WO2025251663A1 - Feuille d'électrode négative et son procédé de préparation, et batterie et dispositif électrique - Google Patents

Feuille d'électrode négative et son procédé de préparation, et batterie et dispositif électrique

Info

Publication number
WO2025251663A1
WO2025251663A1 PCT/CN2025/076051 CN2025076051W WO2025251663A1 WO 2025251663 A1 WO2025251663 A1 WO 2025251663A1 CN 2025076051 W CN2025076051 W CN 2025076051W WO 2025251663 A1 WO2025251663 A1 WO 2025251663A1
Authority
WO
WIPO (PCT)
Prior art keywords
carbon material
hard carbon
active layer
negative electrode
battery
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2025/076051
Other languages
English (en)
Chinese (zh)
Inventor
鲍春晓
张震
王学万
彭宇东
何科峰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BYD Co Ltd
Original Assignee
BYD Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BYD Co Ltd filed Critical BYD Co Ltd
Publication of WO2025251663A1 publication Critical patent/WO2025251663A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • 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
    • H01M4/62—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
    • H01M2004/026—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

  • This application relates to the field of battery technology, specifically to a negative electrode sheet and its preparation method, a battery, and an electrical device.
  • Sodium-ion batteries are cheaper than lithium-ion batteries, but the energy density of existing sodium-ion battery systems is much lower than that of lithium-ion batteries, which limits the application scenarios of sodium-ion batteries.
  • sodium-ion battery anodes have significant room for improvement in specific capacity and compaction.
  • improving the specific capacity of the anode requires improving its plateau region around 0V, which would increase the capacity proportion of the plateau region. But this would lead to a decrease in the capacity proportion of the ramp region, i.e., a decrease in power performance. It is difficult to achieve both simultaneously.
  • the purpose of this application is to provide a negative electrode sheet and its preparation method, a battery, and an electrical device to solve the problem of the difficulty in balancing the power performance and battery capacity of sodium-ion batteries.
  • this application provides a negative electrode sheet, comprising:
  • a current collector having a first surface
  • n active layers are sequentially stacked on the first surface along a first direction, wherein the first direction is perpendicular to the first surface;
  • Each of the active layers includes a first hard carbon material and/or a second hard carbon material; the content of the first hard carbon material in the (m+1)th active layer is less than the content of the first hard carbon material in the mth active layer, the content of the second hard carbon material in the (m+1)th active layer is greater than the content of the second hard carbon material in the mth active layer, the mth active layer is closer to the first surface than the (m+1)th active layer, and satisfies 1 ⁇ m ⁇ n-1, where m and n are both positive integers;
  • the slope region capacity ratio of the first hard carbon material is b1, and the slope region capacity ratio of the second hard carbon material is b2, satisfying: b1 ⁇ b2;
  • the capacity of the slope region of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process at 0.1V vs. Na + /Na.
  • the following condition is also satisfied: 2 ⁇ n ⁇ 4.
  • the reversible specific capacity of the first hard carbon material is a1, which satisfies: a1 ⁇ 290mAh/g.
  • the following condition is also satisfied: 20% ⁇ b1 ⁇ 40%.
  • the following condition is also satisfied: 40% ⁇ b2 ⁇ 70%.
  • the thickness of the active layer is h, which satisfies: h ⁇ 20 ⁇ m.
  • the following condition is also satisfied: 30 ⁇ m ⁇ h ⁇ 60 ⁇ m.
  • the platform region capacity ratio of the first hard carbon material is e1, satisfying: 60% ⁇ e1 ⁇ 80%; the platform region capacity ratio of the second hard carbon material is e2, satisfying: 30% ⁇ e2 ⁇ 60%, and the capacity of the platform regions of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process from 0V vs. Na + /Na to 0.1V vs. Na + /Na.
  • this application provides a method for preparing a negative electrode sheet, comprising the following steps:
  • a current collector is provided, the current collector having a first surface
  • n active layers are sequentially stacked on the first surface along a first direction, wherein the first direction is perpendicular to the first surface;
  • Each of the active layers includes a first hard carbon material and/or a second hard carbon material; the content of the first hard carbon material in the (m+1)th active layer is less than the content of the first hard carbon material in the mth active layer, the content of the second hard carbon material in the (m+1)th active layer is greater than the content of the second hard carbon material in the mth active layer, the mth active layer is closer to the first surface than the (m+1)th active layer, and satisfies 1 ⁇ m ⁇ n-1, where m and n are both positive integers;
  • the slope region capacity ratio of the first hard carbon material is b1, and the slope region capacity ratio of the second hard carbon material is b2, satisfying: b1 ⁇ b2;
  • the capacity of the slope region of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process above 0.1V vs. Na + /Na.
  • this application provides a battery including a positive electrode, a separator, and a negative electrode as described in any of the first aspects, wherein the separator is disposed between the positive electrode and the negative electrode.
  • this application provides an electrical device, including an electrical appliance and a battery as described in the third aspect, wherein the battery supplies power to the electrical appliance.
  • the negative electrode sheet of this application has multiple active layers.
  • the active layers contain a first hard carbon material to improve battery capacity and a second hard carbon material to improve battery rate.
