WO2024239684A1 - 一种负极颗粒及其制备方法、负极极片及储能装置 - Google Patents

一种负极颗粒及其制备方法、负极极片及储能装置 Download PDF

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WO2024239684A1
WO2024239684A1 PCT/CN2024/072970 CN2024072970W WO2024239684A1 WO 2024239684 A1 WO2024239684 A1 WO 2024239684A1 CN 2024072970 W CN2024072970 W CN 2024072970W WO 2024239684 A1 WO2024239684 A1 WO 2024239684A1
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negative electrode
particles
particle
temperature
electrode particles
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French (fr)
Inventor
谌庆春
王铈汶
林颖鑫
朱开达
张敏
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Xiamen Hithium Energy Storage Technology Co Ltd
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Xiamen Hithium Energy Storage Technology Co Ltd
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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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C01B32/205—Preparation
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • 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
    • 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
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • 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 field of battery technology, and in particular to a negative electrode particle and a preparation method thereof, a negative electrode plate and an energy storage device.
  • the negative electrode material faces a series of challenges.
  • the gram capacity and first coulomb efficiency of the negative electrode material are low, resulting in the inability to further improve the energy density of the battery.
  • the nanopores in the negative electrode material can increase the storage sites of active ions, thereby increasing the gram capacity of the negative electrode material.
  • an embodiment of the present application provides a negative electrode particle, which has a higher gram capacity and a higher first efficiency, and does not affect the cycle performance of the energy storage device.
  • a first aspect of the present application provides a negative electrode particle, comprising: closed pores located inside the negative electrode particle and open pores located on the surface of the negative electrode particle, wherein the ratio of the pore volume of the closed pores to the pore volume of the open pores is in the range of 6 ⁇ C1/C2 ⁇ 11; and the pore volume of the closed pores is in the range of 0.03cm 3 /g ⁇ C1 ⁇ 0.12cm 3 /g.
  • a second aspect of the present application provides a method for preparing negative electrode particles, which comprises:
  • first particles include the precursor and the soluble salt dispersed in the precursor, and the first temperature is higher than the melting temperature of the soluble salt;
  • the second particles are carbonized at a second temperature to obtain the negative electrode particles, wherein the second temperature is greater than the first temperature, the negative electrode particles have closed pores located inside the negative electrode particles and open pores located on the surface of the negative electrode particles, the ratio of the pore volume of the closed pores to the pore volume of the open pores is in the range of 6 ⁇ C1/C2 ⁇ 11, and the range of the pore volume of the closed pores is 0.03cm3 / g ⁇ C1 ⁇ 0.12cm3 /g.
  • the third aspect of the present application provides a negative electrode plate, which includes: a current collector and an active material layer, wherein the active material layer is arranged on the surface of the current collector, and the active material layer includes the negative electrode particles described in the embodiment of the present application.
  • the fourth aspect of the present application provides an energy storage device, comprising: an electrolyte, a positive electrode plate, a diaphragm, and the negative electrode plate described in the embodiment of the present application, wherein the positive electrode plate is at least partially immersed in the electrolyte, the diaphragm is located on one side of the positive electrode plate and is at least partially immersed in the electrolyte, and the negative electrode plate is arranged on the side of the diaphragm away from the positive electrode plate and is at least partially immersed in the electrolyte.
  • the negative electrode particles of the present application have closed pores located inside the negative electrode particles and open pores located on the surface of the negative electrode particles.
  • the open pores on the surface of the negative electrode particles not only provide storage sites for active ions and facilitate the electrolyte to infiltrate the negative electrode particles and construct ion conduction channels, but the open pores on the surface of the negative electrode particles also increase the side reactions between the negative electrode particles and the electrolyte, thereby reducing the initial efficiency of the negative electrode particles.
  • the closed pores inside the negative electrode particles increase the storage sites for active ions, and to a certain extent improve the gram capacity and initial efficiency of the negative electrode particles, but too many closed pores inside the negative electrode particles will affect the electrolyte infiltration of the negative electrode particles, resulting in limited ion conduction channels, thereby reducing the gram capacity of the negative electrode particles.
  • the ratio of the pore volume of the closed pores to the pore volume of the open pores to be between 6 and 11, the pore volume of the closed pores is in the range of 0.03 cm 3 /g to 0.12 cm 3 /g, so that a certain ion conduction channel can be constructed and serious side reactions between the negative electrode particles and the electrolyte can be avoided.
  • the negative electrode particles have more active ion storage sites, so that the negative electrode particles have higher gram capacity and first efficiency.
  • FIG. 1 is a schematic diagram of the structure of negative electrode particles according to an embodiment of the present application.
  • FIG. 2 is a flow chart of a method for preparing negative electrode particles according to an embodiment of the present application.
  • FIG. 3 is a schematic diagram of the structure of a negative electrode plate according to an embodiment of the present application.
  • FIG4 is a schematic diagram of the cross-sectional structure of the negative electrode sheet of one embodiment of the present application along the A-A direction in FIG3 .
  • FIG. 5 is a schematic structural diagram of an energy storage device according to an embodiment of the present application.
  • FIG6 is a schematic diagram of the cross-sectional structure of the energy storage device according to an embodiment of the present application along the B-B direction in FIG5 .
  • the negative electrode material faces a series of challenges.
  • the gram capacity and first coulomb efficiency of the negative electrode material are low, resulting in the inability to further improve the energy density of the battery.
  • the nanopores in the negative electrode material can increase the storage sites of active ions, thereby increasing the gram capacity of the negative electrode material.
  • the side reactions between the negative electrode material and the electrolyte increase, resulting in poor cycle performance of the battery.
  • the first embodiment of the present application provides a negative electrode particle 100, which includes: closed pores 101 located inside the negative electrode particle 100 and open pores 102 located on the surface of the negative electrode particle 100, and the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is in the range of 6 ⁇ C1/C2 ⁇ 11; the pore volume of the closed pores 101 is in the range of 0.03cm3 / g ⁇ C1 ⁇ 0.12cm3 /g.
  • the ratio of the pore volume of the closed cells 101 to the pore volume of the open cells 102 may be 6, 7, 8, 9, 10, 11, and any values in between.
  • the pore volume of the closed cells 101 may be 0.03 cm 3 /g, 0.04 cm 3 /g, 0.05 cm 3 /g, 0.06 cm 3 /g, 0.07 cm 3 /g, 0.08 cm 3 /g , 0.09 cm 3 /g, 0.10 cm 3 /g, 0.11 cm 3 /g, 0.12 cm 3 /g, and any values in between.
  • closed pores 101 refer to cavities and channels inside the particles that are not connected to the outside world; and the open pores 102 refer to cavities and channels inside the particles that are connected to the outside world.
  • the negative electrode particles 100 may be, but are not limited to, hard carbon, graphite, soft carbon, etc.
  • the open pore 102 on the surface of the negative electrode particle 100 not only provides a storage site for active ions and facilitates the electrolyte to infiltrate the negative electrode particle 100 to construct an ion conduction channel, but the open pore 102 on the surface of the negative electrode particle 100 102 will also lead to an increase in the side reactions between the negative electrode particles 100 and the electrolyte, reducing the initial efficiency of the negative electrode particles 100.
  • the closed pores 101 inside the negative electrode particles 100 increase the storage sites of active ions, which improve the gram capacity and initial efficiency of the negative electrode particles 100 to a certain extent, but too many closed pores 101 inside the negative electrode particles 100 will affect the electrolyte infiltration of the negative electrode particles 100, resulting in limited ion conduction channels, thereby reducing the gram capacity of the negative electrode particles 100.
  • the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 to be between 6 and 11, the pore volume of the closed pores 101 is in the range of 0.03 cm 3 /g to 0.12 cm 3 /g, so that a certain ion conduction channel can be constructed and serious side reactions between the negative electrode particles 100 and the electrolyte can be avoided.
  • the negative electrode particles 100 have more active ion storage sites, so that the negative electrode particles 100 have higher gram capacity and first efficiency.
  • the cycle performance of the energy storage device 300 will not be affected.
  • the pore volume C2 of the opening 102 is in the range of 0.005 cm 3 /g ⁇ C2 ⁇ 0.01 cm 3 /g. Specifically, the pore volume C2 of the opening 102 may be 0.005 cm 3 /g, 0.006 cm 3 /g, 0.007 cm 3 /g, 0.008 cm 3 /g , 0.009 cm 3 /g, 0.01 cm 3 /g, and any value therebetween.
  • the pore volume of the opening 102 When the pore volume of the opening 102 is less than 0.005 cm 3 /g, it is difficult for the electrolyte to infiltrate the negative electrode particles 100, and the rate performance of the negative electrode particles 100 is poor. When the pore volume of the opening 102 is greater than 0.01 cm 3 /g, the side reactions between the negative electrode particles 100 and the electrolyte increase, which reduces the initial efficiency of the negative electrode particles 100. When the pore volume of the opening 102 is between 0.005 cm 3 /g and 0.01 cm 3 /g, the negative electrode particles 100 have both good rate performance and high initial efficiency.
  • the average pore size D1 of the closed pores 101 of the negative electrode particles 100 is in the range of 0.8 nm ⁇ D1 ⁇ 2.0 nm. Specifically, the average pore size D1 of the closed pores 101 of the negative electrode particles 100 may be 0.8 nm, 1.0 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm, 2.0 nm, and any value in between.
  • the active ions are difficult to embed, which affects the gram capacity of the negative electrode particles 100.
  • the average pore size of the closed pores 101 is greater than 2.0 nm, the binding energy of the active ions becomes larger, which is not conducive to the embedding and detachment of the active ions.
  • the average pore size of the closed pores 101 is between 0.8 nm and 2.0 nm, the active ions are easier to embed and detach, which is conducive to improving the gram capacity of the negative electrode particles 100.
  • the ratio of the specific surface area S1 of the closed pores 101 of the negative electrode particles 100 to the specific surface area S of the negative electrode particles 100 is in the range of 40 ⁇ S1/S ⁇ 200.
  • the ratio of the specific surface area S1 of the closed pores 101 of the negative electrode particles 100 to the specific surface area S of the negative electrode particles 100 may be 40, 50, 70, 90, 110, 130, 150, 170, 190, 200, and any values in between.
  • the specific surface area of the closed pores 101 of the negative electrode particles 100 refers to the total area of the inner walls of the closed pores 101 of the negative electrode particles 100 per unit weight.
  • the specific surface area of the negative electrode particles 100 is the specific surface area of the negative electrode particles 100 per unit weight and the specific surface area of the openings 102 in the negative electrode particles 100 .
  • the ratio of the specific surface area S1 of the closed pores 101 to the specific surface area S of the negative electrode particles 100 is less than 40, the specific surface area S of the negative electrode particles 100 is large, and the contact area between the negative electrode particles 100 and the electrolyte increases, which will reduce the initial efficiency of the negative electrode particles 100.
