WO2024016250A1 - 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置 - Google Patents

负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置 Download PDF

Info

Publication number
WO2024016250A1
WO2024016250A1 PCT/CN2022/106981 CN2022106981W WO2024016250A1 WO 2024016250 A1 WO2024016250 A1 WO 2024016250A1 CN 2022106981 W CN2022106981 W CN 2022106981W WO 2024016250 A1 WO2024016250 A1 WO 2024016250A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
oxide
negative active
oxide precursor
amphiphilic polymer
Prior art date
Application number
PCT/CN2022/106981
Other languages
English (en)
French (fr)
Inventor
赵欣
王国宝
王文轩
李雪
浦晨凯
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to PCT/CN2022/106981 priority Critical patent/WO2024016250A1/zh
Publication of WO2024016250A1 publication Critical patent/WO2024016250A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, and in particular to a negative active material and a preparation method thereof, a secondary battery, a battery module, a battery pack and an electrical device.
  • lithium-ion batteries have been increasingly widely used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. fields. Due to the great development of lithium-ion batteries, higher requirements have been put forward for their energy density, cycle performance and safety performance. Based on the higher requirements for the energy density of secondary batteries, a lot of research has also been carried out around high-capacity negative active materials.
  • Graphite and silicon are commonly used as negative active materials.
  • graphite negative active materials have a low theoretical gram capacity
  • silicon negative active materials have serious volume effects, which limit the energy density of lithium-ion batteries and sodium-ion batteries. Improvement, thereby limiting the development of lithium-ion batteries and sodium-ion batteries.
  • This application was made in view of the above-mentioned issues, and aims to provide a negative active material and a preparation method thereof, a secondary battery, a battery module, a battery pack and a power device, so as to solve the problem of limited increase in the gram capacity of existing negative active materials. .
  • the first aspect of the present application provides a preparation method of a negative active material, including:
  • the first oxide is selected from one of V 2 O 3 , Fe 2 O 3 and CuO;
  • a second oxide precursor is assembled on the assembled first oxide to form an amphiphilic polymer material-first oxide-second oxide precursor composite, wherein the second oxide precursor is One of K 2 SnO 3 , Na 2 SiO 3 , Na 2 GeO 3 , NaAlO 2 , NaBO 4 ⁇ 4H 2 O; and
  • the composite is heated to remove the amphiphilic polymer material and allow the second oxide precursor to form the second oxide, thereby obtaining a negative active material having a hexagonal hollow structure.
  • the preparation method of the negative active material of the present application uses an amphiphilic polymer material as a template to prepare a negative active material with a hexagonal hollow structure. Normally, during the charge and discharge process of the negative active material, the insertion of active ions easily causes volume expansion/contraction.
  • the hexagonal hollow structure negative active material of the present application has a certain buffering effect on volume expansion/contraction, and can Overcome the volume change caused by the active ion intercalation process, thereby maintaining the overall structural stability of the negative active material.
  • the present application forms a negative active material by combining the first oxide and the second oxide, which can better exert their complementary advantages and make up for each other's shortcomings.
  • the negative electrode of the present application The active material embeds more active ions and further increases the reversible capacity, thus increasing the gram capacity and specific surface area of the negative active material, further increasing the energy density of the secondary battery.
  • the negative electrode material includes V 2 O 3 -SnO 2 , Fe 2 O 3 -SnO 2 , Fe 2 O 3 -GeO 2 , Fe 2 O 3 -Al 2 O 3 , Fe One of 2 O 3 -B 2 O 3 and CuO-SiO 2 , optionally V 2 O 3 -SnO 2 or Fe 2 O 3 -SnO 2 .
  • these specific optional negative electrode materials all present a hexagonal hollow structure, have a high specific surface area and a certain buffering effect, and can overcome the volume change caused by the active ion intercalation process. Therefore, the above-mentioned The overall structural stability of the negative active material is good.
  • the composite first oxide and the second oxide have better synergy.
  • the amphiphilic polymeric material is selected from polyvinylpyrrolidone.
  • polyvinylpyrrolidone is a linear polymer polymerized from the monomer vinylpyrrolidone, and is soluble in water and polar solvents such as alcohols, halogenated hydrocarbons, carboxylic acids, and alcoholamines.
  • polar solvents such as alcohols, halogenated hydrocarbons, carboxylic acids, and alcoholamines.
  • the molecular chain skeleton of polyvinylpyrrolidone and -CH 2 - in pyrrolidone are hydrophobic, while the amide group in the pyrrolidone ring is hydrophilic.
  • polyvinylpyrrolidone molecules can aggregate to form micelles whose outer layer is composed of the hydrophilic groups of polyvinylpyrrolidone.
  • the hydrophilic groups of polyvinylpyrrolidone can become sites for interaction with metal atoms through complexation and/or electrostatic adsorption, so that polyvinylpyrrolidone micelles can serve as templates for assembly to form metal
  • the first oxide is assembled on the amphiphilic polymer material template, specifically including:
  • the dispersion system is heated so that the first oxide precursor forms the first oxide, and the assembled first oxide is obtained.
  • the amphiphilic polymer material and the first oxide precursor are fully dispersed in an alkaline dispersion medium, and the polyvinylpyrrolidone molecules can aggregate to form micelles, the outer layer of which is made of polyvinylpyrrolidone.
  • the hydrophilic group of polyvinylpyrrolidone can become a site that interacts with metal atoms through complexation and/or electrostatic adsorption, so that the first oxide precursor is adsorbed on the site .
  • the dispersion system is heated to form the first oxide precursor from the first oxide precursor.
  • the heating temperature of the dispersion system is required to satisfy all the first oxide precursors to form the first oxide and improve the conversion rate of the first oxide precursor; it is also necessary to control the heating temperature of the dispersion system not to be too high to prevent amphiphilicity.
  • the polymer material is volatilized and removed, maintaining the stability of the amphiphilic polymer material template to ensure the subsequent assembly of the second oxide precursor.
  • the first oxide precursor is selected from one of Co 3 V 2 O 8 , Fe(NO 3 ) 3 and Cu(NO 3 ) 2 .
  • the amphiphilic polymer material is combined with one of Co 3 V 2 O 8 , Fe(NO 3 ) 3 and Cu(NO 3 ) 2 to have higher performance in an alkaline dispersion medium.
  • the solubility allows the first oxide precursor to be fully dispersed and avoids the loss of the first oxide during the assembly process to ensure the yield and purity of the product.
  • the mass ratio of the amphiphilic polymer material to the first oxide precursor is 1: (1-2).
  • the amphiphilic polymer material and the first oxide precursor have a suitable mass ratio, so that the first oxide precursor is fully assembled on the amphiphilic polymer material template. Moreover, an appropriate mass ratio can ensure that the final negative active material with a hexagonal hollow structure is obtained.
  • the dispersion system is heated to a temperature of 200°C to 400°C and a time of 5h to 7h.
  • appropriate heating temperature and heating time can ensure that the first oxide precursor is completely converted into the first oxide and improve product yield.
  • heating the dispersion system to a temperature of 200°C to 400°C can reduce the loss of the amphiphilic polymer material and maintain the stability of the amphiphilic polymer material template.
  • appropriate heating temperature and heating time can reduce energy consumption and reduce production costs.
  • assembling and forming a second oxide precursor on the assembled first oxide specifically includes:
  • the assembled first oxide and the second oxide precursor are sufficiently dispersed in the dispersion medium so that the assembled first oxide and the second oxide precursor are in contact.
  • the assembled first oxide and the second oxide precursor are fully dispersed in the dispersion medium, and the second oxide precursor is assembled into the assembled first oxide precursor through physical adsorption. on things.
  • the mass ratio of the assembled first oxide and the second oxide precursor is 1: (1 ⁇ 2).
  • the assembled first oxide and the second oxide precursor have an appropriate mass ratio, which can ensure that the negative electrode active material with a hexagonal hollow structure is finally obtained.
  • the mass concentration of the amphiphilic polymer material in the dispersion medium is 15% to 25%.
  • amphiphilic polymer material has a certain mass such that polyvinylpyrrolidone molecules can aggregate to form micelles in an alkaline dispersion medium.
  • the temperature of the heated composite is 400°C to 600°C, and the time is 5h to 7h.
  • appropriate heating temperature and heating time can ensure that the second oxide precursor is completely converted into the second oxide and improve product yield.
  • the amphiphilic polymer material in the composite can be removed, and the second oxide undergoes an alloying reaction and combines with the first oxide after heating, and the electrostatic attraction between the metal ions forms a strong Metal keys.
  • the average particle size Dv50 of the negative active material is 100 ⁇ m to 200 ⁇ m, optionally 120 ⁇ m to 180 ⁇ m.
  • the average particle size Dv50 of the negative active material is within an appropriate range, which is conducive to obtaining a higher compacted density of the negative active material layer and having a suitable porosity to meet the requirements of the electrochemical reaction.
  • the required amount of electrolyte infiltration also has a shorter migration path for active ions and electrons within the particles, which can improve the energy density and cycle performance of the negative active material layer.
  • a second aspect of the present application also provides a negative active material prepared by the preparation method of the first aspect of the present application.
  • the negative active material of the present application is composed of a first oxide and a second oxide.
  • the negative active material exhibits a hexagonal hollow structure, so that the negative active material has a higher gram capacity and specific surface area.
  • the second oxide formed by its preparation The energy density of secondary batteries is also higher.
  • the specific surface area of the negative active material is 175 m 2 /g ⁇ 400 m 2 /g, optionally 300 m 2 /g ⁇ 400 m 2 /g.
  • the specific surface area of the negative active material is within the above range, which ensures that the negative active material has a high active specific surface area and is conducive to reducing side reactions of the electrolyte on the surface of the negative active material, thereby improving Capacity development and cycle life of negative active materials.
  • the gram capacity of the negative active material is 490mAh/g ⁇ 1100mAh/g, optionally 500mAh/g ⁇ 700mAh/g.
  • the negative active material of the present application has a larger gram capacity, thereby enabling the secondary battery to have a larger energy density.
  • a third aspect of the present application provides a secondary battery, including a negative active material prepared by the preparation method of the first aspect of the present application or a negative active material of the second aspect of the present application.
  • a fourth aspect of the present application provides a battery module including the secondary battery of the third aspect of the present application.
  • a fifth aspect of the present application provides a battery pack, including the battery module of the fourth aspect of the present application.
  • a sixth aspect of the present application provides an electrical device, including at least one selected from the secondary battery of the third aspect of the present application, the battery module of the fourth aspect of the present application, or the battery pack of the fifth aspect of the present application. kind.
  • FIG. 1 shows a flow chart of a method for preparing a negative active material according to an embodiment of the present application.
  • Figure 2 shows a diagram of the lithium insertion state during the charge and discharge process of the negative active material according to an embodiment of the present application.
  • FIG. 3 shows a flow chart of an exemplary process of forming a first oxide in a method for preparing a negative active material.
  • Figure 4 shows an SEM image of a negative active material according to an embodiment of the present application.
  • Figure 5 shows an SEM image of a negative active material according to another embodiment of the present application.
  • FIG. 6 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 7 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 6 .
  • Figure 8 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 9 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 10 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 9 .
  • FIG. 11 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.
  • Ranges disclosed herein are defined in terms of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive of the endpoints, and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, understand that ranges of 60-110 and 80-120 are also expected. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.
  • the numerical range “a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range “0-5" means that all real numbers between "0-5" have been listed in this article, and "0-5" is just an abbreviation of these numerical combinations.
  • a certain parameter is an integer ⁇ 2
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • step (c) means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c). , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b), etc.
  • condition "A or B” is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; Or both A and B are true (or exist).
  • lithium-ion batteries and sodium-ion batteries have achieved great development, higher requirements have been put forward for their energy density, cycle performance and safety performance.
  • the negative active material in lithium-ion batteries or sodium-ion batteries is one of the main factors affecting the performance of lithium-ion batteries or sodium-ion batteries.
  • lithium-ion batteries are widely used in electronic products such as mobile phones, tablets, and drones. People have put forward increasingly higher requirements for the battery capacity of electronic products in order to increase the battery capacity as much as possible in a limited space.
  • the theoretical gram capacity of the currently used graphite anode active material is about 370mAh/g, which cannot meet the demand for higher energy density lithium-ion batteries.
  • the applicant improved the preparation method of the negative active material.
  • the negative active material was synthesized through the template method.
  • the preparation method is simple, and the prepared negative active material has a high active ion embedded amount, which improves the The gram capacity and specific surface area of the negative active material are increased, further improving the energy density of the secondary battery.
  • FIG. 1 shows a flow chart of a method for preparing a negative active material according to an embodiment of the present application.
  • the first aspect of this application provides a method for preparing a negative active material, including:
  • the first oxide is selected from one of V 2 O 3 , Fe 2 O 3 and CuO;