  • the first hard carbon material decreases in gradient along the direction away from the current collector in the active layers, while the second hard carbon material increases in gradient along the direction away from the current collector, i.e., closer to the electrode.
  • the gradient of the first and second hard carbon materials in the multi-layer active layers improves the ion exchange rate near the electrode and the ion capacity near the current collector.
  • the corresponding sodium-ion battery can achieve both improved power performance and battery capacity, resulting in improved battery capacity while having better rate performance and shorter fast charging time.
  • Figure 1 is a side view of the negative electrode and separator according to an embodiment
  • Figure 2 is a flowchart of a method for preparing a negative electrode sheet according to an embodiment.
  • a component when a component is said to be “fixed” to another component, it can be directly on the other component or it can be in a middle component.
  • a component When a component is said to be “connected” to another component, it can be directly connected to the other component or it may be in a middle component.
  • this application provides a negative electrode 100, including a current collector 10 and n active layers 20.
  • the current collector 10 has a first surface 11.
  • the n active layers 20 are sequentially stacked on the first surface 11 along a first direction X, which is perpendicular to the first surface 11.
  • Each active layer 20 includes a first hard carbon material and/or a second hard carbon material.
  • the content of the first hard carbon material in the (m+1)th active layer 20 is less than the content of the first hard carbon material in the mth active layer 20, and the content of the second hard carbon material in the (m+1)th active layer 20 is greater than the content of the second hard carbon material in the mth active layer 20.
  • the mth active layer 20 is closer to the first surface 11 than the (m+1)th active layer 20, and satisfies 1 ⁇ m ⁇ n-1, where m and n are both positive integers.
  • the first hard carbon material and the second hard carbon material have specific special properties, namely: the slope region capacity ratio of the first hard carbon material is b1, and the slope region capacity ratio of the second hard carbon material is b2, satisfying: b1 ⁇ b2.
  • the capacity of the slope region of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process above 0.1V vs. Na + /Na.
  • the corresponding current collector 10 can be any one of copper foil, composite copper foil or carbon-coated copper foil, or any one of aluminum foil, composite aluminum foil or carbon-coated aluminum foil.
  • the first and second hard carbon materials can be resin carbon (such as phenolic resin, epoxy resin, polyfurfuryl alcohol resin, etc.), organic polymer carbon (such as polyvinyl alcohol, polyvinyl chloride, polyvinylidene fluoride, polyacrylonitrile, etc.), carbon black (acetylene black prepared by chemical vapor deposition, etc.), biomass carbon (such as plant residues and shells, etc.), without limitation.
  • Hard carbon materials, as a negative electrode material for sodium-ion batteries are suitable for sodium-ion intercalation and deintercalation due to their large interlayer spacing and irregular structure.
  • the reversible specific capacity of the first hard carbon material is a1, satisfying: a1 ⁇ 290mAh/g.
  • a1 can be 290mAh/g, 300mAh/g, 350mAh/g, 400mAh/g, etc., and is not limited.
  • the following condition is also satisfied: 20% ⁇ b1 ⁇ 40%.
  • b1 can be 20%, 25%, 30%, 35%, or 40%, without limitation.
  • b1 also satisfies 30% ⁇ b1 ⁇ 40%.
  • the first hard carbon material has a1 ⁇ 290mAh/g and the slope region capacity ratio b1 satisfies 20% ⁇ b1 ⁇ 40%, making the first hard carbon material a capacity-type hard carbon material. This results in a higher energy density for the battery and the more electricity it can store.
  • the following condition is also satisfied: 40% ⁇ b2 ⁇ 70%.
  • b2 can be 40%, 50%, 60%, or 70%, without limitation.
  • b1 is 40%, then b2 cannot be 40%.
  • the second hard carbon material is a rate-controlled hard carbon material, enabling the battery to release or absorb energy more quickly, resulting in faster charging and discharging speeds and improved device efficiency.
  • the total mass of the first hard carbon material and the second hard carbon material in each active layer 20 may or may not be the same.
  • the number of active layers 20, n satisfies 1 ⁇ m ⁇ n-1. Optionally, it also satisfies 2 ⁇ n ⁇ 4; specifically, n can be 2, 3, or 4.
  • Multiple active layers 20 are stacked on the current collector 10, and as the active layers move away from the current collector 10 along the first direction X, the content gradient of the first hard carbon material in the active layers 20 decreases, while the content gradient of the second hard carbon material in the active layers 20 increases.
  • the active layer 20 directly stacked on the first surface 11 is the first active layer 20, and the active layer 20 furthest from the first surface 11 is the nth active layer 20.
  • the nth active layer 20 is in close contact with the diaphragm 200.
  • all the hard carbon material in the first active layer 20 is the first hard carbon material
  • all the hard carbon material in the nth active layer 20 is the second hard carbon material.
  • the negative electrode 100 of this application is provided with multiple active layers 20.
  • the active layers 20 are provided with a first hard carbon material to improve battery capacity and a second hard carbon material to improve battery rate.
  • the first hard carbon material in the active layers 20 decreases in a gradient away from the current collector 10, and the second hard carbon material in the active layers 20 increases in a gradient away from the current collector 10, i.e., closer to the electrode.
  • the multi-layer active layers 20 are provided with gradient-changing first and second hard carbon materials, which improves the ion exchange rate in the part near the electrode and the ion capacity in the part near the current collector.
  • the corresponding sodium-ion battery can improve battery capacity while having better rate performance and shorter fast charging time.
