CN111900454A - Lithium ion battery with high cycle performance and rate performance - Google Patents

Lithium ion battery with high cycle performance and rate performance Download PDF

Info

Publication number
CN111900454A
CN111900454A CN202010599920.5A CN202010599920A CN111900454A CN 111900454 A CN111900454 A CN 111900454A CN 202010599920 A CN202010599920 A CN 202010599920A CN 111900454 A CN111900454 A CN 111900454A
Authority
CN
China
Prior art keywords
solution
negative electrode
carbon
lithium ion
ion 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.)
Granted
Application number
CN202010599920.5A
Other languages
Chinese (zh)
Other versions
CN111900454B (en
Inventor
李国华
杜小红
励铠鸿
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.)
Zhejiang University of Technology ZJUT
Original Assignee
Zhejiang University of Technology ZJUT
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 Zhejiang University of Technology ZJUT filed Critical Zhejiang University of Technology ZJUT
Priority to CN202010599920.5A priority Critical patent/CN111900454B/en
Publication of CN111900454A publication Critical patent/CN111900454A/en
Application granted granted Critical
Publication of CN111900454B publication Critical patent/CN111900454B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

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

Abstract

The invention relates to the field of lithium battery materials, in particular to a lithium ion battery with high cycle performance and rate capability. It includes a positive electrode, a negative electrode and a separator; the positive electrode formula comprises: a ternary positive electrode material, carbon nanotubes and conductive carbon black; the negative electrode formula comprises: a negative electrode material and a negative electrode conductive agent; the negative electrode material is core-shell structure particles formed by coating graphite with amorphous carbon, and the preparation method comprises the following steps: dissolving an organic carbon source in a solvent to prepare an organic carbon solution, adding fine graphite powder into the organic carbon solution, uniformly dispersing to obtain a graphite dispersion solution, carrying out low-temperature coking on the graphite dispersion solution to obtain a pre-sol, adding a biomass carrier into the pre-sol, soaking and adsorbing until the biomass carrier is saturated, filtering out the biomass carrier, and sequentially carrying out secondary thermal coking, sintering and curing to obtain the powdery anode material. The battery has the advantages of high energy density, excellent cycle performance and rate capability and high and low temperature resistance.