  • the second oxide precursor is selected from one of K 2 SnO 3 , Na 2 SiO 3 , Na 2 GeO 3 , NaAlO 2 , and NaBO 4 ⁇ 4H 2 O;
  • the preparation method of the negative active material of the present application uses an amphiphilic polymer material as a template to prepare a negative active material with a hexagonal hollow structure.
  • the hexagonal hollow structure negative active material of the present application has a certain buffering effect on volume expansion/contraction, and can Overcome the volume change caused by the active ion intercalation process, thereby maintaining the overall structural stability of the negative active material.
  • the present application forms a negative active material by combining the first oxide and the second oxide, which can better bring into play their complementary advantages and the synergistic effect of making up for each other's shortcomings.
  • the negative electrode of the present application The active material embeds more active ions and further increases the reversible capacity, thus increasing the gram capacity and specific surface area of the negative active material, further increasing the energy density of the secondary battery.
  • amphiphilic polymers are polymers that have both hydrophobic and hydrophilic properties.
  • amphiphilic polymer molecules when dissolved in a dispersion medium, amphiphilic polymer molecules can associate to form micelles, in which the hydrophobic groups of the amphiphilic polymer molecules can attract each other to form the core of the micelle.
  • the hydrophilic group forms the outer layer of the micelle.
  • the hydrophilic groups in the outer layer of the micelles can electrostatically adsorb and/or complex with metal atoms and become sites that can bind metal atoms, so that amphiphilic polymer materials can be used as a component to assemble metal oxides. template.
  • the amphiphilic polymer material is polyvinylpyrrolidone.
  • Polyvinylpyrrolidone is a linear polymer polymerized from the monomer vinylpyrrolidone. It is soluble in water and polar solvents such as alcohols, halogenated hydrocarbons, carboxylic acids, and alcoholamines.
  • the molecular chain skeleton of polyvinylpyrrolidone and -CH 2 - in pyrrolidone are hydrophobic, while the amide group in the pyrrolidone ring is hydrophilic.
  • polyvinylpyrrolidone molecules can aggregate to form micelles whose outer layer is composed of the hydrophilic groups of polyvinylpyrrolidone.
  • the hydrophilic groups of polyvinylpyrrolidone can become sites for binding metal atoms through complexation and/or electrostatic adsorption, so that polyvinylpyrrolidone micelles can serve as templates for assembly to form metal oxides.
  • the first oxide is selected from V 2 O 3 , Fe 2 O 3 and CuO. These first oxides contain transition metal elements and have good ionic properties when applied to secondary batteries. The insertion and detachment are reversible, the chemical properties are stable in the electrolyte, and it has a large lithium ion storage density.
  • the second oxide precursor is selected from one of K 2 SnO 3 , Na 2 SiO 3 , Na 2 GeO 3 , NaAlO 2 , and NaBO 4 ⁇ 4H 2 O. These second oxides are easily soluble in the dispersion medium.
  • the amphiphilic polymer material-first oxide-second oxide precursor complex is heated in step S3.
  • the amphiphilic polymer material can be removed by heating, so as to A negative active material composed of a first oxide and a second oxide is obtained; on the other hand, the second oxide precursor is heated to form a second oxide, and the second oxide undergoes an alloying reaction and combines with the first oxide after heating. , and form strong metallic bonds through electrostatic attraction between metal ions.
  • Figure 2 shows a diagram of the lithium insertion state during the charge and discharge process of the negative active material according to an embodiment of the present application.
  • the negative active material of the hexagonal hollow structure of the present application has a large amount of embedded active ions.
  • the anode material includes V 2 O 3 -SnO 2 , Fe 2 O 3 -SnO 2 , Fe 2 O 3 -GeO 2 , Fe 2 O 3 -Al 2 O 3 , Fe 2 O 3 -B 2 One of O3 and CuO- SiO2 .
  • the negative electrode material is V 2 O 3 -SnO 2 or Fe 2 O 3 -SnO 2 .
  • tin has the advantages of high theoretical specific capacity and high packing density.
  • the volume expansion of the tin negative electrode is large (more than 300%) during the charge and discharge process, and the electrode material structure is easily pulverized, which greatly reduces the cycle performance of the battery.
  • the negative active material of this application is based on the use of a template method to prepare the negative active material forming a hexagonal hollow structure, thereby achieving tin doping.
  • transition metal elements such as V, Fe, and Cu are also introduced to stabilize the structure of the negative active material through alloying.
  • alloying with transition metal elements can serve as a supporting framework to reduce the expansion factor of the negative active material.
  • these specific optional negative electrode materials all present a hexagonal hollow structure, have a high specific surface area and a certain buffering effect, and can overcome the volume change caused by the active ion intercalation process. Therefore, the above-mentioned The overall structural stability of the negative active material is good.
  • FIG. 3 shows a flow chart of an exemplary process of forming a first oxide in a method of preparing a negative active material.
  • step S1 the first oxide is assembled on the amphiphilic polymer material template, specifically including:
  • step S11 of this application the amphiphilic polymer material and the first oxide precursor are fully dispersed in an alkaline dispersion medium, and the polyvinylpyrrolidone molecules can aggregate to form micelles whose outer layer is made of polyethylene.
  • the hydrophilic groups of polyvinylpyrrolidone can become sites for interaction with metal atoms through complexation and/or electrostatic adsorption, thereby assembling on the amphiphilic polymer material template to form the third monoxide.
  • step S11 specifically includes: dispersing the amphiphilic polymer material and the first oxide precursor into an alkaline dispersion medium, and stirring for more than 5 hours. Under fully stirred conditions, the amphiphilic polymer material can be fully dispersed in the dispersion medium and aggregate to form micelles, exposing more sites and assembling more molecules on the amphiphilic polymer template. First oxide precursor.
  • magnetic stirring is used for stirring.
  • the stirring time is 5h to 8h.
  • step S12 of the present application the dispersion system in step S11 is heated to form the first oxide precursor into the first oxide.
  • the heating temperature in step S12 needs to be controlled so that all the first oxide precursors form the first oxide and the conversion rate of the first oxide precursor is improved; and the heating temperature of the dispersion system in step S12 needs to be controlled not to exceed High, preventing the amphiphilic polymer material from being removed and maintaining the stability of the amphiphilic polymer material template to ensure the subsequent assembly of the second oxide precursor.
  • the temperature at which the dispersion system is heated is less than or equal to 400°C.
  • the method of assembling the first oxide on the amphiphilic polymer material template is simple and easy to operate, and the prepared assembled first oxide has the characteristics of uniform chemical composition and large specific surface area. .
  • the first oxide precursor is selected from one of Co 3 V 2 O 8 , Fe(NO 3 ) 3 , and Cu(NO 3 ) 2 .
  • one of Co 3 V 2 O 8 , Fe(NO 3 ) 3 and Cu(NO 3 ) 2 has higher solubility in an alkaline dispersion medium, so that the first The oxide precursor is fully dispersed to avoid the loss of the first oxide during the assembly process to ensure product yield and purity.
  • the mass ratio of the amphiphilic polymer material to the first oxide precursor is 1: (1 ⁇ 2).
  • the amphiphilic polymer material and the first oxide precursor have a suitable mass ratio so that the first oxide precursor is fully assembled on the amphiphilic polymer material template. Moreover, an appropriate mass ratio can ensure that the final negative active material with a hexagonal hollow structure is obtained.
  • the mass concentration of the amphiphilic polymer material in the dispersion medium is 15% to 25%.
  • amphiphilic polymer material has a mass such that polyvinylpyrrolidone molecules can aggregate to form micelles in an alkaline dispersion medium.
  • the dispersion system is heated to a temperature of 200°C to 400°C and a time of 5h to 7h.
  • the temperature at which the dispersion system is heated is 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C °C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C or other ranges composed of any two of the above endpoints.
  • the temperature at which the dispersion system is heated is 280°C to 350°C.
  • the dispersion is heated in an oven or calciner.
  • appropriate heating temperature and heating time can ensure that the first oxide precursor is completely converted into the first oxide and improve product yield.
  • heating the dispersion system to a temperature of 200°C to 400°C can reduce the loss of amphiphilic polymer materials and maintain the stability of the amphiphilic polymer material template.
  • appropriate heating temperature and heating time can reduce energy consumption and reduce production costs.
  • assembling and forming a second oxide precursor on the assembled first oxide in step S2 specifically includes:
  • the assembled first oxide and the second oxide precursor are sufficiently dispersed in the dispersion medium to connect the assembled first oxide and the second oxide precursor.
  • the dispersion medium is water or ethanol.
  • the assembled first oxide and the second oxide precursor are fully dispersed in the dispersion medium, and the second oxide precursor is assembled into the assembled first oxide precursor through physical adsorption. on things.
  • the mass ratio of the assembled first oxide and the second oxide precursor is 1: (1 ⁇ 2).
  • the assembled first oxide and the second oxide precursor have an appropriate mass ratio, which can ensure that the negative electrode active material with a hexagonal hollow structure is finally obtained.
  • the temperature of the heated composite is 400°C to 600°C, and the time is 5h to 7h.
  • the temperature of the heating composite is 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C , 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C or other ranges composed of any two of the above endpoints.
  • the temperature of the heated composite is 480°C to 550°C.
  • the composite is heated in an oven or calciner.
  • appropriate heating temperature and heating time can ensure that the second oxide precursor is completely converted into the second oxide and improve product yield.
  • the amphiphilic polymer material in the composite can be removed.
  • the second oxide undergoes an alloying reaction and combines with the first oxide after heating, and the electrostatic attraction between metal ions forms a strong metal bond. .
  • the average particle size Dv50 of the negative active material is 100 ⁇ m ⁇ 200 ⁇ m.
  • the average particle size Dv50 of the negative active material is 100 ⁇ m, 110 ⁇ m, 120 ⁇ m, 130 ⁇ m, 140 ⁇ m, 150 ⁇ m, 160 ⁇ m, 170 ⁇ m, 180 ⁇ m, 190 ⁇ m, 200 ⁇ m or is composed of any two of the above endpoints. within other ranges.
  • the average particle size Dv50 of the negative active material is 120 ⁇ m to 180 ⁇ m.
  • the average particle size Dv50 of the negative active material is controlled by parameters during the preparation process so that the particle size of the material is between 100 ⁇ m and 200 ⁇ m.
  • the volume average particle size Dv50 of the negative active material can be measured using conventional methods in the art. For example, you can refer to the GB/T 19077-2016 particle size distribution laser diffraction method and use a laser particle size analyzer to conveniently measure it, such as the Mastersizer 2000E laser particle size analyzer of Malvern Instruments Co., Ltd. in the United Kingdom.
  • the average particle size Dv50 of the negative active material is too large, there will still be large gaps between the particles, which will reduce the compaction density of the negative electrode sheet, resulting in low energy density of the secondary battery. If the average particle size Dv50 of the negative active material is too small, undesirable agglomeration will occur, thereby reducing the compacted density of the negative electrode sheet. Moreover, there are insufficient gaps between the particles to retain the electrolyte, which will reduce the poor cycle performance of the negative active material layer.
  • the average particle size Dv50 of the negative active material is within an appropriate range, which is conducive to obtaining a higher compacted density of the negative active material layer and having a suitable porosity to meet the requirements of the electrochemical reaction.
  • the required amount of electrolyte infiltration also has a shorter migration path for active ions and electrons within the particles, which can improve the energy density and cycle performance of the negative active material layer.
  • the negative active material in this application has a hexagonal hollow structure.
  • Figure 4 shows an SEM image of a negative active material according to an embodiment of the present application.
  • the scanning electron microscope (SEM) image can be obtained, for example, by using the ZEISS Gemini SEM 300 scanning electron microscope, selecting the backscattered electron mode at a magnification of 15k, and scanning the negative active material.
  • a negative active material with a hexagonal hollow structure As shown in Figure 4, a negative active material with a hexagonal hollow structure, the first oxide V 2 O 3 (smaller particle size and lighter color in the picture) and the second oxide SnO 2 (larger particle size and lighter color in the picture) Deeper) compound.
  • FIG. 5 shows an SEM image of a negative active material according to another embodiment of the present application.
  • the scanning electron microscope (SEM) image can be obtained, for example, as follows: using a ZEISS Gemini SEM 300 scanning electron microscope, selecting the backscattered electron mode at a magnification of 80k to scan the negative active material.
  • the negative active material with a hexagonal hollow structure is composed of the first oxide Fe 2 O 3 (smaller particle size and lighter color in the picture) and the second oxide SnO 2 (larger particle size and lighter color in the picture). Deeper) compound.
  • a second aspect of the present application also provides a negative active material prepared by the preparation method of the first aspect of the present application.
  • the negative active material of the present application is composed of a first oxide and a second oxide.
  • the negative active material exhibits a hexagonal hollow structure, so that the negative active material has a higher gram capacity and specific surface area.
  • the second oxide formed by its preparation The energy density of secondary batteries is also higher.
  • the negative active material has a specific surface area of 175 m 2 /g to 400 m 2 /g.
  • it is 300m 2 /g ⁇ 400m 2 /g.
  • the specific surface area of the negative active material is within the above range, which ensures that the negative active material has a high active specific surface area and is conducive to reducing side reactions of the electrolyte on the surface of the negative active material, thereby improving Capacity development and cycle life of negative active materials.
  • the negative active material has a gram capacity of 490 mAh/g to 1100 mAh/g.
  • the negative active material of the present application has a larger gram capacity, thereby enabling the secondary battery to have a larger energy density.
  • FIG. 6 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 7 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 6 .
