Metal matrix composite material, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of composite materials, and relates to a metal matrix composite material, and a preparation method therefor and a use thereof. The metal matrix composite material comprises a substrate material and an active material loaded on the substrate material; the active material comprises a metal matrix and nanodiamond particles distributed in the metal matrix; and the nanodiamond particles each comprise a diamond core and an amorphous carbon layer, wherein the amorphous carbon layer covers at least part of the surface of the diamond core. By using the nanodiamond particles each comprising an amorphous carbon layer and a diamond core, the present invention can effectively improve the wettability of an interface electrolyte, improve the structural stability of the material, inhibit cracks and structural damages caused by the volume expansion of the material, effectively improve the structural stability of the composite material, optimize the transmission path of metal cations, and improve the cycle performance and high-rate charging and discharging performance of the material.

Description

A metal matrix composite material, its preparation method and application Technical Field

[0001] This invention relates to the field of composite materials technology, and in particular to a metal matrix composite material, its preparation method, and its application. Background Technology

[0002] In the field of new energy batteries, rechargeable batteries have attracted much attention due to their efficient energy storage mechanism and cost advantages. These batteries utilize the rocking motion of metal cations between the negative and positive electrodes or the reversible redox reaction between anions and metal cations at the positive and negative electrodes to achieve energy storage and release. Metals with alloying properties, such as tin, antimony, bismuth, aluminum, and zinc, are highly regarded due to their high theoretical alloying capacity. For example, tin (Sn) is considered a promising choice as a negative electrode material for rechargeable 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 stored metal cations, which limit its performance in batteries. Poor contact between tin and the electrolyte, as well as the slow reaction kinetics of stored metal cations, affect the battery's rate performance. Its significant volume expansion during charge and discharge can lead to electrode structure cracking, thus affecting the battery's cycle stability and lifespan.

[0003] Currently, researchers are modifying alloy metal anode materials using various methods to improve their electrochemical performance, including nano-sizing, alloying, and coating techniques. For example, existing technologies involve increasing the specific surface area of ​​materials by nano-sizing metal particles such as tin, antimony, and bismuth, thereby improving the contact between the electrode and the electrolyte and enhancing battery performance. Another type of technology uses alloying (such as tin-antimony alloys or tin-zinc alloys) to improve the cycle stability and electrochemical reactivity of the alloy, mitigating volume expansion and enhancing ion diffusion. Furthermore, some technologies propose using carbon-based coatings or other nanomaterials to coat alloy metals to enhance electrode stability, reduce electrolyte corrosion, and increase ion conduction speed. While these modification methods have improved the performance of alloy metal anodes to some extent, they still present many challenges. For instance, while nano-sizing technology increases the specific surface area of ​​the alloy and electrolyte wettability, it typically requires complex preparation processes and specialized equipment, and faces high costs in large-scale production. Furthermore, while alloying strategies effectively mitigate the volume expansion problem, the diverse alloy compositions often require precise control of the proportions and preparation process, leading to complex and costly manufacturing processes. Although coating methods can improve electrode surface properties, they typically face challenges such as poor coating uniformity and difficulty in controlling thickness, thus affecting the overall performance of the electrode.

[0004] In summary, while existing modification methods have achieved some success in improving the performance of tin and other metal-based anode materials, they still involve complex preparation processes and high costs, and have not fully solved the problems of slow cation diffusion kinetics and structural instability under high-rate charge-discharge conditions in alloy-type metal materials. Therefore, developing a novel metal-based composite anode material with optimized structure and performance is of great significance for promoting the commercial application of secondary battery technology. Summary of the Invention

[0005] This invention aims to address the problems of poor battery cycle and rate performance caused by the poor wettability of alloy metals as negative electrode materials in existing secondary batteries, poor cation diffusion kinetics, and significant volume expansion. Therefore, one objective of this invention is to provide a metal-based composite material that exhibits good wettability with the electrolyte, as well as good structural stability and electrochemical performance.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned metal matrix composite material.

[0007] The third objective of this invention is to provide a negative electrode material.

[0008] The fourth objective of this invention is to provide a battery.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A first aspect of the present invention provides a metal matrix composite material comprising a substrate material and an active material loaded on the substrate material; the active material comprising a metal matrix and nanodiamond particles distributed in the metal matrix; the nanodiamond particles comprising a diamond core and an amorphous carbon layer, the amorphous carbon layer coating at least a portion of the surface of the diamond core.

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

[0012] This invention utilizes the amorphous carbon layer on the surface of nanodiamond particles to effectively improve the wettability of the interfacial electrolyte, promote the formation of a uniform and stable solid electrolyte interphase (SEI) film, and enhance the electrochemical stability of the material. Meanwhile, the diamond core, with its high hardness and good chemical stability, suppresses cracks and structural damage caused by volume expansion, effectively improving the structural stability of the composite material. Furthermore, this invention significantly increases the electrochemical contact area of ​​the material and optimizes the transport path of metal cations through the composite structure of nanodiamond particles and a metal matrix. Specifically, the introduction of nanodiamond particles facilitates the formation of abundant heterogeneous interfaces, providing rapid diffusion pathways for metal cations, thereby improving the high-rate charge-discharge performance of the battery. The introduction of diamond particles also induces heterogeneous nucleation in the metal matrix, inhibiting excessive grain growth and effectively addressing volume expansion and stress gradients caused by alloying reactions, thus improving the overall structural stability. Finally, the high thermal conductivity of nanodiamond particles helps enhance the heat dissipation capacity and thermal stability of the composite material, reducing the risk of thermal runaway and ensuring the safety and stability of the material under high load or high temperature conditions.

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

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

[0015] In some embodiments of the present invention, the nanodiamond particles are distributed in a metal matrix according to a content gradient that gradually decreases from the surface to the interior.