  • the ratio of the specific surface area S1 of the closed pores 101 to the specific surface area S of the negative electrode particles 100 is greater than 200, the specific surface area of the open pores 102 is too small, the contact area between the negative electrode particles 100 and the electrolyte is small, the electrolyte is difficult to infiltrate the negative electrode particles 100, and the rate performance of the negative electrode particles 100 is poor.
  • the ratio of the specific surface area S1 of the closed pores 101 to the specific surface area S of the negative electrode particles 100 is between 40 and 200, the initial efficiency and rate performance of the negative electrode particles 100 are both good.
  • the specific surface area S1 of the closed cells 101 is in the range of 40m 2 /g ⁇ S1 ⁇ 400m 2 /g.
  • the specific surface area of the closed cells 101 may be 40m 2 /g, 60m 2 /g, 80m 2 /g, 100m 2 /g, 120m 2 /g, 140m 2 /g, 160m 2 /g, 180m 2 /g, 200m 2 /g, 220m 2 /g, 240m 2 /g, 260m 2 /g, 280m 2 /g, 300m 2 /g, 320m 2 /g, 340m 2 /g, 360m 2 /g, 380m 2 /g, 400m 2 /g, and any values in between.
  • the negative electrode particles 100 When the specific surface area of the closed pores 101 is less than 40 m 2 /g, the negative electrode particles 100 have fewer storage sites for active ions, and the negative electrode particles 100 have a lower gram capacity. When the specific surface area of the closed pores 101 is greater than 400 m 2 /g, the structure of the negative electrode particles 100 is not stable enough, which reduces the compaction density of the negative electrode particles 100. When the specific surface area of the closed pores 101 is between 40 m 2 /g and 400 m 2 /g, the negative electrode particles 100 have a higher gram capacity and a higher compaction density.
  • the specific surface area S of the negative electrode particles 100 is in the range of: 1m 2 /g ⁇ S ⁇ 5m 2 /g. Specifically, the specific surface area S of the negative electrode particles 100 may be 1m 2 /g, 2m 2 /g, 3m 2 /g, 4m 2 /g, 5m 2 /g, and any value therebetween.
  • the specific surface area S of the negative electrode particles 100 is less than 1 m 2 /g, the contact area between the negative electrode particles 100 and the electrolyte is small, the electrolyte is difficult to infiltrate the negative electrode particles 100, and the rate performance of the negative electrode particles 100 is poor.
  • the specific surface area S of the negative electrode particles 100 is greater than 5 m 2 /g, the contact area between the negative electrode particles 100 and the electrolyte increases, which will reduce the initial efficiency of the negative electrode particles 100.
  • the specific surface area S of the negative electrode particles 100 is between 1 m 2 /g and 5 m 2 /g, the initial efficiency and rate performance of the negative electrode particles 100 are both good.
  • the ratio of the true density ⁇ 1 of the negative electrode particles 100 to the theoretical true density ⁇ 2 of the negative electrode particles 100 is in the range of: 0.75 ⁇ 1/ ⁇ 2 ⁇ 0.95.
  • the ratio of the true density ⁇ 1 of the negative electrode particles 100 to the theoretical true density ⁇ 2 of the negative electrode particles 100 can be 0.75, 0.8, 0.85, 0.9, 0.95, and any value in between the above values.
  • the true density refers to the actual mass of a solid substance per unit volume in an absolutely dense state, that is, the density after removing internal pores or gaps between particles.
  • the theoretical true density refers to the highest true density of the material under an ideal state, that is, there are no pores inside the material or no gaps between particles.
  • the theoretical true density of the layered negative electrode particle 100 is 2.26 g/cm 3 .
  • the ratio of the true density ⁇ 1 of the negative electrode particles 100 to the theoretical density ⁇ 2 of the negative electrode particles 100 is lower than 0.75, the compacted density of the negative electrode particles 100 is low, and when the negative electrode particles 100 are applied to the energy storage device 300, the energy density of the energy storage device 300 will be reduced.
  • the ratio of the true density ⁇ 1 of the negative electrode particles 100 to the theoretical density ⁇ 2 of the negative electrode particles 100 is greater than 0.95, the storage sites of the active ions of the negative electrode particles 100 are less, and the gram capacity of the negative electrode particles 100 is lower.
  • the ratio of the true density ⁇ 1 of the negative electrode particles 100 to the theoretical density ⁇ 2 of the negative electrode particles 100 is between 0.75 and 0.95, the compacted density of the negative electrode particles 100 is higher and also has a higher gram capacity.
  • the true density ⁇ 1 of the negative electrode particle 100 is in the range of 1.8 g/ cm3 ⁇ 1 ⁇ 2.1 g/ cm3 .
  • the true density of the negative electrode particle 100 may be 1.8 g/ cm3 , 1.9 g/ cm3 , 2.0 g/ cm3 , 2.1 g/ cm3 , and any value therebetween.
  • the true density of the negative electrode particles 100 is less than 1.8 g/cm 3 , the compaction density of the negative electrode particles 100 is low, and when the negative electrode particles 100 are used in the energy storage device 300, the energy density of the energy storage device 300 will be reduced.
  • the true density of the negative electrode particles 100 is greater than 2.1 g/cm 3 , the storage sites of the active ions of the negative electrode particles 100 are less, and the gram capacity of the negative electrode particles 100 is lower.
  • the true density of the negative electrode particles 100 is between 1.8 g/cm 3 and 2.1 g/cm 3 , the compaction density of the negative electrode particles 100 is higher, and the gram capacity is also higher.
  • a second embodiment of the present application provides a method for preparing negative electrode particles 100 , which includes:
  • the negative electrode particles 100 carbonizing the second particles at a second temperature to obtain the negative electrode particles 100, wherein the second temperature is greater than the first temperature, the negative electrode particles 100 have closed pores 101 located inside the negative electrode particles 100 and open pores 102 located on the surface of the negative electrode particles 100, the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is in the range of 6 ⁇ C1/C2 ⁇ 11, and the pore volume of the closed pores 101 is in the range of 0.03cm3 / g ⁇ C1 ⁇ 0.12cm3 /g.
  • the precursor is placed in the soluble salt system, and pre-carbonized at the first temperature.
  • the fusible salt is in a molten state.
  • the volatile matter in the precursor gradually evaporates at the first temperature and leaves holes.
  • the molten fusible salt occupies the holes.
  • carbonization is performed to obtain negative electrode particles 100.
  • the holes in the negative electrode particles 100 are small, and the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is in the range of 6 to 11.
  • the pore volume of the closed pores 101 is in the range of 0.03 cm 3 /g to 0.12 cm 3 /g.
  • the negative electrode particles 100 are free from serious side reactions with the electrolyte, and at the same time, the negative electrode particles 100 have more active ion storage sites.
  • the negative electrode particles 100 have higher gram capacity and first efficiency. When the negative electrode particles 100 are applied to the energy storage device 300, the cycle performance of the energy storage device 300 will not be affected.
  • the precursor may be, but is not limited to, at least one of asphalt, petroleum coke, sub-bituminous coal, bituminous coal, biomass resin, coconut shell, walnut shell, and the like.
  • the carbon content of the precursor ranges from 20% to 70%.
  • a numerical value range from a to b when a numerical value range from a to b is involved, unless otherwise specified, it means that the numerical value can be any numerical value between a and b, including the endpoint numerical value a and the endpoint numerical value b.
  • the carbon content of the precursor may be in the range of 20%, 40%, 60%, 70%, and any value in between.
  • the carbon content of the precursor is less than 20%, the carbon yield of the negative electrode particles 100 is low, that is, the conversion rate of the negative electrode particles 100 obtained from the precursor is low.
  • the carbon content of the precursor is greater than 70%, the precursor has less volatile matter, and the negative electrode particles 100 finally obtained have fewer pores.
  • the carbon content of the precursor is between 20% and 70%, the carbon yield of the precursor is higher, and the negative electrode particles 100 obtained have more pores, so that the negative electrode particles 100 have more active ion storage sites.
  • the soluble salt refers to a salt that can be dissolved in a liquid (eg, a salt that is soluble in water, a salt that is soluble in an organic solvent, etc.).
  • the soluble salt may be, but is not limited to, at least one of sodium chloride, potassium chloride, calcium chloride, sodium fluoride, potassium fluoride, sodium hydroxide, potassium hydroxide, and the like.
  • the mass ratio of the soluble salt to the precursor ranges from 10% to 200%.
  • the mass ratio of the soluble salt to the precursor can be 10%, 20%, 40%, 60%, 80%, 100%, 120%, 140%, 160%, 180%, 200%, and any value in between.
  • the mass ratio of the soluble salt to the precursor When the mass ratio of the soluble salt to the precursor is less than 10%, the volatile matter in the precursor gradually evaporates and leaves holes, and the molten fusible salt cannot completely occupy the holes, resulting in the holes being easily closed at high temperatures, reducing the active ion storage sites in the negative electrode particles 100 and reducing the gram capacity.
  • the mass ratio of the soluble salt to the precursor is greater than 200%, the preparation cost of the negative electrode particles 100 increases.
  • the mass ratio of the soluble salt to the precursor is between 10% and 200%, the negative electrode particles 100 have more active ion storage sites, a higher gram capacity, and a lower preparation cost.
  • the density of the precursor is greater than or equal to the density of the soluble salt in a molten state. In other words, the density of the precursor is greater than or equal to the density of the soluble salt melt.
  • the density of the precursor is greater than or equal to the density of the soluble salt in a molten state
  • the precursor can fully contact the soluble salt, and the molten soluble salt can better occupy the pores in the precursor, thereby preventing the pores from shrinking rapidly or even closing under high temperature.
  • the precursor is placed in the soluble salt system and pre-carbonized at a first temperature, including placing the precursor in the soluble salt system and heating the temperature to a first temperature at a first heating rate R1 in the range of 0.5°C/min ⁇ R1 ⁇ 3°C/min to pre-carbonize the precursor, wherein the first temperature T1 is in the range of 400°C ⁇ T1 ⁇ 1000°C.
  • the first heating rate R1 can be 0.5°C/min, 1°C/min, 2°C/min, 3°C/min, and any value in between.
  • the first temperature T1 can be 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, and any value in between.
  • the first heating rate R1 When the first heating rate R1 is less than 0.5°C/min, the heating process takes too long, increasing the manufacturing cost. When the first heating rate R1 is greater than 3°C/min, the volatiles escape faster, resulting in larger pores, which increases the binding energy of the active ions and is not conducive to the embedding and extraction of active ions. When the first heating rate R1 is between 0.5°C/min and 3°C/min, it helps to form smaller pores without increasing the manufacturing cost too much.
  • the fusible salt cannot be molten, or the volatile matter cannot be completely volatilized.
  • the pores obtained after the volatile matter escape will shrink or even partially close, resulting in the inability to remove the fusible salt in the subsequent process, affecting the gram capacity of the negative electrode particles 100 and increasing the manufacturing cost.
  • the fusible salt is in a molten state, and the precursor The volatile matter gradually evaporates at the first temperature and leaves holes, the molten fusible salt occupies the holes, and the fusible salt can be easily removed in the subsequent process. After the fusible salt is removed, carbonization is performed to obtain the negative electrode particles 100, and the holes in the negative electrode particles 100 are relatively small.