  • Figure 8 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 9 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 10 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 9 .
  • FIG. 11 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.
  • a third aspect of the present application provides a secondary battery, including a negative active material prepared by the preparation method of the first aspect of the present application or a negative active material of the second aspect of the present application.
  • a secondary battery typically includes a positive electrode plate, a negative electrode plate, an electrolyte and a separator.
  • active ions are inserted and detached back and forth between the positive and negative electrodes.
  • the electrolyte plays a role in conducting ions between the positive and negative electrodes.
  • the isolation film is placed between the positive electrode piece and the negative electrode piece. It mainly prevents the positive and negative electrodes from short-circuiting and allows ions to pass through.
  • the positive electrode current collector has two surfaces opposite in its own thickness direction, and the positive electrode active material layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil can be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on polymer material substrates (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the cathode active material may be a cathode active material known in the art for batteries.
  • the cathode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials of batteries can also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination.
  • lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO 2 ), lithium nickel oxides (such as LiNiO 2 ), lithium manganese oxides (such as LiMnO 2 , LiMn 2 O 4 ), lithium Nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (can also be abbreviated to NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (can also be abbreviated to NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (can also be abbreviated to NCM 622 ), LiNi At least one of 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as Li Li
  • the olivine structure contains Examples of lithium phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), composites of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), lithium manganese phosphate and carbon. At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • composites of lithium iron phosphate and carbon such as LiMnPO 4
  • LiMnPO 4 lithium manganese phosphate and carbon.
  • At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • the cathode active material layer may further include a conductive agent to improve the conductive performance of the cathode.
  • a conductive agent to improve the conductive performance of the cathode.
  • the conductive agent can be one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene and carbon nanofibers.
  • the positive active material layer may further include a binder to firmly bond the positive active material and optional conductive agent to the positive current collector.
  • a binder to firmly bond the positive active material and optional conductive agent to the positive current collector.
  • the binder may be polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyacrylic acid (PAA), polyvinyl alcohol (PVA), ethylene-vinyl acetate copolymer (EVA), styrene-butadiene At least one of rubber (SBR), carboxymethyl cellulose (CMC), sodium alginate (SA), polymethacrylic acid (PMA) and carboxymethyl chitosan (CMCS).
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PAA polyacrylic acid
  • PVA polyvinyl alcohol
  • EVA ethylene-vinyl acetate copolymer
  • SBR carboxymethyl cellulose
  • SA
  • the positive electrode current collector can be a conductive carbon sheet, metal foil, carbon-coated metal foil, porous metal plate or composite current collector, wherein the conductive carbon material of the conductive carbon sheet can be superconducting carbon, acetylene black, carbon One or more of black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene and carbon nanofibers, the metal materials of metal foil, carbon-coated metal foil and porous metal plate can be independently selected from At least one of copper, aluminum, nickel and stainless steel.
  • the composite current collector may be a composite current collector formed by a combination of a metal foil material and a polymer base film.
  • the positive electrode current collector is, for example, one or more of copper foil, aluminum foil, nickel foil, stainless steel foil, stainless steel mesh, and carbon-coated aluminum foil. Aluminum foil is preferably used.
  • the above-mentioned positive electrode sheet can be prepared according to conventional methods in the art.
  • the positive electrode active material and optional conductive agent and binder are dispersed in a solvent (such as N-methylpyrrolidone, referred to as NMP) to form a uniform positive electrode slurry, and the positive electrode slurry is coated on the positive electrode current collector , after drying and cold pressing, the positive electrode piece is obtained.
  • a solvent such as N-methylpyrrolidone, referred to as NMP
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, where the negative electrode active material layer includes a negative electrode active material.
  • the negative active material is a negative active material prepared by the preparation method of the first aspect of the present application or the negative active material of the second aspect of the present application. Therefore, the previous description of the embodiments of the negative active material according to the present application is also applicable to the negative active material in the secondary battery, and the same content will not be described again.
  • the negative electrode current collector has two surfaces opposite in its own thickness direction, and the negative electrode active material layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base material.
  • the composite current collector can be formed by forming metal materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative active material layer optionally further includes a binder.
  • the binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), polyacrylic acid sodium (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), poly At least one of methacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative active material layer optionally further includes a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative active material layer optionally also includes other auxiliaries, such as thickeners (such as sodium carboxymethyl cellulose (CMC-Na)) and the like.
  • auxiliaries such as thickeners (such as sodium carboxymethyl cellulose (CMC-Na)) and the like.
  • the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as negative active materials, conductive agents, binders and any other components in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode piece can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays a role in conducting ions between the positive electrode piece and the negative electrode piece.
  • the type of electrolyte in this application can be selected according to needs.
  • the electrolyte can be liquid, gel, or completely solid.
  • the electrolyte is an electrolyte solution.
  • the electrolyte solution includes electrolyte salts and solvents.
  • the electrolyte salt may be NaPF 6 , NaClO 4 , NaBF 4 , KPF 6 , KClO 4 , KBF 4 , LiPF 6 , LiClO 4 , LiBF 4 , Zn(PF 6 ) 2 , Zn(ClO 4 ) 2 , one or more of Zn(BF 4 ) 2 .
  • the electrolyte salt can be selected from one or more of NaPF 6 , NaClO 4 , and NaBF 4 .
  • the solvent may be selected from the group consisting of ethylene carbonate, propylene carbonate, methylethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, Butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate At least one of ester, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte optionally further includes additives.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain properties of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.
  • isolation membrane there is no particular restriction on the type of isolation membrane, and any well-known porous structure isolation membrane with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation film can be a single-layer film or a multi-layer composite film, with no special restrictions. When the isolation film is a multi-layer composite film, the materials of each layer can be the same or different, and there is no particular limitation.
  • the positive electrode piece, the negative electrode piece, and the separator film can be made into an electrode assembly through a winding process or a lamination process.
  • the secondary battery may include an outer packaging.
  • the outer packaging can be used to package the above-mentioned electrode assembly and electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft bag, such as a bag-type soft bag.
  • the material of the soft bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, polybutylene succinate, and the like.
  • FIG. 4 shows a square-structured secondary battery 5 as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity.
  • the housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 can cover the opening to close the accommodation cavity.
  • the positive electrode piece, the negative electrode piece and the isolation film can be formed into the electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the containing cavity.
  • the electrolyte soaks into the electrode assembly 52 .
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • secondary batteries can be assembled into battery modules, and the number of secondary batteries contained in the battery module can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery module.
  • FIG. 6 shows a battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4 .
  • the plurality of secondary batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having a receiving space in which a plurality of secondary batteries 5 are received.
  • the above-mentioned battery modules can also be assembled into a battery pack.
  • the number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery pack.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box 2 and a lower box 3 .
  • the upper box 2 can be covered with the lower box 3 and form a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application.
  • the secondary battery, battery module, or battery pack may be used as a power source for the electrical device, or may be used as an energy storage unit for the electrical device.
  • the electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, and electric golf carts). , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.
  • FIG. 9 shows an electrical device as an example.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc.
  • a battery pack or battery module can be used.
  • the device may be a mobile phone, a tablet, a laptop, etc.
  • the device is usually required to be thin and light, and a secondary battery can be used as a power source.
  • the assembled first oxide and 0.12g potassium stannate trihydrate were dispersed in 20 ml of deionized water, and magnetically stirred for 5 minutes to obtain the complex;
  • the composite was then placed in an oven and heated at 500°C for 6 hours to obtain the negative active material.
  • the negative active materials of Examples 1 to 23 and Comparative Examples 1 to 12 were prepared according to Table 1 below.
  • the negative electrode active materials of the above-mentioned Examples 1 to 23 and Comparative Examples 1 to 12 were respectively prepared into secondary batteries as follows, and corresponding tests were performed.
  • EC ethylene carbonate
  • DEC diethyl carbonate
  • DMC dimethyl carbonate
  • Electrode assembly Stack and wind the positive electrode sheet, isolation film, and negative electrode sheet in order to obtain the electrode assembly.
  • Put the electrode assembly into the outer packaging add the electrolyte prepared above, and then go through packaging, standing, chemical composition, aging, etc. After the process, a secondary battery is obtained,
  • the negative active materials and secondary batteries of each example and comparative example were tested according to the following test methods.
  • the nitrogen adsorption specific surface area analysis test method is used to test and calculated using the BET (Brunauer Emmett Teller) method.
  • the nitrogen adsorption specific surface area analysis test can pass the Tri-Star 3020 type specific surface area of the American Micromeritics company. Pore size analysis tester for testing.
  • Examples 1 to 23 have all achieved good results, the gram capacity and specific surface area of the negative active material are both high, and the secondary battery formed of the negative active material has a high energy density.
  • an amphiphilic polymer material is used as a template to prepare a negative active material with a hexagonal hollow structure. Normally, during the charge and discharge process of the negative active material, the insertion of active ions easily causes volume expansion/contraction.
  • the hexagonal hollow structure negative active material of the present application has a certain buffering effect on volume expansion/contraction, and can Overcome the volume change caused by the active ion intercalation process, thereby maintaining the overall structural stability of the negative active material.
  • the present application forms a negative active material by combining the first oxide and the second oxide, which can better exert their complementary advantages and make up for each other's shortcomings.
  • the negative electrode of the present application The active material embeds more active ions and further increases the reversible capacity, thus increasing the gram capacity and specific surface area of the negative active material, further increasing the energy density of the secondary battery.
  • Comparative Example 1 is graphite. Compared with graphite, the negative active material of the present application has higher gram capacity and energy density.
  • Comparative Examples 2 and 3 are negative active materials of a metal oxide, with low gram capacity and low energy density. This illustrates that the first oxide and the second oxide of the present application are combined to form a negative active material and can perform better. Their advantages are complementary and synergistic to compensate for each other's shortcomings. Compared with a single substance or a single oxide, the negative active material of the present application has more active ions embedded in it, and further increases the reversible capacity, thus increasing the gram capacity of the negative active material. and specific surface area.
  • the ratio of the added amounts of the amphiphilic polymer material, the first oxide precursor, and the second oxide precursor has a greater impact on the performance of the negative active material. See Comparative Examples 4 to 7 for amphiphilic polymers.
  • the material and the first oxide precursor, as well as the assembled first oxide and the second oxide precursor have an appropriate mass ratio, so that both the first oxide precursor and the second oxide precursor can be assembled on the amphiphilic Polymer material template.
  • an appropriate mass ratio can ensure that the final morphology of the negative active material with a hexagonal hollow structure is hexagonal particles, thereby increasing the gram capacity and specific surface area of the negative active material.
  • the second oxide undergoes an alloying reaction and combines with the first oxide after heating, and forms a strong metal bond through the electrostatic attraction between metal ions to ensure the structural stability of the negative active material. , too high or too low temperature will affect the gram capacity of the negative active material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请实施例提供一种负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置。本申请的负极活性材料的制备方法，包括：在两亲性聚合物材料模板上组装形成第一氧化物，其中，所述第一氧化物选自V 2O 3、Fe 2O 3和CuO中的一种；在所述经组装的第一氧化物上组装形成第二氧化物前驱体，以形成两亲性聚合物材料-第一氧化物-第二氧化物前驱体复合物，其中，所述第二氧化物前驱体选自K 2SnO 3、Na 2SiO 3、Na 2GeO 3、NaAlO 2、NaBO 4·4H 2O中的一种；加热所述复合物，以去除所述两亲性聚合物材料且使得所述第二氧化物前驱体形成第二氧化物，获得具有六方体空心结构的负极活性材料。。