[0016] The design of the nanodiamond particle content gradient in this invention not only improves the wettability of the material with the electrolyte, but also optimizes the mechanical strength and electrochemical performance of the material, effectively reduces stress concentration in the material, enhances the overall structure's resistance to breakage, and ensures that the material has good stability and high-rate performance during battery cycling.

[0017] In some embodiments of the present invention, the content of nanodiamond particles on the surface of the metal matrix is ​​10-80%.

[0018] In some embodiments of the present invention, the total content of nanodiamond particles in the metal matrix is ​​1-50%.

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

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

[0021] Because the oxidation of acid causes the carbon atoms on the surface of diamond raw materials to rearrange, a layer of amorphous carbon structure rich in polar functional groups is generated. This amorphous carbon layer structure rich in polar functional groups can effectively improve the interfacial wettability between the material and the electrolyte, which is conducive to the formation of a uniform and stable SEI film.

[0022] In some embodiments of the present invention, in the method for preparing the nanodiamond particles, the acid includes sulfuric acid, nitric acid, or a combination thereof.

[0023] In some embodiments of the present invention, in the method for preparing the nanodiamond particles, the reaction time of the nanodiamond raw material with acid is 1 to 20 hours.

[0024] The thickness of the amorphous carbon layer can be adjusted by regulating the reaction time between the nanodiamond raw material and the acid.

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

[0026] This invention can use different metal materials as the metal matrix, especially metals such as tin, antimony, bismuth, aluminum or zinc or their alloys. These different metal matrix materials 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 invention, the grain size of the metal matrix exhibits a gradient structure that gradually decreases from the interior to the surface.

[0028] The introduction of nanodiamond particles into the metal matrix induces heterogeneous nucleation of the metal matrix phase, thereby increasing the nucleation density and inhibiting grain growth. In areas with high nanodiamond particle content, the metal matrix phase has a smaller crystal size, thus forming a gradient structure in which the metal matrix grain size gradually decreases from the inside to the surface. This results in 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.

[0029] In some embodiments of the present invention, the metal matrix contains heterogeneous nucleation sites; in some specific embodiments of the present invention, the density of heterogeneous nucleation sites in the metal matrix is ​​10. 8 ~10 12 pcs / cm 2 .

[0030] 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.

[0031] 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.

[0032] 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.

[0033] A second aspect of the present invention provides a method for preparing the metal-based composite material described in the first aspect of the present invention, comprising the following steps: using a solution containing a metal salt and nanodiamond particles as a plating solution, using a substrate material as an electrode, performing an electroplating treatment to obtain the metal-based composite material; wherein the metal element in the metal salt includes the metal element in the metal matrix.

[0034] The method for preparing the metal matrix composite material according to the second aspect of the present invention has at least the following beneficial effects:

[0035] The preparation method provided by this invention is simple and low in cost, and can produce metal-based composite materials with excellent electrochemical and wettability properties, which have good application prospects in the preparation of high-performance electrode materials and batteries.

[0036] In some embodiments of the present invention, the current density of the electroplating treatment is 1–30 mA / cm². 2 .

[0037] In some embodiments of the present invention, the deposition time of the electroplating treatment is 5 to 40 minutes.

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

[0039] A third aspect of the present invention provides a negative electrode material, including the metal matrix composite material described in the first aspect of the present invention, or the metal matrix composite material prepared by the preparation method described in the second aspect of the present invention.

[0040] The negative electrode material according to the third aspect of the present invention has at least the following beneficial effects:

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

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

[0043] The negative electrode material provided in this invention has good structural stability and conductivity, and can achieve good electrochemical performance and energy density without the need to add additional conductive agents and binders.

[0044] A fourth aspect of the present invention provides a battery comprising a positive electrode material, an electrolyte, and a negative electrode material as described in 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] Batteries made using the negative electrode material of the present invention have good structural stability and electrochemical performance, especially 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 iron fluoride.

[0048] In some embodiments of the present invention, 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. Attached Figure Description

[0049] Figure 1 is a schematic diagram of the structure of the tin-based composite anode material of Embodiment 1 of the present invention.

[0050] Figure 2 is a TEM image of the nanodiamond particles of Example 1 of the present invention.

[0051] Figure 3 shows the wetting performance of the composite negative electrode material and electrolyte in Example 1 and Comparative Example 1 of the present invention.

[0052] Figure 4 shows the charge-discharge performance of the composite negative electrode material in Example 1 of the present invention.

[0053] Figure 5 shows the cycling performance of the composite anode materials of Example 1 and Comparative Example 1 at 10C.

[0054] Figure 6 is a TEM image characterizing the density of heterogeneous nucleation sites in Examples 1, 100-103 of the present invention. Detailed Implementation

[0055] The embodiments of the present invention are described in detail below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The term "comprising" and other equivalent descriptive methods used in the specification and claims of this application are intended to cover a non-exclusive inclusion, which includes both the contents explicitly described in the specification and claims and steps or units that are not described in the specification and claims but are inherent in the product, method, or structure.

[0056] A first aspect of the present invention provides a metal matrix composite material, comprising a substrate material and an active material loaded on the substrate 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, the amorphous carbon layer coating at least a portion of the surface of the diamond core.