  • the second particles are carbonized at a second temperature to obtain the negative electrode particles 100, including heating the second particles to a second temperature at a second heating rate R2 in the range of 1°C/min ⁇ R2 ⁇ 10°C/min to carbonize the second particles, wherein the second temperature T2 is in the range of 1000°C ⁇ T2 ⁇ 1700°C.
  • the second heating rate R2 can be 1°C/min, 2°C/min, 3°C/min, 4°C/min, 5°C/min, 6°C/min, 7°C/min, 8°C/min, 9°C/min, 10°C/min, and any value in between.
  • the second temperature T2 can be 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C, and any value in between.
  • the second heating rate R2 When the second heating rate R2 is less than 1°C/min, the heating process takes too long, increasing the manufacturing cost and the content of closed pores 101 inside the negative electrode particles 100 is small, which is not conducive to improving the gram capacity of the negative electrode particles 100.
  • the second heating rate R2 is greater than 10°C/min, the heating equipment has a large loss, reducing the service life of the equipment.
  • the second heating rate R2 is between 1°C/min and 10°C/min, the disorder inside the negative electrode particles 100 will be aggravated, the internal closed pores 101 will increase, and the gram capacity of the negative electrode particles 100 will increase.
  • the negative electrode particles 100 When the second temperature T2 is less than 1000°C, the negative electrode particles 100 have many defects, resulting in a low initial efficiency. When the second temperature T2 is greater than 1700°C, the interlayer spacing of the negative electrode particles 100 becomes smaller, which is not conducive to storing active ions, and the manufacturing cost of the negative electrode particles 100 increases. When the second temperature T2 is between 1000°C and 1700°C, the negative electrode particles 100 have a high initial efficiency, are easy to store active ions, and the manufacturing cost will not increase significantly.
  • the second heating rate R2 is greater than the first heating rate R1.
  • the second heating rate R2 is greater than the first heating rate R1
  • the method further includes: depositing a carbon layer on the surface of the second particle to close some of the open pores 102 on the surface of the second particle to form closed pores 101, so that the obtained negative electrode particles 100 have more closed pores 101 and less open pores 102.
  • the carbon layer may be deposited on the surface of the particles by chemical vapor deposition.
  • part of the open pores 102 on the surface of the second particle are closed to form closed pores 101, which can avoid an increase in side reactions between the negative electrode particle 100 and the electrolyte and avoid a reduction in the initial efficiency of the negative electrode particle 100.
  • the method further includes: depositing a carbon layer on the surface of the carbonized second particles to close some of the open pores 102 on the surface of the carbonized second particles to form closed pores 101.
  • part of the open pores 102 on the surface of the carbonized second particles are closed to form closed pores 101, which can avoid an increase in side reactions between the negative electrode particles 100 and the electrolyte and avoid a reduction in the initial efficiency of the negative electrode particles 100.
  • the carbon layer is deposited at a third temperature T3 for a deposition time of 1 hour to 4 hours, wherein the third temperature T3 is in a range of 800°C ⁇ T3 ⁇ 1200°C.
  • the third temperature T3 may be 800° C., 850° C., 900° C., 950° C., 1000° C., 1100° C., 1200° C., and any value therebetween.
  • the deposition time may be 1 h, 2 h, 3 h, 4 h, and any value therebetween.
  • the third temperature T3 When the third temperature T3 is less than 800°C, the conductivity of the deposited carbon layer is poor. When the third temperature T3 is greater than 1200°C, the interlayer spacing of the negative electrode particles 100 is small, affecting the dynamic performance. When the third temperature T3 is between 800°C and 1200°C, the deposited carbon layer has both good conductivity and good dynamic performance.
  • the third embodiment of the present application provides a negative electrode plate 200, which includes: a current collector 210 and an active material layer 220.
  • the active material layer 220 is arranged on the surface of the current collector 210, and the active material layer 220 includes the negative electrode particles 100 described in the embodiment of the present application.
  • the current collector 210 may be, but is not limited to, copper foil, aluminum foil, etc.
  • the fourth aspect of the present application provides an energy storage device 300, which includes: an electrolyte, a positive electrode plate 320, a diaphragm 310, and the negative electrode plate 200 described in the embodiment of the present application, the positive electrode plate 320 is at least partially immersed in the electrolyte, the diaphragm 310 is located on one side of the positive electrode plate 320 and is at least partially immersed in the electrolyte, and the negative electrode plate 200 is arranged on the side of the diaphragm 310 away from the positive electrode plate 320 and is at least partially immersed in the electrolyte.
  • the energy storage device 300 of the embodiment of the present application may be, but is not limited to, a lithium ion secondary energy storage device 300, a lithium ion primary energy storage device 300, a sodium ion energy storage device 300, a lithium sulfur energy storage device 300, etc.
  • the energy storage device 300 may be, but is not limited to, a battery cell, a battery module, a battery pack, etc.
  • the diaphragm 310 may be, but is not limited to, at least one of a polypropylene film (PP) and a polyethylene film (PE).
  • PP polypropylene film
  • PE polyethylene film
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 650°C at 0.5°C/min under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, and the pre-carbonized precursor coconut shell powder is heated to 1400°C at 2°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • negative electrode sheet 200 Disperse negative electrode particles 100 hard carbon, conductive carbon SP and binder CMC in deionized water at a mass ratio of 90:5:5 and mix them evenly to obtain negative electrode slurry. Apply the negative electrode slurry on the copper foil of negative electrode collector 210 and dry it. The coating weight of negative electrode active material layer 220 is 3 mg/ cm2 . After rolling and punching, negative electrode sheet 200 is obtained.
  • Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed at a volume ratio of 1:1 to obtain a mixed solvent, and dry sodium salt NaPF 6 was added thereto to prepare an electrolyte with a concentration of 1 mol/L.
  • Preparation of energy storage device 300 Provide a sodium sheet, and place the sodium sheet, the above-mentioned diaphragm 310, and the negative electrode plate 200 in the negative electrode side housing of a button battery in order, so that the diaphragm 310 is between the sodium sheet and the negative electrode plate 200 to play an isolating role, drip 2 drops of electrolyte, and then place the button battery into the positive electrode side housing to obtain the energy storage device 300 described in Example 1.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 650°C at a certain first heating rate R1 under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use; the first heating rate R1 is specifically shown in Table 1;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, and the pre-carbonized precursor coconut shell powder is heated to 1400°C at 2°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 650°C at 0.5°C/min under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, and the pre-carbonized precursor coconut shell powder is heated to 1400°C at a certain second heating rate R2 and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the second heating rate R2 is specifically shown in Table 1, and the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 650°C at 0.5°C/min under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, and the pre-carbonized precursor coconut shell powder is heated to a second temperature T2 at 2°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the second temperature T2 is specifically shown in Table 1, and the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 650°C at 0.5°C/min under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, the pre-carbonized precursor coconut shell powder is heated to 1000°C at 2°C/min, a certain proportion of acetylene is introduced and kept warm for 2 hours; after the insulation is completed, the acetylene is stopped and cooled to room temperature under a protective atmosphere to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove the crushed precursor coconut shell powder, using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry it for later use;
  • the precursor coconut shell powder after ash removal is loaded into a crucible, placed in a tubular furnace, and heated to 650°C at 6°C/min under a protective atmosphere and kept warm for 2 hours; after the insulation is completed, the temperature is increased to 1400°C at 2°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove the crushed precursor coconut shell powder, using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry it for later use;
  • the precursor coconut shell powder after ash removal is loaded into a crucible, placed in a tubular furnace, heated to 1400°C at 5°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove ash from the crushed precursor coconut shell using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry the mixture for later use;
  • the third step is to mix the precursor coconut shell powder after ash removal with potassium hydroxide in a ratio of 1:1 and put it into a crucible; put it into a tube furnace, heat it to 300°C at 0.5°C/min under a protective atmosphere and keep it warm for 2 hours; after the insulation is completed, cool it for use;
  • the fourth step is to pour the cooled precursor coconut shell powder and potassium hydroxide mixture into pure water, wash and filter for multiple times to obtain pre-carbonized coconut shell powder, and dry it for later use;
  • a protective gas is introduced into the tubular furnace, and the pre-carbonized precursor coconut shell powder is heated to 1400°C at 5°C/min and kept warm for 6 hours; after the insulation is completed, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the precursor coconut shell was crushed to 8 ⁇ m and collected for later use;
  • the second step is to chemically remove the crushed precursor coconut shell powder, using a mixture of 5M/L hydrochloric acid and 20% hydrofluoric acid, and then wash and dry it for later use;
  • the precursor coconut shell powder after ash removal is loaded into a crucible, placed in a tubular furnace, and heated to 650°C at 0.5°C/min under a protective atmosphere and kept warm for 2 hours; after the insulation, the temperature is increased to 1100°C at 2°C/min and kept warm for 6 hours; after the insulation, it is cooled to room temperature to obtain the negative electrode particles 100 hard carbon; the closed pore volume, true density and other parameters of the hard carbon are shown in Table 2.
  • the pore volume of the closed pores 101 of the negative electrode particle 100 1/ ⁇ 1 - 1/ ⁇ 2 .
  • SAXS small angle X-ray scattering
  • ⁇ is the contrast
  • F(Q,r) is the scattering shape factor
  • V(r) is the volume of the negative electrode particle 100
  • N is the total number of negative electrode particles 100
  • P(r) is the probability of the negative electrode particle 100 of size r appearing.
  • SAXS small angle X-ray scattering
  • the ASAP2460 physical adsorption analyzer was used to place the dried and degassed sample in liquid nitrogen, and different test pressures were adjusted to measure the adsorption of nitrogen, and the adsorption and desorption isotherms were drawn.
  • the shape of the pore was determined according to the shape of the hysteresis loop, and the pore volume of the opening 102 was obtained.
  • the ASAP2460 physical adsorption analyzer is used to place the dried and degassed sample in liquid nitrogen, and different test pressures are adjusted to measure the adsorption amount of nitrogen respectively to obtain the specific surface area of the opening 102.
  • the energy storage device 300 obtained in the above embodiment is subjected to a rate test on a charge and discharge instrument at a test temperature of 25°C. Cycle three times at a rate of 0.5C (i.e., both the charging rate and the discharging rate are 0.5C), record the third charging capacity as C1, then discharge at a rate of 0.1C, and then fully charge at a rate of 0.1C, record the charging capacity as C2, and the 0.5C/0.1C rate capacity retention rate is C2/C1.
  • the energy storage device 300 obtained in the above embodiment is subjected to a charge and discharge cycle test on a charge and discharge instrument, the test temperature is 25°C, the cycle rate is 0.2C (i.e., both the charge rate and the discharge rate are 0.2C), the charging voltage is 5mV to 2V, and the capacity retention rate after the cycle is calculated.
  • cycles refers to the number of times the energy storage device 300 is charged at a preset rate and discharged at a preset rate.
