Metal matrix composite material and method of making and using same

Abstract

The present application relates to a kind of metal matrix composites and its preparation method and application, belong to composite material technical field.The metal matrix composite includes base material and active material loaded on the base material;The active material includes metal matrix and nanodiamond particle distributed in the metal matrix;The nanodiamond particle includes diamond core and amorphous carbon layer, and the amorphous carbon layer is coated in at least part of the surface of the diamond core.The present application utilizes nanodiamond particle containing amorphous carbon layer and diamond core, can effectively improve the wettability of interface electrolyte, improve the structural stability of material, inhibit the crack and structural damage due to the volume expansion of material, effectively improve the structural stability of composite material, and optimize the transmission path of metal cation, improve the cycle performance and high rate charge-discharge performance of material.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a metal-based composite material and a preparation method and application thereof. Background Art

[0002] In the field of new energy batteries, secondary batteries (Sn) have attracted considerable attention due to their efficient energy storage mechanisms and cost advantages. These batteries utilize the rocking motion of metal cations between the negative and positive electrodes, or the reversible redox reactions between anions and metal cations, to store and release energy. Alloying metals, such as tin, antimony, bismuth, aluminum, and zinc, have attracted considerable attention due to their high theoretical alloying capacities. For example, tin (Sn) is considered a promising anode material for secondary batteries due to its high theoretical specific capacity (approximately 994 mAh / g for lithium storage and 847 mAh / g for sodium storage). However, tin suffers from poor electrolyte wettability, significant volume expansion (up to 300%), and slow diffusion kinetics of the metal cation storage, which limit its performance in batteries. The poor contact between tin and the electrolyte and the slow metal cation storage reaction kinetics affect the battery's rate performance. Its significant volume expansion during charge and discharge can lead to electrode structural fracture, thus affecting the battery's cycling stability and service life.

[0003] Currently, researchers are modifying alloy-type metal anode materials through various methods to improve their electrochemical performance, including nano-sizing, alloying, and coating. For example, existing technologies involve nano-sizing metal particles such as tin, antimony, and bismuth to increase the material's specific surface area, improve the contact between the electrode and the electrolyte, and thus enhance battery performance. Another type of technology uses alloying (such as tin-antimony alloy or tin-zinc alloy) to improve the alloy's cycling stability and electrochemical reaction activity, thereby alleviating volume expansion and enhancing ion diffusion capacity. In addition, there are also technologies that propose coating alloy-type metals with carbon-based coatings or other nanomaterials to enhance their electrode stability, reduce electrolyte corrosion, and increase ion conduction speed. Although these modification methods have improved the performance of alloy-type metal anodes to a certain extent, they still have many problems. For example, while nano-sizing technology increases the alloy's specific surface area and electrolyte wettability, it generally requires complex preparation processes and special equipment, and faces high costs in large-scale production. Furthermore, while alloying effectively mitigates the volume expansion issue, the diverse composition of the alloys often requires meticulous control of the ratio and preparation process, leading to complex and costly preparation processes. While coating can improve electrode surface properties, it often faces challenges such as poor coating uniformity and difficulty controlling thickness, which in turn impacts the overall performance of the electrode.

[0004] In summary, the existing modification methods have achieved certain results in improving the performance of metal-based negative electrode materials such as tin, but still involve complex preparation processes, high costs, and have not fully solved the problems of slow cation diffusion kinetics of alloy-type metal materials and structural instability under high-rate charge and discharge conditions. Therefore, developing a new type of metal-based composite negative electrode material with optimized structure and performance is of great significance for promoting the commercial application of secondary battery technology. SUMMARY

[0005] The present application aims to solve the problems of poor battery cycle and rate performance caused by poor electrolyte wettability, poor cation diffusion kinetics and large volume expansion of alloy-type metals as secondary battery negative electrode materials. To this end, one of the purposes of the present application is to provide a metal-based composite material that has good wettability with electrolyte and good structural stability and electrochemical performance.

[0006] The second purpose of the present application is to provide a preparation method of the above-mentioned metal-based composite material.

[0007] The third purpose of the present application is to provide a negative electrode material.

[0008] The fourth purpose of the present application is to provide a battery.

[0009] In order to achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0010] The first aspect of the present application provides a metal-based composite material, comprising a base material and an active material loaded on the base material; the active material comprises a metal matrix and nanodiamond particles distributed in the metal matrix; the nanodiamond particles comprise a diamond core and an amorphous carbon layer, and the amorphous carbon layer is coated on at least part of the surface of the diamond core.

[0011] The metal-based composite material according to the first aspect of the present application has at least the following beneficial effects:

[0012] The amorphous carbon layer on the surface of the nanodiamond particles can effectively improve the wettability of the interface electrolyte, promote the formation of a uniform and stable solid electrolyte interface (SEI) film, and improve the electrochemical stability of the material. The diamond core has high hardness and good chemical stability, which inhibits cracks and structural damage caused by volume expansion of the material, effectively improving the structural stability of the composite material. In addition, the composite structure of nanodiamond particles and metal matrix significantly increases the electrochemical contact area of the material and optimizes the transport path of metal cations. Specifically, the introduction of nanodiamond particles helps to form abundant heterogeneous interfaces, providing a fast diffusion path for metal cations, thereby improving the high-rate charge and discharge performance of the battery. The introduction of diamond particles also induces heterogeneous nucleation of the metal matrix, inhibits excessive grain growth, effectively addresses volume expansion and stress gradient caused by alloying reactions, and improves the overall stability of the structure. In addition, the high thermal conductivity of nanodiamond particles also helps to enhance the heat dissipation capacity and thermal stability of the composite material, reduce the risk of thermal runaway, and ensure the safety and stability of the material under high load or high temperature conditions.

[0013] In some embodiments of the present application, the average particle size of the nanodiamond particles is 0.5-200 nm.

[0014] In some embodiments of the present application, the ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core is 1-40%.

[0015] In some embodiments of the present application, the nanodiamond particles are distributed in the metal matrix with a gradually decreasing content gradient from the surface to the interior.

[0016] The design of the nanodiamond particle content gradient not only helps to improve the wettability of the material and electrolyte, but also optimizes the mechanical strength and electrochemical performance of the material, effectively reduces stress concentration in the material, enhances the anti-cracking performance of the overall structure, and ensures good stability and high-rate performance of the material during battery cycling.

[0017] In some embodiments of the present application, the surface nanodiamond particle content of the metal matrix is 10-80%.

[0018] In some embodiments of the present application, the total nanodiamond particle content of the metal matrix is 1-50%.

[0019] In some embodiments of the present application, the thermal conductivity of the nanodiamond particles is 300-3000 W / m·K.

[0020] In some embodiments of the present application, the nanodiamond particles are prepared by a method comprising the step of: reacting nanodiamond raw material with an acid to obtain the nanodiamond particles.

[0021] Due to the oxidation of the acid, the surface carbon atoms of the nanodiamond raw material are rearranged to form a layer of amorphous carbon structure rich in polar functional groups, which can effectively improve the interfacial wettability between the material and the electrolyte, and thus facilitate the formation of a uniform and stable SEI film.

[0022] In some embodiments of the present application, the acid comprises sulfuric acid, nitric acid, or a combination thereof.

[0023] In some embodiments of the present application, the reaction time of the nanodiamond raw material with the acid in the preparation method of the nanodiamond particles is 1-20 h.

[0024] By adjusting the reaction time of the nanodiamond raw material with the acid, the thickness of the amorphous carbon layer can be adjusted.

[0025] In some embodiments of the present application, the metal matrix comprises at least one metal element selected from tin, antimony, bismuth, aluminum, or zinc.

