WO2023159863A1 - 一种负极材料及其制备方法、负极片和电池 - Google Patents

一种负极材料及其制备方法、负极片和电池 Download PDF

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WO2023159863A1
WO2023159863A1 PCT/CN2022/106671 CN2022106671W WO2023159863A1 WO 2023159863 A1 WO2023159863 A1 WO 2023159863A1 CN 2022106671 W CN2022106671 W CN 2022106671W WO 2023159863 A1 WO2023159863 A1 WO 2023159863A1
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negative electrode
titanium oxide
porous titanium
electrode material
preparation
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French (fr)
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赵晓锋
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蜂巢能源科技股份有限公司
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    • 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
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • 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 technical field of battery anode materials, in particular to an anode material, a preparation method thereof, an anode sheet and a battery.
  • the negative electrode materials in the market are mainly artificial graphite, and its theoretical specific capacity is 372mAh/g.
  • its theoretical specific capacity is 372mAh/g.
  • the development of negative electrode materials with high specific capacity has always been a priority in the field of lithium-ion batteries.
  • Research hotspots Although silicon-based materials have a high specific capacity (theoretical capacity 3200mAh/g), they also have fatal shortcomings of high volume expansion rate and poor structural stability.
  • the rate performance of Mentor batteries is poor, and it is difficult to meet the needs of fast charging systems for negative electrode materials. , and the cost is higher.
  • Doping and coating the anode material can improve its electrochemical performance to a certain extent.
  • the doping and coating of the anode material is mainly to cover the surface of graphite with amorphous carbon, conductive agent and other measures to improve the rate performance and increase the graphitization temperature to improve
  • the specific capacity of the negative electrode material but there are also defects such as a decrease in the first efficiency and a decrease in the gram capacity, which affects the gram capacity of the positive electrode material of the full battery, and then affects the overall energy density of the battery.
  • the technical problem to be solved in this application is to overcome the defect that the energy density and rate of the lithium battery obtained by the negative electrode material used in the prior art cannot be balanced, that is, while improving the rate performance of the battery, the energy density is also improved, thereby providing A negative electrode material and a preparation method thereof.
  • the application provides a negative electrode material, comprising:
  • an inner core comprising boron-doped graphite
  • An outer shell covering the inner core, the outer shell includes porous titanium oxide, amorphous carbon and a conductive agent.
  • the porosity of the porous titanium oxide is 5-50%, and the average pore diameter is 10-500nm.
  • the porosity and average pore diameter in this application are measured by nitrogen adsorption method, specifically measured by nitrogen adsorption porosity tester JW-BK300C.
  • the mass ratio of the inner core to the outer shell is 90-99:1-10.
  • the mass ratio of the porous titanium oxide to the amorphous carbon is 1-10:88-98.5.
  • the mass ratio of the porous titanium oxide to the amorphous carbon is 5-10:88-95.
  • the mass ratio of the porous titanium oxide to the conductive agent is 1-10:0.5-2.
  • the mass ratio of the porous titanium oxide to the conductive agent is 5-10:1-2.
  • the doping ratio of boron in boron-doped graphite is 1-20wt%
  • the doping ratio of boron refers to the percentage of the mass of boron atoms in the total mass of boron-doped graphite.
  • the conductive agent is selected from at least one of carbon nanotubes, graphene and super carbon black.
  • the full name of super carbon black is super conductive carbon black (SP). It is a kind of conductive carbon black similar to furnace black method. Compression and other subsequent processing molding. Wherein carbon nanotube, graphene and super carbon black all can be selected conventional carbon nanotube, graphene and super carbon black of this area for use.
  • the present application also provides a preparation method of negative electrode material, comprising the following steps:
  • the preparation method also satisfies at least one of the following 1)-8):
  • the raw material of described amorphous carbon is resin, optionally, described resin is selected from at least one in phenolic resin, furfural resin and epoxy resin; Wherein, the carbon-containing of phenolic resin, furfural resin and epoxy resin The value is 25%, that is, the mass of the amorphous carbon obtained after the resin is dried and carbonized accounts for 25% of the mass of the raw resin.
  • the organic solvent is selected from at least one of carbon tetrachloride, N-methylpyrrolidone, cyclohexane, tetrahydrofuran and xylene; and/or, the conductive agent is selected from carbon nanotubes, graphene and At least one of super carbon black; And/or, the boron-containing compound is selected from at least one of boron oxide, titanium diboride, magnesium diboride, chromium diboride and boron carbide;
  • the raw material of the graphite is needle coke, and the needle coke is selected from at least one of petroleum-based needle coke and coal-based needle coke;
  • the binder is asphalt
  • steps (1) and/or (2) After the mixing of steps (1) and/or (2), grinding, stirring and/or ultrasonic treatment are also included;
  • step (1) the heating process is to first heat to 200-300°C under inert gas and keep it warm in this temperature range for 1-6h, then raise the temperature to 700-1000°C under inert gas and within this temperature range Insulation 1-6h;
  • step (2) the carbonization temperature is 600-1000°C, and the time is 1-6h;
  • the mass ratio of porous titanium oxide to resin is 10-50:50-400; and/or, the mass ratio of porous titanium oxide to conductive agent is 1-10:0.5-2; and/or, the graphite
  • the mass ratio of the raw material to the boron-containing compound is 100:1-10.
  • petroleum-based needle coke and coal-based needle coke can be conventional petroleum-based needle coke and coal-based needle coke; for example, it meets the standard "GB/T 37308-2019 Oil-based needle coke” Standard petroleum-based needle coke and coal-based needle coke that meet the standard "GB T 32158-2015 Coal-based Needle Coke", phenolic resin, furfural resin and epoxy resin can be selected from various specifications of phenolic resin in this field, Epoxy and furfural resins. Asphalt can be selected from petroleum asphalt and coal tar pitch of various specifications in the field.
  • step (1) the porous titanium oxide is added to the organic solvent containing the resin, and mixed with the organic solvent containing the conductive agent to obtain a coating solution.
  • Mass volume percent can be expressed as % (w/v).
  • the mass volume percentage of the resin in the resin-containing organic solvent is 1-15%, which means that the mass of the resin contained in 100ml of the resin-containing organic solvent is 1-15g.
  • the volume ratio of the mass of porous titanium oxide to the resin-containing organic solvent is 1-10g:2000-7600mL;
  • the mass volume percentage of the organic solvent containing the conductive agent is 0.5-2%; it means that every 100ml of the organic solvent containing the conductive agent contains 0.5-2g of the conductive agent.