  • the energy storage device 300 completing one charge and discharge process is called one cycle, and the 0.2C/0.2C cycle 50 cycle capacity retention rate refers to the capacity retention rate of the energy storage device 300 after 50 charge and discharge processes at a test temperature of 25°C at a charge rate of 0.2C and a discharge rate of 0.2C.
  • test data of the energy storage device 300 is shown in Table 3:
  • the closed pore 101 pore volume of the negative electrode particle 100 of Comparative Example 1 is 0.139 cm 3 /g
  • the ratio of the pore volume of the closed pore 101 to the pore volume of the open pore 102 is 12.99
  • the pore diameter of the closed pore 101 is 2.6 nm
  • the gram capacity of the negative electrode particle 100 is only 262 mAh/g
  • the first efficiency is 86.5%, which is much lower than the gram capacity and first efficiency of Example 1. This is because there is no soluble salt during pre-carbonization in Comparative Example 1, and the first heating rate is fast, the volatile matter escapes faster, and the pore diameter of the obtained hole is larger.
  • the pore volume of the closed pores 101 is too large, the pore diameter of the closed pores 101 is relatively large, the binding energy of the active ions becomes larger, which is not conducive to the embedding and extraction of the active ions.
  • the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is relatively large, which affects the infiltration of the electrolyte into the negative electrode particles 100, resulting in the limitation of the ion conduction channel, thereby reducing the gram capacity of the negative electrode particles 100.
  • the closed pores 101 of the negative electrode particles 100 of Comparative Example 2 have a pore volume of 0.135 cm 3 /g, a ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 of 12.86, a pore diameter of the closed pores 101 of 2.4 nm, a gram capacity of the negative electrode particles 100 of only 267 mAh/g, and a first efficiency of 86.1%, which are much lower than the gram capacity and first efficiency of Example 1.
  • Comparative Example 2 does not have a pre-carbonization process, and directly uses a larger second heating rate for carbonization, which causes the volatiles in the precursor to escape too quickly, resulting in an increase in the pore size.
  • the pore volume of the closed pores 101 is too large, the pore diameter of the closed pores 101 is relatively large, the binding energy of the active ions becomes larger, which is not conducive to the embedding and extraction of the active ions.
  • the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is relatively large, which affects the infiltration of the electrolyte into the negative electrode particles 100, resulting in the limitation of the ion conduction channel, thereby reducing the gram capacity of the negative electrode particles 100.
  • the closed pore 101 pore volume of the negative electrode particle 100 of comparative example 3 is 0.132 cm 3 /g, the ratio of the pore volume of the closed pore 101 to the pore volume of the open pore 102 is 12.69, the pore diameter of the closed pore 101 is 2.2 nm, the gram capacity of the negative electrode particle 100 is only 274 mAh/g, and the first efficiency is 86.7%, which is much lower than the gram capacity and first efficiency of Example 1.
  • the first temperature in comparative example 3 is relatively low, the soluble salt is not melted, and only part of the volatiles escape during the pre-carbonization process to form some pores, but the soluble salt is not melted and cannot occupy the pores; the second heating rate is relatively fast, resulting in faster escape of volatiles during the carbonization process, and the pore diameter of the closed pore 101 is relatively large, the binding energy of the active ions becomes larger, which is not conducive to the embedding and release of the active ions, thereby reducing the gram capacity of the negative electrode particle 100.
  • the closed pores 101 of the negative electrode particles 100 of Example 2 have a pore size of 1.6 nm, a ratio of the specific surface area of the closed pores 101 to the specific surface area of the negative electrode particles 100 of 45.5, a gram capacity of the negative electrode particles 100 of 288 mAh/g, and a first efficiency of 88.4%, which are lower than the gram capacity and first efficiency of Example 1.
  • the closed pores 101 of the negative electrode particles 100 of Example 3 have a pore size of 1.8 nm, a ratio of the specific surface area of the closed pores 101 to the specific surface area of the negative electrode particles 100 of 47.7, a gram capacity of the negative electrode particles 100 of 281 mAh/g, and a first efficiency of 87.7%, which are slightly lower than the gram capacity and first efficiency of Example 2. This is because as the first heating rate increases, the pore size of the closed pores 101 is larger, the binding energy of the active ions becomes larger, which is not conducive to the embedding and extraction of the active ions, so that the gram capacity and first efficiency of the negative electrode particles 100 are reduced.
  • the closed pore 101 pore volume of the negative electrode particle 100 of Example 4 is 0.0651 cm 3 /g, the ratio of the pore volume of the closed pore 101 to the pore volume of the open pore 102 is 8.14, the gram capacity of the negative electrode particle 100 is 305 mAh/g, and the capacity retention rate after 50 cycles of 0.2C/0.2C is 90%, which is slightly higher than the gram capacity of Example 1. This is because the second heating rate of Example 4 is larger, and the negative electrode particle 100 The internal disorder degree will be aggravated, the tendency of microcrystals to combine into pores will be larger, the internal micropores will be increased, and the gram capacity of the negative electrode particles 100 will be increased.
  • the closed pore 101 pore volume of the negative electrode particles 100 of Example 5 is 0.0677 cm 3 /g