[0026] The present application can use different metal materials as the metal matrix, especially tin, antimony, bismuth, aluminum, or zinc, and alloys thereof. These different metal matrices can support the performance requirements of different batteries, such as sodium-based, lithium-based, calcium-based, potassium-based, and zinc-based batteries, and obtain good specific capacity and cycle stability.

[0027] In some embodiments of the present application, the metal matrix has a gradient structure with gradually decreasing grain size from the inside to the surface.

[0028] Due to the introduction of the nanodiamond particle phase into the metal matrix, heterogeneous nucleation of the metal matrix phase is induced, thereby increasing the nucleation density and inhibiting grain growth. In areas with high content of nanodiamond particles, the metal matrix phase has smaller crystal grain size, thereby forming a gradient structure with gradually refined grain size from the inside to the surface of the metal matrix, and forming a performance distribution with external strength and internal toughness, which can well adapt to the volume expansion and stress gradient caused by alloying reaction and improve the structural stability.

[0029] In some embodiments of the present application, the metal matrix contains heterogeneous nucleation points; in some specific embodiments of the present application, the density of the heterogeneous nucleation points in the metal matrix is 10 8 ~10 12 cm 2 .

[0030] In some embodiments of the present application, the base material comprises a porous material or a non-porous material; in some specific embodiments of the present application, the base material is selected from a porous material.

[0031] In some embodiments of the present application, the porous material comprises at least one of porous aluminum, porous copper, porous nickel or porous stainless steel; in some specific embodiments of the present application, the porous material is selected from porous aluminum.

[0032] In some embodiments of the present application, the non-porous material comprises at least one of aluminum foil, copper foil, titanium foil, stainless steel foil, platinum foil, zinc foil, gold foil, nickel mesh, tungsten mesh, graphene film, carbon cloth or carbon paper.

[0033] The second aspect of the present application provides a preparation method of the metal matrix composite material of the first aspect of the present application, comprising the following steps: taking a solution containing metal salt and nanodiamond particles as a plating solution, taking a base material as an electrode, and performing electroplating treatment to obtain the metal matrix composite material; the metal element in the metal salt comprises the metal element in the metal matrix.

[0034] According to the preparation method of the metal matrix composite material of the second aspect of the present application, at least the following beneficial effects are achieved:

[0035] The preparation method provided by the present application has simple process flow and low cost, and can prepare a metal matrix composite material with excellent electrochemical performance and wettability, which has good application prospect in the preparation of high-performance electrode materials and batteries.

[0036] In some embodiments of the present application, the current density of the electroplating treatment is 1-30 mA / cm 2 .

[0037] In some embodiments of the present application, the deposition time of the electroplating treatment is 5-40 min.

[0038] In some embodiments of the present application, the plating solution further contains gelatin; in some specific embodiments of the present application, the mass content of gelatin in the plating solution is 0.1-5%.

[0039] The third aspect of the present application provides a negative electrode material comprising the metal matrix composite material of the first aspect of the present application or the metal matrix composite material prepared by the preparation method of the second aspect of the present application.

[0040] According to the negative electrode material of the third aspect of the present application, at least the following beneficial effects are achieved:

[0041] The metal-based composite material provided in the present invention has good comprehensive properties such as structural stability, cycle performance, high-rate charge and discharge performance, and safety performance, and can be used to prepare negative electrode materials with excellent electrochemical properties.

[0042] In some embodiments of the present invention, the negative electrode material does not include a conductive agent and a binder.

[0043] The negative electrode material provided in the present invention has good structural stability and electrical conductivity, and can obtain good electrochemical performance and energy density without adding additional conductive agents and binders.

[0044] The fourth aspect of the present invention provides a battery comprising a positive electrode material, an electrolyte, and the negative electrode material according to the third aspect of the present invention.

[0045] The battery according to the fourth aspect of the present invention has at least the following beneficial effects:

[0046] The battery prepared by adopting the negative electrode material of the present invention has good structural stability and electrochemical performance, especially has excellent specific capacity and cycle performance.

[0047] In some embodiments of the present invention, the positive electrode material includes at least one of graphite, sodium cobalt oxide, sodium nickel manganese oxide, sodium nickel sulfide, sodium manganese oxide, sodium iron phosphate, sodium nickel iron cyanide, vanadium-based oxide or sodium ferric fluoride.

[0048] In some embodiments of the present invention, the battery comprises at least one of a sodium ion battery, a lithium ion battery, a calcium ion battery, a potassium ion battery, or a zinc ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The schematic diagram of the structure of the tin-based composite negative electrode material of Example 1 of the present invention is as follows Figure 1 shown.

[0050] Figure 2 This is a TEM image of the nano-diamond particles of Example 1 of the present invention.

[0051] Figure 3 Graph showing the wettability of the composite negative electrode material and the electrolyte in Example 1 and Comparative Example 1 of the present invention.

[0052] Figure 4 This is a charge and discharge performance diagram of the composite negative electrode material of Example 1 of the present invention.

[0053] Figure 5 Graph showing the cycle performance of the composite negative electrode materials of Example 1 and Comparative Example 1 of the present invention at 10C.

[0054] Figure 6TEM images showing the density of heterogeneous nucleation points in Examples 1 and 100-103 of the present invention. DETAILED DESCRIPTION

[0055] The following describes in detail embodiments of the present invention. These embodiments are illustrative and intended only to explain the present invention and are not to be construed as limiting the present invention. The term "comprising" and its equivalents in the specification and claims of this application are intended to cover non-exclusive inclusions, encompassing both those explicitly described in the specification and claims and steps or units inherent in a product, method, or structure that are not described in the specification and claims.

[0056] A first aspect of an embodiment of the present invention provides a metal-based composite material, comprising a base material and an active material loaded on the base material; the active material comprises a metal matrix and nano-diamond particles distributed in the metal matrix; the nano-diamond particles comprise a diamond core and an amorphous carbon layer, and the amorphous carbon layer covers at least a portion of the surface of the diamond core.

[0057] The present invention utilizes the amorphous carbon layer on the surface of nano-diamond particles to effectively improve the wettability of the interfacial electrolyte, promote the formation of a uniform and stable solid electrolyte interface (SEI) film, and improve the electrochemical stability of the material; and the diamond core has the characteristics of high hardness and good chemical stability, which inhibits the cracks and structural damage caused by the volume expansion of the material, and effectively improves the structural stability of the composite material. In addition, the present invention significantly increases the electrochemical contact area of ​​the material through the composite structure of nano-diamond particles and metal matrix, and optimizes the transmission path of metal cations. Specifically, the introduction of nano-diamond particles is conducive to the formation of a rich heterogeneous interface, providing a fast metal cation diffusion path, thereby improving the high-rate charge and discharge performance of the battery; and the introduction of diamond particles can also induce heterogeneous nucleation of the metal matrix, inhibit excessive grain growth, effectively deal with the volume expansion and stress gradient caused by the alloying reaction, and improve the overall stability of the structure; and the high thermal conductivity of nano-diamond particles also helps to enhance the heat dissipation capacity and thermal stability of the composite material, reduce the risk of thermal runaway, and ensure the safety and stability of the material under high load or high temperature conditions.

[0058] In some embodiments of the present invention, the average particle size of the nanodiamond particles is 0.5 to 200 nm; in some specific embodiments of the present invention, the average particle size of the nanodiamond particles is 1 to 80 nm; in some examples of the present invention, the average particle size of the nanodiamond particles is 1.5 to 30 nm. Non-limiting specific examples include 1.5 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 10 nm, 15 nm, 20 nm, 25 nm, and 30 nm.