  • the volume ratio of the mass of the porous titanium oxide to the organic solvent containing the conductive agent is 1-10g:100-500mL.
  • the preparation method of the porous titanium oxide comprises the following steps:
  • Heating titanate aqueous solution adding acid solution to adjust pH value, reacting, separating solid and liquid, taking solid, drying and carbonizing to prepare porous titanium oxide.
  • the titanate is selected from at least one of calcium titanate, magnesium titanate, lithium titanate, aluminum titanate and potassium titanate; and/or, the heating temperature is 60-100°C, and the time is at least 1h (eg 1-6h); and/or, the reaction time is at least 1h (eg 1-12h); and/or, the carbonization temperature is 600-1000°C, and the time is 1-6h; and/or, adjust the pH value to 4-6; and/or, the acid solution is hydrochloric acid solution, sulfuric acid solution, citric acid solution, acetic acid solution or phosphoric acid solution.
  • the mass percentage of the titanate in the titanate aqueous solution is 1-10wt%.
  • the present application also provides a negative electrode sheet, comprising any one of the above-mentioned negative electrode materials or a negative electrode material prepared by any of the above-mentioned preparation methods.
  • the negative electrode sheet can be prepared by conventional methods, such as homogenization, coating and the like.
  • the present application also provides a battery, which includes the negative electrode sheet described in the claims, and also includes a battery casing, a positive electrode sheet, a separator and an electrolyte.
  • the battery may be a lithium ion battery, a sodium ion battery, a potassium ion battery, an aluminum ion battery, or the like.
  • the anode material provided by this application not only significantly improves the ion/electron transmission of the anode material by adopting a shell covering boron-doped graphite including porous titanium oxide, amorphous carbon and conductive agent, and cooperating with each other. rate, improve the conductivity, and can also improve the lithium ion intercalation of the lithium battery formed by the negative electrode material, reduce the loss of irreversible capacity of the battery, improve the first efficiency and rate performance of the battery, especially the use of porous titanium oxide, also makes The structure of the negative electrode material is more stable, which significantly improves the cycle performance of the battery.
  • the negative electrode material provided by this application can further improve the initial efficiency and rate performance of the battery composed of the negative electrode material by controlling the porosity of the porous titanium oxide to 5-50% and the average pore diameter to 10-500nm.
  • Fig. 1 is the SEM electron micrograph of the negative electrode material that the application embodiment 1 makes;
  • Fig. 2 is that the cycle graph comparison of embodiment 1 and comparative example 1;
  • phenolic resin satisfy solid content: 10-90%, free phenol (%): ⁇ 20, the phenolic resin of viscosity: 10-1000mpa.S (25 °C) is all suitable for this application, such as following examples and
  • the phenolic resin used is the phenolic resin from Wuxi Guangming Chemical Co., Ltd., the model is 2130; the oil-based needle coke is purchased from Daqing Petrochemical or Jinzhou Petrochemical, both of which meet the standard "GB/T 37308-2019 Oil-based needle coke coke”; coal-based needle coke materials were purchased from Tangshan Rixin Energy Co., Ltd., meeting the standard “GB T 32158-2015 coal-based needle coke”.
  • the carbon nanotubes in the following examples and comparative examples come from Jiangsu Tiannai Technology Co., Ltd., model LB107-44; the graphene comes from Jiangsu Tiannai Technology Co., Ltd., model: LB2G3-85; pitch is purchased from Jining Chaolianxin Material Technology Co., Ltd., model: GB/8175; furfural resin was purchased from Wuhan Yuanyuan Technology Development Co., Ltd., model: FL type resin; epoxy resin was purchased from Wuxi Arz Chemical Co., Ltd., model: 128 epoxy resin.
  • the negative electrode material includes an inner core and a shell covering the inner core, the inner core is boron-doped graphite; the doping ratio of boron in boron-doped graphite The mass fraction is 9.6%; the shell includes porous titanium oxide, amorphous carbon and carbon nanotubes. Porous titanium oxide has a porosity of 20% and an average pore diameter of 100 nm.
  • the mass ratio of the inner core to the shell is 95:5; the mass ratio of the porous titanium oxide to the amorphous carbon is 5:94, and the mass ratio of the porous titanium oxide to the carbon nanotube is 5:1.
  • Its preparation method includes:
  • porous titanium oxide add 50 g of calcium titanate to 1000 g of deionized water to form a calcium titanate aqueous solution with a mass concentration of 5%, and react at 80° C. for 6 hours to obtain the first solution; A 5vt% hydrochloric acid solution was added dropwise to adjust the pH to 4, and left to react for 3 hours to obtain a second solution. Filtrating the second solution, drying in vacuum, and then carbonizing the obtained solid in a muffle furnace at 800° C. for 3 hours to obtain porous titanium oxide;
  • the negative electrode material includes an inner core and a shell covering the inner core, the inner core is boron-doped graphite; the doping ratio of boron in boron-doped graphite 2%, mass fraction; the shell includes porous titanium oxide, amorphous carbon and graphene. Porous titanium oxide has a porosity of 5% and an average pore diameter of 10 nm.
  • the mass ratio of the inner core to the shell is 99:1; the mass ratio of the porous titanium oxide to amorphous carbon is 10:89, and the mass ratio of the porous titanium oxide to graphene is 10:1.
  • Its preparation method includes:
  • porous titanium oxide add 20g of lithium titanate to 2000g of deionized water to form a lithium titanate aqueous solution with a mass concentration of 1%, and react at 60°C for 12h to obtain the first solution; 10vt% hydrochloric acid solution was added dropwise to adjust the pH to 4, and left to react for 1 hour to obtain the second solution. Filtrating the second solution, drying in vacuum, and then carbonizing the obtained solid in a muffle furnace at 600° C. for 6 hours to obtain a porous titanium oxide material;
  • the negative electrode material includes an inner core and a shell covering the inner core, the inner core is boron-doped graphite; the doping ratio of boron in boron-doped graphite
  • the mass fraction is 20%; the shell includes porous titanium oxide, amorphous carbon and carbon nanotubes.
  • the porosity of porous titanium oxide is 50%, and the average pore diameter is 500nm.
  • the mass ratio of the inner core to the shell is 90:10; the mass ratio of the porous titanium oxide to the amorphous carbon is 10:88, and the mass ratio of the porous titanium oxide to the carbon nanotube is 10:2.
