modified electrolyte provided by the embodiment, the preparation method thereof is different from that of embodiment 1 in that the electroless nickel plating time is 8 min.

[0106] Example 6

[0107] The modified electrolyte provided by the embodiment, the preparation method thereof is different from that of embodiment 1 in that the electroless nickel plating time is 10 min.

[0108] Example 7

[0109] The modified electrolyte provided by the embodiment, the preparation method thereof is different from that of embodiment 1 in that the electroless nickel plating time is 10 min.

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

[0111] (2) Electroless copper plating: 2 g of the activated product is placed in 100 ml of electroless plating solution, which comprises a mixed aqueous solution of CuSO4 6 g / L, sodium hypophosphite 4 g / L, ethylenediaminetetraacetic acid disodium Na2(EDTA) 10 g / L, and ammonium chloride 2 mg / L. Magnetism is stirred at 65°C and 500 r / min for 5 min, which is the electroless copper plating time. Take out;

[0112] (3) The copper-plated product is placed in a Buchner funnel and washed with deionized water for 5 times, and then washed with anhydrous ethanol for 3 times and dried;

[0113] (4) The washed product is 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 differs from that in Example 1 in that the base electrolyte is replaced with a solid electrolyte LLZO (Li7La3Zr2O). 12 Solid electrolyte LLZO(Li7La3Zr2O) 12 The preparation method of this product differs from the basic electrolyte provided in Example 1 in that the raw material powder is replaced with the product according to the chemical formula Li7La3Zr2O. 12 The stoichiometric ratios of lithium source (LiOH), lanthanum source (La2O3), and zirconium source (ZrO2) are used.

[0116] Comparative Example 1

[0117] The modified electrolyte provided in this comparative example is prepared by the following steps: 100g of LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3) The solid electrolyte was soaked 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 is prepared by the following steps: 100g of LATP solid electrolyte and 1g of nickel powder are ball-milled and mixed for 1h to obtain a mixed powder.

[0120] Detection methods and results

[0121] Figure 1a shows the above LATP(Li) 1.3 Al 0.3 Ti 1.7 (PO4)3) Scanning electron microscope image of the solid electrolyte before nickel plating, as shown in Figure 1b, is LATP(Li) in Example 3. 1.3 Al 0.3 Ti 1.7 (PO4)3) Scanning electron microscope image of the modified electrolyte obtained by nickel plating of solid electrolyte.

[0122] Battery fabrication: Lithium iron phosphate solid-state coin cells were used as the evaluation standard. The positive electrode composition had the following mass ratio: active material lithium iron phosphate : conductive additive conductive carbon black : binder polyvinylidene fluoride : modified electrolyte of each example 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, negative electrode is metallic lithium. All the above batteries were tested for charge and discharge at 1C rate.

[0123] The battery's internal resistance can be read directly from the battery internal resistance meter.

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

[0125] The limitation of metal particles in the modified electrolyte of the batteries of each 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 after using a specific solid electrolyte as a base electrolyte and then modifying the surface of the solid electrolyte by attaching specific modified metal particles thereto, the electrical properties of the solid-state battery containing the modified electrolyte can be effectively improved, and the battery with the above-mentioned positive electrode material has both lower interface impedance and good electrochemical properties.

[0129] Each of the technical features of the above-described embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of each of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present disclosure.

[0130] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims, and the description and drawings can be used to explain the scope of the claims.

Claims

1. A modified electrolyte, characterized in that, The modified electrolyte comprises: a base electrolyte and metal particles attached to the surface of the base electrolyte; wherein the chemical formula of the base electrolyte comprises 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 La3Zr 2-j E j O 12 one or more of Ge and Al, E comprises one or more of Nb, Ta, Te, and W; 0 the material of the metal particles comprises one or more of nickel element, copper element, tin element, iron element, cobalt element and noble metal element.

2. The modified electrolyte of claim 1, wherein 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, wherein the mass ratio of the base electrolyte to the metal particles is (10-2000000):

1.

4. A method for producing a modified electrolyte, characterized by, The method for preparing the modified electrolyte comprises the following steps: providing a base electrolyte, activating the base electrolyte to prepare an activated product; carrying out electroless plating of metal particles on the surface of the activated product; wherein the chemical formula of the base electrolyte comprises 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 La3Zr 2-j E j O 12 one or more of Ge and Al, E comprises one or more of Nb, Ta, Te, and W; 0 the material of the metal particles comprises one or more of nickel element, copper element, tin element, iron element, cobalt element and noble metal element.

5. The production method according to claim 4, wherein The step of preparing the activated product comprises: activating the base electrolyte in an activation solution.

6. The production method according to claim 5, wherein one or more of the following conditions are met: (1) the composition of 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 to 10.5; (3) the ratio of the base electrolyte to the activation solution is (80-120) g:(80-120) ml; (4) the activation time is 0.5 min to 8 min.

7. The production method according to any one of claims 4 to 6, characterized by, The step of carrying out electroless plating of metal particles on the surface of the activated product comprises: carrying out electroless plating of the activated product in a plating solution.

8. The production method according to claim 7, wherein one or more of the following conditions are met: (1) the composition of 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 electroless plating is 40°C to 70°C; (4) the electroless plating time is 1 min to 10 min.

9. An electrode material, characterized by The modified electrolyte is prepared by the method of any one of claims 1-3.

10. A battery, characterized by The solid-state electrolyte comprises the electrode material of claim 9.

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