[0059] In some embodiments of the present invention, the ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core is 1-40%; in some specific embodiments of the present invention, the ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core is 3-20%; in some examples of the present invention, the ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core is 5-15%. Non-limiting specific examples include 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%.

[0060] In some embodiments of the present invention, the nano-diamond particles are distributed in the metal matrix in a content gradient that gradually decreases from the surface to the interior.

[0061] The design of the nano-diamond particle content gradient of the present invention is not only conducive to improving the wettability of the material with the electrolyte, but also can optimize the mechanical strength and electrochemical properties of the material, effectively reduce stress concentration in the material, enhance the anti-fracture performance of the overall structure, and ensure that the material has good stability and high-rate performance during the battery cycle.

[0062] In some embodiments of the present invention, the surface content of nano-diamond particles on the metal substrate is 10-80%; in some specific embodiments of the present invention, the surface content of nano-diamond particles on the metal substrate is 50-80%; in some examples of the present invention, the surface content of nano-diamond particles on the metal substrate is 50-70%. Non-limiting specific examples include 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, and 70%.

[0063] In some embodiments of the present invention, the total content of nano-diamond particles in the metal matrix is ​​1-50%; in some specific embodiments of the present invention, the total content of nano-diamond particles in the metal matrix is ​​5-40%; in some examples of the present invention, the total content of nano-diamond particles in the metal matrix is ​​10-30%. Non-limiting specific examples include 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, and 30%.

[0064] In some embodiments of the present invention, the thermal conductivity of the nanodiamond particles is 300 to 3000 W / m·K; in some specific embodiments of the present invention, the thermal conductivity of the nanodiamond particles is 500 to 2000 W / m·K; in some examples of the present invention, the thermal conductivity of the nanodiamond particles is 700 to 1200 W / m·K. Non-limiting specific examples include 700 W / m·K, 750 W / m·K, 800 W / m·K, 850 W / m·K, 900 W / m·K, 950 W / m·K, 1000 W / m·K, 1050 W / m·K, 1100 W / m·K, 1150 W / m·K, and 1200 W / m·K.

[0065] In some embodiments of the present invention, the nano-diamond particles are prepared by a method comprising the following steps: reacting a nano-diamond raw material with an acid to obtain the nano-diamond particles.

[0066] Due to the oxidation effect of acid, the surface carbon atoms of the diamond raw material will be rearranged, thereby generating an amorphous carbon layer structure rich in polar functional groups. This amorphous carbon layer structure rich in polar functional groups can effectively improve the interface wettability between the material and the electrolyte, thereby facilitating the formation of a uniform and stable SEI film.

[0067] In some embodiments of the present invention, in the method for preparing nanodiamond particles, the acid includes sulfuric acid, nitric acid, or a combination thereof; in some specific embodiments of the present invention, the acid includes sulfuric acid and nitric acid; in some examples of the present invention, in the acid, the volume ratio of sulfuric acid to nitric acid is 1:(0.5-2); non-limiting specific examples include 1:0.5, 1:1, 1:1.5, and 1:2.

[0068] In some embodiments of the present invention, the sulfuric acid is concentrated sulfuric acid, and the nitric acid is concentrated nitric acid.

[0069] In some embodiments of the present invention, in the method for preparing nanodiamond particles, the reaction time of the nanodiamond raw material and the acid is 1 to 20 hours; in some specific embodiments of the present invention, the reaction time of the nanodiamond raw material and the acid is 1.5 to 15 hours; in some examples of the present invention, the reaction time of the nanodiamond raw material and the acid is 2 to 10 hours. Non-limiting specific examples include 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0070] The thickness of the amorphous carbon layer can be adjusted by adjusting the reaction time of the nanodiamond raw material and the acid.

[0071] In some embodiments of the present invention, the metal matrix includes at least one metal element selected from tin, antimony, bismuth, aluminum, or zinc; in some specific embodiments of the present invention, the metal matrix includes one metal element selected from tin, antimony, bismuth, aluminum, or zinc.

[0072] The present invention can use different metal materials as the metal matrix, especially metals such as tin, antimony, bismuth, aluminum or zinc or their alloys. These metal matrices of different materials can support the performance requirements of different batteries such as sodium-based, lithium-based, calcium-based, potassium-based, and zinc-based, and obtain good specific capacity and cycle stability.

[0073] In some embodiments of the present invention, the grain size of the metal matrix presents a gradient structure that gradually decreases from the interior to the surface.

[0074] Due to the introduction of nano-diamond particle phase into the metal matrix, heterogeneous nucleation of the metal matrix phase is induced, thereby increasing the nucleation density and inhibiting grain growth. In areas with high nano-diamond particle content, the metal matrix phase has a smaller crystal grain size, thereby forming a gradient structure in which the metal matrix grain size gradually refines from the inside to the surface, forming a performance distribution that is strong on the outside and tough on the inside, which can well adapt to the volume expansion and stress gradient caused by the alloying reaction and improve structural stability.

[0075] In some embodiments of the present invention, the metal matrix contains heterogeneous nucleation sites.

[0076] By introducing second-phase nanodiamond particles into the metal matrix, it is beneficial to form abundant heterogeneous nucleation sites, provide fast diffusion channels for ions, and improve the reaction kinetics of the material.

[0077] In some embodiments of the present invention, the density of heterogeneous nucleation sites in the metal matrix is ​​10 8 ~10 12 pieces / cm 2 In some specific embodiments of the present invention, the density of heterogeneous nucleation points in the metal matrix is ​​5×10 8 ~5×10 11 pieces / cm 2 In some examples of the present invention, the density of heterogeneous nucleation points in the metal matrix is ​​10 9 ~10 11 pieces / cm 2 . Non-limiting specific examples include 10 9 pieces / cm 2 , 2×10 9 pieces / cm 2 , 5×10 9 pieces / cm 2 , 8×10 9 pieces / cm 2 , 10 10 pieces / cm 2 , 2×10 10 pieces / cm 2 , 5×10 10 pieces / cm 2 , 8×10 10 pieces / cm 2 , 10 11 pieces / cm 2 .

[0078] In some embodiments of the present invention, the substrate material includes a porous material or a non-porous material; in some specific embodiments of the present invention, the substrate material is selected from porous materials.

[0079] In some embodiments of the present invention, the porous material is prepared by a method comprising the following steps: electrochemically etching a non-porous material of the same material, wherein the current density used in the electrochemical etching is 10-30 mA / cm 2 , and a porous material is obtained.

[0080] In some specific embodiments of the present invention, the current density used for electrochemical etching is 15-25 mA / cm 2 ; Non-limiting specific examples such as 15mA / cm 2 , 18mA / cm 2 , 20mA / cm 2 , 22mA / cm 2 or 25mA / cm 2 .

[0081] In some specific embodiments of the present invention, the etching time of the electrochemical etching is 15 to 35 minutes; non-limiting specific examples include 15 minutes, 20 minutes, 25 minutes, 30 minutes or 35 minutes.

[0082] In some specific embodiments of the present invention, the etching solution used in electrochemical etching is an acidic solution; in some examples of the present invention, the acidic solution includes at least one of a hydrochloric acid solution, a sulfuric acid solution or a nitric acid solution; in some examples of the present invention, the acidic solution is selected from a hydrochloric acid solution.

[0083] In some specific embodiments of the present invention, the concentration of the acidic solution is 5 to 10 mol / L; non-limiting specific examples include 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L or 10 mol / L.

[0084] In some embodiments of the present invention, the porous material includes at least one of porous aluminum, porous copper, porous nickel or porous stainless steel; in some specific embodiments of the present invention, the porous material is selected from porous aluminum.