[0057] This invention utilizes the amorphous carbon layer on the surface of nanodiamond particles to effectively improve the wettability of the interfacial electrolyte, promote the formation of a uniform and stable solid electrolyte interphase (SEI) film, and enhance the electrochemical stability of the material. Meanwhile, the diamond core, with its high hardness and good chemical stability, suppresses cracks and structural damage caused by volume expansion, effectively improving the structural stability of the composite material. Furthermore, this invention significantly increases the electrochemical contact area of ​​the material and optimizes the transport path of metal cations through the composite structure of nanodiamond particles and a metal matrix. Specifically, the introduction of nanodiamond particles facilitates the formation of abundant heterogeneous interfaces, providing rapid diffusion pathways for metal cations, thereby improving the high-rate charge-discharge performance of the battery. The introduction of diamond particles also induces heterogeneous nucleation in the metal matrix, inhibiting excessive grain growth and effectively addressing volume expansion and stress gradients caused by alloying reactions, thus improving the overall structural stability. Finally, the high thermal conductivity of nanodiamond particles helps enhance the heat dissipation capacity and thermal stability of the composite material, reducing the risk of thermal runaway and ensuring 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 0.5–200 nm; in some specific embodiments of the present invention, the average particle size of the nanodiamond particles is 1–80 nm; in some examples of the present invention, the average particle size of the nanodiamond particles is 1.5–30 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% to 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% to 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% to 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 nanodiamond particles are distributed in a metal matrix according to a content gradient that gradually decreases from the surface to the interior.

[0061] The design of the nanodiamond particle content gradient in this invention not only improves the wettability of the material with the electrolyte, but also optimizes the mechanical strength and electrochemical performance of the material, effectively reduces stress concentration in the material, enhances the overall structure's resistance to breakage, and ensures that the material has good stability and high-rate performance during battery cycling.

[0062] In some embodiments of the present invention, the content of nanodiamond particles on the surface of the metal substrate is 10-80%; in some specific embodiments of the present invention, the content of nanodiamond particles on the surface of the metal substrate is 50-80%; in some examples of the present invention, the content of nanodiamond particles on the surface of 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 nanodiamond particles in the metal matrix is ​​1-50%; in some specific embodiments of the present invention, the total content of nanodiamond particles in the metal matrix is ​​5-40%; in some examples of the present invention, the total content of nanodiamond 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 300–3000 W / m·K; in some specific embodiments of the present invention, the thermal conductivity of the nanodiamond particles is 500–2000 W / m·K; in some examples of the present invention, the thermal conductivity of the nanodiamond particles is 700–1200 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 nanodiamond particles are prepared by a method comprising the following steps: reacting nanodiamond raw material with acid to obtain nanodiamond particles.

[0066] Because the oxidation of acid causes the carbon atoms on the surface of diamond raw materials to rearrange, a layer of amorphous carbon structure rich in polar functional groups is generated. This amorphous carbon layer structure rich in polar functional groups can effectively improve the interfacial wettability between the material and the electrolyte, which is conducive to the formation of a uniform and stable SEI film.

[0067] In some embodiments of the present invention, the acid used in the preparation method of nanodiamond particles 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, the volume ratio of sulfuric acid to nitric acid in the 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, the reaction time of the nanodiamond raw material with acid in the preparation method of nanodiamond particles is 1-20 h; in some specific embodiments of the present invention, the reaction time of the nanodiamond raw material with acid is 1.5-15 h; in some examples of the present invention, the reaction time of the nanodiamond raw material with acid is 2-10 h. Non-limiting specific examples include 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, and 10 h.

[0070] The thickness of the amorphous carbon layer can be adjusted by regulating the reaction time between 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] This invention can use different metal materials as the metal matrix, especially metals such as tin, antimony, bismuth, aluminum or zinc or their alloys. These different metal matrix materials 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.

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

[0074] The introduction of nanodiamond particles into the metal matrix induces heterogeneous nucleation of the metal matrix phase, thereby increasing the nucleation density and inhibiting grain growth. In areas with high nanodiamond particle content, the metal matrix phase has a smaller crystal size, thus forming a gradient structure in which the metal matrix grain size gradually decreases from the inside to the surface. This results in 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] Introducing second-phase nanodiamond particles into a metal matrix facilitates the formation of abundant heterogeneous nucleation sites, providing rapid diffusion channels for ions and improving 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 pcs / cm 2 In some specific embodiments of the present invention, the density of heterogeneous nucleation sites in the metal matrix is ​​5 × 10⁻⁶. 8 ~5×10 11 pcs / cm 2 In some examples of this invention, the density of heterogeneous nucleation sites in the metal matrix is ​​10. 9 ~10 11 pcs / cm 2 Non-restrictive specific examples are shown in 10. 9 pcs / cm 2 2×10 9 pcs / cm 2 5×10 9 pcs / cm 2 8×10 9 pcs / cm 2 10 10 pcs / cm 2 2×10 10 pcs / cm 2 5×10 10 pcs / cm 2 8×10 10 pcs / cm 2 10 11 pcs / 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 for electrochemical etching is 10–30 mA / cm². 2 This yields porous materials.

[0080] In some specific embodiments of the present invention, the current density used for electrochemical etching is 15–25 mA / cm². 2 Non-limiting specific examples include 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 for electrochemical etching is 15 to 35 min; non-limiting specific examples include 15 min, 20 min, 25 min, 30 min or 35 min.

[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 hydrochloric acid solution, sulfuric acid solution or nitric acid solution; in some examples of the present invention, the acidic solution is selected from 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 to other porous materials, porous aluminum may have higher porosity, better pore structure distribution and material conductivity after electrochemical etching. Furthermore, the more uniform pore structure of porous aluminum is more conducive to electrolyte penetration. These characteristics together improve its ion transport 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: electrochemical etching of aluminum foil in a hydrochloric acid solution; the current density being 10–30 mA / cm².2 The etching time is 20-30 min; in some specific embodiments of the present invention, the concentration of hydrochloric acid solution is 5-10 mol / L.