Description

负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置 技术领域
本申请涉及电池技术领域，特别是涉及一种负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置。
背景技术
近年来，锂离子电池已被越来越广泛地应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。由于锂离子电池取得了极大的发展，因此对其能量密度、循环性能和安全性能等也提出了更高的要求。基于对二次电池的能量密度的更高要求，围绕高容量的负极活性材料也开展了大量研究。
有普遍使用的是石墨和硅作为负极活性材料，但是，石墨负极活性材料理论克容量较低，而硅负极活性材料存在严重的体积效应，这都限制了锂离子电池和钠离子电池能量密度的提升，从而限制了锂离子电池和钠离子电池的发展。
发明内容
本申请是鉴于上述课题而进行的，旨在提供一种负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置，以解决现有负极活性材料克容量提升有限的问题。
为了达到上述目的，本申请的第一方面提供了一种负极活性材料的制备方法，包括：
在两亲性聚合物材料模板上组装形成第一氧化物，其中，第一氧化物选自V 2O 3、Fe 2O 3和CuO中的一种；
在经组装的第一氧化物上组装形成第二氧化物前驱体，以形成两亲性聚合物材料-第一氧化物-第二氧化物前驱体复合物，其中，第二氧化物前驱体选自 K 2SnO 3、Na 2SiO 3、Na 2GeO 3、NaAlO 2、NaBO 4·4H 2O中的一种；以及
加热复合物，以去除两亲性聚合物材料且使得第二氧化物前驱体形成第二氧化物，获得具有六方体空心结构的负极活性材料。
本申请的负极活性材料的制备方法通过使用两亲性聚合物材料作为模板，制备得到了具有六方体空心结构的负极活性材料。通常情况下，负极活性材料在充放电过程中，活性离子在嵌入容易引起体积的膨胀/收缩，然而，本申请的六方体空心结构的负极活性材料对于体积膨胀/收缩具有一定的缓冲作用，能够克服活性离子嵌入过程中引起的体积变化，从而维持负极活性材料整体的结构稳定性。此外，本申请通过第一氧化物与第二氧化物复合形成负极活性材料，能更好地发挥它们的优势互补和弥补彼此缺点的协同作用，相比于单质或单一氧化物，本申请的负极活性材料嵌入活性离子的量更多，并进一步增加可逆容量，从而提高了负极活性材料的克容量和比表面积，进一步提高二次电池的能量密度。
在本申请第一方面的一些实施方式中，负极材料包括V 2O 3-SnO 2、Fe 2O 3-SnO 2、Fe 2O 3-GeO 2、Fe 2O 3-Al 2O 3、Fe 2O 3-B 2O 3和CuO-SiO 2中的一种，可选地为V 2O 3-SnO 2或Fe 2O 3-SnO 2。
在这些可选的实施例中，这些具体可选的负极材料均呈现六方体空心结构，具有较高的比表面积和一定的缓冲作用，能够克服活性离子嵌入过程中引起的体积变化，因此，上述负极活性材料的整体结构稳定性均较好。此外，根据这些负极材料的实施例，复合的第一氧化物与第二氧化物具有更好的协同作用。
在本申请第一方面的一些实施方式中，两亲性聚合物材料选自聚乙烯吡咯烷酮。
在这些可选的实施例中，聚乙烯吡咯烷酮是由单体乙烯吡咯烷酮聚合而成的线型聚合物，可溶于水以及醇、卤代烃、羧酸、醇胺等极性溶剂。聚乙烯吡咯烷酮的分子链骨架以及吡咯烷酮中的-CH 2-具有疏水性，而吡咯烷酮环中的酰胺基团具有亲水性。在分散介质中溶解后，聚乙烯吡咯烷酮分子可以聚集形成胶束，该胶束的外层由聚乙烯吡咯烷酮的亲水性基团构成。聚乙烯吡咯烷酮的亲水性基团可以通过络合作用和/或静电吸附成为与金属原子作用的位点，从而使得聚乙烯吡咯烷酮胶束可以作为组装形成金属氧化物的模板。
在本申请第一方面的一些实施方式中，在两亲性聚合物材料模板上组装形 成第一氧化物，具体包括：
将两亲性聚合物材料与第一氧化物前驱体充分分散在碱性的分散介质中，以获得其中第一氧化物前驱体组装在两亲性聚合物材料模板上的分散体系；
对分散体系进行加热，以使得第一氧化物前驱体形成第一氧化物，获得经组装的第一氧化物。
在这些可选的实施例中，两亲性聚合物材料与第一氧化物前驱体充分分散在碱性的分散介质中，聚乙烯吡咯烷酮分子可以聚集形成胶束，该胶束的外层由聚乙烯吡咯烷酮的亲水性基团构成，聚乙烯吡咯烷酮的亲水性基团可以通过络合作用和/或静电吸附成为与金属原子作用的位点，从而第一氧化物前驱体吸附在位点上。对分散体系进行加热，以将第一氧化物前驱体形成第一氧化物。其中，需要分散体系加热温度，既满足第一氧化物前驱体全部形成第一氧化物，提高第一氧化物前驱体的转化率；又需要控制分散体系的加热温度不能过高，防止两亲性聚合物材料挥发而被去除，保持两亲性聚合物材料模板的稳定性，以保证后续的第二氧化物前驱体的组装。
在本申请第一方面的一些实施方式中，第一氧化物前驱体选自Co 3V 2O 8、Fe(NO 3) 3和Cu(NO 3) 2中的一种。
在这些可选的实施例中，两亲性聚合物材料与Co 3V 2O 8、Fe(NO 3) 3和Cu(NO 3) 2中的一种在碱性的分散介质中具有较高的溶解性，使得第一氧化物前驱体充分分散，避免组装过程中第一氧化物的损失，以保证产品的得率和纯度。
在本申请第一方面的一些实施方式中，两亲性聚合物材料与第一氧化物前驱体的质量比为1∶(1～2)。
在这些可选的实施例中，两亲性聚合物材料与第一氧化物前驱体具有适宜的质量比，使得第一氧化物前驱体充分组装在两亲性聚合物材料模板上。而且，适宜的质量比，能够保证最终获得的具有六方体空心结构的负极活性材料。
在本申请第一方面的一些实施方式中，对分散体系加热的温度为200℃～400℃，时间为5h～7h。
在这些可选的实施例中，适宜的加热温度和加热时间能够保证第一氧化物前驱体全部转化为第一氧化物，提高产品得率。此外，对分散体系加热的温度为200℃～400℃，能够降低两亲性聚合物材料的损耗，保持两亲性聚合物材料模板的稳定性。此外，适宜的加热温度和加热时间能够降低能耗，降低生产成本。
在本申请第一方面的一些实施方式中，在经组装的第一氧化物上组装形成第二氧化物前驱体具体包括：
将经组装的第一氧化物和第二氧化物前驱体充分分散在分散介质中，以使所述经组装的第一氧化物和所述第二氧化物前驱体接触。
在这些可选的实施例中，经组装的第一氧化物与第二氧化物前驱体充分分散在分散介质中，第二氧化物前驱体通过物理性吸附的方式组装至经组装的第一氧化物上。
在本申请第一方面的一些实施方式中，经组装的第一氧化物与第二氧化物前驱体的质量比为1∶(1～2)。
在这些可选的实施例中，经组装的第一氧化物与第二氧化物前驱体具有适宜的质量比，能够保证最终获得的具有六方体空心结构的负极活性材料。
在本申请第一方面的一些实施方式中，两亲性聚合物材料在分散介质中的质量浓度为15％～25％。
在这些可选的实施例中，两亲性聚合物材料具有一定质量，使得在碱性的分散介质中，聚乙烯吡咯烷酮分子可以聚集形成胶束。
在本申请第一方面的一些实施方式中，加热复合物的温度为400℃～600℃，时间为5h～7h。
在这些可选的实施例中，适宜的加热温度和加热时间能够保证第二氧化物前驱体全部转化为第二氧化物，提高产品得率。通过加热复合物，能够将复合物中的两亲性聚合物材料去除，而且，第二氧化物经过加热发生合金反应与第一氧化物结合，并将金属离子之间的静电吸引力形成牢固的金属键。
在本申请第一方面的一些实施方式中，负极活性材料的平均粒径Dv50为100μm～200μm，可选地为120μm～180μm。
在这些可选的实施例中，负极活性材料的平均粒径Dv50在适当范围内，有利于使负极活性材料层获得较高的压实密度，同时具有合适的孔隙率，来满足电化学反应所需的电解液浸润量，还具有较短的颗粒内活性离子和电子的迁移路径，由此能够提高负极活性材料层的能量密度和循环性能。
本申请的第二方面还提供一种负极活性材料，通过本申请第一方面的制备方法制得的负极活性材料。
本申请的负极活性材料是由第一氧化物与第二氧化物复合而成，负极活性材料呈现六方体空心结构，从而使得负极活性材料具有较高的克容量和比表面积，其制备形成的二次电池的能量密度也较高。
在本申请第二方面的任一实施方式中，负极活性材料的比表面积为175m 2/g～400m 2/g，可选地为300m 2/g～400m 2/g。
在这些可选的实施例中，负极活性材料的比表面积在上述范围内，保证了负极活性材料具有较高的活性比表面积，同时有利于减少电解液在负极活性材料表面的副反应，从而提高负极活性材料的容量发挥及循环寿命。
在本申请第二方面的任一实施方式中，负极活性材料的克容量为490mAh/g～1100mAh/g，可选地为500mAh/g～700mAh/g。
在这些可选的实施例中，本申请的负极活性材料具有较大克容量，从而使得二次电池具有较大的能量密度。
本申请的第三方面提供一种二次电池，包括通过本申请第一方面的制备方法制得的负极活性材料或本申请第二方面的负极活性材料。
本申请的第四方面提供一种电池模块，包括本申请的第三方面的二次电池。
本申请的第五方面提供一种电池包，包括本申请的第四方面的电池模块。
本申请的第六方面提供一种用电装置，包括选自本申请的第三方面的二次电池、本申请的第四方面的电池模块或本申请的第五方面的电池包中的至少一种。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据附图获得其他的附图。
图1示出了根据本申请一实施方式的负极活性材料的制备方法的流程图。
图2示出了根据本申请一实施方式的负极活性材料充放电过程中嵌锂状态图。
图3示出了负极活性材料的制备方法中形成第一氧化物的示例性过程的流程图。
图4示出了根据本申请一实施方式的负极活性材料SEM图。
图5示出了根据本申请另一实施方式的负极活性材料SEM图。
图6是本申请一实施方式的二次电池的示意图。
图7是图6所示的本申请一实施方式的二次电池的分解图。
图8是本申请一实施方式的电池模块的示意图。
图9是本申请一实施方式的电池包的示意图。
图10是图9所示的本申请一实施方式的电池包的分解图。
图11是本申请一实施方式的二次电池用作电源的用电装置的示意图。
附图标记说明：
1电池包；2上箱体；3下箱体；4电池模块；5二次电池；51壳体；52电极组件；53盖板。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的负极活性材料及其制备方法、极片、二次电池、电池模块、电池包和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
随着锂离子电池和钠离子电池都取得了极大的发展，对二者的能量密度、循环性能和安全性能等也提出了更高的要求。其中，锂离子电池或钠离子电池中的负极活性材料是影响锂离子电池或钠离子电池性能的主要因素之一。其中，锂离子电池广泛应用于手机、平板、无人机等电子产品，人们对电子产品的电池容量提出越来越高的要求，以在有限的空间里尽可能提高电池容量。目前使用的石墨负极活性材料理论克容量约有370mAh/g，不能满足对更高能量密度锂离子电池的需求；虽然硅材料理论克容量明显高于目前商业化的石墨负极活性材料，但是，硅材料在高度嵌锂过程中存在非常明显的体积膨胀(＞300％)，负极极片膨胀后导致负极粉化掉料，严重影响了电池的循环稳定性和循环寿命。基于此，发明人通过硅与石墨通过热还原的方法制备具有优异的电化学性能以及高容量的复合负极活性材料。但是，上述复合负极活性材料合成路线复杂，工艺要求严苛，且在嵌锂过程中同样存在体积膨胀明显的缺陷。
基于申请人发现的上述问题，申请人对负极活性材料的制备方法进行了改进，通过模板法合成负极活性材料，制备方法简单，且制备得到的负极活性材料具有 较高的活性离子嵌入量，提高了负极活性材料的克容量和比表面积，进一步提高二次电池的能量密度。
负极活性材料的制备方法
图1示出了根据本申请一实施方式的负极活性材料的制备方法的流程图。
如图1所示，本申请的第一方面提供了一种负极活性材料的制备方法，包括：
S1、在两亲性聚合物材料模板上组装形成第一氧化物；
其中，第一氧化物选自V 2O 3、Fe 2O 3和CuO中的一种；
S2、在经组装的第一氧化物上组装形成第二氧化物前驱体，以形成两亲性聚合物材料-第一氧化物-第二氧化物前驱体复合物；
其中，第二氧化物前驱体选自K 2SnO 3、Na 2SiO 3、Na 2GeO 3、NaAlO 2、NaBO 4·4H 2O中的一种；以及