[0085] Compared with other porous materials, porous aluminum may have higher porosity, better pore structure distribution and material conductivity after electrochemical etching. In addition, the pore structure of porous aluminum is more uniform, which is more conducive to the penetration of electrolyte. These characteristics together improve its ion transfer efficiency and electrode stability.

[0086] In some embodiments of the present invention, the non-porous material includes at least one of aluminum foil, copper foil, titanium foil, stainless steel foil, platinum foil, zinc foil, gold foil, nickel mesh, tungsten mesh, graphene film, carbon cloth or carbon paper.

[0087] In some embodiments of the present invention, porous aluminum is prepared by a method comprising the following steps: electrochemically etching aluminum foil in a hydrochloric acid solution;2 In some embodiments of the present application, the concentration of the hydrochloric acid solution is 5-10 mol / L.

[0088] The second aspect of the embodiments of the present application provides a preparation method of the metal matrix composite material of the first aspect of the embodiments of the present application, comprising the following steps: taking a solution containing metal salt and nanodiamond particles as a plating solution, taking a base material as an electrode, and performing electroplating treatment to obtain a metal matrix composite material; the metal element in the metal salt comprises the metal element in the metal matrix.

[0089] The preparation method provided by the present application has simple process flow and low cost, and can prepare a metal matrix composite material with excellent electrochemical performance and wettability, which has good application prospect in the preparation of high-performance electrode materials and batteries.

[0090] In some embodiments of the present application, the current density of the electroplating treatment is 1-30 mA / cm 2 ; in some embodiments of the present application, the current density of the electroplating treatment is 7-18 mA / cm 2 ; in some embodiments of the present application, the current density of the electroplating treatment is 9-12 mA / cm 2 . Non-limiting specific examples include 9 mA / cm 2 , 9.5 mA / cm 2 , 10 mA / cm 2 , 10.5 mA / cm 2 , 11 mA / cm 2 , 11.5 mA / cm 2 , 12 mA / cm 2 .

[0091] In some embodiments of the present application, the deposition time of the electroplating treatment is 5-40 min; in some embodiments of the present application, the deposition time of the electroplating treatment is 15-30 min; in some embodiments of the present application, the deposition time of the electroplating treatment is 18-22 min. Non-limiting specific examples include 18 min, 18.5 min, 19 min, 19.5 min, 20 min, 20.5 min, 21 min, 21.5 min, and 22 min.

[0092] In some embodiments of the present application, the plating solution further contains gelatin.

[0093] The addition of gelatin in the plating solution can effectively control the co-deposition process of nanodiamond and tin, avoid excessive aggregation, and ensure the uniform distribution of the metal matrix and good electrode structure.

[0094] In some embodiments of the present application, the mass content of gelatin in the plating solution is 0.1-5%; in some embodiments of the present application, the mass content of gelatin in the plating solution is 0.3-3%; in some embodiments of the present application, the mass content of gelatin in the plating solution is 0.5-2%. Non-limiting specific examples include 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, and 2%.

[0095] The third aspect of the embodiments of the present application provides a negative electrode material comprising the metal matrix composite of the first aspect of the embodiments of the present application or the metal matrix composite prepared by the preparation method of the second aspect of the embodiments of the present application.

[0096] The metal matrix composite provided in the embodiments of the present application has good comprehensive performance such as structural stability, cycle performance, high-rate charge-discharge performance, and safety performance, and can be used to prepare a negative electrode material with excellent electrochemical performance.

[0097] In some embodiments of the present application, the negative electrode material does not comprise a conductive agent and a binder.

[0098] The negative electrode material provided in the embodiments of the present application has good structural stability and electrical conductivity, and can obtain good electrochemical performance and energy density without adding additional conductive agents and binders.

[0099] The fourth aspect of the embodiments of the present application provides a battery comprising a positive electrode material, an electrolyte, and the negative electrode material of the third aspect of the embodiments of the present application.

[0100] The battery prepared by using the negative electrode material in the embodiments of the present application has good structural stability and electrochemical performance, and in particular has excellent specific capacity and cycle performance.

[0101] In some embodiments of the present application, the positive electrode material comprises at least one of graphite, sodium cobalt oxide (e.g., NaCoO2), sodium nickel manganese oxide (e.g., NaNi 0.5 Mn 0.5 O2), sodium nickel sulfide (e.g., Na3Ni2SbO6), sodium manganese oxide (e.g., NaMnO2), sodium iron phosphate (e.g., NaFePO4), sodium nickel iron cyanide (e.g., sodium nickel [hexacyanoferrate(II)] Na2NiFe(CN)6), vanadium-based oxide (e.g., NaVO3), or sodium iron fluoride (e.g., NaFeF3); in some embodiments of the present application, the positive electrode material is selected from graphite; in some embodiments of the present application, the positive electrode material is selected from expanded graphite.

[0102] Using expanded graphite as the positive electrode material has excellent cycle stability and is suitable for long-term application.

[0103] In some embodiments of the present invention, the battery comprises at least one of a sodium ion battery, a lithium ion battery, a calcium ion battery, a potassium ion battery, or a zinc ion battery.

[0104] The present invention will be described in further detail below by way of specific examples. It should be understood that the following examples are only intended to further illustrate the present invention and are not to be construed as limiting the scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles set forth herein all fall within the scope of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, and are not intended to be limited to the specific data exemplified below. The raw materials, reagents, or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial sources or can be obtained by existing known methods.

[0105] Example 1

[0106] This embodiment provides a tin-based composite negative electrode material (PAL-Sn@ND), the structure of which is shown in FIG. Figure 1 As shown, it includes porous aluminum and a tin@nanodiamond active functional layer supported on the porous aluminum; the tin@nanodiamond active functional layer includes a tin matrix and nanodiamond particles distributed in the tin matrix. The TEM image of the nanodiamond particles in this example is shown in FIG. Figure 2 As shown, (a) is a zoomed-out view, (b) and (c) are magnified views, and (c) also marks the position and thickness (1 nm) of the amorphous carbon layer. Figure 2 It can be seen that the nano-diamond particles include a diamond core and an amorphous carbon layer, and the amorphous carbon layer covers at least a portion of the surface of the diamond core.

[0107] The tin-based composite negative electrode material (PAL-Sn@ND) in this example was prepared by preparing a tin@nano-diamond composite active functional layer on porous aluminum using a nanocomposite electroplating method. The specific preparation method is as follows:

[0108] S1. Preparation of Nanodiamond Suspension: Weigh an appropriate amount of nanodiamond raw material powder with an average particle size of 10 nm and place it in a reactor. Pour concentrated nitric acid and concentrated sulfuric acid into the reactor in a 1:1 volume ratio. Add a magnetic stirrer at 450-500 rpm and react for 3 hours. After the reaction, take a sample into a centrifuge tube and centrifuge at 5000 rpm for 10 minutes. After centrifugation, discard the supernatant and add an appropriate amount of deionized water. Repeat this process 3-5 times and collect the resulting centrifuged product. Then, add an appropriate amount of a water-soluble emulsifying dispersant, sodium dodecylbenzenesulfonate, and ultrasonically disperse for 30 minutes to obtain a uniformly dispersed nanodiamond suspension.

[0109] S2. Preparation of a plating solution: Stannous sulfate, potassium pyrophosphate decahydrate, and gelatin are mixed in an electroplating tank, and the nanodiamond suspension prepared in step S1 is added. Ultrasonic stirring is performed until uniform, to obtain a plating solution. The mass ratio of stannous sulfate to potassium pyrophosphate decahydrate is 2:8, the mass content of gelatin in the plating solution is 1%, and the mass content of nanodiamonds in the plating solution is 1%.