  • the ratio of the pore volume of the closed pore 101 to the pore volume of the open pore 102 is 8.36
  • the gram capacity of the negative electrode particles 100 is 309 mAh/g
  • the capacity retention rate of 0.2C/0.2C cycle 50 cycles is 90%, which is slightly lower than the cycle capacity retention rate of Example 4. This is because as the second heating rate continues to increase, the disorder degree of the negative electrode particles 100 continues to increase, so that the gram capacity of the negative electrode particles 100 increases.
  • the gram capacity of the negative electrode particles 100 is 276 mAh/g, which is slightly lower than the gram capacity of Example 6. This is because the second temperature of Example 7 is relatively high. As the second temperature continues to increase, the interlayer spacing of the negative electrode particles 100 becomes smaller, which is not conducive to storing active ions, resulting in a decrease in the gram capacity of the negative electrode particles 100.
  • the pore volume of the closed pores 101 of the negative electrode particles 100 of Example 8 is 0.0783 cm 3 /g
  • the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102 is 10.3
  • the gram capacity of the negative electrode particles 100 is 316 mAh/g
  • the first efficiency is 90.3%, which are significantly higher than the gram capacity and first efficiency of Example 1.
  • Example 5 adds chemical vapor deposition to perform closed pore 101 treatment, which increases the closed pores 101 of the negative electrode particles 100, and increases the ratio of the pore volume of the closed pores 101 to the pore volume of the open pores 102, thereby avoiding serious side reactions between the negative electrode particles 100 and the electrolyte.
  • the negative electrode particles 100 have more active ion storage sites, so that the negative electrode particles 100 have higher gram capacity and initial efficiency.
  • chemical vapor deposition is used to perform closed pore 101 treatment, a carbon layer is deposited on the surface, so the specific surface area of the negative electrode particles 100 is small, but there are more closed pores 101 inside, so the rate performance is also better.

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Abstract

一种负极颗粒及其制备方法、负极极片及储能装置。所述负极颗粒包括：具有位于所述负极颗粒内部的闭孔和位于所述负极颗粒表面的开孔，所述闭孔的孔容与所述开孔的孔容之比的范围为：6≤C1/C2≤11；所述闭孔的孔容的范围为：0.03cm 3/g≤C1≤0.12cm 3/g。所述负极颗粒既可以构建出一定的离子导通通道，又可以避免负极颗粒与电解液的副反应严重，同时负极颗粒具有较多的活性离子储存位点，使得所述负极颗粒具有较高的克容量与首次效率，当所述负极颗粒应用于储能装置时，不会影响储能装置的循环性能。

Description

一种负极颗粒及其制备方法、负极极片及储能装置 技术领域
本申请涉及电池技术领域，具体涉及一种负极颗粒及其制备方法、负极极片及储能装置。
背景技术
随着电池技术的不断发展，要求电池有更高的能量密度和更优异的循环性能，负极材料作为电池中的关键材料，面临着一系列的挑战。负极材料的克容量以及首次库伦效率较低，导致电池的能量密度无法进一步提升。负极材料中的纳米孔道可以提高活性离子的储存位点，从而提高负极材料的克容量，然而随着纳米孔道的增加，容易导致负极材料与电解液的副反应增加，导致电池的循环性能变差。
发明内容
针对上述问题，本申请实施例提供一种负极颗粒，其具有较高的克容量以及较高的首次效率，并且不会影响储能装置的循环性能。
本申请第一方面实施例提供了一种负极颗粒，其包括：具有位于所述负极颗粒内部的闭孔和位于所述负极颗粒表面的开孔，所述闭孔的孔容与所述开孔的孔容之比的范围为：6≤C1/C2≤11；所述闭孔的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
本申请第二方面实施例提供了一种负极颗粒的制备方法，其包括：
提供前驱体及可溶盐；
将所述前驱体置于所述可溶盐体系，于第一温度下对所述前驱体进行预碳化，以得到第一颗粒，其中，所述第一颗粒包括所述前驱体及分散于所述前驱体内的可溶盐，所述第一温度高于所述可溶盐的熔融温度；
去除所述第一颗粒内的可溶盐以得到第二颗粒；以及
于第二温度下，对所述第二颗粒进行碳化，以得到所述负极颗粒，其中，所述第二温度大于所述第一温度，所述负极颗粒具有位于负极颗粒内部的闭孔及位于负极颗粒表面的开孔，所述闭孔的孔容与所述开孔的孔容之比的范围为：6≤C1/C2≤11，所述闭孔的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
本申请第三方面实施例提供一种负极极片，其包括：集流体与活性物质层，所述活性物质层设置于所述集流体的表面，所述活性物质层包括本申请实施例所述的负极颗粒。
本申请第四方面实施例提供一种储能装置，其包括：电解液、正极极片、隔膜以及本申请实施例所述的负极极片，所述正极极片至少部分浸渍于所述电解液中，所述隔膜位于所述正极极片的一侧，且至少部分浸渍于所述电解液中，所述负极极片设置于所述隔膜背离所述正极极片的一侧且至少部分浸渍于所述电解液中。
本申请的所述负极颗粒具有位于所述负极颗粒内部的闭孔和位于所述负极颗粒表面的开孔，所述负极颗粒表面的开孔除了提供活性离子的储存位点并且有利于所述电解液浸润所述负极颗粒，构建出离子导通通道，然而负极颗粒表面的开孔也会导致负极颗粒与电解液的副反应增多，使负极颗粒的首次效率降低。所述负极颗粒内部的闭孔增加了活性离子的储存位点，一定程度上提高了负极颗粒的克容量和首次效率，但负极颗粒内部的闭孔过多会影响电解液浸润所述负极颗粒，导致离子导通通道受限，从而使得负极颗粒的克容量降低。通过控制所述闭孔的孔容与所述开孔的孔容之比的范围在6至11之间，所述闭孔的孔容的范围为0.03cm3/g至0.12cm3/g之间，既可以构建出一定的离子导通通道，又可以避免负极颗粒与电解液的副反应严重，同时负极颗粒具有较多的活性离子储存位点，使得所述负极颗粒具有较高的克容量与首次效率，当所述负极颗粒应用于储能装置时，不会影响储能装置的循环性能。
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，下面描述中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，还可以根据这些附图获得其他的附图。
图1是本申请一实施例的负极颗粒的结构示意图。
图2是本申请一实施例的负极颗粒的制备方法的流程图。
图3是本申请一实施例的负极极片的结构示意图。
图4是本申请一实施例的负极极片沿图3中A-A方向的剖视结构示意图。
图5是本申请一实施例的储能装置的结构示意图。
图6是本申请一实施例的储能装置沿图5中B-B方向的剖视结构示意图。
附图标记说明：
100-负极颗粒，101-闭孔，102-开孔，200-负极极片，210-集流体，220-活性物质层，
300-储能装置，310-隔膜，320-正极极片。
具体实施方式
为了使本技术领域的人员更好地理解本申请方案，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
本申请的说明书和权利要求书及上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序。此外，术语“包括”和“具有”以及它们任何变形，意图在于覆盖不排他的包含。例如包含了一系列步骤或单元的过程、方法、系统、产品或设备没有限定于已列出的步骤或单元，而是可选地还包括没有列出的步骤或单元，或可选地还包括对于这些过程、方法、产品或设备固有的其他步骤或单元。
下面将结合附图，对本申请实施例中的技术方案进行描述。
需要说明的是，为便于说明，在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。
随着电池技术的不断发展，要求电池有更高的能量密度和更优异的循环性能，负极材料作为电池中的关键材料，面临着一系列的挑战。负极材料的克容量以及首次库伦效率较低，导致电池的能量密度无法进一步提升。负极材料中的纳米孔道可以提高活性离子的储存位点，从而提高负极材料的克容量，然而随着纳米孔道的增加，负极材料与电解液的副反应增加，导致电池的循环性能变差。
请参见图1，本申请第一方面实施例提供了一种负极颗粒100，其包括：具有位于所述负极颗粒100内部的闭孔101和位于所述负极颗粒100表面的开孔102，所述闭孔101的孔容与所述开孔102的孔容之比的范围为：6≤C1/C2≤11；所述闭孔101的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
具体的，所述闭孔101的孔容与所述开孔102的孔容之比可以为6、7、8、9、10、11，以及上述数值之间的任意数值。具体的，所述闭孔101的孔容可以为0.03cm3/g、0.04cm3/g、0.05cm3/g、0.06cm3/g、0.07cm3/g、0.08cm3/g、0.09cm3/g、0.10cm3/g、0.11cm3/g、0.12cm3/g，以及上述数值之间的任意数值。
可以理解的是，所述闭孔101是指颗粒内部不与外界连通的空腔和孔道；所述开孔102是指颗粒内部与外界连通的空腔和孔道。
可以理解的是，所述负极颗粒100中的真实的开孔102和真实的闭孔101是不规则的，图1中的规则形状仅为方便示意。
可以理解的是，所述负极颗粒100可以但不限于为硬碳、石墨、软碳等。
当所述负极颗粒100具有位于所述负极颗粒100内部的闭孔101和位于所述负极颗粒100表面的开孔102，所述负极颗粒100表面的开孔102除了提供活性离子的储存位点并且有利于所述电解液浸润所述负极颗粒100，构建出离子导通通道，然而负极颗粒100表面的开孔 102也会导致负极颗粒100与电解液的副反应增多，使负极颗粒100的首次效率降低。所述负极颗粒100内部的闭孔101增加了活性离子的储存位点，一定程度上提高了负极颗粒100的克容量和首次效率，但负极颗粒100内部的闭孔101过多会影响电解液浸润所述负极颗粒100，导致离子导通通道受限，从而使得负极颗粒100的克容量降低。通过控制所述闭孔101的孔容与所述开孔102的孔容之比的范围在6至11之间，所述闭孔101的孔容的范围为0.03cm3/g至0.12cm3/g之间，既可以构建出一定的离子导通通道，又可以避免负极颗粒100与电解液的副反应严重，同时负极颗粒100具有较多的活性离子储存位点，使得所述负极颗粒100具有较高的克容量与首次效率，当所述负极颗粒100应用于储能装置300时，不会影响储能装置300的循环性能。
在一些实施例中，所述开孔102的孔容C2的范围为：0.005cm3/g≤C2≤0.01cm3/g。具体的，所述开孔102的孔容C2可以为0.005cm3/g、0.006cm3/g、0.007cm3/g、0.008cm3/g、0.009cm3/g、0.01cm3/g，以及上述数值之间的任意数值。