  • the thickness of the active layer 20 is h, satisfying: h ⁇ 20 ⁇ m. Specifically, 30 ⁇ m ⁇ h ⁇ 60 ⁇ m. h can be 20 ⁇ m, 30 ⁇ m, 40 ⁇ m, 50 ⁇ m, or 60 ⁇ m, and is not limited.
  • the active layer 20 can provide more electrochemical reaction area, thereby improving the battery capacity and energy density.
  • an excessively thick active layer 20 may increase the transport distance of electrons and ions, thereby increasing the battery's internal resistance and charging/discharging time.
  • An excessively thick active layer 20 is also susceptible to the effects of lithium dendrites, leading to a decrease in battery performance.
  • the active layer 20 can balance battery capacity, energy density, and charging/discharging speed, and can also reduce battery weight, thereby improving battery energy density and portability.
  • the platform region capacity ratio of the first hard carbon material is e1, satisfying: 60% ⁇ e1 ⁇ 80%; the platform region capacity ratio of the second hard carbon material is e2, satisfying: 30% ⁇ e2 ⁇ 60%, and the capacity of the platform regions of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process from 0V vs. Na+ /Na to 0.1V vs. Na + /Na.
  • e1 can be 60%, 65%, 70%, 75%, 80%, etc., without restriction.
  • e2 can be 30%, 40%, 50%, 60%, etc., without restriction. Specifically, the sum of e1 and b1 is 100%, and the sum of e2 and b2 is 100%.
  • the first hard carbon material has a large plateau region capacity, which enables it to have a high specific capacity; the second hard carbon material has a large plateau region capacity, which enables it to have better rate performance.
  • this application also provides a method for preparing a negative electrode 100, comprising the following steps:
  • Step S10 Provide a current collector 10, the current collector 10 having a first surface 11;
  • Step S20 n active layers 20 are sequentially stacked on the first surface 11 along the first direction X, where the first direction X is perpendicular to the first surface 11.
  • Each active layer 20 includes a first hard carbon material and/or a second hard carbon material; the content of the first hard carbon material in the (m+1)th active layer 20 is less than the content of the first hard carbon material in the mth active layer 20, the content of the second hard carbon material in the (m+1)th active layer 20 is greater than the content of the second hard carbon material in the mth active layer 20, the mth active layer 20 is closer to the first surface 11 than the (m+1)th active layer, and satisfies 1 ⁇ m ⁇ n-1, where m and n are both positive integers;
  • the capacity ratio of the slope region of the first hard carbon material is b1, and the capacity ratio of the slope region of the second hard carbon material is b2, satisfying: b1 ⁇ b2; wherein, the capacity of the slope region of the first hard carbon material and the second hard carbon material is the capacity of the battery sodium intercalation process above 0.1V vs. Na+/Na.
  • step S20 n active layers 20 are sequentially stacked on the first surface 11 along the first direction X, which can be achieved by a multilayer coating method.
  • This application provides a battery including a positive electrode, a separator 200 and a negative electrode 100 as described in any of the preceding embodiments, wherein the separator 200 is disposed between the positive electrode and the negative electrode 100.
  • the battery can be a prismatic battery, a cylindrical battery, or other types such as a prismatic battery, without any restrictions.
  • the battery also includes a casing with a receiving cavity in which the positive electrode plate, separator 200, and negative electrode plate 100 are housed.
  • the casing is made of a material with high structural strength, specifically metal, high-strength plastic, ceramic, etc. Metal materials include aluminum, aluminum alloy, magnesium alloy, iron, and iron alloys.
  • the casing includes a base plate and side plates.
  • the casing can be a one-piece structure, meaning the base plate and side plates are manufactured using a single molding process, such as stamping or casting, without limitation.
  • the casing can also be a separate structure, with the side plates and base plate connected and fixed by welding, bonding, snap-fitting, screwing, etc.
  • the wall thickness of the casing can be approximately uniform throughout, meaning the side plates can have a roughly uniform thickness, and the base plate and side plates can also have roughly the same thickness.
  • the positive electrode material of the battery can be a sodium-ion battery positive electrode active material. In specific embodiments, it includes one or more of sodium transition metal oxides, Prussian blue/white compounds, polyanionic compounds, mixed metal oxides, and layered oxides.
  • the separator 200 can be any type of woven membrane, nonwoven membrane (non-woven fabric), microporous membrane, composite membrane, rolled membrane, etc., without limitation. Several layers of separator 200 are used to separate several layers of positive and negative electrode sheets 100.
  • the positive electrode material, conductive agent, and binder are uniformly mixed and dispersed in NMP (N-methylpyrrolidone), coated onto a foil, and baked to obtain the positive electrode sheet.
  • the conductive agent includes one or more of graphite, carbon black, acetylene black, graphene, carbon fiber, C60 (carbon 60), and carbon nanotubes;
  • the binder includes one or more of polyvinylidene chloride, soluble polytetrafluoroethylene, styrene-butadiene rubber, hydroxypropyl methylcellulose, methylcellulose, carboxymethyl cellulose, polyvinyl alcohol, acrylonitrile copolymer, sodium alginate, chitosan, and chitosan derivatives, without limitation. This application does not specifically limit these materials; suitable materials can be selected according to actual application requirements.
  • This application provides an electrical device, including an electrical device and a battery as described in the foregoing embodiments, wherein the battery supplies power to the electrical device.