[0088] A second aspect of the present invention provides a method for preparing a metal-based composite material according to the first aspect of the present invention, comprising the following steps: using a solution containing a metal salt and nanodiamond particles as a plating solution, using a substrate material as an electrode, performing electroplating treatment to obtain a metal-based composite material; the metal elements in the metal salt include the metal elements in the metal matrix.

[0089] The preparation method provided by this invention is simple and low in cost, and can produce metal-based composite materials with excellent electrochemical and wettability properties, which have good application prospects in the preparation of high-performance electrode materials and batteries.

[0090] In some embodiments of the present invention, the current density of the electroplating process is 1–30 mA / cm². 2 In some specific embodiments of the present invention, the current density of the electroplating process is 7–18 mA / cm². 2 In some examples of this invention, the current density for the electroplating process is 9–12 mA / cm². 2 Non-limiting specific examples include 9mA / cm. 2 9.5mA / cm 2 10mA / cm 2 10.5 mA / cm 2 11mA / cm 2 11.5 mA / cm 2 12mA / cm 2 .

[0091] In some embodiments of the present invention, the deposition time for electroplating is 5–40 min; in some specific embodiments of the present invention, the deposition time for electroplating is 15–30 min; in some examples of the present invention, the deposition time for electroplating 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 invention, the plating solution also contains gelatin.

[0093] Adding gelatin to the plating solution can act as a stabilizer and binder, effectively controlling the co-deposition process of nanodiamond and tin, avoiding excessive aggregation, and ensuring uniform distribution of the metal substrate and a good electrode structure.

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

[0095] A third aspect of the present invention provides a negative electrode material, including a metal-based composite material of the first aspect of the present invention, or a metal-based composite material prepared by the preparation method of the second aspect of the present invention.

[0096] The metal-based composite material provided in this embodiment of the invention has good comprehensive properties such as structural stability, cycle performance, high-rate charge-discharge performance and safety performance, and can be used to prepare anode materials with excellent electrochemical performance.

[0097] In some embodiments of the present invention, the negative electrode material does not include conductive agents and binders.

[0098] The negative electrode material provided in this embodiment of the invention has good structural stability and conductivity, and can achieve good electrochemical performance and energy density without the need to add additional conductive agents and binders.

[0099] A fourth aspect of the present invention provides a battery comprising a positive electrode material, an electrolyte, and a negative electrode material according to a third aspect of the present invention.

[0100] The battery made using the negative electrode material in the embodiments of the present invention has good structural stability and electrochemical performance, especially excellent specific capacity and cycle performance.

[0101] In some embodiments of the present invention, the positive electrode material includes graphite, sodium cobalt oxide (e.g., NaCoO2), and sodium nickel manganese oxide (e.g., NaNi). 0.5 Mn 0.5 At least one of the following: 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 [hexacyanoferric(II)]Na2NiFe(CN)6), vanadium-based oxide (e.g., NaVO3), or sodium iron fluoride (e.g., NaFeF3); in some specific embodiments of the present invention, the positive electrode material is selected from graphite; in some examples of the present invention, the positive electrode material is selected from expanded graphite.

[0102] Using expanded graphite as the cathode material results in excellent cycle stability, making it suitable for long-term applications.

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

[0104] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described in the present invention are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments can be obtained from conventional commercial channels or by existing known methods.

[0105] Example 1

[0106] This embodiment provides a tin-based composite anode material (PAL-Sn@ND), the structure of which is shown in Figure 1. 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 within the tin matrix. A TEM image of the nanodiamond particles in this example is shown in Figure 2, where (a) is a reduced-size view, and (b) and (c) are enlarged views. The position and thickness (1 nm) of the amorphous carbon layer are also marked in (c). As can be seen from Figure 2, the nanodiamond particles include a diamond core and an amorphous carbon layer, with the amorphous carbon layer covering at least a portion of the surface of the diamond core.

[0107] In this example, the tin-based composite anode material (PAL-Sn@ND) was prepared by a nanocomposite electroplating method to fabricate a tin@nanodiamond composite active functional layer on porous aluminum. 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 reaction vessel. Add concentrated nitric acid and concentrated sulfuric acid in a 1:1 volume ratio to the reaction vessel, add magnetic stirring at 450-500 rpm, and react for 3 hours. After the reaction, transfer the sample to 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 the above operation 3-5 times and collect the centrifuged product. Then add an appropriate amount of water-soluble emulsifying dispersant sodium dodecylbenzenesulfonate and ultrasonically disperse for 30 minutes to obtain a uniformly dispersed nanodiamond suspension.

[0109] S2. Preparation of plating solution: Stannous sulfate, potassium pyrophosphate decahydrate, and gelatin are mixed in an electroplating tank. The nanodiamond suspension prepared in step S1 is added, and the mixture is ultrasonically stirred until homogeneous to obtain the 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 ≥99.9% and a thickness of 50μm, and wash it with a 1% sodium hydroxide solution to remove the surface oxide film; immerse the aluminum foil in an 8mol / L hydrochloric acid solution and perform electrochemical etching with a current density of 20mA / cm². 2 The etching time is 25 minutes. The etched porous aluminum foil is then immersed in ethanol and deionized water in sequence and ultrasonically washed for 2 minutes. This process is repeated 2-3 times. The foil is then vacuum dried at 50°C for 5 hours.

[0111] S4. Preparation of the tin@nanodiamond active functional layer: The treated porous aluminum cathode and tin foil anode were placed in an electroplating bath and connected to a circuit for nanocomposite co-plating. The current density was 10 mA / cm². 2 The electroplating time was 20 minutes. After electroplating, the prepared electrode sheets were immersed in acetone, ethanol, and deionized water in sequence and ultrasonically washed for 2 minutes. This process was repeated 2-3 times. The electrodes were then vacuum dried at 50°C for 12 hours to obtain the PAL-Sn@ND composite anode material with a tin@nanodiamond active functional layer.