S3、加热复合物，以去除两亲性聚合物材料且使得第二氧化物前驱体形成第二氧化物，获得具有六方体空心结构的负极活性材料。
本申请的负极活性材料的制备方法通过使用两亲性聚合物材料作为模板，制备得到了具有六方体空心结构的负极活性材料。通常情况下，负极活性材料在充放电过程中，活性离子在嵌入容易引起体积的膨胀/收缩，然而，本申请的六方体空心结构的负极活性材料对于体积膨胀/收缩具有一定的缓冲作用，能够克服活性离子嵌入过程中引起的体积变化，从而维持负极活性材料整体的结构稳定性。此外，本申请通过第一氧化物与第二氧化物复合形成负极活性材料，能更好地发挥它们的优势互补和弥补彼此缺点的协同作用，相比于单质或单一氧化物，本申请的负极活性材料嵌入活性离子的量更多，并进一步增加可逆容量，从而提高了负极活性材料的克容量和比表面积，进一步提高二次电池的能量密度。
根据本申请的实施例，两亲性聚合物是既具有疏水性又具有亲水性的高分子。并非意在受限于任何理论或解释，当溶解在分散介质中后，两亲性聚合物分子可以缔合形成胶束，其中，两亲性聚合物分子的疏水基可以相互吸引构成胶束内核，亲水基构成胶束外层。处于胶束外层的亲水基团由于可以与金属原子发生静电吸附和/或络合作用，成为能够结合金属原子的位点，从而使得两亲性聚合物材料可以作为组装形成金属氧化物的模板。
在一些实施例中，两亲性聚合物材料为聚乙烯吡咯烷酮。
聚乙烯吡咯烷酮是由单体乙烯吡咯烷酮聚合而成的线型聚合物，可溶于水以及醇、卤代烃、羧酸、醇胺等极性溶剂。聚乙烯吡咯烷酮的分子链骨架以及吡咯烷酮中的-CH 2-具有疏水性，而吡咯烷酮环中的酰胺基团具有亲水性。在分散介质中溶解后，聚乙烯吡咯烷酮分子可以聚集形成胶束，该胶束的外层由聚乙烯吡咯烷酮的亲水性基团构成。聚乙烯吡咯烷酮的亲水性基团可以通过络合作用和/或静电吸附成为结合金属原子的位点，从而使得聚乙烯吡咯烷酮胶束可以作为组装形成金属氧化物的模板。
在本申请一些实施例中，第一氧化物选自V 2O 3、Fe 2O 3和CuO，这些第一氧化物含有过渡金属元素，将其应用于二次电池时，具有很好的离子嵌入和脱出可逆性，且在电解质中化学性能稳定，且具有较大的锂离子存储密度。
在本申请一些实施例中，第二氧化物前驱体选自K 2SnO 3、Na 2SiO 3、Na 2GeO 3、NaAlO 2、NaBO 4·4H 2O中的一种。上述这些第二氧化物易于溶解在分散介质中。
在本申请一些实施例中，步骤S3中对两亲性聚合物材料-第一氧化物-第二氧化物前驱体复合物进行加热，一方面，通过加热可以去除两亲性聚合物材料，以获得第一氧化物与第二氧化物复合的负极活性材料；另一方面，经过加热第二氧化物前驱体形成第二氧化物，且第二氧化物经过加热发生合金反应与第一氧化物结合，并且通过金属离子之间的静电吸引力形成牢固的金属键。
图2示出了根据本申请一实施方式的负极活性材料充放电过程中嵌锂状态图。参见图2，图2中本申请的六方体空心结构的负极活性材料嵌入活性离子的量较多。
在一些实施例中，负极材料包括V 2O 3-SnO 2、Fe 2O 3-SnO 2、Fe 2O 3-GeO 2、Fe 2O 3-Al 2O 3、Fe 2O 3-B 2O 3和CuO-SiO 2中的一种。
可选地，负极材料为V 2O 3-SnO 2或Fe 2O 3-SnO 2。锡作为负极具有理论比容量高，堆积密度高的优势，但是锡负极在充放电过程中体积膨胀倍数大(大于300％)，电极材料结构容易粉化，大大降低了电池的循环性能。本申请的负极活性材料，基于采用模板法制备形成六方体空心结构的负极活性材料，实现了锡的掺杂。而且，还引入了V、Fe和Cu等过渡金属元素，以合金化的方式稳定负极活性材料的机 构，而且，过渡金属元素进行合金化可以作为支撑骨架降低负极活性材料的膨胀倍数。
在这些可选的实施例中，这些具体可选的负极材料均呈现六方体空心结构，具有较高的比表面积和一定的缓冲作用，能够克服活性离子嵌入过程中引起的体积变化，因此，上述负极活性材料的整体结构稳定性均较好。
参见图3，图3示出了负极活性材料的制备方法中形成第一氧化物的示例性过程的流程图。
在一些实施例中，如图3所示，步骤S1中，在两亲性聚合物材料模板上组装形成第一氧化物，具体包括：
S11、将两亲性聚合物材料模板与第一氧化物前驱体充分分散在碱性的分散介质中，以获得其中第一氧化物前驱体组装在两亲性聚合物材料模板上的分散体系；
S12、对分散体系进行加热，以使得第一氧化物前驱体形成第一氧化物，获得经组装的第一氧化物。
在本申请的步骤S11中，两亲性聚合物材料与第一氧化物前驱体充分分散在碱性的分散介质中，聚乙烯吡咯烷酮分子可以聚集形成胶束，该胶束的外层由聚乙烯吡咯烷酮的亲水性基团构成，聚乙烯吡咯烷酮的亲水性基团可以通过络合作用和/或静电吸附成为与金属原子作用的位点，从而在两亲性聚合物材料模板上组装形成第一氧化物。
在本申请一些实施例中，步骤S11中具体包括：两亲性聚合物材料与第一氧化物前驱体分散至碱性的分散介质中，并搅拌5h以上。在充分搅拌的调条件下，两亲性聚合物材料能够充分的分散在分散介质中并聚集形成胶束，且暴露出更多的位点，在两亲性聚合物材料模板上组装更多的第一氧化物前驱体。
可选地，搅拌采用磁力搅拌。
可选地，搅拌时间为5h～8h。
在本申请的步骤S12中，对步骤S11中分散体系进行加热，以将第一氧化物前驱体形成第一氧化物。其中，需要控制步骤S12中的加热温度，既满足第一氧化物前驱体全部形成第一氧化物，提高第一氧化物前驱体的转化率；又需要控制对S12中分散体系的加热温度不能过高，防止两亲性聚合物材料被去除，保持两亲性聚合物材料模板的稳定性，以保证后续的第二氧化物前驱体的组装。
可选地，对分散体系加热的温度小于等于400℃。
在这些可选的实施例中，第一氧化物组装在两亲性聚合物材料模板上的方法简单，且易于操作，制备的经组装的第一氧化物具有化学成分均匀和比表面积大的特点。
在一些实施例中，第一氧化物前驱体选自Co 3V 2O 8、Fe(NO 3) 3和Cu(NO 3) 2中的一种。
在这些可选的实施例中，Co 3V 2O 8、Fe(NO 3) 3和Cu(NO 3) 2中的一种在碱性的分散介质中具有较高的溶解性，使得第一氧化物前驱体充分分散，避免组装过程中第一氧化物的损失，以保证产品的得率和纯度。
在一些实施例中，两亲性聚合物材料与第一氧化物前驱体的质量比为1∶(1～2)。
在这些可选的实施例中，两亲性聚合物材料与第一氧化物前驱体具有适宜的质量比，使得第一氧化物前驱体充分组装在两亲性聚合物材料模板上。而且，适宜的质量比，能够保证最终获得的具有六方体空心结构的负极活性材料。
在一些实施例中，两亲性聚合物材料在分散介质中的质量浓度为15％～25％。
在这些可选的实施例中，两亲性聚合物材料具有一定质量，从而在碱性的分散介质中，聚乙烯吡咯烷酮分子可以聚集形成胶束。
在一些实施例中，对分散体系加热的温度为200℃～400℃，时间为5h～7h。
在本申请的一些实施例中，对分散体系加热的温度为200℃、210℃、220℃、230℃、240℃、250℃、260℃、270℃、280℃、290℃、300℃、310℃、320℃、330℃、340℃、350℃、360℃、370℃、380℃、390℃、400℃或在由上述的任意两个端点所组成的其它范围内。
可选地，对分散体系加热的温度为280℃～350℃。
可选地，在烘箱或煅烧炉中对分散体系进行加热。
在这些可选的实施例中，适宜的加热温度和加热时间能够保证第一氧化物前驱体全部转化为第一氧化物，提高产品得率。此外，对分散体系加热的温度为200℃～400℃，能够降低两亲性聚合物材料的损耗，保持两亲性聚合物材料模板的稳 定性。此外，适宜的加热温度和加热时间能够降低能耗，降低生产成本。
在一些实施例中，在步骤S2中在经组装的第一氧化物上组装形成第二氧化物前驱体具体包括：
将经组装的第一氧化物和第二氧化物前驱体充分分散在分散介质中，以使经组装的第一氧化物和所述第二氧化物前驱体接。
可选地，分散介质为水或乙醇。
在这些可选的实施例中，经组装的第一氧化物与第二氧化物前驱体充分分散在分散介质中，第二氧化物前驱体通过物理性吸附的方式组装至经组装的第一氧化物上。
在一些实施例中，经组装的第一氧化物与第二氧化物前驱体的质量比为1∶(1～2)。
在这些可选的实施例中，经组装的第一氧化物与第二氧化物前驱体具有适宜的质量比，能够保证最终获得的具有六方体空心结构的负极活性材料。
在一些实施例中，加热复合物的温度为400℃～600℃，时间为5h～7h。
在本申请的一些实施例中，加热复合物的温度为400℃、410℃、420℃、430℃、440℃、450℃、460℃、470℃、480℃、490℃、500℃、510℃、520℃、530℃、540℃、550℃、560℃、570℃、580℃、590℃、600℃或在由上述的任意两个端点所组成的其它范围内。
可选地，加热复合物的温度为480℃～550℃。
可选地，在烘箱或煅烧炉中加热复合物。
在这些可选的实施例中，适宜的加热温度和加热时间能够保证第二氧化物前驱体全部转化为第二氧化物，提高产品得率。通过加热，能够将复合物中的两亲性聚合物材料去除，而且，第二氧化物经过加热发生合金反应与第一氧化物结合，并将金属离子之间的静电吸引力形成牢固的金属键。
从而获得两种金属氧化物复合的负极活性材料。
在一些实施例中，负极活性材料的平均粒径Dv50为100μm～200μm。
在本申请的一些实施例中，负极活性材料的平均粒径Dv50为100m、110μm、120μm、130μm、140μm、150μm、160μm、170μm、180μm、190μm、200μm或在由上述的任意两个端点所组成的其它范围内。
可选地，负极活性材料的平均粒径Dv50为120μm～180μm。
在本申请的一些实施例中，负极活性材料的平均粒径Dv50在制备过程中通过参数的调控使得材料的粒径尺寸在100μm～200μm之间。根据本申请，负极活性材料的体积平均粒径Dv50可以采用本领域的常规方式测量。例如可以参照GB/T 19077-2016粒度分布激光衍射法，采用激光粒度分析仪方便地测定，如英国马尔文仪器有限公司的Mastersizer 2000E型激光粒度分析仪。
若负极活性材料的平均粒径Dv50过大，颗粒之间仍然存在较大的间隙，会降低负极极片的压实密度，进而导致二次电池的能量密度低。若负极活性材料的平均粒径Dv50过小，会发生不期望的团聚，从而会降低负极极片的压实密度。而且，颗粒之间无足够的间隙保留电解液，会降低负极活性材料层的循环性能差。
在这些可选的实施例中，负极活性材料的平均粒径Dv50在适当范围内，有利于使负极活性材料层获得较高的压实密度，同时具有合适的孔隙率，来满足电化学反应所需的电解液浸润量，还具有较短的颗粒内活性离子和电子的迁移路径，由此能够提高负极活性材料层的能量密度和循环性能。
本申请中的负极活性材料具有六方体空心结构。图4示出了根据本申请一实施方式的负极活性材料SEM图。该扫描电镜(SEM)图例如可以通过如下方式获得：利用ZEISS Gemini SEM 300扫描式电子显微镜，在15k的倍率下选择背散射电子模式，对负极活性材料进行扫描。
如图4所示，具有六方体空心结构的负极活性材料，第一氧化物V 2O 3(图中粒度较小、颜色较浅)与第二氧化物SnO 2(图中粒度较大、颜色较深)复合。
图5示出了根据本申请另一实施方式的负极活性材料SEM图。该扫描电镜(SEM)图例如可以通过如下方式获得：利用ZEISS Gemini SEM 300扫描式电子显微镜，在80k的倍率下选择背散射电子模式，对负极活性材料进行扫描。
如图5所示，具有六方体空心结构的负极活性材料，第一氧化物Fe 2O 3(图中粒度较小、颜色较浅)与第二氧化物SnO 2(图中粒度较大、颜色较深)复合。
负极活性材料
本申请的第二方面还提供一种负极活性材料，通过本申请第一方面的制备方法制得的负极活性材料。
本申请的负极活性材料是由第一氧化物与第二氧化物复合而成，负极活性 材料呈现六方体空心结构，从而使得负极活性材料具有较高的克容量和比表面积，其制备形成的二次电池的能量密度也较高。
在一些实施例中，负极活性材料的比表面积为175m 2/g～400m 2/g。
可选地为300m 2/g～400m 2/g。
在这些可选的实施例中，负极活性材料的比表面积在上述范围内，保证了负极活性材料具有较高的活性比表面积，同时有利于减少电解液在负极活性材料表面的副反应，从而提高负极活性材料的容量发挥及循环寿命。
在一些实施例中，负极活性材料的克容量为490mAh/g～1100mAh/g。
可选地为500mAh/g～700mAh/g。
在这些可选的实施例中，本申请的负极活性材料具有较大克容量，从而使得二次电池具有较大的能量密度。