  • the first hard carbon material and the second hard carbon material are mixed with conductive agent, binder and other materials in deionized water in a certain proportion, and then uniformly coated on the surface of current collector 10.
  • the resulting negative electrode sheet 100 is baked and rolled.
  • the positive electrode, separator 200 and negative electrode 100 are wound sequentially and orderly to obtain the electrode core.
  • This embodiment provides a negative electrode 100, which includes a current collector 10 and two active layers 20.
  • the first active layer 20 of the two active layers 20 is disposed on the first surface 11 of the current collector 10, and the second active layer 20 is disposed on the surface of the first active layer 20 away from the current collector 10.
  • the mass ratio of the first hard carbon material and the second hard carbon material of the negative electrode 100 is 1:1.
  • the first hard carbon material is resin carbon
  • the second hard carbon material is biomass carbon.
  • the thickness h of both the first active layer 20 and the second active layer 20 is 40 ⁇ m ⁇ 2 ⁇ m.
  • the a1 of the first hard carbon material is 315.6 mAh/g
  • the reversible specific capacity of the second hard carbon material is a2
  • a2 is 280.4 mAh/g
  • the b1 of the first hard carbon material is 34.3%
  • the b2 of the second hard carbon material is 43.4%.
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 6:4.
  • the mass ratio of the first hard carbon material to the second hard carbon material in the second active layer 20 is 4:6.
  • This embodiment provides a negative electrode 100, which is basically the same as that in Embodiment 1, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 8:2.
  • the mass ratio of the first hard carbon material to the second hard carbon material is 2:8.
  • This embodiment provides a negative electrode 100, which is basically the same as that in Embodiment 1, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 10:0.
  • the mass ratio of the first hard carbon material to the second hard carbon material in the second active layer 20 is 0:10.
  • This embodiment provides a negative electrode 100, which is basically the same as that in embodiment 3, except that:
  • the second hard carbon material is resin carbon
  • the a2 of the second hard carbon material is 262.6 mAh/g, and the b2 of the second hard carbon material is 60%.
  • This embodiment provides a negative electrode 100, which is basically the same as that in embodiment 4, except that:
  • the a2 of the second hard carbon material is 248.8 mAh/g, and the b2 of the second hard carbon material is 70%.
  • This embodiment provides a negative electrode 100, which is basically the same as that in embodiment 3, except that:
  • the a1 of the first hard carbon material is 300 mAh/g, and the b1 of the first hard carbon material is 36%.
  • This embodiment provides a negative electrode 100, which is basically the same as that in embodiment 3, except that:
  • the a1 of the first hard carbon material is 290 mAh/g, and the b1 of the first hard carbon material is 39%.
  • This comparative example provides a negative electrode 100, which is basically the same as that in Example 1, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the active layer 20 is 5:5.
  • This comparative example provides a negative electrode 100, which is basically the same as that in Example 1, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 4:6.
  • the mass ratio of the first hard carbon material to the second hard carbon material is 6:4.
  • This comparative example provides a negative electrode 100, which is basically the same as that in Example 2, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 2:8.
  • the mass ratio of the first hard carbon material to the second hard carbon material in the second active layer 20 is 8:2.
  • This comparative example provides a negative electrode 100, which is basically the same as that in Example 3, except that:
  • the mass ratio of the first hard carbon material to the second hard carbon material in the first active layer 20 is 0:10.
  • the mass ratio of the first hard carbon material to the second hard carbon material is 10:0.
  • This comparative example provides a negative electrode 100, which is basically the same as that in Example 4, except that:
  • This comparative example provides a negative electrode sheet that is basically the same as that in Example 5, except that:
  • This comparative example provides a negative electrode sheet that is basically the same as that in Example 6, except that:
  • This comparative example provides a negative electrode sheet that is basically the same as that in Example 7, except that:
  • Table 1 shows the distribution of the mass ratio of the first hard carbon material and the second hard carbon material in each layer of the current collector 10 in the negative electrode sheets of Examples 1-7 and Comparative Examples 1-8.
  • Table 2 shows the data on the reversible specific capacity and the proportion of the ramp region of the first hard carbon material and the second hard carbon material in Examples 1-7 and Comparative Examples 1-8.
  • Table 3 compares the energy density and charging capacity of the batteries corresponding to Examples 1-7 and Comparative Examples 1-8.
  • Example 1 Comparing Example 1 with Comparative Example 2, Example 2 with Comparative Example 3, and Example 3 with Comparative Example 4, it can be seen that when the mass ratio of the first hard carbon material and the second hard carbon material in the corresponding active layer 20 is reversed, the fast charging time of the battery increases.
  • the battery with a higher proportion of the first hard carbon material has a higher specific capacity but a longer fast charging time; the battery with a higher proportion of the second hard carbon material has a shorter fast charging time but a higher specific capacity; adding both the first and second hard carbon materials can balance the specific capacity and fast charging performance of the battery; further gradient design of the first and second hard carbon materials can further improve the fast charging performance of the battery.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