Description

Lithium ion battery with high cycle performance and rate performance
Technical Field
The invention relates to the field of lithium battery materials, in particular to a lithium ion battery with high cycle performance and rate capability.
Background
With the gradual enhancement of the awareness of energy environmental protection, new energy automobiles have been developed greatly in recent years. Among them, the electric vehicle is one of the main directions. Among the power batteries of electric vehicles, lithium ion batteries occupy a very important position.
At present, the negative electrode material of the lithium ion power battery on the market is mainly graphite.
For example, chinese patent application No. 201210092946.6 discloses a method for preparing a negative electrode material for a lithium ion battery, which is obtained by disposing a graphite carbon material in a plasma processing apparatus. The invention also provides a lithium ion battery cathode and a lithium ion battery. The obtained lithium ion battery cathode material has good wettability to electrolyte. The wettability of the lithium ion battery cathode prepared from the lithium ion battery cathode material is also improved correspondingly. Therefore, the infiltration degree of the negative electrode to the electrolyte under the condition that the compaction density of the negative electrode of the lithium ion battery is higher is ensured, and the purposes of improving the unit volume filling amount of the graphite carbon material of the negative electrode of the lithium ion battery and further improving the energy density of the lithium ion battery are achieved.
The negative electrode of the lithium ion power battery in the prior art has the defects of low capacity, low compaction density and low power of the negative electrode material, and the performance of the lithium ion battery is limited. In addition, the problems of large particles of the conventional negative electrode material and poor adhesion and uniformity of the negative electrode on the copper foil further cause the problems of high internal resistance of the battery and poor performance at low temperature and high temperature.
Disclosure of Invention
The invention provides a lithium ion battery with high cycle performance and rate capability, aiming at solving the problems that the existing lithium ion battery has low energy density and can only keep high electrical performance in a narrow temperature range, and a negative electrode material has large volume expansion rate and fast performance reduction in the using process.
The invention aims to:
firstly, improving the energy density of the battery;
the adaptability of the battery to temperature is improved, and good electrical performance can be kept under the conditions of higher and lower temperature ranges;
and thirdly, the cycle performance of the battery is improved, and the adverse effect caused by volume expansion of the negative electrode material is reduced.
In order to achieve the purpose, the invention adopts the following technical scheme.
A lithium ion battery with high cycle performance and rate capability,
comprises a positive electrode, a negative electrode and a diaphragm;
the positive electrode formula comprises:
a ternary positive electrode material, carbon nanotubes and conductive carbon black;
the negative electrode formula comprises:
a negative electrode material and a negative electrode conductive agent;
the negative electrode material is core-shell structure particles formed by coating graphite with amorphous carbon, and the preparation method of the negative electrode material comprises the following steps:
dissolving an organic carbon source in a solvent to prepare an organic carbon solution, adding fine graphite powder into the organic carbon solution, uniformly dispersing to obtain a graphite dispersion solution, carrying out low-temperature coking on the graphite dispersion solution to obtain a pre-sol, adding a biomass carrier into the pre-sol, soaking and adsorbing until the biomass carrier is saturated, filtering out the biomass carrier, and sequentially carrying out secondary thermal coking, sintering and curing to obtain the powdery anode material.
In the preparation scheme, firstly, pre-sol is preliminarily prepared by a sol-gel method, then a biomass carrier is added into the pre-sol to adsorb the pre-sol through the porous adsorbability of the biomass carrier, and then secondary thermal coking and sintering curing treatment are carried out to prepare the negative electrode material similar to the double-layer amorphous carbon coated graphite, wherein the inner layer is a compact coated amorphous carbon layer formed by an organic carbon solvent, the outer layer is a loose amorphous carbon layer which is biased to be conveyed and has a stable porous structure of the biomass carrier, and a series of problems that cracking, a core-shell structure is damaged and the like are not easy to generate during volume expansion are generated. In addition, carry out effectual utilization to common waste gas biomass carrier, also green more.
The preparation process of the core part graphite comprises the following steps:
mixing mosaic coke and asphalt in a mass ratio of (10-30): 1, mixing at 65-75 ℃, heating to 380-400 ℃ after uniformly mixing, carrying out thermal polymerization reaction for 3-5 h, then treating for 1-2 h at 380-450 ℃ and under the vacuum degree of-0.10-0.08 MPa to remove light components, and then carrying out thermal treatment for 5-10 h at 2600-2800 ℃ to obtain the artificial graphite. The mosaic coke is selected as the aggregate of the negative electrode material, belongs to one type of coke, has different properties from the traditional needle coke, and has higher capacity, compaction density and power performance compared with the needle coke. The single-particle structure artificial graphite is obtained by thermal polymerization together with asphalt, low-temperature modification treatment and high-temperature heat treatment, has good high-current charge and discharge performance, is prepared into a compact small-particle size artificial graphite base material, and has the characteristics of high capacity, high compaction density and high power performance.
In the technical scheme of the invention, the negative electrode material adopts core-shell structure particles formed by coating graphite with amorphous carbon, has the advantages of small particle size, high power, high capacity and the like, and under the discharge condition of 0.5C, the capacity can reach more than 420 mAh/g, and the compaction density can reach 1.73 g/cm3The lithium ion battery cathode material has good adhesive force and high uniformity after adhesion, can effectively reduce the contact internal resistance of a cathode material and a copper foil when used for a cathode of the battery, effectively shortens the diffusion distance of lithium ions, increases the infiltration area of electrolyte, reduces the OI value of a pole piece, and can obviously improve the rate capability and the cycle performance of the battery. Furthermore, the stone is coated with amorphous carbonThe surface of the negative electrode material of the ink is smooth, and the amorphous carbon formed by coating the surface can effectively reduce the consumption of the electrolyte by active points and greatly reduce the electrochemical reaction impedance of the material, so that the power performance and the low-temperature performance of the battery are improved.