  • Its preparation method includes:
  • This comparative example provides a kind of negative electrode material, and its preparation method is as follows:
  • the negative electrode material includes an inner core and a shell covering the inner core, and the inner core is boron-doped graphite; the doping ratio of boron in boron-doped graphite The mass fraction is 9.6%; the shell includes ordinary titanium oxide, amorphous carbon and carbon nanotubes.
  • the mass ratio of the inner core to the outer shell is 95:5; the mass ratio of the common titanium oxide to amorphous carbon is 5:94, and the mass ratio of the common titanium oxide to carbon nanotubes is 5:1.
  • Its preparation method includes:
  • coating solution 5g of ordinary titanium oxide (purchased from Guangzhou Hongwu Material Technology Co., Ltd.) was added to 7520ml of carbon tetrachloride containing 5% (w/v) phenolic resin, and then 100ml of carbon tetrachloride containing 1% (w/v) NMP dispersion of carbon nanotubes, mixed evenly to obtain coating solution;
  • the negative electrode material includes an inner core and a shell covering the inner core, and the inner core is boron-doped graphite; the doping ratio of boron in boron-doped graphite
  • the mass fraction is 9.6%;
  • the shell includes porous iron oxide, amorphous carbon and carbon nanotubes.
  • the porosity of the porous iron oxide is 30%, and the average pore diameter is 100nm.
  • the mass ratio of the inner core to the shell is 95:5; the mass ratio of the porous iron oxide to amorphous carbon is 5:94, and the mass ratio of the porous iron oxide to carbon nanotubes is 5:1.
  • Its preparation method includes:
  • the negative electrode material includes an inner core and an outer shell covering the inner core, the inner core is graphite; the outer shell includes porous titanium oxide, amorphous carbon and graphite alkene. Porous titanium oxide has a porosity of 5% and an average pore diameter of 10 nm.
  • the mass ratio of the inner core to the shell is 99:1; the mass ratio of the porous titanium oxide to amorphous carbon is 10:89, and the mass ratio of the porous titanium oxide to graphene is 10:1.
  • Its preparation method includes:
  • the negative electrode material prepared in Example 1 was taken for SEM testing, and the test results are shown in FIG. 1 . It can be seen from Figure 1 that the negative electrode material prepared in Example 1 has a granular structure with a uniform size and a particle size between 10-18 ⁇ m.
  • the specific surface area of the negative electrode material prepared by each embodiment of the present application is significantly higher than that of Comparative Examples 1-4.
  • the reason is that the surface of the composite material is coated with porous titanium oxide material or the inner core is made of boron doped material. Both can increase the specific surface area of the material, and the prepared negative electrode material has an appropriate tap density.
  • the negative electrode materials prepared in each example and comparative example were assembled into button batteries a1, a2, a3, b1, b2, b3 and b4, respectively.
  • the assembly method is as follows: add binder, conductive agent and solvent to the negative electrode material, stir and make slurry, and then coat the slurry on the copper foil, dry and roll to obtain the negative electrode sheet, and the coating of the electrode sheet
  • the density on one side is 6 mg/cm 2 ;
  • the binder used is LA132 binder, the conductive agent is SP, and the solvent is twice distilled water.
  • the button cell is assembled in an argon-filled glove box, and the electrochemical performance test is carried out on Wuhan Landian CT2001A battery tester.
  • the charge and discharge voltage range is from 0.005V to 2.0V, and the test charge and discharge rate is under 0.1C.
  • the first discharge capacity and first efficiency, and test the discharge capacity at 3C and 0.2C rate, get the rate (3C/0.2C), the test results are shown in Table 2.
  • the first discharge capacity, first charge and discharge efficiency and rate performance of the lithium-ion battery prepared by the composite materials of Examples 1-4 of the present application are significantly higher than those of the comparative example.
  • the surface of the graphite core is coated with porous titanium oxide, amorphous carbon and conductive agent, which can make better use of the structural stability of porous titanium oxide, improve the intercalation of lithium ions, reduce the loss of irreversible capacity of the material, and improve the first-time efficiency. It can also make better use of the high conductivity of titanium oxide lithium ions to improve the rate performance of button batteries.
  • the negative electrode materials prepared by each embodiment and comparative example were used to prepare negative electrode sheets respectively, and the method and process conditions were the same as in Experimental Example 3; the ternary material (LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) was used as As the positive electrode material, LiPF 6 solution (the solvent is EC+DEC, the volume ratio is 1:1, and the concentration of LiPF 6 is 1.3mol/L) is used as the electrolyte, and celegard2400 is used as the separator to prepare 5Ah soft pack batteries A1, A2, A3, B1, B2, B3 and B4. Then test the cycle performance and rate performance of the pouch battery.
  • LiPF 6 solution the solvent is EC+DEC, the volume ratio is 1:1, and the concentration of LiPF 6 is 1.3mol/L
  • celegard2400 is used as the separator to prepare 5Ah soft pack batteries A1, A2, A3, B1, B2, B3 and B4. Then test the cycle performance and rate performance of the pouch battery.
  • Cycle performance test conditions charge and discharge current 1C/1C, voltage range 2.8-4.2V, cycle times 500 times.
  • Rate performance test conditions charge rate 1C/3C/5C/8C, discharge rate 1C; voltage range 2.8-4.2V.
  • the cycle performance of the pouch battery prepared by using the composite materials of Examples 1-3 is better than that of the comparative example, especially when the cycle is 500 times, the reason is: in terms of 1C/1C rate cycle performance , the deposition of porous titanium oxide, amorphous carbon, and conductive agent on the surface of the boron-doped graphite core can significantly increase the transmission rate of lithium ions; at the same time, the cycle performance is improved by utilizing the stable structure of porous titanium oxide.
  • the pouch battery prepared by using the negative electrode materials of Examples 1-3 has a better constant current ratio.
  • the reason is that the surface of the boron-doped graphite core is coated with porous titanium oxide, amorphous Carbon and conductive agent can better improve the lithium ion intercalation rate of the material during the rate charging process, thereby improving the rate charging performance.