当所述开孔102的孔容小于0.005cm3/g时，所述电解液较难浸润所述负极颗粒100，所述负极颗粒100的倍率性能较差。当所述开孔102的孔容大于0.01cm3/g时，所述负极颗粒100与电解液的副反应增多，使负极颗粒100的首次效率降低。当所述开孔102的孔容在0.005cm3/g至0.01cm3/g之间时，所述负极颗粒100即具有良好的倍率性能，又具有较高的首次效率。
在一些实施例中，所述负极颗粒100的闭孔101的平均孔径D1的范围为：0.8nm≤D1≤2.0nm。具体的，所述负极颗粒100的闭孔101的平均孔径D1可以为0.8nm、1.0nm、1.2nm、1.4nm、1.6nm、1.8nm、2.0nm，以及上述数值之间的任意数值。
当所述闭孔101的平均孔径小于0.8nm时，所述活性离子不好嵌入，影响负极颗粒100的克容量。当所述闭孔101的平均孔径大于2.0nm时，所述活性离子的结合能变大，不利于活性离子的嵌入与脱出。当所述闭孔101的平均孔径在0.8nm至2.0nm之间时，所述活性离子较容易嵌入与脱出，有利于提高负极颗粒100的克容量。
在一些实施例中，所述负极颗粒100的闭孔101的比表面积S1与所述负极颗粒100的比表面积S之比的范围为：40≤S1/S≤200。具体的，所述负极颗粒100的闭孔101的比表面积S1与所述负极颗粒100的比表面积S之比可以为40、50、70、90、110、130、150、170、190、200，以及上述数值之间的任意数值。
可以理解的是，所述负极颗粒100的闭孔101的比表面积是指单位重量的所述负极颗粒100的闭孔101的内壁的面积总和。
可以理解的是，所述负极颗粒100的比表面积为单位重量的所述负极颗粒100的外表面积以及所述负极颗粒100中开孔102的比表面积。
当所述闭孔101的比表面积S1与所述负极颗粒100的比表面积S之比小于40时，所述负极颗粒100的比表面积S较大，所述负极颗粒100与电解液接触面积增加，会降低负极颗粒100的首次效率。当所述闭孔101的比表面积S1与所述负极颗粒100的比表面积S之比大于200时，所述开孔102比表面积太小，负极颗粒100与电解液接触面积小，所述电解液较难浸润所述负极颗粒100，所述负极颗粒100的倍率性能较差。当所述闭孔101的比表面积S1与所述负极颗粒100的比表面积S之比在40至200之间时，所述负极颗粒100的首次效率和倍率性能均较好。
在一些实施例中，所述闭孔101的比表面积S1的范围为：40m2/g≤S1≤400m2/g。具体的，所述闭孔101的比表面积可以为40m2/g、60m2/g、80m2/g、100m2/g、120m2/g、140m2/g、160m2/g、180m2/g、200m2/g、220m2/g、240m2/g、260m2/g、280m2/g、300m2/g、320m2/g、340m2/g、360m2/g、380m2/g、400m2/g，以及上述数值之间的任意数值。
当所述闭孔101的比表面积小于40m2/g，所述负极颗粒100的活性离子的储存位点较少，所述负极颗粒100的克容量较低。当所述闭孔101的比表面积大于400m2/g，所述负极颗粒100的结构不够稳定，降低负极颗粒100的压实密度。当所述闭孔101的比表面积在40m2/g至400m2/g时，所述负极颗粒100的克容量较高，也具有较高的压实密度。
在一些实施例中，所述负极颗粒100的比表面积S的范围为：1m2/g≤S≤5m2/g。具体的，所述负极颗粒100的比表面积S可以为1m2/g、2m2/g、3m2/g、4m2/g、5m2/g，以及上述数值之间的任意数值。
当所述负极颗粒100的比表面积S小于1m2/g时，负极颗粒100与电解液接触面积小，所述电解液较难浸润所述负极颗粒100，所述负极颗粒100的倍率性能较差。当所述负极颗粒100的比表面积S大于5m2/g时，所述负极颗粒100与电解液接触面积增加，会降低负极颗粒100的首次效率。当所述负极颗粒100的比表面积S在1m2/g至5m2/g之间时，所述负极颗粒100的首次效率和倍率性能均较好。
在一些实施例中，当所述负极颗粒100为层状结构时，所述负极颗粒100的真密度ρ1与所述负极颗粒100的理论真密度ρ2的比值范围为：0.75≤ρ1/ρ2≤0.95。具体的，所述负极颗粒100的真密度ρ1与所述负极颗粒100的理论真密度ρ2的比值可以为0.75、0.8、0.85、0.9、0.95，以及上述数值之间的任意数值。
可以理解的是，所述真密度是指材料在绝对密实的状态下单位体积的固体物质的实际质量，即去除内部孔隙或者颗粒间的空隙后的密度。
可以理解的是，由于真密度的测试采用氮气吸附，此处去除的内部孔隙，仅仅是开孔102的孔隙。
可以理解的是，所述理论真密度是指材料理想状态下的最高真密度，理想状态即材料内部没有孔隙或者颗粒间没有空隙。所述层状结构的负极颗粒100的理论真密度为2.26g/cm3。
当所述负极颗粒100的真密度ρ1与所述负极颗粒100的理论密度ρ2的比值低于0.75时，所述负极颗粒100的压实密度较低，当所述负极颗粒100应用于储能装置300时，会降低储能装置300的能量密度。当所述负极颗粒100的真密度ρ1与所述负极颗粒100的理论密度ρ2的比值大于0.95时，所述负极颗粒100的活性离子的储存位点较少，所述负极颗粒100的克容量较低。当所述负极颗粒100的真密度ρ1与所述负极颗粒100的理论密度ρ2的比值在0.75至0.95之间时，所述负极颗粒100的压实密度较高，也具有较高的克容量。
在一些实施例中，所述负极颗粒100的真密度ρ1的范围为：1.8g/cm3≤ρ1≤2.1g/cm3。具体的，所述负极颗粒100的真密度可以为1.8g/cm3、1.9g/cm3、2.0g/cm3、2.1g/cm3，以及上述数值之间的任意数值。
当所述负极颗粒100的真密度小于1.8g/cm3时，所述负极颗粒100的压实密度较低，当所述负极颗粒100应用于储能装置300时，会降低储能装置300的能量密度。当所述负极颗粒100的真密度大于2.1g/cm3时，所述负极颗粒100的活性离子的储存位点较少，所述负极颗粒100的克容量较低。当所述负极颗粒100的真密度在1.8g/cm3至2.1g/cm3之间时，所述负极颗粒100的压实密度较高，也具有较高的克容量。
请参见图2，本申请第二方面实施例提供了一种负极颗粒100的制备方法，其包括：
S201，提供前驱体及可溶盐；
S202，将所述前驱体置于所述可溶盐体系，于第一温度下对所述前驱体进行预碳化，以得到第一颗粒，其中，所述第一颗粒包括所述前驱体及分散于所述前驱体内的可溶盐，所述第一温度高于所述可溶盐的熔融温度；
S203，去除所述第一颗粒内的可溶盐以得到第二颗粒；以及
S204，于第二温度下，对所述第二颗粒进行碳化，以得到所述负极颗粒100，其中，所述第二温度大于所述第一温度，所述负极颗粒100具有位于负极颗粒100内部的闭孔101及位于负极颗粒100表面的开孔102，所述闭孔101的孔容与所述开孔102的孔容之比的范围为：6≤C1/C2≤11，所述闭孔101的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
通过将前驱体置于所述可溶盐体系，在所述第一温度下进行预碳化，所述可熔盐为熔融态，所述前驱体中的挥发分在第一温度下逐渐挥发并留下孔洞，所述熔融态的可熔盐占据所述孔洞，在去除所述可熔盐后进行碳化，得到负极颗粒100，所述负极颗粒100中的孔洞较小，且所述闭孔101的孔容与所述开孔102的孔容之比的范围在6至11之间，所述闭孔101的孔容的范围为0.03cm3/g至0.12cm3/g之间，既可以构建出一定的离子导通通道，又可以避 免负极颗粒100与电解液的副反应严重，同时负极颗粒100具有较多的活性离子储存位点，所述负极颗粒100具有较高的克容量与首次效率，当所述负极颗粒100应用于储能装置300时，不会影响储能装置300的循环性能。
可以理解的是，所述前驱体可以但不限于为沥青、石油焦、次烟煤、烟煤、生物质树脂、椰壳、核桃壳等中的至少一种。
进一步的，所述前驱体的碳含量的范围在20％至70％。
本申请实施例中，当涉及到数值范围a至b时，如未特别指明，表示该数值可以为a至b之间的任意数值，包括端点数值a及端点数值b。
具体的，所述前驱体的碳含量的范围可以为20％、40％、60％、70％，以及上述数值之间的任意数值。
当所述前驱体的碳含量低于20％，所述负极颗粒100的得碳率低，也就是说所述前驱体得到的负极颗粒100的转换率低。当所述前驱体的碳含量大于70％，所述前驱体挥发分少，最终得到的负极颗粒100中的孔隙少。当所述前驱体的碳含量在20％至70％之间时，所述前躯体的得碳率较高，得到的负极颗粒100有较多的孔隙，使负极颗粒100具有较多的活性离子储存位点。
可以理解的是，所述可溶盐是指的是在液体中可以溶解的盐(例如溶解于水的盐、溶解于有机溶剂的盐等)。
可以理解的是，所述可溶盐可以但不限于为氯化钠、氯化钾、氯化钙、氟化钠、氟化钾、氢氧化钠、氢氧化钾等中的至少一种。
在一些实施例中，所述可溶盐与所述前驱体的质量比的范围为10％至200％。
具体的，所述可溶盐与所述前驱体的质量比可以为10％、20％、40％、60％、80％、100％、120％、140％、160％、180％、200％，以及上述数值之间的任意数值。
当所述可溶盐与所述前驱体的质量比小于10％时，在前驱体中的挥发分逐渐挥发并留下孔洞，所述熔融态的可熔盐无法完全占据所述孔洞，导致孔洞在高温下容易闭合，负极颗粒100中活性离子储存位点减少，克容量降低。当所述可溶盐与所述前驱体的质量比大于200％时，导致负极颗粒100的制备成本增加。当所述可溶盐与所述前驱体的质量比在10％至200％之间时，负极颗粒100中活性离子储存位点较多，克容量较高，并且制备成本较低。
在一些实施例中，所述前驱体的密度大于或等于所述可溶盐熔融状态下的密度。换言之，所述前驱体的密度大于或等于可溶盐熔融液的密度。
当所述前驱体的密度大于或等于所述可溶盐熔融状态下的密度时，在所述可熔盐熔融状态时，所述前驱体能够充分与可熔盐接触，所述熔融态的可熔盐能够较好的占据所述前驱体中的孔洞，避免所述孔洞在高温作用下快速缩小甚至闭合。
在一些实施例中，将所述前驱体置于所述可溶盐体系，于第一温度下进行预碳化，包括将所述前驱体置于所述可溶盐体系，以第一升温速率R1的范围为0.5℃/min≤R1≤3℃/min进行升温至第一温度，以对所述前驱体进行预碳化，其中，第一温度T1的范围为：400℃≤T1≤1000℃。
具体的，所述第一升温速率R1可以为0.5℃/min、1℃/min、2℃/min、3℃/min，以及上述数值之间的任意数值。具体的，所述第一温度T1可以为400℃、500℃、600℃、700℃、800℃、900℃、1000℃，以及上述数值之间的任意数值。
当所述第一升温速率R1小于0.5℃/min时，所述升温过程耗时过长，增加制造成本。当所述第一升温速率R1大于3℃/min时，所述挥发分逸出的较快，得到的孔洞孔径较大，导致所述活性离子的结合能变大，不利于活性离子的嵌入与脱出。当所述第一升温速率R1在0.5℃/min至3℃/min之间时，即有助于形成较小的孔洞，又不会过多的增加制造成本。
当所述第一温度T1小于400℃时，所述可熔盐无法变成融熔态，或者挥发分无法完全挥发。当所述第一温度T1大于1000℃时，所述挥发分逸出之后得到的孔洞会缩小，甚至部分闭合，导致所述可熔盐在后续过程中无法去除，影响负极颗粒100的克容量，并且会增加制造成本。当所述第一温度T1在400℃至1000℃之间时，所述可熔盐为熔融态，所述前驱体中 的挥发分在第一温度下逐渐挥发并留下孔洞，所述熔融态的可熔盐占据所述孔洞，并且能够在后续过程中易于去除所述可熔盐，在去除所述可熔盐后进行碳化，得到负极颗粒100，所述负极颗粒100中的孔洞较小。
在一些实施例中，所述于第二温度下，对所述第二颗粒进行碳化，以得到所述负极颗粒100，包括以第二升温速率R2的范围为1℃/min≤R2≤10℃/min进行升温至第二温度，以对所述第二颗粒进行碳化，其中，第二温度T2的范围为：1000℃≤T2≤1700℃。
具体的，所述第二升温速率R2可以为1℃/min、2℃/min、3℃/min、4℃/min、5℃/min、6℃/min、7℃/min、8℃/min、9℃/min、10℃/min，以及上述数值之间的任意数值。具体的，所述第二温度T2可以为1000℃、1100℃、1200℃、1300℃、1400℃、1500℃、1600℃、1700℃，以及上述数值之间的任意数值。
当所述第二升温速率R2小于1℃/min时，所述升温过程耗时过长，增加制造成本且负极颗粒100内部的闭孔101含量较少，不利于提高负极颗粒100的克容量。当所述第二升温速率R2大于10℃/min时，所述升温设备损耗较大，减低设备使用寿命。当所述第二升温速率R2在1℃/min至10℃/min之间时，所述负极颗粒100内部的无序程度会加剧，会增加内部闭孔101，增加负极颗粒100的克容量。
当所述第二温度T2小于1000℃时，所述负极颗粒100缺陷多，导致首次效率变低。当所述第二温度T2大于1700℃时，负极颗粒100的层间距变小，不利于存储活性离子，并且所述负极颗粒100制造成本增加。当所述第二温度T2在1000℃至1700℃时，所述负极颗粒100首次效率较高，容易存储活性离子，并且制造成本也不会明显增加。
在一些实施例中，所述第二升温速率R2大于第一升温速率R1。
当所述第二升温速率R2大于第一升温速率R1时，既有助于形成较小的孔洞，又能够使负极颗粒100内部的无序程度会加剧，会增加内部微孔，增加负极颗粒100的克容量。
在一些实施例中，所述去除所述第一颗粒内的可溶盐以得到第二颗粒之后，所述于第二温度下，对所述第二颗粒进行碳化之前，所述方法还包括：在所述第二颗粒的表面沉积碳层，以使位于所述第二颗粒表面的部分开孔102闭合形成闭孔101，以使制得的负极颗粒100具有较多的闭孔101的量，较少的开孔102的量。
可以理解的是，可以通过化学气相沉积在所述颗粒表面沉积碳层。
通过在所述第二颗粒的表面沉积碳层，以使位于所述第二颗粒表面的部分开孔102闭合形成闭孔101，能够避免所述负极颗粒100与电解液的副反应增多，避免负极颗粒100的首次效率降低。