另外，以下适当参照附图6至图11，对本申请的二次电池、电池模块、电池包和用电装置进行说明。图6是本申请一实施方式的二次电池的示意图。图7是图6所示的本申请一实施方式的二次电池的分解图。图8是本申请一实施方式的电池模块的示意图。图9是本申请一实施方式的电池包的示意图。图10是图9所示的本申请一实施方式的电池包的分解图。图11是本申请一实施方式的二次电池用作电源的用电装置的示意图。
本申请的第三方面提供一种二次电池，包括通过本申请第一方面的制备方法制得的负极活性材料或本申请第二方面的负极活性材料。
通常情况下，二次电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极活性材料层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施例中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对 苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施例中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施例中，正极活性材料层还可以包括导电剂，以改善正极的导电性能。本申请对导电剂的种类不做具体限制，可以根据实际需求进行选择。作为示例，导电剂可以为超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨、石墨烯及碳纳米纤维中的一种或几种。
在一些实施例中，正极活性材料层还可以包括粘结剂，以将正极活性材料和可选的导电剂牢固地粘结在正极集流体上。本申请对粘结剂的种类不做具体限制，可以根据实际需求进行选择。作为示例，粘结剂可以为聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚丙烯酸(PAA)、聚乙烯醇(PVA)、乙烯-醋酸乙烯酯共聚物(EVA)、丁苯橡胶(SBR)、羧甲基纤维素(CMC)、海藻酸钠(SA)、聚甲基丙烯酸(PMA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施例中，正极集流体可以采用导电碳片、金属箔材、涂炭金属箔材、多孔金属板或复合集流体，其中导电碳片的导电碳材质可以为超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨、石墨烯及碳纳米纤维中的一种或几种，金属 箔材、涂炭金属箔材和多孔金属板的金属材质各自独立地可以选自铜、铝、镍及不锈钢中的至少一种。复合集流体可以为金属箔材与高分子基膜复合形成的复合集流体。正极集流体例如为铜箔、铝箔、镍箔、不锈钢箔、不锈钢网及涂炭铝箔中的一种或几种，优选采用铝箔。
以按照本领域常规方法制备上述正极极片。通常将正极活性材料及可选的导电剂和粘结剂分散于溶剂(例如N-甲基吡咯烷酮，简称为NMP)中，形成均匀的正极浆料，将正极浆料涂覆在正极集流体上，经烘干、冷压后，得到正极极片。
在本申请的一些实施例中，负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极活性材料层，所述负极活性材料层包括负极活性材料。
所述负极活性材料为通过本申请第一方面的制备方法制得的负极活性材料或本申请第二方面的负极活性材料。因此，前面对于根据本申请的负极活性材料的实施例的描述同样适用于二次电池中的负极活性材料，相同的内容不再赘述。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极活性材料层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施例中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施例中，负极活性材料层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施例中，负极活性材料层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施例中，负极活性材料层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施例中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
在本申请的一些实施例中，电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施例中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施例中，电解质盐可选NaPF 6、NaClO 4、NaBF 4、KPF 6、KClO 4、KBF 4、LiPF 6、LiClO 4、LiBF 4、Zn(PF 6) 2、Zn(ClO 4) 2、Zn(BF 4) 2中的一种或几种。
在一些实施例中，电解质盐可选自NaPF 6、NaClO 4、NaBF 4中的一种或几种。
在一些实施例中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一些实施例中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
在本申请的一些实施例中，对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施例中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施例中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施例中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施例中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图4示出了作为一个示例的方形结构的二次电池5。
在一些实施方式中，参照图5，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
图6示出了作为一个示例的电池模块4。参照图6，在电池模块4中，多个二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
图7和图8示出了作为一个示例的电池包1。参照图7和图8，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
图9示出了作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对二次电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用二次电池作为电源。
实施例
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例1
将3.8g聚乙烯吡咯烷酮(PVP)和2.5g Co 3V 2O 8分散于20ml 0.05mol NaOH溶液中，磁力搅拌5h，再在烘箱中300℃加热6h，获得经组装的第一氧化物；
经组装的第一氧化物和0.12g三水锡酸钾分散于20ml去离子水，磁力搅拌5min，获得复合物；
再将复合物放置烘箱中500℃加热6h，获得负极活性材料。
其他实施例2～23与对比例1～12与实施例1粘结剂的获得方法相同或相近。
将实施例1～23和对比例1～12的负极活性材料按照下表1进行制备。
另外，将上述实施例1～23和对比例1～12的负极活性材料，分别如下所示制备成二次电池，进行相应的测试。
(1)、正极极片的制备
把正极浆料涂布于10μm厚的铝箔上，外加磁场涂覆厚度500μm，经干燥、压片，得到厚度400μm的正极极片；正极浆料为NCM96∶磁修饰材料∶SP∶SWCNT∶PVDF＝96％∶2％∶0.6％∶0.2％∶1.2％；正极浆料粘度为7500mpa·s，固含量为68％。
(2)、负极极片的制备
将上述制备的负极活性材料、导电剂Super P、粘结剂SBR、增稠剂CMC-Na按质量比95∶2∶2∶1在适量的去离子水中充分搅拌混合，使其形成均匀的负极浆料；将负极浆料涂覆于负极集流体铜箔的表面上，经干燥、冷压后，得到负极极片。
(3)、隔离膜
采用PP/PE复合隔离膜。
(4)、电解液的制备
将碳酸亚乙酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)按体积比1∶1∶1混合，然后将LiPF 6均匀溶解在上述溶液中，得到电解液。该电解液中，LiPF 6的浓度为1mol/L，电解液在25℃的离子电导率为10mS/cm。
(5)、二次电池的制备
将正极极片、隔离膜、负极极片按顺序堆叠并卷绕，得到电极组件，将电极组件放入外包装中，加入上述制备的电解液，经封装、静置、化成分容、老化等工序后，得到二次电池，
按照如下的测试方法测试各实施例和对比例的负极活性材料和二次电池的的测试。
(1)负极活性材料的克容量：
在25℃下，以0.05C恒流放电至0.005V，静置10分钟，以50μA的电流再恒流放电至0.005V，静置10分钟，以10μA再恒流放电至0.005V；然后以0.1C恒流充电至2V，记录充电容量。充电容量与负极活性材料质量的比值即为所制备负极活性材料的克容量。
(2)负极活性材料的比表面积
参照GB/T 19587-2017，采用氮气吸附比表面积分析测试方法测试，并用BET(Brunauer Emmett Teller)法计算得出，其中氮气吸附比表面积分析测试可以通过美国Micromeritics公司的Tri-Star 3020型比表面积孔径分析测试仪进行测试。
表1实施例1～23与对比例1～12的参数结果
Figure PCTCN2022106981-appb-000001
Figure PCTCN2022106981-appb-000002
根据上述结果可知，实施例1至23，均取得了良好的效果，负极活性材料的克容量和比表面积均较高，以及上述负极活性材料形成的二次电池具有较高的能量密度。本申请通过使用两亲性聚合物材料作为模板，制备得到了具有六方体空心结构的负极活性材料。通常情况下，负极活性材料在充放电过程中，活性离子在嵌入容易引起体积的膨胀/收缩，然而，本申请的六方体空心结构的负极活性材料对于体积膨胀/收缩具有一定的缓冲作用，能够克服活性离子嵌入过程中引起的体积变化，从而维持负极活性材料整体的结构稳定性。此外，本申请通过第一氧化物与第二氧化物复合形成负极活性材料，能更好地发挥它们的优势互补和弥补彼此缺点的协同作用，相比于单质或单一氧化物，本申请的负极活性材料嵌入活性离子的量更多，并进一步增加可逆容量，从而提高了负极活性材料的克容量和比表面积，进一步提高二次电池的能量密度。
对比例1为石墨，相比于石墨，本申请的负极活性材料的克容量和能量密度均较高。
对比例2和3为一种金属氧化物的负极活性材料，克容量和能量密度均较低， 说明了本申请的第一氧化物与第二氧化物复合形成负极活性材料，能更好地发挥它们的优势互补和弥补彼此缺点的协同作用，相比于单质或单一氧化物，本申请的负极活性材料嵌入活性离子的量更多，并进一步增加可逆容量，从而提高了负极活性材料的克容量和比表面积。
两亲性聚合物材料、第一氧化物前驱体和第二氧化物前驱体的添加量的比对形成负极活性材料的性能影响较大，参见对比例4至对比例7，两亲性聚合物材料与第一氧化物前驱体，以及经组装的第一氧化物与第二氧化物前驱体具有适宜的质量比，使得第一氧化物前驱体、第二氧化物前驱体均能组装在两亲性聚合物材料模板上。而且，适宜的质量比，能够保证最终获得具有六方体空心结构的负极活性材料的形貌为六方体颗粒，从而提高负极活性材料的克容量和比表面积。
参见对比例8和对比例9，适宜的加热温度和加热时间能够保证第一氧化物前驱体全部转化为第一氧化物，提高产品得率，温度过高或过低都会影响负极活性材料的比表面积。
参见对比例10和对比例11，第二氧化物经过加热发生合金反应与第一氧化物结合，并且通过金属离子之间的静电吸引力形成牢固的金属键，以保证负极活性材料的结构稳定性，温度过高或过低都会影响负极活性材料的克容量。
参见对比例12，制备方法顺序的调整，同样会影响负极活性材料的比表面积和克容量。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (16)