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Abstract

本申请公开了一种负极材料及其制备方法、负极片和电池，该负极材料呈现核壳结构，内核为硼掺杂石墨，外壳是包括多孔氧化钛、无定形碳和导电剂。通过采用包括多孔氧化钛、无定形碳和导电剂的外壳包覆硼掺杂石墨，各组分相互配合，不仅显著提升了负极材料的离子/电子的传输速率，提高导电率，还能够提升由该负极材料形成的锂电池的锂离子的嵌出，降低电池不可逆容量的损失，提升电池的首次效率和倍率性能，尤其是多孔氧化钛的使用，还使得负极材料结构更加稳定，明显提升电池的循环性能。

Description

一种负极材料及其制备方法、负极片和电池
交叉引用
本申请要求在2022年2月25日提交中国国家知识产权局、申请号为202210179436.6、发明名称为“一种负极材料及其制备方法、负极片和电池”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电池负极材料技术领域，具体涉及一种负极材料及其制备方法、负极片和电池。
背景技术
目前市场化的负极材料主要是以人造石墨为主，其理论比容量为372mAh/g，随着锂离子电池对能量密度要求的日益提高，开发高比容量的负极材料一直是锂离子电池领域的研究热点。硅基材料虽然具有高的比容量(理论容量3200mAh/g)，但是也存在体积膨胀率高，结构稳定性差的致命缺点，导师电池的倍率性能较差，难以满足快充体系对负极材料的需求，且成本较高。
通过掺杂包覆负极材料对其电化学性能具有一定的改善作用，负极材料掺杂包覆主要是在石墨的表面包覆无定形碳、导电剂等措施改善倍率性能，提升石墨化温度以提升负极材料的比容量，但是也存在首次效率降低，克容量降低的缺陷，影响其全电池正极材料的克容量发挥，进而影响电池的整体能量密度。
发明内容
因此，本申请要解决的技术问题在于克服现有技术中采用的负极材料得到的锂电池能量密度与倍率不能兼顾的缺陷，即在提升电池的倍率性能的同时，能量密度也得到提升，从而提供一种负极材料及其制备方法。
本申请提供了一种负极材料，包括：
内核，所述内核包括硼掺杂石墨；
包覆于所述内核外的外壳，所述外壳包括多孔氧化钛、无定形碳和导电剂。
进一步地，所述多孔氧化钛的孔隙率为5-50％，平均孔径为10-500nm。本申请中的孔隙率和平均孔径通过氮吸附法测定，具体是通过氮吸附孔隙率测试仪JW-BK300C测得。
进一步地，所述内核与外壳的质量比为90-99:1-10。
进一步地，所述多孔氧化钛和无定形碳的质量比为1-10:88-98.5。可选地，所述多孔氧化钛和无定形碳的质量比为5-10:88-95。
进一步地，所述多孔氧化钛与导电剂的质量比为1-10:0.5-2。可选地，所述多孔氧化钛与导电剂的质量比为5-10:1-2。
进一步地，硼掺杂石墨中硼的掺杂比例为1-20wt％；
其中，硼的掺杂比例是指硼原子的质量占硼掺杂石墨总质量的百分比。
进一步地，所述导电剂选自碳纳米管、石墨烯和超级炭黑中的至少一种。超级炭黑全称超级导电炭黑(SP)，其是一款类炉黑法的导电炭黑，是由直径为40nm左右的原生粒子团聚成150-200nm的原生聚集体，再通过软团聚和人工压缩等后续加工成型。其中碳纳米管、石墨烯和超级炭黑均 可选用本领域常规的碳纳米管、石墨烯和超级炭黑。
本申请还提供了一种负极材料的制备方法，包括如下步骤：
(1)取多孔氧化钛、无定形碳的原料、导电剂与有机溶剂混合，制得包覆液；取石墨的原料、含硼化合物和粘结剂混合，加热，得到前驱体材料；
(2)将前驱体材料与包覆液混合，干燥，碳化，制得负极材料。
进一步地，所述制备方法还满足如下1)-8)中的至少一项：
1)所述无定形碳的原料为树脂，可选的，所述树脂选自酚醛树脂、糠醛树脂和环氧树脂中的至少一种；其中，酚醛树脂、糠醛树脂和环氧树脂的含碳值为25％，即树脂经干燥、碳化处理后得到的无定形碳的质量占其原料树脂质量的25％。
2)所述有机溶剂选自四氯化碳、N-甲基吡咯烷酮、环己烷、四氢呋喃和二甲苯中的至少一种；和/或，所述导电剂选自碳纳米管、石墨烯和超级炭黑中的至少一种；和/或，所述含硼化合物选自氧化硼、二硼化钛、二硼化镁、二硼化铬和碳化硼中的至少一种；
3)所述石墨的原料为针状焦，所述针状焦选自石油系针状焦、煤系针状焦中的至少一种；
4)所述粘结剂为沥青；
5)步骤(1)和/或(2)的混合之后还包括研磨、搅拌和/或超声处理；
6)步骤(1)中，加热过程为先在惰性气体下加热到200-300℃并在该温度范围内保温1-6h，然后在惰性气体下升温至700-1000℃并在该温度范围内保温1-6h；
7)步骤(2)中，碳化的温度为600-1000℃，时间为1-6h；
8)多孔氧化钛与树脂的质量比为10-50:50-400；和/或，所述多孔氧化钛与导电剂的质量比为1-10:0.5-2；和/或，所述石墨的原料与含硼化合物的质量比为100:1-10。
本申请中，石油系针状焦和煤系针状焦均可采用本领域常规的石油系针状焦和煤系针状焦；例如满足标准《GB/T 37308-2019油系针状焦》标准的石油系针状焦和满足标准《GB T 32158-2015煤系针状焦》的煤系针状焦，酚醛树脂、糠醛树脂和环氧树脂皆可选用本领域各种规格的酚醛树脂、环氧树脂和糠醛树脂。沥青可选用本领域各种规格的石油沥青和煤沥青。
进一步地，步骤(1)中，将多孔氧化钛加入到含树脂的有机溶剂中，与含导电剂的有机溶剂混合，得到包覆液。
质量体积百分数可表述为％(w/v)。
在某些可选的实施方式中，含树脂的有机溶剂中树脂的质量体积百分数为1-15％；是指每100ml的含树脂的有机溶剂中含有树脂的质量为1-15g。
在某些可选的实施方式中，多孔氧化钛的质量与含树脂的有机溶剂的体积比为1-10g:2000-7600mL；
在某些可选的实施方式中，含导电剂的有机溶剂中质量体积百分数为0.5-2％；是指每100ml的含导电剂的有机溶剂中含有0.5-2g导电剂。
在某些可选的实施方式中，多孔氧化钛的质量与含导电剂的有机溶剂的体积比为1-10g:100-500mL。