[0110] S3. Preparation of porous aluminum: Take aluminum foil with a purity of ≥99.9% and a thickness of 50 μm, wash it with a 1% sodium hydroxide solution to remove the surface oxide film; place the aluminum foil in a hydrochloric acid solution with a concentration of 8 mol / L, connect the current for electrochemical etching, and the current density is 20 mA / cm 2 , etching time 25min; immerse the etched porous aluminum foil in ethanol and deionized water in sequence and ultrasonically wash for 2min, repeat 2-3 times, and vacuum dry at 50℃ for 5h.

[0111] S4. Preparation of tin@nanodiamond active functional layer: Place the treated porous aluminum cathode and tin foil anode in the electroplating tank and connect the circuit for nanocomposite co-plating at a current density of 10 mA / cm 2 The electroplating time was 20 minutes. After the electroplating was completed, the prepared electrode was immersed in acetone, ethanol, and deionized water in sequence and ultrasonically cleaned for 2 minutes. This was repeated 2-3 times, and then vacuum-dried at 50°C for 12 hours to obtain a PAL-Sn@ND composite anode material with a tin@nanodiamond active functional layer.

[0112] Pole sheet preparation, battery assembly and testing:

[0113] Cut the vacuum-dried composite negative electrode material sheet into pieces of appropriate size and store them in a glove box for later use. Preparation of the battery graphite positive electrode: Weigh expanded graphite, conductive carbon black, and polytetrafluoroethylene in a mass ratio of 8:1:1 in a grinding machine. Add N-methylpyrrolidone solvent and grind thoroughly to obtain a uniform slurry. Then, evenly coat the slurry on the surface of aluminum foil, controlling the surface density of the electrode to 10 mg / cm. 2, vacuum-dry at 80°C for 12 hours. The dried electrode sheet was cut into pieces of appropriate size, weighed, and placed in a glove box for later use. Separator Preparation: Cut glass fiber paper into appropriate sizes, dry in a drying oven, and place in a glove box for later use as a separator. Electrolyte Preparation: In a glove box, weigh 2M NaPF6 and add it to 10mL of a mixed solvent of ethyl methyl carbonate (EMC), ethylene carbonate (EC), and dimethyl carbonate (DMC) (volume ratio = 3:2:2). Stir until the NaPF6 is completely dissolved to form a 2M NaPF6 / (ethyl methyl carbonate (EMC), ethylene carbonate (EC), dimethyl carbonate (DMC)) solution, which is used as the electrolyte for later use. Battery Assembly: In an argon-protected glove box, stack the prepared battery negative electrode, separator, and battery positive electrode in sequence. Then, add an appropriate amount of electrolyte dropwise and encapsulate the battery in a battery casing to complete the battery assembly and obtain a secondary battery.

[0114] The electrochemical performance of the prepared secondary battery was tested using the NEWARE battery testing system; and the electrolyte was dripped onto the vacuum-dried composite negative electrode material electrode sheet to test the wetting performance of the composite negative electrode material and the electrolyte.

[0115] Comparative Example 1

[0116] Comparative Example 1 provides a tin-based composite anode material (PAL-Sn). This material differs from Example 1 in that the active functional layer comprises only tin. The preparation method of this example differs from that of Example 1 in that step S1 is omitted, and the plating solution in step S2 does not contain a nanodiamond suspension. The remaining preparation steps are identical to those of Example 1, with tin being electrochemically deposited solely on porous aluminum. The electrochemical and wetting properties of Comparative Example 1 were tested using the methods of Example 1.

[0117] Figure 3 The wettability diagram of the composite negative electrode material and the electrolyte of Example 1 and Comparative Example 1, wherein (a) is Comparative Example 1 and (b) is Example 1; Figure 3 It can be seen that the PAL-Sn@ND tin-based composite negative electrode material electrode sheet prepared in Example 1 has better wettability with the electrolyte.

[0118] Figure 4 This is a charge and discharge performance diagram of the composite negative electrode material of Example 1; Figure 5 The cycle performance diagram of the composite negative electrode material of Example 1 and Comparative Example 1 at 10C. Figure 4 It can be seen that the composite negative electrode material of Example 1 has good charge and discharge performance; Figure 5It can be seen that the porous aluminum-tin@nanodiamond composite negative electrode material obtained by nanodiamond and tin nano-composite electroplating modification in Example 1 has higher cycle stability, and the capacity retention rate is 80% when cycled at 10C (5 mA / g) high rate to 5100 cycles; compared with the porous aluminum-tin composite negative electrode material obtained in Comparative Example 1 (the capacity retention rate is 80% when cycled to 600 cycles), it is increased by 850%.

[0119] Examples 2-16

[0120] Examples 2-16 each provide a tin-based composite negative electrode material (different substrate-Sn@ND), which is different from Example 1 in that the substrate material of Examples 2-16 is replaced by different substrate materials, and the specific substrate materials are shown in Table 1; other preparation steps and raw materials are the same as those of Example 1.

[0121] The electrochemical performance of Examples 2-16 is tested by the method in Example 1, and compared with the performance of Example 1 of the application. The electrochemical performance of the substrate types and materials used in Examples 1-16 is shown in Table 1 below.

[0122] Table 1 Electrochemical performance of substrate types and materials used in Examples 1-16

[0123]

[0124]

[0125] As can be seen from Table 1, the battery using porous aluminum as the substrate in Example 1 performs best in specific capacity and cycle number. This may be due to the porous aluminum structure providing a larger surface area and more active sites, promoting the penetration of electrolyte and ion transmission efficiency. At the same time, the good electrical conductivity and mechanical stability of porous aluminum also help to maintain the integrity of the electrode structure and electrochemical activity, thereby significantly improving the cycle stability and service life of the battery. These characteristics make porous aluminum an ideal choice for making high-performance secondary battery negative electrodes.

[0126] Examples 17-27

[0127] Examples 17-27 each provide a tin-based composite negative electrode material (PAL-Sn@ND), which is different from Example 1 in that the average particle size of the nanodiamonds in Examples 17-27 is different, and the specific average particle size of the nanodiamonds is shown in Table 2; other preparation steps and raw materials are the same as those of Example 1.

[0128] The electrochemical performance of Examples 17-27 is tested by the method in Example 1, and compared with the performance of Example 1 of the application. The electrochemical performance of the nanodiamond particle size and materials used in Examples 1, 17-27 is shown in Table 2 below.

[0129] Table 2 Average particle size of nanodiamond and electrochemical performance of materials of Examples 1, 17-27

[0130]

[0131]

[0132] As can be seen from Table 2, the particle size of nanodiamond has a significant influence on the electrochemical performance of the PAL-Sn@ND composite anode material. The best performance appears when using nanodiamonds with a particle size of about 10 nm, at which the specific capacity and cycle number are the highest. As the particle size increases, the specific capacity decreases slightly, and especially when the particle size exceeds 40 nm, the cycle number decreases significantly, indicating that nanodiamonds with larger particle sizes can lead to unevenness of the electrode structure and a decrease in electrochemical activity. This indicates that smaller nanodiamond particle sizes are more conducive to improving the structural stability and electrochemical performance of the electrode.

[0133] Examples 28-34

[0134] Examples 28-34 each provide a tin-based composite anode material (PAL-Sn@ND), which differs from Example 1 in that the ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core in Examples 28-34 is different (the thickness of the amorphous carbon layer is adjusted mainly by adjusting the reaction time of the diamond and acid in step S1, and the thickness of the amorphous carbon layer is obtained by TEM testing), and specific ratios are shown in Table 3; other preparation steps and raw materials are the same as in Example 1.