  1. 一种负极活性材料的制备方法，包括：
    在两亲性聚合物材料模板上组装形成第一氧化物，其中，所述第一氧化物选自V 2O 3、Fe 2O 3和CuO中的一种；
    在所述经组装的第一氧化物上组装形成第二氧化物前驱体，以形成两亲性聚合物材料-第一氧化物-第二氧化物前驱体复合物，其中，所述第二氧化物前驱体选自K 2SnO 3、Na 2SiO 3、Na 2GeO 3、NaAlO 2、NaBO 4·4H 2O中的一种；以及
    加热所述复合物，以去除所述两亲性聚合物材料且使得所述第二氧化物前驱体形成第二氧化物，获得具有六方体空心结构的负极活性材料。
  2. 根据权利要求1所述的负极活性材料的制备方法，其中，
    所述负极材料包括V 2O 3-SnO 2、Fe 2O 3-SnO 2、Fe 2O 3-GeO 2、Fe 2O 3-Al 2O 3、Fe 2O 3-B 2O 3和CuO-SiO 2中的一种，可选地为V 2O 3-SnO 2或Fe 2O 3-SnO 2。
  3. 根据权利要求1或2所述的负极活性材料的制备方法，其中，
    所述两亲性聚合物材料选自聚乙烯吡咯烷酮。
  4. 根据权利要求1至3任一项所述的负极活性材料的制备方法，其中，所述在两亲性聚合物材料模板上组装形成第一氧化物，具体包括：
    将两亲性聚合物材料与第一氧化物前驱体充分分散在碱性的分散介质中，以获得其中第一氧化物前驱体组装在两亲性聚合物材料模板上的分散体系；
    对所述分散体系进行加热，以使得第一氧化物前驱体形成第一氧化物，获得所述经组装的第一氧化物。
  5. 根据权利要求4所述的负极活性材料的制备方法，其中，
    所述负极活性材料满足下述(1)～(4)中的一个或几个：
    (1)所述第一氧化物前驱体选自Co 3V 2O 8、Fe(NO 3) 3和Cu(NO 3) 2中的一种；
    (2)所述两亲性聚合物材料与所述第一氧化物前驱体的质量比为1∶(1～2)；
    (3)所述两亲性聚合物材料在所述分散介质中的质量浓度为15％～25％；
    (4)对所述分散体系进行加热的温度为200℃～400℃，时间为5h～7h。
  6. 根据权利要求1至5任一项所述的负极活性材料的制备方法，其中，所述在所述经组装的第一氧化物上组装形成第二氧化物前驱体具体包括：
    将所述经组装的第一氧化物和所述第二氧化物前驱体充分分散在分散介质中，以使所述经组装的第一氧化物和所述第二氧化物前驱体接触。
  7. 根据权利要求6所述的负极活性材料的制备方法，其中，
    所述经组装的第一氧化物与所述第二氧化物前驱体的质量比为1∶(1～2)。
  8. 根据权利要求1至7任一项所述的负极活性材料的制备方法，其中，
    对所述复合物进行加热的温度为400℃～600℃，时间为5h～7h。
  9. 根据权利要求1至8任一项所述的负极活性材料的制备方法，其中，
    所述负极活性材料的平均粒径Dv50为100μm～200μm，可选地为120μm～180μm。
  10. 一种负极活性材料，通过权利要求1至9中任一项所述的制备方法制得的负极活性材料。
  11. 根据权利要求10所述的负极活性材料，其中，
    所述负极活性材料的比表面积为175m 2/g～400m 2/g，可选地为300m 2/g～400m 2/g。
  12. 根据权利要求10或11所述的负极活性材料，其中，
    所述负极活性材料的克容量为490mAh/g～1100mAh/g，可选地为550mAh/g～700mAh/g。
  13. 一种二次电池，其特征在于，包括通过权利要求1～9中任一项所述的制备方法制得的负极活性材料或权利要求10～12中任一项所述的负极活性材料。
  14. 一种电池模块，其特征在于，包括权利要求13所述的二次电池。
  15. 一种电池包，其特征在于，包括权利要求14所述的电池模块。
  16. 一种用电装置，其特征在于，包括选自权利要求13所述的二次电池、权利要求14所述的电池模块或权利要求15所述的电池包中的至少一种。
PCT/CN2022/106981 2022-07-21 2022-07-21 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置 WO2024016250A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/106981 WO2024016250A1 (zh) 2022-07-21 2022-07-21 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/106981 WO2024016250A1 (zh) 2022-07-21 2022-07-21 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置