进一步地，所述多孔氧化钛的制备方法包括如下步骤：
取钛酸盐水溶液加热，加酸溶液调节pH值，反应，固液分离，取固体，干燥，碳化，制得多孔氧化钛。
进一步地，所述钛酸盐选自钛酸钙、钛酸镁、钛酸锂、钛酸铝和钛酸 钾中的至少一种；和/或，加热温度为60-100℃，时间为至少1h(例如1-6h)；和/或，反应的时间为至少1h(例如1-12h)；和/或，碳化温度为600-1000℃，时间为为1-6h；和/或，调节pH值至4-6；和/或，所述酸溶液为盐酸溶液、硫酸溶液、枸橼酸溶液、醋酸溶液或者磷酸溶液。钛酸盐水溶液中钛酸盐的质量百分数为1-10wt％。
本申请还提供了一种负极片，包括上述任一所述的负极材料或者上述任一所述的制备方法制得的负极材料。该负极片可采用常规方法制备，例如匀浆、涂布等。
本申请还提供了一种电池，包括权利要求所述的负极片，还包括电池外壳、正极片、隔离膜和电解液。其中该电池可以是锂离子电池、钠离子电池、钾离子电池、铝离子电池等。
本申请技术方案，具有如下优点：
(1)本申请提供的负极材料，通过采用包括多孔氧化钛、无定形碳和导电剂的外壳包覆硼掺杂石墨，各组分相互配合，不仅显著提升了负极材料的离子/电子的传输速率，提高导电率，还能够提升由该负极材料形成的锂电池的锂离子的嵌出，降低电池不可逆容量的损失，提升电池的首次效率和倍率性能，尤其是多孔氧化钛的使用，还使得负极材料结构更加稳定，明显提升电池的循环性能。
(2)本申请提供的负极材料，通过控制多孔氧化钛的孔隙率为5-50％，平均孔径为10-500nm，可以进一步提升由该负极材料构成的电池的首次效率和倍率性能。
附图说明
为了更清楚地说明本申请具体实施方式或现有技术中的技术方案，下面将对具体实施方式或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图是本申请的一些实施方式，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，还可以根据这些附图获得其他的附图。
图1是本申请实施例1制得的负极材料的SEM电镜图；
图2为实施例1与对比例1的循环曲线图比较；
具体实施方式
提供下述实施例是为了更好地进一步理解本申请，并不局限于所述最佳实施方式，不对本申请的内容和保护范围构成限制，任何人在本申请的启示下或是将本申请与其他现有技术的特征进行组合而得出的任何与本申请相同或相近似的产品，均落在本申请的保护范围之内。
实施例中未注明具体实验步骤或条件者，按照本领域内的文献所描述的常规实验步骤的操作或条件即可进行。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试剂产品。对于酚醛树脂来说，满足固含量：10-90％，游离酚(％)：≤20，粘度：10-1000mpa.S(25℃)的酚醛树脂均适用于本申请，例如下述实施例和对比例中，酚醛树脂采用的是来自无锡光明化工有限公司的酚醛树脂，型号为2130；油系针状焦购自大庆石化或者锦州石化，均满足标准《GB/T 37308-2019油系针状焦》；煤系针状焦材料购自唐山东日新能源有限公司，满足标准《GB T 32158-2015煤系针状焦》。下述实施例和对比例中的碳纳米管来自江苏天奈科技股份有限公司，型号LB107-44；石墨烯来自江苏天奈科技股份有限公司，型号： LB2G3-85；沥青购自济宁超联新材料科技有限公司，型号：GB/8175；糠醛树脂购自武汉远程科技发展有限公司，型号：FL型树脂；环氧树脂购自无锡阿尔兹化工有限公司，型号：128环氧树脂。
以实施例1为例，下述参数的计算公式如下：掺杂比例＝硼原子质量/(针状焦材料的质量+硼原子质量)×100％；内核的质量＝前驱体材料的质量；外壳的质量＝(多孔氧化钛的总质量+树脂的总质量×含碳值+碳纳米管的总质量)/(含酚醛树脂的四氯化碳溶液的体积+含纳米管的NMP分散液的体积)×负极材料使用的包覆液的实际体积。
实施例1
本实施例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为硼掺杂石墨；硼掺杂石墨中硼的掺杂比例为9.6％，质量分数；所述外壳包括多孔氧化钛、无定形碳和碳纳米管。多孔氧化钛的孔隙率为20％，平均孔径为100nm。所述内核与外壳的质量比为95：5；所述多孔氧化钛和无定形碳的质量比为5：94，所述多孔氧化钛与碳纳米管的质量比为5：1。
其制备方法包括：
(1)多孔氧化钛的制备：将50g钛酸钙添加到1000g去离子水中配置成质量浓度为5％的钛酸钙水溶液，在80℃下反应6h，得到第一溶液；往第一溶液中滴加5vt％盐酸溶液，调节pH为4，放置使其反应3h，得到第二溶液。将第二溶液过滤，真空干燥，之后将得到的固体物在马弗炉中800℃下碳化3h，得到多孔氧化钛；
(2)包覆液的制备：将5g多孔氧化钛添加到7520ml，含5％(w/v) 酚醛树脂的四氯化碳中，之后添加100ml，含1％(w/v)碳纳米管的N-甲基吡咯烷酮(NMP)分散液，混合均匀得到包覆液；
(3)负极材料的制备：称取92g石油系针状焦材料(大庆石化)、31g二硼化钛及5g沥青混合均匀，并通过球磨机在转速为50rpm/min，球磨48h，之后在氩气惰性气氛下加热到250℃进行软化，并保温3h，之后在氩气惰性气氛下升温到800℃并保温3h，之后自然降温到室温，粉碎得到前驱体材料。之后取95g前驱体材料添加到381ml包覆液中，球磨，真空干燥，并在氩气惰性气氛下，在温度为800℃下碳化3h，得到负极材料。
实施例2
本实施例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为硼掺杂石墨；硼掺杂石墨中硼的掺杂比例为2％，质量分数；所述外壳包括多孔氧化钛、无定形碳和石墨烯。多孔氧化钛的孔隙率为5％，平均孔径为10nm。所述内核与外壳的质量比为99：1；所述多孔氧化钛和无定形碳的质量比为10：89，所述多孔氧化钛与石墨烯的质量比为10：1。
其制备方法包括：