[0112] Electrode preparation, battery assembly and testing:

[0113] The vacuum-dried composite negative electrode material was cut into appropriately sized sheets and collected in a glove box for later use. Preparation of the graphite positive electrode: Expanded graphite, conductive carbon black, and polytetrafluoroethylene were weighed in a grinding apparatus at a mass ratio of 8:1:1, and N-methylpyrrolidone solvent was added. The mixture was then thoroughly ground to obtain a uniform slurry. The slurry was then uniformly coated onto the surface of aluminum foil, controlling the areal density of the electrode sheet to be 10 mg / cm³. 2The electrode sheets were vacuum dried at 80℃ for 12 hours. The dried electrode sheets were then cut into appropriately sized pieces, weighed, and placed in a glove box for later use. Separator preparation: Glass fiber paper was cut to appropriate sizes, dried in a drying oven, and then placed in a glove box as a separator for later use. Electrolyte preparation: 2M NaPF6 was weighed in the glove box and added to 10mL of a mixed solvent of ethyl methyl carbonate (EMC), ethylene carbonate (EC), and dimethyl carbonate (DMC) (volume ratio = 3:2:2). The mixture was stirred until the NaPF6 was completely dissolved, preparing a 2M NaPF6 / (ethyl methyl carbonate (EMC), ethylene carbonate (EC), dimethyl carbonate (DMC)) solution for later use as the electrolyte. Battery assembly: In an argon-protected glove box, the prepared negative electrode, separator, and positive electrode were stacked sequentially. An appropriate amount of electrolyte was then added, and the battery was sealed in a battery casing to complete the battery assembly, resulting in a secondary battery.

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

[0115] Comparative Example 1

[0116] Comparative Example 1 provides a tin-based composite anode material (PAL-Sn), which differs from Example 1 in that the active functional layer is only tin. The preparation method in this example differs from Example 1 in that step S1 is omitted, and the plating solution in step S2 does not include a nanodiamond suspension. Other preparation steps are the same as in Example 1, with tin being electrochemically deposited separately on porous aluminum. The electrochemical performance and wetting properties of Comparative Example 1 were tested using the method described in Example 1.

[0117] Figure 3 shows the wetting performance of the composite negative electrode material of Example 1 and Comparative Example 1 with electrolyte, where (a) is Comparative Example 1 and (b) is Example 1. As can be seen from Figure 3, the PAL-Sn@ND tin-based composite negative electrode material prepared in Example 1 has better wetting performance with electrolyte.

[0118] Figure 4 shows the charge-discharge performance of the composite anode material of Example 1; Figure 5 shows the cycle performance of the composite anode materials of Example 1 and Comparative Example 1 at 10C. As can be seen from Figure 4, the composite anode material of Example 1 exhibits good charge-discharge performance. As can be seen from Figure 5, after composite modification by electroplating of nanodiamond and tin nanocomposite materials, the porous aluminum-tin@nanodiamond composite anode material obtained in Example 1 has higher cycle stability. Using a high-rate cycle of 10C (5 mA / g), the capacity retention reaches 80% after 5100 cycles; this is an 850% improvement compared to the porous aluminum-tin composite anode material obtained in Comparative Example 1 (capacity retention of 80% after 600 cycles).

[0119] Example 2-16

[0120] Examples 2-16 each provide a tin-based composite anode material (different substrates - Sn@ND). The difference from Example 1 is that Examples 2-16 use different substrate materials to replace the porous aluminum substrate. The specific substrate materials are shown in Table 1. Other preparation steps and raw materials are the same as in Example 1.

[0121] The electrochemical performance of Examples 2-16 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The substrate types and electrochemical performance of the materials used in Examples 1-16 are shown in Table 1 below.

[0122] Table 1. Substrate types and electrochemical properties of materials used in Examples 1-16

[0123] As shown in Table 1, the battery in Example 1 using porous aluminum as the substrate exhibits the best performance in terms of specific capacity and cycle life. This may be attributed to the fact that the porous aluminum structure provides a larger surface area and more active sites, promoting electrolyte penetration and ion transport efficiency. Simultaneously, the good conductivity and mechanical stability of porous aluminum also help maintain the integrity of the electrode structure and electrochemical activity, thereby significantly improving the battery's cycle stability and lifespan. These properties make porous aluminum an ideal choice for fabricating high-performance secondary battery anodes.

[0124] Examples 17-27

[0125] Examples 17-27 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the average particle size of the nanodiamonds in Examples 17-27 is different. The specific average particle size of the nanodiamonds is shown in Table 2. Other preparation steps and raw materials are the same as in Example 1.

[0126] The electrochemical performance of Examples 17-27 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The nanodiamond particle size and electrochemical performance of the materials used in Examples 1, 17-27 are shown in Table 2 below.

[0127] Table 2. Average particle size of nanodiamonds and electrochemical properties of materials in Examples 1, 17-27

[0128] Table 2 shows that the particle size of nanodiamonds significantly affects the electrochemical performance of the PAL-Sn@ND composite anode material. Optimal performance occurs when using nanodiamonds with a particle size of approximately 10 nm, resulting in the highest specific capacity and cycle life. With increasing particle size, the specific capacity decreases slightly, especially when the particle size exceeds 40 nm, leading to a significant reduction in cycle life. This indicates that larger nanodiamond particle sizes may result in electrode structural inhomogeneity and reduced electrochemical activity. Therefore, smaller nanodiamond particle sizes are more beneficial for improving the structural stability and electrochemical performance of the electrode.