在一些实施例中，所述于第二温度下，对所述第二颗粒进行碳化之后，所述方法还包括：在经碳化后的所述第二颗粒的表面沉积碳层，以使位于经碳化后的所述第二颗粒表面的部分开孔102闭合形成闭孔101。
通过在经碳化后的所述第二颗粒的表面沉积碳层，以使位于经碳化后的所述第二颗粒表面的部分开孔102闭合形成闭孔101，能够避免所述负极颗粒100与电解液的副反应增多，避免负极颗粒100的首次效率降低。
在一些实施例中，沉积碳层于第三温度T3下进行，沉积时间为1h至4h，其中第三温度T3的范围为：800℃≤T3≤1200℃。
具体的，所述第三温度T3可以为800℃、850℃、900℃、950℃、1000℃、1100℃、1200℃，以及上述数值之间的任意数值。所述沉积时间可以为1h、2h、3h、4h，以及上述数值之间的任意数值。
当第三温度T3小于800℃时，所述沉积得到的碳层导电性较差。当第三温度T3大于1200℃时，使得所述负极颗粒100层间距较小，影响动力学性能。当所述第三温度T3在800℃至1200℃之间时，所述沉积得到的碳层既有较好的导电性又有较好的动力学性能。
请参见图3与图4，本申请第三方面实施例提供一种负极极片200，其包括：集流体210与活性物质层220，所述活性物质层220设置于所述集流体210的表面，所述活性物质层220包括本申请实施例所述的负极颗粒100。
可以理解的是，所述集流体210可以但不限于为铜箔、铝箔等。
请参见图5与图6，本申请第四方面实施例提供一种储能装置300，其包括：电解液、正极极片320、隔膜310以及本申请实施例所述的负极极片200，所述正极极片320至少部分浸渍于所述电解液中，所述隔膜310位于所述正极极片320的一侧，且至少部分浸渍于所述电解液中，所述负极极片200设置于所述隔膜310背离所述正极极片320的一侧且至少部分浸渍于所述电解液中。
本申请实施例的储能装置300可以为但不限于为锂离子二次储能装置300、锂离子一次储能装置300、钠离子储能装置300、锂硫储能装置300等。
可以理解的是，所述储能装置300可以但不限于为电池单体、电池模组、电池包等。
可选地，所述隔膜310可以为但不限于为聚丙烯膜(PP)、聚乙烯膜(PE)中的至少一种。
下面结合实施例，进一步阐述本申请。应理解，本申请提供的实施例仅仅是帮助理解本申请，不应视为对本申请的具体限制。
为便于理解，本申请列举实施例如下。本领域技术人员应该明了实施例中未注明具体条件者，按照常规条件进行。
实施例1
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以0.5℃/min升温至650℃并保温2h；保温结束后，冷却备用；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以2℃/min升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：将负极颗粒100硬碳、导电炭SP及粘结剂CMC按照质量比90：5：5分散于去离子水中进行混合均匀得到负极浆料，将负极浆料涂布于负极集流体210铜箔上，烘干，负极活性物质层220的涂布重量为3mg/cm2，经过辊压、冲片后，得到负极极片200。
3)隔膜310的制备：
以16um的聚乙烯薄膜为隔膜310。
4)电解液的制备：
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)按体积比1:1混合得到混合溶剂，再向其中加入干燥的钠盐NaPF6，配成浓度为1mol/L的电解液。
5)储能装置300的制备：提供钠片，将钠片、上述隔膜310、负极极片200按照顺序依次放入扣式电池负极侧外壳中，使得隔膜310处于钠片与负极极片200的之间起到隔离的作用，滴入2滴电解液，然后放入扣式电池正极侧外壳，获得实施例1所述的储能装置300。
实施例2与实施例3
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以一定的第一升温速率R1升温至650℃并保温2h；保温结束后，冷却备用；所述第一升温速率R1具体见表1；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以2℃/min升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
实施例4与实施例5
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以0.5℃/min升温至650℃并保温2h；保温结束后，冷却备用；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以一定的第二升温速率R2升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述第二升温速率R2具体见表1，所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
实施例6与实施例7
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以0.5℃/min升温至650℃并保温2h；保温结束后，冷却备用；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以2℃/min升温至第二温度T2并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述第二温度T2具体见表1，所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
实施例8
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以0.5℃/min升温至650℃并保温2h；保温结束后，冷却备用；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以2℃/min升温至1000℃，通入一定比例的乙炔并保温2h；保温结束后，停止通入乙炔，在保护性气氛下冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
对比例1
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳粉进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉装入坩埚，放入管式炉中，在保护气氛下以6℃/min升温至650℃并保温2h；保温结束后，以2℃/min升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
对比例2
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳粉进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉装入坩埚，放入管式炉中，以5℃/min升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
对比例3
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉与氢氧化钾以1：1的比例混合后装入坩埚；放入管式炉中，在保护气氛下以0.5℃/min升温至300℃并保温2h；保温结束后，冷却备用；
第四步，将冷却后的前驱体椰子壳粉与氢氧化钾混合物倒入纯水中，经多次洗涤过滤后得到预碳化的椰子壳粉，干燥备用；
第五步，管式炉中通入保护性气体，将预碳化后的前驱体椰子壳粉以5℃/min升温至1400℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
对比例4
1)负极颗粒100的制备：
第一步，将前驱体椰子壳粉碎到8μm，收集待用；
第二步，将粉碎后的前驱体椰子壳粉进行化学除灰，除灰试剂为5M/L的盐酸和20％的氢氟酸混合液，水洗干燥后备用；
第三步，将除灰后的前驱体椰子壳粉装入坩埚，放入管式炉中，在保护气氛下以0.5℃/min升温至650℃并保温2h；保温结束后，以2℃/min升温至1100℃并保温6h；保温结束后，冷却至室温，即得到负极颗粒100硬碳；所述硬碳的闭孔101孔容、真密度等参数见表2。
2)负极极片200的制备：同实施例1中负极极片200的制备。
3)隔膜310的制备：同实施例1中隔膜310的制备。
4)电解液的制备：同实施例1中电解液的制备。
5)储能装置300的制备：同实施例1所述储能装置300的制备。
性能测试
1)负极颗粒100的闭孔101的孔容
所述负极颗粒100的闭孔101的孔容＝1/ρ1－1/ρ2。
2)负极颗粒100的闭孔101的孔径
采用小角X射线散射仪(SAXS)测试，得到以下参数：
所述闭孔101的其中，△ρ是对比度，F(Q,r)是散射形状因子，V(r)是负极颗粒100的体积，N是负极颗粒100的总数，P(r)为大小为r的负极颗粒100出现的概率。
3)负极颗粒100的闭孔101的比表面积
采用小角X射线散射仪(SAXS)，得到散射矢量q与散射强度I(q)，其中，2θ为散射角，λ为X射线波长，其中，K＝limq→∞q4I(q)，K为Porod常数，所述闭孔101的比表面积其中，A为负极颗粒100的孔隙度。
4)负极颗粒100的开孔102的孔容
采用ASAP2460物理吸附分析仪，将烘干脱气处理后的样品置于液氮中，调节不同试验压力，分别测出对氮气的吸附量，并绘出吸附和脱附等温线。根据滞后环的形状确定孔的形状，得到开孔102的孔容。
5)负极颗粒100的开孔102的比表面积
采用ASAP2460物理吸附分析仪，将烘干脱气处理后的样品置于液氮中，调节不同试验压力，分别测出对氮气的吸附量，得到开孔102的比表面积。
6)负极颗粒100真密度
真密度采用美国康塔UltraPYC 1200e型全自动真密度分析仪，通过真密度液体分析法测试。
7)储能装置300倍率性能
将上述实施例中所得到的储能装置300在充放电仪上进行倍率测试，测试温度为25℃、 以0.5C的倍率(即充电倍率与放电倍率均为0.5C)循环3次，记录第3次的充电容量为C1，然后以0.1C的倍率放电，再以0.1C的倍率充满电，记录充电容量为C2，0.5C/0.1C倍率容量保持率为C2/C1。
8)储能装置300循环性能
将上述实施例中所得到的储能装置300在充放电仪上进行充放电循环测试，测试温度为25℃，循环倍率为0.2C(即充电倍率与放电倍率均为0.2C)，充电电压为5mV到2V，计算循环后的容量保持率。容量保持率计算公式为：第n次循环后的容量保持率＝(第n次循环后的充电容量/循环充电容量的最大值)×100％。
可以理解的是，本申请术语“圈数”指所述储能装置300以预设倍率进行充电，并以预设倍率进行放电的次数。所述储能装置300完成一次充放电过程称为一圈，0.2C/0.2C循环50圈循环容量保持率是指，测试温度25℃下，储能装置300以0.2C充电倍率和0.2C的放电倍率经过50次的充放电过程之后的容量保持率。
所述实施例1至实施例8以及对比例1至对比例4的第一升温速率及第一温度等见表1：
表1
表2
所述储能装置300测试数据见表3：
表3
从表2的数据来看，对比例1的负极颗粒100的闭孔101孔容为0.139cm3/g，闭孔101的孔容与所述开孔102的孔容之比为12.99，闭孔101孔径为2.6nm，负极颗粒100的克容量仅有262mAh/g，首次效率为86.5％，远低于实施例1的克容量和首次效率。这是由于对比例1预碳化时没有可溶盐，并且第一升温速率较快，所述挥发分逸出的较快，得到的孔洞孔径较大。对比例1的闭孔101孔容太大，闭孔101孔径较大，所述活性离子的结合能变大，不利于活性离子的嵌入与脱出，闭孔101的孔容与开孔102的孔容的比值较大，影响电解液浸润所述负极颗粒100，导致离子导通通道受限，从而使得负极颗粒100的克容量降低。
对比例2的负极颗粒100的闭孔101孔容为0.135cm3/g，闭孔101的孔容与所述开孔102的孔容之比为12.86，闭孔101孔径为2.4nm，负极颗粒100的克容量仅有267mAh/g，首次效率为86.1％，远低于实施例1的克容量和首次效率。这是由于对比例2没有预碳化过程，直接采用较大的第二升温速率进行碳化，导致前驱体中的挥发分逸出过快，导致孔径变大。对比例2的闭孔101孔容太大，闭孔101孔径较大，所述活性离子的结合能变大，不利于活性离子的嵌入与脱出，闭孔101的孔容与开孔102的孔容的比值较大，影响电解液浸润所述负极颗粒100，导致离子导通通道受限，从而使得负极颗粒100的克容量降低。
对比例3的负极颗粒100的闭孔101孔容为0.132cm3/g，闭孔101的孔容与所述开孔102的孔容之比为12.69，闭孔101孔径为2.2nm，负极颗粒100的克容量仅有274mAh/g，首次效率为86.7％，远低于实施例1的克容量和首次效率。这是由于对比例3中第一温度较低，可溶盐没有熔融，在预碳化过程中仅有部分挥发分逸出，形成部分孔洞，但是可溶盐未熔融，无法占据所述孔洞；第二升温速率较快，导致在碳化过程中挥发分逸出的较快，最终得到的闭孔101孔径较大，所述活性离子的结合能变大，不利于活性离子的嵌入与脱出，从而使得负极颗粒100的克容量降低。
实施例2的负极颗粒100的闭孔101孔径为1.6nm，闭孔101的比表面积与所述负极颗粒100的比表面积之比为45.5，负极颗粒100的克容量为288mAh/g，首次效率为88.4％，低于实施例1的克容量和首次效率。实施例3的负极颗粒100的闭孔101孔径为1.8nm，闭孔101的比表面积与所述负极颗粒100的比表面积之比为47.7，负极颗粒100的克容量为281mAh/g，首次效率为87.7％，稍低于实施例2的克容量和首次效率。这是由于随着第一升温速率增加，得到闭孔101孔径较大，所述活性离子的结合能变大，不利于活性离子的嵌入与脱出，使得所述负极颗粒100的克容量和首次效率降低。