(1)多孔氧化钛的制备：将20g钛酸锂添加到2000g去离子水中配置成质量浓度为1％的钛酸锂水溶液，在60℃下反应12h，得到第一溶液；往第一溶液中滴加10vt％盐酸溶液，调节pH为4，放置使其反应1h，得到第二溶液。将第二溶液过滤，真空干燥，之后将得到的固体物在马弗炉中600℃下碳化6h，得到多孔氧化钛材料；
(2)包覆液的制备：将10g多孔氧化钛材料添加到3560ml，含10％(w/v)糠醛树脂的四氯化碳溶液中，之后添加100ml，含1％(w/v)石墨烯的NMP溶液，混合均匀得到包覆液；
(3)负极材料的制备：称取92.75g油系针状焦材料(锦州石化)、6.25g氧化硼及其1g沥青混合均匀，并通过球磨机在转速为10rpm/min，球磨72h，之后在氩气惰性气氛下加热到200℃进行软化，并保温6h，之后在氩气惰性气氛下升温到700℃并保温6h，之后自然降温到室温，粉碎得到前驱体材料。之后取99g前驱体材料添加36.8ml包覆液中，球磨，真空干燥，并在氩气惰性气氛下，在温度为600℃下碳化6h，得到负极材料。
实施例3
本实施例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为硼掺杂石墨；硼掺杂石墨中硼的掺杂比例为20％，质量分数；所述外壳包括多孔氧化钛、无定形碳和碳纳米管。多孔氧化钛的孔隙率为50％，平均孔径为500nm。所述内核与外壳的质量比为90：10；所述多孔氧化钛和无定形碳的质量比为10：88，所述多孔氧化钛与碳纳米管的质量比为10：2。
其制备方法包括：
(1)多孔氧化钛的制备：将20g钛酸铝添加到200g去离子水中配置成10％的钛酸铝水溶液，在100℃下反应1h，得到第一溶液；往第一溶液中滴加5vt％盐酸溶液，调节pH为4，放置使其反应6h，得到第二溶液。将第二溶液过滤，真空干燥，之后将得到的固体物在马弗炉中 1000℃下碳化1h，得到多孔氧化钛材料；
(2)包覆液的制备：将10g多孔氧化钛材料添加到2356ml，含15％(w/v)环氧树脂的环己烷溶液中，之后添加到200ml，含1％(w/v)石墨烯的NMP分散液中，混合均匀得到包覆液；
(3)负极材料的制备：称取80g煤系针状焦材料、41.6g二硼化镁及其10g沥青混合均匀，并通过球磨机在转速为100rpm/min，球磨12h，之后在氩气惰性气氛下加热到300℃进行软化，并保温1h，之后在氩气惰性气氛下升温到1000℃并保温1h，之后自然降温到室温，粉碎得到前驱体材料。之后取90g前驱体材料添加到255ml包覆液中，球磨，喷雾干燥，并在氩气惰性气氛下，在温度为1000℃下碳化1h，得到负极材料。
对比例1
本对比例提供了一种负极材料，其制备方法如下：
将95g实施例1同批次的油系针状焦添加到100ml，含5％(w/v)酚醛树脂的四氯化碳有机溶剂中，之后通过球磨机在在转速为50rpm/min，球磨48h，之后真空干燥，之后在氩气的气氛下，在管式炉中升温到800℃碳化3h，之后自燃降温到室温，粉碎得到硬碳包覆石墨复合材料。
对比例2
本对比例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为硼掺杂石墨；硼掺杂石墨中硼的掺杂比例为9.6％，质量分数；所述外壳包括普通氧化钛、无定形碳和碳纳米管。所述内核与外壳的质量比为95：5；所述普通氧化钛和无定形碳的质量比为5：94，所述普通氧化钛与碳纳米管的质量比为5：1。
其制备方法包括：
(1)包覆液的制备：将5g普通氧化钛(购自广州宏武材料科技有限公司)添加到7520ml，含5％(w/v)酚醛树脂的四氯化碳中，之后添加100ml，含1％(w/v)碳纳米管的NMP分散液，混合均匀得到包覆液；
(2)负极材料的制备：称取92g实施例1同批次的石油系针状焦材料、31g二硼化钛及其5g沥青混合均匀，并通过球磨机在转速为50rpm/min，球磨48h，之后在氩气惰性气氛下加热到250℃进行软化，并保温3h，之后在氩气惰性气氛下升温到800℃并保温3h，之后自然降温到室温，粉碎得到前驱体材料。之后取95g前驱体材料添加到381ml包覆液中，球磨，真空干燥，并在氩气惰性气氛下，在温度为800℃下碳化3h，得到负极材料。
对比例3
本对比例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为硼掺杂石墨；硼掺杂石墨中硼的掺杂比例为9.6％，质量分数；所述外壳包括多孔氧化铁、无定形碳和碳纳米管。多孔氧化铁的孔隙率为30％，平均孔径为100nm。所述内核与外壳的质量比为95：5；所述多孔氧化铁和无定形碳的质量比为5：94，所述多孔氧化铁与碳纳米管的质量比为5：1。
其制备方法包括：
(1)多孔氧化铁的制备：称取139g FeSO 4·7H 2O溶于7500g超纯水中，搅拌使其完全溶解后，把所得溶液移入聚四氟乙烯内衬的不锈钢反应釜中，封闭拧紧，放入烘箱中，在160℃下，反应12h。反应结束，使所得 反应产物自然冷却。之后将所得反应产物用超纯水和无水乙醇交替清洗，直到清洗液为中性为止。然后，将清洗处理后的反应产物在真空干燥箱中60℃下干燥12h，得到多孔氧化铁前驱体；之后将前驱体置于氮气气氛中，在350℃下煅烧1h，制得多孔氧化铁。
(2)包覆液的制备：将5g多孔氧化铁添加到7520ml，含5％(w/v)酚醛树脂的四氯化碳中，之后添加100ml，含1％(w/v)的碳纳米管的NMP分散液，混合均匀得到包覆液；
(3)负极材料的制备：称取92g实施例同批次的针状焦材料、31g二硼化钛及其5g沥青混合均匀，并通过球磨机在转速为50rpm/min，球磨48h，之后在氩气惰性气氛下加热到250℃进行软化，并保温3h，之后在氩气惰性气氛下升温到800℃并保温3h，之后自然降温到室温，粉碎得到前驱体材料。之后取95g前驱体材料添加到381ml包覆液中，球磨，真空干燥，并在氩气惰性气氛下，在温度为800℃下碳化3h，得到负极材料。
对比例4
本实施例提供了一种负极材料及其制备方法，所述负极材料包括内核和包覆于所述内核外的外壳，所述内核为石墨；所述外壳包括多孔氧化钛、无定形碳和石墨烯。多孔氧化钛的孔隙率为5％，平均孔径为10nm。所述内核与外壳的质量比为99：1；所述多孔氧化钛和无定形碳的质量比为10：89，所述多孔氧化钛与石墨烯的质量比为10：1。