[0135] The electrochemical performance of Examples 28-34 is tested using the method in Example 1, and is compared with the performance of Example 1 of the application. The ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core in Examples 1, 28-34 and the electrochemical performance of the materials are shown in Table 3 below.

[0136] Table 3 Ratio of thickness of amorphous carbon layer to diameter of diamond core in Examples 1, 28-34 and electrochemical performance of materials

[0137]

[0138] As can be seen from Table 3, the ratio of the thickness of the amorphous carbon layer on the surface of the nanodiamond particles to the diameter of the diamond core has a significant influence on the electrochemical performance of the battery. The use of a ratio of 10% in Example 1 shows the best performance, with the highest specific capacity and cycle number. When the ratio is lower or higher than 10%, the cycle stability and specific capacity of the battery generally show a downward trend, and especially when the ratio reaches 50%, the performance decreases significantly. This indicates that a moderate thickness of the amorphous carbon layer helps to optimize the contact of the electrolyte and the transport of ions, thereby improving the performance of the battery. Too thin or too thick carbon layers can hinder these processes.

[0139] Examples 35-41

[0140] Examples 35-41 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the surface nanodiamond content of the negative electrode materials of Examples 35-41 is different (the surface nanodiamond content is mainly adjusted by adjusting the amount of nanodiamond suspension added in step S2, and the surface nanodiamond content is obtained by measuring the carbon content on the sample surface by energy dispersive X-ray spectroscopy EDS). The specific content is shown in Table 4; the other preparation steps and raw materials are the same as those in Example 1.

[0141] The electrochemical properties and wetting properties of Examples 35-41 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The surface nanodiamond content, electrochemical properties and contact angles of Examples 1 and 35-41 are shown in Table 4 below.

[0142] Table 4 Surface nanodiamond content, electrochemical properties and contact angles of Examples 1, 35-41

[0143]

[0144] As can be seen from Table 4, the surface nanodiamond content has a significant effect on the electrochemical performance of the PAL-Sn@ND composite negative electrode material. When the content is 60% (Example 1), the specific capacity and number of cycles are the highest, the contact angle is the smallest, and the interface wettability is good. As the content decreases, the contact angle increases, the wettability deteriorates, and the specific capacity and number of cycles decrease (Examples 35-38). When the content increases to 50%-80% (Examples 39-41), the contact angle decreases significantly, the wettability improves, and the electrochemical performance is restored, especially at 50%-70%, which shows better cycle performance. In summary, a nanodiamond content of 60% can achieve the best electrochemical performance and interface characteristics.

[0145] Examples 42-46

[0146] Examples 42-46 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the distribution concentration of the nanodiamonds in Examples 42-46 in the metal matrix is ​​different (the distribution concentration is mainly adjusted by adjusting the amount of nanodiamond suspension added in step S2). The specific distribution concentrations are shown in Table 5; the other preparation steps and raw materials are the same as those in Example 1.

[0147] The electrochemical properties of Examples 42-46 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The distribution concentration of nanodiamonds in the metal matrix and the electrochemical properties of the materials of Example 1 and Examples 42-46 are shown in Table 5 below.

[0148] Table 5 Distribution concentration of nanodiamonds in metal matrix and electrochemical properties of materials in Examples 1, 42-46

[0149]

[0150] As can be seen from Table 5, the distribution concentration of nanodiamonds in the metal matrix has a significant effect on the electrochemical performance of the PAL-Sn@ND composite negative electrode material. When the concentration is 20% (Example 1), the specific capacity and the number of cycles reach the highest values, which are 95 mAh / g and 5100 times, respectively. As the concentration decreases (Examples 42-43), the specific capacity and the number of cycles decrease, but when the concentration is 10% (Example 43), the number of cycles increases to 4122 times, indicating that it has good cycle performance at this concentration. As the concentration increases (Examples 44-46), the specific capacity reaches 90 mAh / g at 30%, but the number of cycles decreases slightly. At high concentrations (40%-50%), the electrochemical performance decreases, indicating that excessively high nanodiamond concentrations may lead to reduced electrode performance.

[0151] Examples 47-51

[0152] Examples 47-51 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the thermal conductivity of the nanodiamonds in Examples 47-51 is different (the thermal conductivity is mainly adjusted by adjusting the amount of nanodiamonds). The specific thermal conductivity is shown in Table 6; the other preparation steps and raw materials are the same as those in Example 1.

[0153] The electrochemical properties of Examples 47-51 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The thermal conductivity of the nanodiamonds and the electrochemical properties of the materials of Example 1 and Examples 47-51 are shown in Table 6 below.

[0154] Table 6 Thermal conductivity of nanodiamonds and electrochemical properties of materials in Examples 1, 47-51

[0155] Example No. Thermal conductivity of nanodiamond (W / m·K) Specific capacity (mAh / g) Number of cycles (times) 1 1000 95 5100 47 500 94 4402 48 700 92 4680 49 1200 93 4698 50 1500 93 4005 51 2000 94 4578

[0156] As can be seen from Table 6, the thermal conductivity of nanodiamonds has a significant impact on the electrochemical performance of the PAL-Sn@ND composite negative electrode material. When the thermal conductivity is 1000 W / m·K (Example 1), the specific capacity and cycle number are 95 mAh / g and 5100 times, respectively. When the thermal conductivity is reduced to 500 W / m·K (Example 47), the specific capacity drops slightly to 94 mAh / g, and the cycle number decreases to 4402 times. When the thermal conductivity is in the range of 700-1200 W / m·K (Examples 48-49), the cycle number is higher, at 4680 and 4698 times, respectively, but the specific capacity is relatively low, at approximately 92-93 mAh / g. When the thermal conductivity is further increased to 1500-2000 W / m·K (Examples 50-51), the specific capacity and cycle number both decrease, indicating that excessively high thermal conductivity may affect electrode performance. In general, when the thermal conductivity is in the range of 700-1200 W / m·K, the material shows better cycle performance.

[0157] Examples 52-56

[0158] Examples 52-56 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the gelatin content in the plating solution of step S2 in Examples 52-56 is different, and the specific gelatin content is shown in Table 7; the other preparation steps and raw materials are the same as those in Example 1.

[0159] The electrochemical properties of Examples 52-56 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The gelatin content in the plating solution of Example 1 and Examples 52-56 and the electrochemical properties of the materials are shown in Table 7 below.

[0160] Table 7 Gelatin content in the plating solution of Examples 1, 52-56 and electrochemical properties of the materials

[0161] Example No. Gelatin content in plating solution (%) Specific capacity (mAh / g) Number of cycles (times) 1 1 95 5100 52 0 89 3000 53 0.5 92 4290 54 1.5 90 4350 55 3 88 3730 56 5 90 2220

[0162] As can be seen from Table 7, the gelatin content in the plating solution has a significant effect on the electrochemical properties of the PAL-Sn@ND composite negative electrode material. The ratio of 1% gelatin used in Example 1 shows the best performance. This may be because the appropriate gelatin content helps to optimize the microstructure and surface properties of the electrode material, and improve its uniformity and adhesion. Gelatin acts as a stabilizer and binder in the plating solution, which can effectively control the co-deposition process of nanodiamonds and tin, avoid excessive aggregation, and ensure the uniform distribution of tin and a good electrode structure. A moderate gelatin content (1%) not only ensures the integrity of the deposited layer, but also maintains good electrical conductivity and ion transport channels, thereby achieving a higher specific capacity and excellent cycle stability.

[0163] Examples 57-67

[0164] Examples 57-67 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the current density in step S4 of Examples 57-67 is different, and the specific current density is shown in Table 8; the other preparation steps and raw materials are the same as Example 1.