L'invention concerne une feuille d'électrode négative (100) et son procédé de préparation, ainsi qu'une batterie et un dispositif électrique. La feuille d'électrode négative (100) comprend un collecteur de courant (10) et n couches actives (20), le collecteur de courant (10) ayant une première surface (11) ; les n couches actives (20) étant empilées séquentiellement sur la première surface (11) dans une première direction (X), la première direction (X) étant perpendiculaire à la première surface (11) ; chaque couche active (20) comprenant un premier matériau carboné dur et/ou un second matériau carboné dur ; la teneur en premier matériau carboné dur dans une (m+1)-ième couche active (20) étant inférieure à la teneur en premier matériau carboné dur dans une m-ième couche active (20), la teneur en second matériau carboné dur dans la (m+1)-ième couche active (20) étant supérieure à la teneur en second matériau carboné dur dans la m-ième couche active (20), la m-ième couche active (20) étant plus proche de la première surface (11) que la (m+1)-ième couche active (20), et la formule 1 ≤ m ≤ n -1 étant satisfaite, m et n étant des nombres entiers positifs ; et la proportion de la capacité de région inclinée du premier matériau carboné dur étant b1, et la proportion de la capacité de région inclinée du second matériau carboné dur étant b2, satisfaisant b1 < b2. Au moyen de la feuille d'électrode négative (100), une batterie obtient à la fois une densité d'énergie élevée et une bonne capacité de charge.
PCT/CN2025/076051 2024-06-03 2025-02-06 Feuille d'électrode négative et son procédé de préparation, et batterie et dispositif électrique Pending WO2025251663A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202410711813.5A CN118738266B (zh) 2024-06-03 2024-06-03 负极片及其制备方法、电池和用电设备
CN202410711813.5 2024-06-03