[0129] Examples 28-34

[0130] Examples 28-34 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the ratio of the amorphous carbon layer thickness to the diamond core diameter in Examples 28-34 is different (mainly by adjusting the reaction time of diamond and acid in step S1 to adjust the amorphous carbon layer thickness, which is obtained by TEM testing). The specific ratio is shown in Table 3. Other preparation steps and raw materials are the same as in Example 1.

[0131] The electrochemical performance of Examples 28-34 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The ratio of the amorphous carbon layer thickness to the diamond core diameter and the electrochemical performance of the materials in Examples 1, 28-34 are shown in Table 3 below.

[0132] Table 3. Ratio of amorphous carbon layer thickness to diamond core diameter and electrochemical properties of materials in Examples 1, 28-34

[0133] As shown in 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 impact on the electrochemical performance of the battery. In Example 1, a ratio of 10% showed the best performance, exhibiting the highest specific capacity and cycle life. When the ratio was below or above 10%, the cycle stability and specific capacity of the battery generally showed a decreasing trend, especially when the ratio reached 50%, performance decreased significantly. This indicates that a moderate thickness of the amorphous carbon layer helps optimize electrolyte contact and ion transport, thereby improving battery performance. Carbon layers that are too thin or too thick may hinder these processes.

[0134] Examples 35-41

[0135] Examples 35-41 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the surface nanodiamond content of the anode materials in Examples 35-41 is different (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 using energy-dispersive X-ray spectroscopy (EDS)). The specific content is shown in Table 4. Other preparation steps and raw materials are the same as in Example 1.

[0136] The electrochemical and wetting properties of Examples 35-41 were tested using the method described in Example 1 and compared with those of Example 1 of the present invention. The surface nanodiamond content, electrochemical properties, and contact angles of Examples 1, 35-41 are shown in Table 4 below.

[0137] Table 4. Surface nanodiamond content, electrochemical properties, and contact angle of Examples 1, 35-41

[0138] As shown in Table 4, the surface nanodiamond content significantly affects the electrochemical performance of the PAL-Sn@ND composite anode material. When the content is 60% (Example 1), the specific capacity and cycle life are highest, the contact angle is smallest, and the interfacial wettability is good. With decreasing content, the contact angle increases, wettability deteriorates, and the specific capacity and cycle life decrease (Examples 35-38). When the content increases to 50%-80% (Examples 39-41), the contact angle significantly decreases, wettability improves, and electrochemical performance recovers somewhat, especially exhibiting better cycle performance at 50%-70%. In summary, a nanodiamond content of 60% achieves the best electrochemical performance and interfacial characteristics.

[0139] Examples 42-46

[0140] Examples 42-46 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the distribution concentration of nanodiamonds in the metal matrix in Examples 42-46 is different (mainly adjusted by adjusting the amount of nanodiamond suspension added in step S2). The specific distribution concentrations are shown in Table 5. Other preparation steps and raw materials are the same as in Example 1.

[0141] The electrochemical performance of Examples 42-46 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The distribution concentration of nanodiamond in the metal matrix and the electrochemical performance of the materials in Examples 1, 42-46 are shown in Table 5 below.

[0142] Table 5. Distribution and concentration of nanodiamond in the metal matrix and electrochemical properties of the materials in Examples 1, 42-46

[0143] As shown in Table 5, the concentration of nanodiamonds in the metal matrix significantly affects the electrochemical performance of the PAL-Sn@ND composite anode material. At a concentration of 20% (Example 1), the specific capacity and cycle life reached their highest values ​​of 95 mAh / g and 5100 cycles, respectively. With decreasing concentration (Examples 42-43), the specific capacity and cycle life decreased, but at a concentration of 10% (Example 43), the cycle life increased to 4122 cycles, indicating good cycling performance at this concentration. With increasing concentration (Examples 44-46), the specific capacity reached 90 mAh / g at 30%, but the cycle life decreased slightly. At high concentrations (40%-50%), the electrochemical performance decreased, indicating that excessively high nanodiamond concentrations may lead to reduced electrode performance.

[0144] Examples 47-51

[0145] Examples 47-51 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the thermal conductivity of the nanodiamond in Examples 47-51 is different (mainly by adjusting the amount of nanodiamond used to adjust its thermal conductivity). The specific thermal conductivity is shown in Table 6. Other preparation steps and raw materials are the same as in Example 1.

[0146] The electrochemical performance of Examples 47-51 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The thermal conductivity and electrochemical performance of nanodiamond materials in Examples 1, 47-51 are shown in Table 6 below.

[0147] Table 6. Thermal conductivity and electrochemical properties of nanodiamond materials in Examples 1, 47-51

[0148] As shown in Table 6, the thermal conductivity of nanodiamonds significantly affects the electrochemical performance of the PAL-Sn@ND composite anode material. When the thermal conductivity is 1000 W / m·K (Example 1), the specific capacity and cycle life are 95 mAh / g and 5100 cycles, respectively. When the thermal conductivity decreases to 500 W / m·K (Example 47), the specific capacity slightly decreases to 94 mAh / g, and the cycle life decreases to 4402 cycles. In the thermal conductivity range of 700-1200 W / m·K (Examples 48-49), the cycle life is higher, at 4680 and 4698 cycles, respectively, but the specific capacity is relatively lower, approximately 92-93 mAh / g. When the thermal conductivity is further increased to 1500-2000 W / m·K (Examples 50-51), both the specific capacity and cycle life decrease, indicating that excessively high thermal conductivity may affect electrode performance. Overall, the material exhibits good cycling performance when the thermal conductivity is in the range of 700-1200 W / m·K.

[0149] Examples 52-56

[0150] Examples 52-56 each provide a tin-based composite anode material (PAL-Sn@ND). The difference from Example 1 is that the gelatin content in the plating solution in step S2 of Examples 52-56 is different. The specific gelatin content is shown in Table 7. Other preparation steps and raw materials are the same as in Example 1.