其制备方法包括：
(1)多孔氧化钛的制备：同实施例2；
(2)包覆液的制备：同实施例2；
(3)负极材料的制备：称取92.75g油系针状焦及其1g沥青混合均匀，并通过球磨机在转速为10rpm/min，球磨72h，之后在氩气惰性气氛下加热到200℃进行软化，并保温6h，之后在氩气惰性气氛下升温到700℃并保温6h，之后自然降温到室温，粉碎得到前驱体材料。之后取99g前驱体材料添加36.8ml包覆液中，球磨，真空干燥，并在氩气惰性气氛下，在温度为600℃下碳化6h，得到负极材料。
实验例1SEM测试
取实施例1制备的负极材料进行SEM测试，测试结果如图1所示。从图1可以看出，实施例1制备的负极材料为颗粒状结构，大小均一，粒径介于10-18μm之间。
实施例2
按照GB/T 24533-2009《锂离子电池石墨类负极材料》测试各实施例和对比例制得的负极材料的比表面积和振实密度，测试结果如表1所示。
表1负极材料的比表面积结果
项目 比表面积(m 2/g) 振实密度(g/cm 3)
实施例1 4.3 1.15
实施例2 4.1 1.14
实施例3 4.6 1.13
对比例1 1.7 1.01
对比例2 1.8 1.17
对比例3 3.8 1.02
对比例4 3.3 0.94
从表1可以看出，本申请各实施例制备的负极材料的比表面积明显高于对比例1-4，究其原因为：复合材料表面包覆有多孔氧化钛材料或者内核 采用硼掺杂材料均能够提高材料的比表面积，且制得的负极材料具有适当的振实密度。
实验例3扣式电池测试
分别将各实施例和对比例制备的负极材料组装成扣式电池a1、a2、a3、b1、b2、b3和b4。组装方法为：在负极材料中添加粘结剂、导电剂及溶剂，进行搅拌制浆，之后将浆料涂覆在铜箔上，经过烘干、碾压制得负极片，极片的涂布单面密度为6mg/cm 2；所用粘结剂为LA132粘结剂，导电剂为SP，溶剂为二次蒸馏水。各组分的比例为：负极材料：SP：LA132：二次蒸馏水＝95g：1g：4g：220mL；电解液为LiPF 6/EC+DEC(六氟磷酸锂LiPF 6的浓度为1.2mol/L，碳酸乙烯酯EC与碳酸二乙酯DEC的体积比为1:1)，金属锂片为对电极，隔膜采用celegard2400。扣式电池的装配在充氩气的手套箱中进行，电化学性能测试在武汉蓝电CT2001A型电池测试仪上进行，充放电电压范围为0.005V至2.0V，测试充放电倍率为0.1C下的首次放电容量和首次效率，并测试其3C和0.2C倍率下的放电容量，得到倍率(3C/0.2C)，测试结果如表2所示。
表2实施例与对比例的负极材料制备的扣式电池的性能比较
Figure PCTCN2022106671-appb-000001
Figure PCTCN2022106671-appb-000002
从表2可以看出，采用本申请实施例1-4的复合材料制备的锂离子电池的首次放电容量、首次充放电效率和倍率性能明显高于对比例，究其原因为：在硼掺杂石墨内核的表面包覆多孔氧化钛、无定形碳和导电剂，可以更好地利用多孔氧化钛结构稳定性，提升锂离子的嵌出，降低材料不可逆容量的损失，提升首次效率。也可以更好地利用氧化钛锂离子导电性高，提升扣式电池的倍率性能。
实验例4软包电池测试
采用各实施例和对比例制得的负极材料，分别制备负极片，其方法和工艺条件与实验例3相同；以三元材料(LiNi 1/3Co 1/3Mn 1/3O 2)作为正极材料，以LiPF 6溶液(溶剂为EC+DEC，体积比为1：1，LiPF 6的浓度为1.3mol/L)作为电解液，celegard2400作为隔膜，分别制备出5Ah软包电池A1、A2、A3、B1、B2、B3和B4。之后测试软包电池的循环性能和倍率性能。
循环性能测试条件：充放电电流1C/1C，电压范围2.8-4.2V，循环次数500次。
倍率性能测试条件：充电倍率1C/3C/5C/8C，放电倍率1C；电压范围2.8-4.2V。
测试结果如表3、表4所示。
表3实施例与对比例的负极材料制备的软包电池的循环性能比较
Figure PCTCN2022106671-appb-000003
Figure PCTCN2022106671-appb-000004
从表3可以看出，采用实施例1-3的复合材料制备的软包电池的循环性能优于对比例，尤其是在循环500次时，究其原因为：在1C/1C倍率循环性能方面，在硼掺杂石墨内核表面沉积多孔氧化钛、无定形碳和导电剂能够明显提升了锂离子的传输速率；同时，利用多孔氧化钛自身结构稳定的特性，提升了循环性能。
表4实施例与对比例的复合材料制备的软包电池的倍率充电性能比较
Figure PCTCN2022106671-appb-000005
从表4可以看出，采用实施例1-3的负极材料制备的软包电池具有更好的恒流比，究其原因为：在硼掺杂石墨内核的表面包覆多孔氧化钛、无定形碳和导电剂，可以更好地提升材料在倍率充电过程中锂离子的嵌出速率， 从而提升了倍率充电性能。
显然，上述实施例仅仅是为清楚地说明所作的举例，而并非对实施方式的限定。对于所属领域的普通技术人员来说，在上述说明的基础上还可以做出其它不同形式的变化或变动。这里无需也无法对所有的实施方式予以穷举。而由此所引伸出的显而易见的变化或变动仍处于本申请创造的保护范围之中。

Claims (10)

  1. 一种负极材料，其特征在于，包括：
    内核，所述内核包括硼掺杂石墨；
    包覆于所述内核外的外壳，所述外壳包括多孔氧化钛、无定形碳和导电剂。
  2. 根据权利要求1所述负极材料，其特征在于，所述多孔氧化钛的孔隙率为5-50％，平均孔径为10-500nm。
  3. 根据权利要求1或2所述的负极材料，其特征在于，所述内核与外壳的质量比为90-99:1-10；和/或，所述多孔氧化钛和无定形碳的质量比为1-10:88-98.5；和/或，所述多孔氧化钛与导电剂的质量比为1-10:0.5-2；和/或，硼掺杂石墨中硼的掺杂比例为1-20wt％；和/或，所述导电剂选自碳纳米管、石墨烯和超级炭黑中的至少一种。
  4. 一种负极材料的制备方法，其特征在于，包括如下步骤：