Publications (1)

Publication Number Publication Date
WO2024016250A1 true WO2024016250A1 (zh) 2024-01-25

Family

ID=89616667

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/106981 WO2024016250A1 (zh) 2022-07-21 2022-07-21 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置

Country Status (1)

Country Link
WO (1) WO2024016250A1 (zh)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101453017A (zh) * 2008-12-12 2009-06-10 中国科学院化学研究所 锂电负极材料及其制备方法
CN105514359A (zh) * 2015-12-05 2016-04-20 许昌学院 滤纸模板法制备Fe-Sn复合氧化物的方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101453017A (zh) * 2008-12-12 2009-06-10 中国科学院化学研究所 锂电负极材料及其制备方法
CN105514359A (zh) * 2015-12-05 2016-04-20 许昌学院 滤纸模板法制备Fe-Sn复合氧化物的方法

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
DING YANHUA; LIU BING; ZOU JIAJIA; LIU HUANQING; XIN TUO; XIA LINHUA; WANG YIQIAN: "α-Fe2O3/SnO2heterostructure composites: A high stability anode for lithium-ion battery", MATERIALS RESEARCH BULLETIN, ELSEVIER, KIDLINGTON., GB, vol. 106, 18 May 2018 (2018-05-18), GB , pages 7 - 13, XP085429755, ISSN: 0025-5408, DOI: 10.1016/j.materresbull.2018.05.014 *
FANG ZEBO; HUANG JUNJIE; HE WENJIE; ZHANG XIAOSONG; WU YANPING; QING JIANWEN: "Electrochemical performance of SnO2–Fe2O3hollow spheres prepared by solid acid template me", ELECTROCHIMICA ACTA, ELSEVIER, AMSTERDAM, NL, vol. 109, 7 August 2013 (2013-08-07), AMSTERDAM, NL , pages 454 - 460, XP028754507, ISSN: 0013-4686, DOI: 10.1016/j.electacta.2013.08.003 *
GU CUIPING, GUAN WENMEI, SHIM JAE-JIN, FANG ZHEN, HUANG JIARUI: "Size-controlled synthesis and electrochemical performance of porous Fe 2 O 3 /SnO 2 nanocubes as an anode material for lithium ion batteries", CRYSTENGCOMM, ROYAL SOCIETY OF CHEMISTRY, CAMBRIDGE, GB, vol. 19, no. 4, 1 January 2017 (2017-01-01), GB , pages 708 - 715, XP093131671, ISSN: 1466-8033, DOI: 10.1039/C6CE02288J *
WANG NA; DU YUNCHEN; MA WENJIE; XU PING; HAN XIJIANG: "Rational design and synthesis of SnO2-encapsulatedα-Fe2O3nanocubes as a robust and stable photo-Fenton catalyst", APPLIED CATALYSIS B. ENVIRONMENTAL, ELSEVIER, AMSTERDAM, NL, vol. 210, 15 March 2017 (2017-03-15), AMSTERDAM, NL , pages 23 - 33, XP029992244, ISSN: 0926-3373, DOI: 10.1016/j.apcatb.2017.03.037 *
ZHANG LEI, WU HAO BIN, LOU XIONG WEN (DAVID): "Metal–Organic-Frameworks-Derived General Formation of Hollow Structures with High Complexity", JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, AMERICAN CHEMICAL SOCIETY, vol. 135, no. 29, 24 July 2013 (2013-07-24), pages 10664 - 10672, XP093131670, ISSN: 0002-7863, DOI: 10.1021/ja401727n *

Similar Documents

Publication Publication Date Title
WO2024040501A1 (zh) 碳材料及其制备方法与应用、负极片、二次电池及用电装置
WO2023240544A1 (zh) 正极材料及其制备方法、具备其的二次电池
WO2023185206A1 (zh) 一种电化学装置及包含其的电器
WO2023197807A1 (zh) 正极材料及其制备方法、复合正极材料、正极极片及二次电池
WO2023134340A1 (zh) 负极活性材料、负极极片、二次电池、电池模块、电池包及其用电装置
US20230146274A1 (en) Silicon carbon negative electrode material, negative electrode sheet, secondary battery, battery module, battery pack and power consumption apparatus
WO2023216168A1 (zh) 造孔剂、正极浆料、正极极片基体、电池单体及其制备方法、电池模块、电池包和用电装置
WO2024011405A1 (zh) 硅碳复合材料及包含其的负极极片
WO2023133814A1 (zh) 蛋黄核壳结构复合材料及制备方法和含该材料的二次电池
WO2023173395A1 (zh) 一种碳纳米管及其制法、用途、二次电池、电池模块、电池包和用电装置
WO2023137624A1 (zh) 二次电池、电池模块、电池包以及用电装置
WO2023122890A1 (zh) 二次电池以及包含其的用电装置
WO2024016250A1 (zh) 负极活性材料及其制备方法、二次电池、电池模块、电池包和用电装置
WO2024020795A1 (zh) 一种复合正极材料、其制备方法、二次电池、电池模块、电池包和用电装置
WO2023130976A1 (zh) 正极极片、二次电池、电池模块、电池包和用电装置
CN116314833B (zh) 硅-金属氧化物复合材料、其制法、二次电池及用电装置
WO2023050837A1 (zh) 负极活性材料及其制备方法、具备其的二次电池
WO2023082157A1 (zh) 一种二次电池和用电装置
WO2023060587A1 (zh) 负极极片、二次电池、电池模块、电池包及用电装置
WO2023225937A1 (zh) 负极极片及其制备方法、二次电池、电池模块、电池包及用电装置
WO2023245597A1 (zh) 一种正极活性材料、二次电池、电池模块、电池包和用电装置
WO2023023926A1 (zh) 人造石墨及其制备方法、负极极片、二次电池、电池模块、电池包及用电装置
WO2023206140A1 (zh) 二次电池、电池模块、电池包和用电装置
WO2023130851A1 (zh) 一种硅负极材料以及包含其的二次电池、电池模块、电池包和用电装置
WO2024036485A1 (zh) 负极活性材料、制法、二次电池和用电装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22951527

Country of ref document: EP

Kind code of ref document: A1