[0151] The electrochemical performance of Examples 52-56 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The gelatin content in the plating solution of Examples 1 and Examples 52-56 and the electrochemical performance of the materials are shown in Table 7 below.

[0152] Table 7. Gelatin content in plating solutions and electrochemical properties of materials in Examples 1 and 52-56

[0153] As shown in Table 7, the gelatin content in the plating bath has a significant impact on the electrochemical performance of the PAL-Sn@ND composite anode material. The formulation using 1% gelatin in Example 1 exhibited the best performance. This is likely because an appropriate gelatin content helps optimize the microstructure and surface properties of the electrode material, improving its uniformity and adhesion. Gelatin acts as a stabilizer and binder in the plating bath, effectively controlling the co-deposition process of nanodiamonds and tin, avoiding excessive aggregation, and ensuring uniform tin distribution and a good electrode structure. A moderate gelatin content (1%) ensures both the integrity of the deposited layer and maintains good conductivity and ion transport channels, thereby achieving high specific capacity and excellent cycle stability.

[0154] Examples 57-67

[0155] Examples 57-67 each provide a tin-based composite anode material (PAL-Sn@ND). The difference between Examples 57-67 and Example 1 is that the current density in step S4 is different. The specific current density is shown in Table 8. Other preparation steps and raw materials are the same as in Example 1.

[0156] The electrochemical performance of Examples 57-67 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The current density and electrochemical performance of the materials in Examples 1, 57-67 are shown in Table 8 below.

[0157] Table 8 Current densities and electrochemical properties of materials in Examples 1, 57-67

[0158] As shown in Table 8, current density has a significant impact on the electrochemical performance of PAL-Sn@ND tin composite anode materials prepared by nanocomposite electroplating. Lower current densities (e.g., 1-2 mA / cm²) are more effective. 2 While it offers high specific capacity, the low cycle life suggests a potentially loose or inhomogeneous electrode structure. As the current density increases to a moderate range (9-12 mA / cm²), the current density decreases. 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 (above 15 mA / cm²), the cycling stability of the electrode is significantly improved. 2 The specific capacity and cycle life both decreased, possibly due to increased stress and rapid degradation of the electrode material caused by excessively high current density.

[0159] From a microstructural perspective, the PAL-Sn@ND tin-based composite anode materials deposited at different current densities exhibit significant differences. Lower current densities (1-2 mA / cm²) show greater variation. 2 At medium current density (9-12 mA / cm²), the electrode structure is loose and has high porosity, resulting in poor cycle stability. 2 Under these conditions, the material's surface morphology is more uniform and dense, the grain size is effectively controlled, the porosity is moderate, and a stable electrolyte wetting channel is formed; while at high current densities (≥15mA / cm²), 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 wetting channel is formed; 2 Under these conditions, stress concentration is significant in the material, surface cracks increase, and the electrode degrades rapidly. This indicates that current density has a direct impact on the electrode structural characteristics, and these characteristics can be adjusted by regulating the current density.

[0160] Examples 68-78

[0161] Examples 68-78 each provide a tin-based composite anode material (PAL-Sn@ND). The difference between Examples 68-78 and Example 1 is that the electroplating deposition time in step S4 is different. The specific electroplating deposition time is shown in Table 9. Other preparation steps and raw materials are the same as in Example 1.

[0162] The electrochemical performance of Examples 68-78 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The electroplating deposition time and electrochemical performance of the materials in Examples 1, 68-78 are shown in Table 9 below.

[0163] Table 9 Electroplating deposition time and electrochemical properties of materials in Examples 1, 68-78

[0164] As shown in Table 9, the electroplating deposition time has a significant impact on the electrochemical performance of the PAL-Sn@ND composite anode material. Shorter deposition times (e.g., 5-9 minutes) provide higher specific capacity but lower cycle counts, indicating that the electrode may be relatively thin or uneven. With increasing deposition time, the cycle stability of the electrode gradually improves, suggesting that longer deposition times are beneficial for forming a more uniform and structurally stable electrode layer. However, when the deposition time is too long (exceeding 22 minutes), the specific capacity begins to decrease, possibly due to increased internal resistance caused by excessive electrode thickness, affecting battery performance. The optimal deposition time is between 18 and 22 minutes, yielding good overall performance.

[0165] Examples 79-91

[0166] Examples 79-91 each provide a metal-based composite anode 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 anodes containing different main phase metals I, and to assemble them into different types of batteries. The specific main phase metals I and battery types are shown in Table 10. Other preparation steps and raw materials are the same as in Example 1.

[0167] The electrochemical performance of Examples 79-91 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The electrochemical performance of the main phase metal I, battery type and materials of Examples 1, 79-91 are shown in Table 10 below.

[0168] Table 10. Main Phase Metal I, Battery Type, and Electrochemical Performance of Materials in Examples 1 and 79-91

[0169] As can be seen from Table 10, by changing the type of main phase metal I, the composite anode material of this invention exhibits 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 specific battery types but also optimizes specific properties such as specific capacity and cycle stability. This allows the material to be customized according to application needs, providing the versatility and wide range of applications required when designing battery materials.

[0170] Examples 92-99

[0171] Examples 92-99 each provide a rocking chair sodium-ion battery. The difference from Example 1 is that in Examples 92-99, the prepared tin-based composite anode material (PAL-Sn@ND) is combined with different cathode materials to assemble a rocking chair sodium-ion battery. The specific types of cathode materials are shown in Table 11. The preparation steps and raw materials of the tin-based composite anode material are the same as those in Example 1.

[0172] The electrochemical performance of Examples 92-99 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The types of cathode materials and their electrochemical performance in Examples 1, 92-99 are shown in Table 11 below.