    (1)取多孔氧化钛、无定形碳的原料、导电剂与有机溶剂混合，制得包覆液；取石墨的原料、含硼化合物和粘结剂混合，加热，得到前驱体材料；
    (2)将前驱体材料与包覆液混合，干燥，碳化，制得负极材料。
  5. 根据权利要求4所述的制备方法，其特征在于，所述的制备方法满足如下1)-8)中的至少一项：
    1)所述无定形碳的原料为树脂，可选的，所述树脂选自酚醛树脂、糠醛树脂和环氧树脂中的至少一种；
    2)所述有机溶剂选自四氯化碳、N-甲基吡咯烷酮、环己烷、四氢呋喃和二甲苯中的至少一种；和/或，所述导电剂选自碳纳米管、石墨烯和超级炭黑中的至少一种；和/或，所述含硼化合物选自氧化硼、二硼化钛、二硼化镁、二硼化铬和碳化硼中的至少一种；
    3)所述石墨的原料为针状焦，可选地，所述针状焦选自石油系针状焦、煤系针状焦中的至少一种；
    4)所述粘结剂为沥青；
    5)步骤(1)和/或(2)的混合之后还包括研磨、搅拌和/或超声处理；
    6)步骤(1)中，加热过程为先在惰性气体下加热到200-300℃并在该温度范围内保温1-6h，然后在惰性气体下升温至700-1000℃并在该温度范围内保温1-6h；
    7)步骤(2)中，碳化的温度为600-1000℃，时间为1-6h；
    8)多孔氧化钛与树脂的质量比为10-50:50-400；和/或，所述多孔氧化钛与导电剂的质量比为1-10:0.5-2；和/或，所述石墨的原料与含硼化合物的质量比为100:1-10。
  6. 根据权利要求4或5所述的制备方法，其特征在于，步骤(1)中，将多孔氧化钛加入到含树脂的有机溶剂中，与含导电剂的有机溶剂混合，得到包覆液；
    可选的，含树脂的有机溶剂中树脂的质量体积百分数为1-15％；
    可选的，多孔氧化钛的质量与含树脂的有机溶剂的体积比为1-10g:2000-7600mL；
    可选的，含导电剂的有机溶剂中导电剂的质量体积百分数为0.5-2％；
    可选的，多孔氧化钛的质量与含导电剂的有机溶剂的体积比为1-10g:100-500mL。
  7. 根据权利要求4-6中任一所述的制备方法，其特征在于，所述多孔氧化钛的制备方法包括如下步骤：
    取钛酸盐水溶液加热，加酸溶液调节pH值，反应，固液分离，取固体，干燥，碳化，制得多孔氧化钛。
  8. 根据权利要求7所述的制备方法，其特征在于，所述钛酸盐选自钛酸钙、钛酸镁、钛酸锂、钛酸铝和钛酸钾中的至少一种；和/或，加热温度为 60-100℃，时间为至少1h；和/或，反应的时间为至少1h；和/或，碳化温度为600-1000℃，时间为为1-6h；和/或，调节pH值至4-6；和/或，所述酸溶液为盐酸溶液、硫酸溶液、枸橼酸溶液、醋酸溶液或者磷酸溶液。
  9. 一种负极片，其特征在于，包括权利要求1-3中任一所述的负极材料或者权利要求4-8中任一所述的制备方法制得的负极材料。
  10. 一种电池，其特征在于，包括权利要求9所述的负极片，还包括电池外壳、正极片、隔离膜和电解液。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1225196A (zh) * 1996-05-07 1999-08-04 东洋炭素株式会社 锂离子二次电池负极用材料及其制造方法以及使用该负极材料的锂离子二次电池
CN105762340A (zh) * 2016-02-26 2016-07-13 焦作聚能能源科技有限公司 一种TiO2/C包覆石墨复合材料、制备方法及其作为锂离子电池负极材料的应用
CN108574098A (zh) * 2018-05-16 2018-09-25 华南师范大学 一种纳米二氧化钛包覆石墨锂离子电池负极材料及其制备方法
CN109119603A (zh) * 2014-04-29 2019-01-01 华为技术有限公司 复合负极材料及其制备方法、锂离子二次电池负极极片和锂离子二次电池
CN111509198A (zh) * 2019-01-31 2020-08-07 贝特瑞新材料集团股份有限公司 一种核壳结构复合材料、其制备方法及在锂离子电池的用途
CN113764644A (zh) * 2021-09-15 2021-12-07 河北坤天新能源科技有限公司 一种快充复合石墨材料及其制备方法
CN114551836A (zh) * 2022-02-25 2022-05-27 蜂巢能源科技股份有限公司 一种负极材料及其制备方法、负极片和电池

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1225196A (zh) * 1996-05-07 1999-08-04 东洋炭素株式会社 锂离子二次电池负极用材料及其制造方法以及使用该负极材料的锂离子二次电池
CN109119603A (zh) * 2014-04-29 2019-01-01 华为技术有限公司 复合负极材料及其制备方法、锂离子二次电池负极极片和锂离子二次电池
CN105762340A (zh) * 2016-02-26 2016-07-13 焦作聚能能源科技有限公司 一种TiO2/C包覆石墨复合材料、制备方法及其作为锂离子电池负极材料的应用
CN108574098A (zh) * 2018-05-16 2018-09-25 华南师范大学 一种纳米二氧化钛包覆石墨锂离子电池负极材料及其制备方法
CN111509198A (zh) * 2019-01-31 2020-08-07 贝特瑞新材料集团股份有限公司 一种核壳结构复合材料、其制备方法及在锂离子电池的用途
CN113764644A (zh) * 2021-09-15 2021-12-07 河北坤天新能源科技有限公司 一种快充复合石墨材料及其制备方法
CN114551836A (zh) * 2022-02-25 2022-05-27 蜂巢能源科技股份有限公司 一种负极材料及其制备方法、负极片和电池

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