[0165] The electrochemical properties of Examples 57-67 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The current density and electrochemical properties of the materials of Example 1 and Examples 57-67 are shown in Table 8 below.

[0166] Table 8 Current density and electrochemical properties of materials in Examples 1, 57-67

[0167] Example No. <![CDATA[电流密度(mA / cm 2 )]]> Specific capacity (mAh / g) Number of cycles (times) 1 10 95 5100 57 1 102 484 58 2 106 496 59 4 98 927 60 6 100 1422 61 9 94 3468 62 12 97 3932 63 15 90 2021 64 18 93 2083 65 21 89 1843 66 25 91 1719 67 30 90 1519

[0168] As can be seen from Table 8, the current density has a significant effect on the electrochemical performance of the PAL-Sn@ND tin composite negative electrode material prepared by nanocomposite electroplating. 2 ) can provide high specific capacity, but the cycle number is low, which reflects that the electrode structure may be loose or uneven. As the current density increases to the medium range (9-12mA / cm 2 ), the cycling stability of the electrode is significantly improved, indicating that at this current density, the deposition process is more conducive to forming a stable and uniform electrode structure. However, when the current density is further increased (over 15 mA / cm 2 ), the specific capacity and cycle number decreased, which may be due to the increased stress and rapid degradation of the electrode material caused by the high current density.

[0169] From the microstructural point of view, the PAL-Sn@ND tin-based composite anode materials deposited at different current densities showed significant differences. 2 ) under low current density (9-12 mA / cm), the electrode structure is loose and the porosity is large, resulting in poor cycle stability; at medium current density (9-12 mA / cm 2 ), the surface morphology of the material is more uniform and dense, the grain size is effectively controlled, the porosity is moderate, and a stable electrolyte infiltration channel is formed; and at high current density (≥15mA / cm 2 ), stress concentration is evident in the material, surface cracks increase, and the electrode degrades rapidly. This indicates that current density has a direct impact on the structural characteristics of the electrode and that the electrode structural characteristics can be adjusted by regulating the current density.

[0170] Examples 68-78

[0171] Examples 68-78 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the electroplating deposition time in step S4 of Examples 68-78 is different. The specific electroplating deposition time is shown in Table 9; the other preparation steps and raw materials are the same as those in Example 1.

[0172] The electrochemical properties of Examples 68-78 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The electroplating deposition time and electrochemical properties of the materials of Example 1 and Examples 68-78 are shown in Table 9 below.

[0173] Table 9 Electroplating deposition time and electrochemical properties of materials in Examples 1, 68-78

[0174] Example No. Electroplating deposition time (min) Specific capacity (mAh / g) Number of cycles (times) 1 20 95 5100 68 5 104 544 69 7 98 536 70 9 101 848 71 12 99 1342 72 15 94 2168 73 18 97 2934 74 22 89 2422 75 25 93 2047 76 30 88 1903 77 35 102 1638 78 40 94 1647

[0175] As can be seen from Table 9, the electroplating deposition time has a significant effect on the electrochemical properties of the PAL-Sn@ND composite negative electrode material. Shorter electroplating deposition times (such as 5-9 minutes) provide higher specific capacity, but the number of cycles is lower, indicating that the electrode may be weaker or uneven. As the electroplating deposition time increases, the cycle stability of the electrode gradually improves, indicating that a longer electroplating deposition time is conducive to the formation of a more uniform and structurally stable electrode layer. However, when the electroplating deposition time is too long (more than 22 minutes), the specific capacity begins to decrease, which may be due to the increase in internal resistance caused by the excessive thickness of the electrode, affecting the battery performance. The optimal electroplating deposition time is between 18 and 22 minutes, which can achieve better overall performance.

[0176] Examples 79-91

[0177] Examples 79-91 each provide a metal-based composite negative electrode material (PAL-M@ND, where M is tin, antimony, bismuth, aluminum, or zinc). The difference from Example 1 is that different metal salt plating solutions are used in step S2 of Examples 79-91 to prepare negative electrodes containing different main phase metals I, and to assemble different types of batteries. The specific main phase metals I and battery types are shown in Table 10; the other preparation steps and raw materials are the same as those in Example 1.

[0178] The electrochemical properties of Examples 79-91 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The electrochemical properties of the main phase metal I, battery types and materials of Example 1 and Examples 79-91 are shown in Table 10 below.

[0179] Table 10 Electrochemical properties of main phase metal I, battery type and materials of Examples 1, 79-91

[0180] Example No. Main phase metal Ⅰ Battery Type Specific capacity (mAh / g) Number of cycles (times) 1 tin Sodium-based dual-ion batteries 95 5100 79 tin Lithium-based dual-ion batteries 98 5050 80 tin Potassium-based dual-ion batteries 92 3800 81 tin Calcium-based dual-ion batteries 88 2000 82 antimony Lithium-based dual-ion batteries 89 3500 83 antimony Sodium-based dual-ion batteries 95 4500 84 antimony Potassium-based dual-ion batteries 90 3700 85 antimony Calcium-based dual-ion batteries 87 1760 86 bismuth Lithium-based dual-ion batteries 96 4800 87 bismuth Sodium-based dual-ion batteries 85 4920 88 bismuth Potassium-based dual-ion batteries 90 3000 89 bismuth Calcium-based dual-ion batteries 86 1500 90 aluminum Lithium-based dual-ion batteries 90 2000 91 zinc zinc-based dual-ion batteries 110 2850

[0181] As can be seen from Table 10, by varying the type of primary metal I, the composite anode materials of the present invention demonstrate adaptability and flexibility for different electrochemical systems (sodium-based, lithium-based, calcium-based, potassium-based, and zinc-based). Each metal element (tin, antimony, bismuth, aluminum, and zinc) not only supports the performance requirements of a specific battery type but also optimizes specific properties such as specific capacity and cycle stability. This allows the material to be customized according to application requirements, providing the versatility and wide range of applications required when designing battery materials.

[0182] Examples 92-99

[0183] Examples 92-99 each provide a rocking-chair-type sodium-ion battery. The difference from Example 1 is that Examples 92-99 combine the prepared tin-based composite negative electrode material (PAL-Sn@ND) with different positive electrode materials to assemble into a rocking-chair-type sodium-ion battery. The specific types of positive electrode materials are shown in Table 11; and the preparation steps and raw materials of the tin-based composite negative electrode material are the same as those in Example 1.

[0184] The electrochemical properties of Examples 92-99 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The types of positive electrode materials and the electrochemical properties of the materials of Example 1 and Examples 92-99 are shown in Table 11 below.

[0185] Table 11 Types of positive electrode materials and electrochemical properties of materials in Examples 1 and 92-99

[0186] Example No. Type of positive electrode material Specific capacity (mAh / g) Number of cycles (times) 1 Expanded graphite (C) 95 5100 92 Sodium cobalt oxide (NaCoO2) 190 420 93 Sodium nickel manganese oxide (NaNi 0.5 Mn 0.5 O2)]]> 160 540 94 <![CDATA[钠镍硫化物(Na3Ni2SbO6)]]> 120 335 95 <![CDATA[钠锰氧化物(NaMnO2)]]> 150 325 96 <![CDATA[钠铁磷酸盐(NaFePO4)]]> 120 1200 97 Sodium nickel [hexacyanoferrate (II)] (Na2NiFe(CN)6) 110 500 98 <![CDATA[钒基氧化物(NaVO3)]]> 250 200 99 <![CDATA[氟化铁钠(NaFeF3)]]> 170 350

[0187] As can be seen from Table 11, Example 1, a sodium-based dual-ion battery using expanded graphite as the positive electrode material, exhibits excellent cycle stability and is suitable for long-term applications. In contrast, the traditional sodium-ion batteries in Examples 92-99, which utilize a variety of positive electrode materials, show potential in capacity but have shorter cycle lives, demonstrating that the pursuit of high energy density can compromise the battery's long-term stability and durability. This comparison emphasizes the importance of balancing performance and application requirements when selecting battery type and materials.