[0173] Table 11. Types of cathode materials and their electrochemical properties in Examples 1 and 92-99

[0174] As shown in Table 11, Example 1, as a sodium-based dual-ion battery using expanded graphite as the cathode material, exhibits excellent cycle stability and is suitable for long-term applications. In contrast, the conventional sodium-ion batteries in Examples 92-99 employ various cathode materials, demonstrating potential in capacity but exhibiting shorter cycle life, illustrating that pursuing high energy density may sacrifice long-term stability and durability. This comparison underscores the importance of balancing performance and application requirements when selecting battery type and materials.

[0175] Examples 100-103

[0176] Examples 100-103 each provide a tin-based composite anode material (PAL-Sn@ND). The difference between them and Example 1 is that the heterogeneous nucleation point density in the anode materials of Examples 100-103 is different (by adjusting the electroplating parameters in step S4, such as electric field strength, time, temperature, etc.; the heterogeneous nucleation point density is directly observed by characterization methods such as thermogravimetric analysis (TGA) or transmission electron microscopy (TEM); other preparation steps and raw materials are the same as in Example 1.

[0177] The electrochemical performance of Examples 100-103 was tested using the method described in Example 1 and compared with that of Example 1 of the present invention. The heterogeneous nucleation site density and electrochemical performance of the materials in Examples 1, 100-103 are shown in Table 12 below.

[0178] Table 12. Heterogeneous nucleation site density and electrochemical properties of Examples 1 and 100-103

[0179] Table 12 shows that the heterogeneous nucleation site density has a significant impact on the cycle stability of the PAL-Sn@ND composite anode material. The specific capacity remains relatively stable (93-95 mAh / g), but the number of cycles decreases at a heterogeneous nucleation site density of 10... 10 pcs / cm 2 It performed best at 5100 cycles. Too low a density (10...) 8 pcs / cm 2 ) or too high (10) 12 pcs / cm2 Both of these factors can reduce cycle 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 for improving battery performance.

[0180] Figure 6 shows TEM images characterizing the heterogeneous nucleation point density in Examples 1, 100-103, where (a) is Example 103 with a heterogeneous nucleation point density of 10. 12 pcs / cm 2 (b) Example 102, with a heterogeneous nucleation site density of 10. 11 pcs / cm 2 (c) is Example 1, with a heterogeneous nucleation site density of 10. 10 pcs / cm 2 (d) is Example 101, with a heterogeneous nucleation point density of 10. 9 pcs / cm 2 (e) is Example 100, with a heterogeneous nucleation point density of 10. 8 pcs / cm 2 As shown in Figure 6, by controlling different electroplating parameters, negative electrode materials with different numbers of heterogeneous nucleation sites can be obtained, thereby optimizing the performance of the electrode and the battery.

[0181] The negative electrode material provided in this invention exhibits a gradual decrease in nanodiamond particle content from the surface to the interior, with each particle possessing a bilayer structure: an inner diamond core and an outer amorphous carbon layer. This structural design primarily aims to utilize the polar functional groups abundant in the amorphous carbon layer to improve the wettability of the interfacial electrolyte, promoting the formation of a uniform and stable solid electrolyte interphase (SEI) film and enhancing the electrochemical stability of the electrode. Furthermore, the introduction of nanodiamonds can induce heterogeneous nucleation of the metallic phase, inhibiting excessive grain growth and resulting in a gradually refined grain size from the interior to the surface. This effectively addresses the volume expansion and stress gradient caused by the alloying reaction, improving the overall structural stability. Ultimately, this design not only improves the reaction kinetics of the negative electrode material but also enhances heat dissipation through the high thermal conductivity of nanodiamonds, reducing the risk of thermal runaway and significantly improving the overall performance and safety of the battery.

[0182] In summary, this invention utilizes nanodiamond particles containing an amorphous carbon layer and a diamond core, which can effectively improve the wettability of the interfacial electrolyte, enhance the structural stability of the material, suppress cracks and structural damage caused by the volume expansion of the material, effectively improve the structural stability of the composite material, optimize the transport path of metal cations, and improve the cycling performance and high-rate charge-discharge performance of the material.

Claims

1. A metal-based composite material, characterized in that, The material includes a substrate material and an active material loaded on the substrate material; the active material includes a metal matrix and nanodiamond particles distributed in the metal matrix; the nanodiamond particles include a diamond core and an amorphous carbon layer, the amorphous carbon layer covering 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 nanodiamond 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 nanodiamond 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 surface content of the metal matrix is ​​10-80% nanodiamond particles; And / or, the total content of nanodiamond 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 nanodiamond 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 metallic element selected from tin, antimony, bismuth, aluminum, or zinc; And / or, the grain size of the metal matrix exhibits 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 sites; the density of heterogeneous nucleation sites in the metal matrix is ​​10. 8 ~10 12 pcs / cm 2 .

9. The metal matrix composite material according to claim 1, characterized in that, The substrate material includes porous or non-porous materials; 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 a metal matrix composite material as described in any one of claims 1 to 9, characterized in that, Includes the following steps: An electroplating process is performed using a solution containing metal salts and nanodiamond particles as the plating solution and a substrate material as the electrode to obtain the metal-based composite material; the metal elements in the metal salts include the metal elements in the metal matrix.

11. The preparation method according to claim 10, characterized in that, The current density of the electroplating process is 1–30 mA / cm². 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, Includes 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, It includes a positive electrode material, an electrolyte, and the negative electrode material as described in claim 13.

15. The battery according to claim 14, characterized in that, The cathode 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 iron fluoride. And / or, the battery includes at least one of sodium-ion batteries, lithium-ion batteries, calcium-ion batteries, potassium-ion batteries, or zinc-ion batteries.

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