Publications (1)

Publication Number Publication Date
WO2025251663A1 true WO2025251663A1 (fr) 2025-12-11

Family

ID=92863111

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2025/076051 Pending WO2025251663A1 (fr) 2024-06-03 2025-02-06 Feuille d'électrode négative et son procédé de préparation, et batterie et dispositif électrique

Country Status (2)

Country Link
CN (1) CN118738266B (fr)
WO (1) WO2025251663A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118738266B (zh) * 2024-06-03 2025-09-16 比亚迪股份有限公司 负极片及其制备方法、电池和用电设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113437252A (zh) * 2021-06-21 2021-09-24 宁德新能源科技有限公司 负极、包括该负极的电化学装置和电子装置
CN115224237A (zh) * 2022-08-09 2022-10-21 天津市捷威动力工业有限公司 一种负极极片和锂离子电池
US20230146812A1 (en) * 2021-11-09 2023-05-11 Contemporary Amperex Technology Co., Limited Negative electrode plate, secondary battery, battery module, battery pack, and electric apparatus
CN117423801A (zh) * 2023-12-15 2024-01-19 天津力神电池股份有限公司 负极极片及其制备方法、电池
CN117936700A (zh) * 2024-01-26 2024-04-26 珠海冠宇动力电池有限公司 一种负极片和钠离子电池
CN118738266A (zh) * 2024-06-03 2024-10-01 比亚迪股份有限公司 负极片及其制备方法、电池和用电设备