实施例4的负极颗粒100的闭孔101孔容为0.0651cm3/g，闭孔101的孔容与所述开孔102的孔容之比为8.14，负极颗粒100的克容量为305mAh/g，0.2C/0.2C循环50圈容量保持率为90％，略高于实施例1的克容量。这是由于实施例4的第二升温速率较大，负极颗粒100 内部的无序程度会加剧，微晶间组合成孔的趋势变大，增加了内部微孔，使得负极颗粒100的克容量增加。实施例5的负极颗粒100的闭孔101孔容为0.0677cm3/g，闭孔101的孔容与所述开孔102的孔容之比为8.36，负极颗粒100的克容量为309mAh/g，0.2C/0.2C循环50圈容量保持率为90％，略低于实施例4的循环容量保持率。这是由于随着第二升温速率的持续增加，所述负极颗粒100无序程度继续增加，使得负极颗粒100的克容量增加。
实施例6的负极颗粒100的闭孔101孔容为0.0625cm3/g，闭孔101的孔容与所述开孔102的孔容之比为7.35，负极颗粒100的克容量为283mAh/g，首次效率为88％，稍低于实施例1的克容量和首次效率。这是由于实施例6的第二温度稍低，使得所述负极颗粒100缺陷变多，首次效率和克容量降低。实施例7的负极颗粒100的闭孔101孔容为0.0501cm3/g，闭孔101的孔容与所述开孔102的孔容之比为6.51，负极颗粒100的克容量为276mAh/g，稍低于实施例6的克容量，这是由于实施例7的第二温度较高，随着第二温度的持续增加，负极颗粒100的层间距变小，不利于存储活性离子，导致负极颗粒100的克容量降低。
实施例8的负极颗粒100的闭孔101的孔容为0.0783cm3/g，闭孔101的孔容与所述开孔102的孔容之比为10.3，负极颗粒100的克容量为316mAh/g，首次效率为90.3％，均明显高于实施例1的克容量和首次效率。这是由于实施例5增加了化学气相沉积进行闭孔101处理，使得所述负极颗粒100的闭孔101增加，闭孔101的孔容与开孔102的孔容之比增加，避免负极颗粒100与电解液的副反应严重，同时负极颗粒100具有较多的活性离子储存位点，使得所述负极颗粒100具有较高的克容量与首次效率，并且因为化学气相沉积进行闭孔101处理，碳层沉积在表面，所以负极颗粒100的比表面积小，但内部的闭孔101较多，所以倍率性能也比较好。
在本申请中提及“实施例”“实施方式”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现所述短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本申请所描述的实施例可以与其它实施例相结合。此外，还应该理解的是，本申请各实施例所描述的特征、结构或特性，在相互之间不存在矛盾的情况下，可以任意组合，形成又一未脱离本申请技术方案的精神和范围的实施例。
最后应说明的是，以上实施方式仅用以说明本申请的技术方案而非限制，尽管参照以上较佳实施方式对本申请进行了详细说明，本领域的普通技术人员应当理解，可以对本申请的技术方案进行修改或等同替换都不应脱离本申请技术方案的精神和范围。

Claims (12)

  1. 一种负极颗粒，其中，所述负极颗粒具有位于所述负极颗粒内部的闭孔和位于所述负极颗粒表面的开孔，所述闭孔的孔容与所述开孔的孔容之比的范围为：6≤C1/C2≤11；所述闭孔的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
  2. 根据权利要求1所述的负极颗粒，其中，所述负极颗粒的闭孔的平均孔径D1的范围为：0.8nm≤D1≤2.0nm。
  3. 根据权利要求1所述的负极颗粒，其中，所述负极颗粒的闭孔的比表面积S1与所述负极颗粒的比表面积S之比的范围为：40≤S1/S≤200。
  4. 根据权利要求3所述的负极颗粒，其中，所述闭孔的比表面积S1的范围为：40m2/g≤S1≤400m2/g；所述负极颗粒的比表面积S的范围为：1m2/g≤S≤5m2/g。
  5. 根据权利要求1所述的负极颗粒，其中，当所述负极颗粒为层状结构时，所述负极颗粒的真密度ρ1与所述负极颗粒的理论真密度ρ2的比值范围为：0.75≤ρ1/ρ2≤0.95。
  6. 一种负极颗粒的制备方法，其中，包括：
    提供前驱体及可溶盐；
    将所述前驱体置于所述可溶盐体系，于第一温度下对所述前驱体进行预碳化，以得到第一颗粒，其中，所述第一颗粒包括所述前驱体及分散于所述前驱体内的可溶盐，所述第一温度高于所述可溶盐的熔融温度；
    去除所述第一颗粒内的可溶盐以得到第二颗粒；以及
    于第二温度下，对所述第二颗粒进行碳化，以得到所述负极颗粒，其中，所述第二温度大于所述第一温度，所述负极颗粒具有位于负极颗粒内部的闭孔及位于负极颗粒表面的开孔，所述闭孔的孔容与所述开孔的孔容之比的范围为：6≤C1/C2≤11，所述闭孔的孔容的范围为：0.03cm3/g≤C1≤0.12cm3/g。
  7. 根据权利要求6所述的负极颗粒的制备方法，其中，将所述前驱体置于所述可溶盐体系，于第一温度下进行预碳化，包括：
    将所述前驱体置于所述可溶盐体系，以第一升温速率R1的范围为0.5℃/min≤R1≤3℃/min进行升温至第一温度，以对所述前驱体进行预碳化，其中，第一温度的范围为：400℃≤T1≤1000℃。
  8. 根据权利要求7所述的负极颗粒的制备方法，其中，所述于第二温度下，对第二颗粒进行碳化，以得到所述负极颗粒，包括：
    以第二升温速率R2的范围为1℃/min≤R2≤10℃/min进行升温至第二温度，以对第二颗粒进行碳化，其中，所述第二升温速率R2大于所述第一升温速率R1，第二温度T2的范围为：1000℃≤T2≤1700℃。
  9. 根据权利要求6所述的负极颗粒的制备方法，其中，所述前驱体的密度大于或等于所述可溶盐熔融状态下的密度。
  10. 根据权利要求6所述的负极颗粒的制备方法，其中，所述去除所述第一颗粒内的可溶盐以得到第二颗粒之后，所述于第二温度下，对所述第二颗粒进行碳化之前；或者，所述于第二温度下，对所述第二颗粒进行碳化之后，所述方法还包括：
    在所述第二颗粒或经碳化后的所述第二颗粒的表面沉积碳层，以使位于所述第二颗粒或经碳化后的所述第二颗粒表面的部分开孔闭合形成闭孔。
  11. 一种负极极片，其中，包括：
    集流体；以及
    活性物质层，所述活性物质层设置于所述集流体的表面，所述活性物质层包括权利要求1至10任一项所述的负极颗粒。
  12. 一种储能装置，其中，包括：
    电解液，
    正极极片，所述正极极片至少部分浸渍于所述电解液中；
    隔膜，位于所述正极极片的一侧，且至少部分浸渍于所述电解液中，以及
    权利要求11所述的负极极片，所述负极极片设置于所述隔膜背离所述正极极片的一侧且至少部分浸渍于所述电解液中。
PCT/CN2024/072970 2023-05-22 2024-01-18 一种负极颗粒及其制备方法、负极极片及储能装置 Ceased WO2024239684A1 (zh)

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Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116314729B (zh) * 2023-05-22 2023-07-21 厦门海辰储能科技股份有限公司 一种负极颗粒及其制备方法、负极极片及储能装置
CN118239487A (zh) * 2024-03-25 2024-06-25 武汉科技大学 多孔碳制备富含闭孔的硬碳负极材料的方法及应用
CN117954629B (zh) * 2024-03-27 2024-07-09 深圳市德方创域新能源科技有限公司 负极材料及其制备方法和应用
CN118943365B (zh) * 2024-07-19 2025-08-29 厦门海辰储能科技股份有限公司 石墨负极颗粒、其制备方法、电池及储能装置
CN119812324B (zh) * 2025-03-11 2025-07-29 江苏正力新能电池技术股份有限公司 硬碳材料及其制备方法和电池

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105247713A (zh) * 2013-05-22 2016-01-13 松下知识产权经营株式会社 钠离子二次电池用负极活性物质、其制造方法和钠离子二次电池
CN106450321A (zh) * 2015-08-04 2017-02-22 Gs爱能吉股份有限公司 锂二次电池用阴极活性物质及其制造方法
US20210202929A1 (en) * 2018-11-01 2021-07-01 Ngk Insulators, Ltd. Lithium secondary battery
CN114792782A (zh) * 2021-01-25 2022-07-26 兰溪致德新能源材料有限公司 一种低膨胀硅负极材料
CN115172746A (zh) * 2021-04-02 2022-10-11 贝特瑞新材料集团股份有限公司 复合负极材料及其制备方法、锂离子电池
CN115849332A (zh) * 2022-11-23 2023-03-28 广东工业大学 一种高倍率硬炭负极材料及其制备方法与应用
CN116314729A (zh) * 2023-05-22 2023-06-23 厦门海辰储能科技股份有限公司 一种负极颗粒及其制备方法、负极极片及储能装置

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10031123B4 (de) * 2000-06-30 2005-06-23 Forschungszentrum Jülich GmbH Verfahren zum Herstellen planarer Anodensubstrate für Hochtemperaturbrennstoffzellen
US20160156031A1 (en) * 2014-11-28 2016-06-02 Samsung Electronics Co., Ltd. Anode active material for lithium secondary battery and lithium secondary battery including the anode active material
CN110790263B (zh) * 2015-05-13 2021-12-24 储晞 三维石墨烯生产方法、装置、复合电极材料及制备与应用
US11456458B2 (en) * 2016-12-08 2022-09-27 Samsung Sdi Co., Ltd. Nickel-based active material precursor for lithium secondary battery, preparing method thereof, nickel-based active material for lithium secondary battery formed thereof, and lithium secondary battery comprising positive electrode including the nickel-based active material
CN111864206B (zh) * 2019-04-30 2023-11-03 贝特瑞新材料集团股份有限公司 一种硬炭负极材料及其制备方法和包含其的极片以及锂离子电池
JP2024538356A (ja) * 2021-11-08 2024-10-18 ファラディオン リミテッド 炭素アノード材料
CN114988390A (zh) * 2022-06-28 2022-09-02 广东邦普循环科技有限公司 一种钠离子电池多孔硬碳材料的制备方法及其制品、应用
CN115133028A (zh) * 2022-07-11 2022-09-30 西安交通大学 一种煤基软碳/硬碳复合材料及其制备方法与应用
CN115332532B (zh) * 2022-10-12 2023-04-07 宁德新能源科技有限公司 一种硬碳材料及其制备方法
CN115676804B (zh) 2022-12-23 2024-01-30 郑州中科新兴产业技术研究院 基于沥青的多孔硬碳负极材料及其制备方法和应用
CN116130637A (zh) * 2023-03-22 2023-05-16 四川金汇能新材料股份有限公司 一种硅碳负极材料、制备方法及电池

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105247713A (zh) * 2013-05-22 2016-01-13 松下知识产权经营株式会社 钠离子二次电池用负极活性物质、其制造方法和钠离子二次电池
CN106450321A (zh) * 2015-08-04 2017-02-22 Gs爱能吉股份有限公司 锂二次电池用阴极活性物质及其制造方法
US20210202929A1 (en) * 2018-11-01 2021-07-01 Ngk Insulators, Ltd. Lithium secondary battery
CN114792782A (zh) * 2021-01-25 2022-07-26 兰溪致德新能源材料有限公司 一种低膨胀硅负极材料
CN115172746A (zh) * 2021-04-02 2022-10-11 贝特瑞新材料集团股份有限公司 复合负极材料及其制备方法、锂离子电池
CN115849332A (zh) * 2022-11-23 2023-03-28 广东工业大学 一种高倍率硬炭负极材料及其制备方法与应用
CN116314729A (zh) * 2023-05-22 2023-06-23 厦门海辰储能科技股份有限公司 一种负极颗粒及其制备方法、负极极片及储能装置

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