[0188] Examples 100-103

[0189] Examples 100-103 each provide a tin-based composite negative electrode material (PAL-Sn@ND). The difference from Example 1 is that the density of heterogeneous nucleation points in the negative electrode materials of Examples 100-103 is different (by adjusting the electroplating parameters in step S4, such as electric field strength, time, temperature, etc.; the density of heterogeneous nucleation points is directly observed by characterization methods such as thermogravimetry TGA or transmission electron microscopy TEM); the other preparation steps and raw materials are the same as those in Example 1.

[0190] The electrochemical properties of Examples 100-103 were tested using the method in Example 1 and compared with the performance of Example 1 of the present invention. The heterogeneous nucleation point density and electrochemical properties of the materials of Example 1 and Examples 100-103 are shown in Table 12 below.

[0191] Table 12 Heterogeneous nucleation point density and electrochemical properties of materials in Examples 1 and 100-103

[0192]

[0193]

[0194] The data in Table 12 show that the density of heterogeneous nucleation sites has a significant effect on the cycling stability of the PAL-Sn@ND composite anode material. The specific capacity remains basically stable (93-95 mAh / g), but the cycle number decreases when the density of heterogeneous nucleation sites is 10 10 pieces / cm 2 The best performance is 5100 cycles. 8 pieces / cm 2 ) or too high (10 12 pieces / cm 2 ) will reduce the cycling performance, which may be related to the uniformity of grain distribution and the rate of side reactions. Therefore, optimizing the density of heterogeneous nucleation sites is an important design strategy to improve battery performance.

[0195] Figure 6 TEM images of heterogeneous nucleation point density in Examples 1 and 100-103, wherein (a) is Example 103, and the heterogeneous nucleation point density is 10 12 pieces / cm 2 (b) is Example 102, the heterogeneous nucleation point density is 10 11 pieces / cm 2 (c) is Example 1, the heterogeneous nucleation point density is 10 10 pieces / cm 2 (d) is Example 101, the heterogeneous nucleation point density is 10 9 pieces / cm 2 (e) is Example 100, the heterogeneous nucleation point density is 10 8 pieces / cm 2 .from Figure 6 It can be seen that by controlling different electroplating parameters, negative electrode materials containing different numbers of heterogeneous nucleation sites can be obtained, thereby optimizing the performance of electrodes and batteries.

[0196] The negative electrode material provided in the embodiment of the present invention has a gradually decreasing content of nano-diamond particles from the surface to the inside, and the particles have a double-layer structure, with a diamond core inside and an amorphous carbon layer outside. The main purpose of this structural design is to improve the wettability of the interfacial electrolyte by utilizing the polar functional groups rich in the amorphous carbon layer, promote the formation of a uniform and stable solid electrolyte interface (SEI) film, and improve the electrochemical stability of the electrode. In addition, the introduction of nano-diamonds can also induce heterogeneous nucleation of the metal phase, inhibit excessive grain growth, thereby forming a grain size that gradually refines from the inside to the surface, effectively responding to the volume expansion and stress gradient caused by the alloying reaction, and improving the overall stability of the structure. Ultimately, this design not only improves the reaction kinetics of the negative electrode material, but also enhances the heat dissipation capacity through the high thermal conductivity of nano-diamonds, reduces the risk of thermal runaway, and thus significantly improves the overall performance and safety of the battery.

[0197] In summary, the present invention utilizes nanodiamond particles containing an amorphous carbon layer and a diamond core, which can effectively improve the wettability of the interface electrolyte, enhance the structural stability of the material, inhibit cracks and structural damage caused by the volume expansion of the material, effectively enhance the structural stability of the composite material, and optimize the transmission path of metal cations, thereby enhancing the cycling performance and high-rate charge and discharge performance of the material.

Claims

1. A metal matrix composite material, characterized in that: The invention comprises a base material and an active material loaded on the base material; the active material comprises a metal matrix and nano-diamond particles distributed in the metal matrix; the nano-diamond particles comprise a diamond core and an amorphous carbon layer, and the amorphous carbon layer covers at least a portion of the surface of the diamond core.

2. The metal matrix composite material according to claim 1, characterized in that The average particle size of the nano-diamond particles is 0.5-200 nm.

3. The metal matrix composite material according to claim 1, characterized in that The ratio of the thickness of the amorphous carbon layer to the diameter of the diamond core is 1 to 40%.

4. The metal matrix composite material according to claim 1, characterized in that The nano-diamond particles are distributed in the metal matrix according to a content gradient that gradually decreases from the surface to the interior.

5. The metal matrix composite material according to claim 4, characterized in that: The content of nano-diamond particles on the surface of the metal substrate is 10-80%; And / or, the total content of nano-diamond particles in the metal matrix is ​​1-50%.

6. The metal matrix composite material according to claim 1, characterized in that The thermal conductivity of the nano-diamond particles is 300-3000 W / m·K.

7. The metal matrix composite material according to claim 1, characterized in that The metal matrix includes at least one metal element selected from tin, antimony, bismuth, aluminum or zinc; And / or, the grain size of the metal matrix presents a gradient structure that gradually decreases from the interior to the surface.

8. The metal matrix composite material according to claim 1, characterized in that The metal matrix contains heterogeneous nucleation points; the density of the heterogeneous nucleation points in the metal matrix is ​​10 8 ~10 12 pieces / cm 2 .

9. The metal matrix composite material according to claim 1, characterized in that: The substrate material includes a porous material or a non-porous material; the porous material includes at least one of porous aluminum, porous copper, porous nickel or porous stainless steel; the non-porous material includes at least one of aluminum foil, copper foil, titanium foil, stainless steel foil, platinum foil, zinc foil, gold foil, nickel mesh, tungsten mesh, graphene film, carbon cloth or carbon paper.

10. A method for preparing the metal matrix composite material according to any one of claims 1 to 9, characterized in that: The following steps are involved: A solution containing metal salt and nano-diamond particles is used as a plating solution, and a base material is used as an electrode to perform electroplating treatment to obtain the metal-based composite material; the metal elements in the metal salt include the metal elements in the metal base.

11. The preparation method according to claim 10, characterized in that: The current density of the electroplating treatment is 1 to 30 mA / cm 2 ; And / or, the deposition time of the electroplating treatment is 5 to 40 minutes.

12. The preparation method according to claim 10, characterized in that The plating solution also contains gelatin; the mass content of gelatin in the plating solution is 0.1-5%.

13. A negative electrode material, characterized in that The invention comprises the metal matrix composite material according to any one of claims 1 to 9, or the metal matrix composite material prepared by the preparation method according to any one of claims 10 to 12.

14. A battery, characterized in that: The invention comprises a positive electrode material, an electrolyte and the negative electrode material according to claim 13.

15. The battery according to claim 14, characterized in that The positive electrode material includes at least one of graphite, sodium cobalt oxide, sodium nickel manganese oxide, sodium nickel sulfide, sodium manganese oxide, sodium iron phosphate, sodium nickel iron cyanide, vanadium-based oxide or sodium ferric fluoride; And / or, the battery includes at least one of a sodium ion battery, a lithium ion battery, a calcium ion battery, a potassium ion battery or a zinc ion battery.

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