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113328099B (zh) * 2018-10-31 2022-07-19 宁德时代新能源科技股份有限公司 一种负极极片以及二次电池
GB201820358D0 (en) * 2018-12-13 2019-01-30 Faradion Ltd Sodium-ion batteries
CN116825962A (zh) * 2023-06-29 2023-09-29 江苏天合储能有限公司 钠离子电池复合负极、电池及负极的制备方法
CN117747917A (zh) * 2023-11-24 2024-03-22 天鹏锂能技术(淮安)有限公司 一种钠离子电池

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113437252A (zh) * 2021-06-21 2021-09-24 宁德新能源科技有限公司 负极、包括该负极的电化学装置和电子装置
CN117317137A (zh) * 2021-06-21 2023-12-29 宁德新能源科技有限公司 电化学装置和电子装置
US20230146812A1 (en) * 2021-11-09 2023-05-11 Contemporary Amperex Technology Co., Limited Negative electrode plate, secondary battery, battery module, battery pack, and electric apparatus
CN115224237A (zh) * 2022-08-09 2022-10-21 天津市捷威动力工业有限公司 一种负极极片和锂离子电池
CN117423801A (zh) * 2023-12-15 2024-01-19 天津力神电池股份有限公司 负极极片及其制备方法、电池
CN117936700A (zh) * 2024-01-26 2024-04-26 珠海冠宇动力电池有限公司 一种负极片和钠离子电池
CN118738266A (zh) * 2024-06-03 2024-10-01 比亚迪股份有限公司 负极片及其制备方法、电池和用电设备

Also Published As

Publication number Publication date
CN118738266A (zh) 2024-10-01
CN118738266B (zh) 2025-09-16

Similar Documents

Publication Publication Date Title
CN108807974B (zh) 锂离子电池
CN103855360B (zh) 锂离子电池及其负极极片及制备方法
CN113410469B (zh) 一种负极极片和二次电池以及电动汽车
CN104916809B (zh) 一种一体化柔性电极
CN114665065B (zh) 一种正极极片及其制备方法和应用
CN116632368B (zh) 二次电池及电子装置
CN103904291A (zh) 水系锂离子电池电极及其制备方法、水系锂离子电池
CN109428051A (zh) 锂离子电池及其正极片
CN112259796A (zh) 一种叠片电芯和锂离子电池
CN116435503A (zh) 负极材料层、负极极片及其制备方法、二次电池、电池包、用电设备
WO2021258900A1 (fr) Feuille d&#39;électrode positive et batterie
KR20240005895A (ko) 음극 시트 및 이의 제조 방법, 이차 전지, 전지 모듈, 전지 팩 및 전기 장치
JP2025511106A (ja) 二次電池及び当該電池を含む装置
WO2026002189A1 (fr) Feuille d&#39;électrode, batterie et dispositif électrique
CN111864180A (zh) 一种复合锂金属负极及其制备方法与锂二次电池
WO2025040198A1 (fr) Feuille d&#39;électrode positive, son procédé de préparation et son utilisation
WO2025251663A1 (fr) Feuille d&#39;électrode négative et son procédé de préparation, et batterie et dispositif électrique
CN116504917A (zh) 一种硅碳负极片及锂离子电池
US20250385270A1 (en) Secondary battery
CN115498141A (zh) 一种负极片及其制备方法和电池
WO2026001563A1 (fr) Feuille d&#39;électrode négative, cellule, batterie et dispositif électrique
CN209747641U (zh) 一种复合锂金属负极与锂二次电池
JP2019096475A (ja) リチウム金属二次電池
WO2025130004A1 (fr) Feuille d&#39;électrode positive, procédé de préparation de feuille d&#39;électrode positive et batterie au lithium-ion
WO2024227368A1 (fr) Séparateur pour batterie au sodium, batterie secondaire et appareil électrique

Legal Events

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

Ref document number: 25818727

Country of ref document: EP

Kind code of ref document: A1