As a preference, the first and second liquid crystal compositions are,
the positive electrode formula is as follows:
90-98 parts by weight of a ternary positive electrode material, 0.1-4.0 parts by weight of a carbon nano tube, 1.0-3.0 parts by weight of conductive carbon black and 1.0-3.0 parts by weight of a positive electrode binder;
the cathode formula is as follows:
90-97 parts by weight of a negative electrode material, 0.2-3.0 parts by weight of a negative electrode conductive agent and 1.0-6.0 parts by weight of a negative electrode binder.
The formula has a better actual use effect through tests, and the rate performance, the cycle performance and the high and low temperature resistance of the battery are better.
As a preference, the first and second liquid crystal compositions are,
the negative electrode formulation further includes:
3.0-5.0 parts by weight of silicon-carbon composite sol.
Silicon is also a good cathode material, has extremely high theoretical specific capacity and a lower lithium storage reaction voltage platform, and has a remarkable forward effect on the improvement of the electrochemical performance of the cathode.
As a preference, the first and second liquid crystal compositions are,
the preparation method of the silicon-carbon composite sol comprises the following steps:
a) mixing tetraethoxysilane, absolute ethyl alcohol and toluene according to the mass ratio of (8-10) to (100) (0.1-0.2) to prepare a solution A; mixing 0.5-1.5 mol/L of glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of (20-30) to (6-8) to prepare a solution B; carrying out ultrasonic oscillation treatment on the solution A at 50-60 ℃, and dripping the solution B into the solution A with the mass of 3-4 times of that of the solution B at the speed of 0.5-1.0 mL/s; dropwise adding the solution B, adding sodium bicarbonate with the mass being 0.01-0.03 time of that of the solution A into the solution A, and stirring for 2-4 hours after dropwise adding to prepare silica sol;
b) and mixing the nano carbon sol and the silica sol, and uniformly stirring and mixing to obtain the carbon/silicon composite sol with the carbon-silicon mass ratio (1-3): 1.
The silicon-carbon composite sol prepared by the method overcomes the defects of low electronic conductivity, low ionic conductivity and the like of silicon by compounding silicon and carbon, and the performance of the cathode material is improved more obviously.
As a preference, the first and second liquid crystal compositions are,
the shell structure of the anode material has a porous structure.
Because silicon still has phase transition and volume expansion in the lithiation process, and then produces great stress, cause electrode fracture pulverization easily, resistance increase and cycle performance precipitous drop scheduling problem, adopt the negative pole material that has porous structure can effectively adsorb silicon carbon composite sol, adopt the negative pole material further to wrap silicon composition, simultaneously, also can further ensure the smoothness nature on negative pole material surface after adsorbing silicon carbon composite sol.
As a preference, the first and second liquid crystal compositions are,
the organic carbon solution is a glucose solution, wherein the concentration of glucose is 25-30 wt%;
the particle size of the graphite fine powder is less than or equal to 50 mu m;
the biomass carrier comprises any one or more of shaddock peel, straw, wheat bran or tea residue.
The glucose can be coated on the outer surface of the graphite fine powder to form a compact and smooth amorphous carbon coating, and the glucose shows good reversible specific capacity and first coulombic efficiency. The fine graphite powder is controlled to be fine, so that a fine negative electrode material can be prepared. The biomass carriers are common industrial and agricultural or residual fertilizers, have wide sources and low price, and can generate excellent technical effects.
As a preference, the first and second liquid crystal compositions are,
the low-temperature coking is carried out at the temperature of 110-130 ℃ and the heat is preserved for 2-3 h;
the secondary thermal coking is carried out at the temperature of 190-210 ℃ for 2-3 h;
the sintering and curing are carried out at 1020-1080 ℃ for 2-2.5 h;
and the low-temperature coking, the secondary thermal coking and the sintering and curing are all carried out in a protective atmosphere.
The heat treatment can generate a good treatment effect, the cross-linking coating is primarily realized under the condition of low-temperature coking, then the secondary thermal coking enables the pre-sol to basically form a complete gel structure in the biomass carrier, and finally the carbonization coating of the gel and the pulverization coating of the biomass carrier are realized in the sintering and curing process.
As a preference, the first and second liquid crystal compositions are,
the ternary cathode material is NCA or NCM.
The ternary cathode materials are common ternary cathode materials and have good applicability to the technical scheme of the invention.
As a preference, the first and second liquid crystal compositions are,
the diaphragm is a PP diaphragm, a PE diaphragm, a PP ceramic coating diaphragm, a PE ceramic coating diaphragm, a PP ceramic + PVDF coating diaphragm or a PE ceramic + PVDF coating diaphragm.
The diaphragm has good applicability to the technical scheme of the invention.
The invention has the beneficial effects that:
1) the energy density of the battery can be effectively improved;
2) the service performance of the battery under the conditions of lower temperature and higher temperature can be effectively improved;
3) the battery has good cycle performance and rate performance.
Drawings
FIG. 1 is a graph comparing battery rate performance;
FIG. 2 is a comparison graph of normal temperature cycle performance of a battery;
FIG. 3 is a graph comparing the low temperature cycling performance of a battery;
fig. 4 is a graph comparing high-temperature mixing performance of batteries.
Detailed Description
The invention is described in further detail below with reference to specific embodiments and the attached drawing figures. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.
Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all those known to those skilled in the art.
Example 1
Preparing artificial graphite:
mixing mosaic coke and asphalt in a mass ratio of 20:1, mixing at 70 ℃, heating to 390 ℃ after uniformly mixing, carrying out thermal polymerization reaction for 4 h, then treating at 410 ℃ and the vacuum degree of-0.09 MPa for 1.5 h to remove light components, and then carrying out heat treatment at 2700 ℃ for 7 h to obtain the artificial graphite which is detected to be graphite fine powder with the mesh number of more than or equal to 400.
Example 2
Preparing artificial graphite:
mixing mosaic coke and asphalt in a mass ratio of 10:1, mixing at 65 ℃, heating to 380 ℃ after uniformly mixing, carrying out thermal polymerization reaction for 3 h, then treating at 380 ℃ and under the vacuum degree of-0.08 MPa for 1 h to remove light components, and then carrying out heat treatment at 2600 ℃ for 5 h to obtain artificial graphite, wherein the artificial graphite is detected to be graphite fine powder with the mesh number of more than or equal to 400.
Example 3
Preparing artificial graphite:
mixing mosaic coke and asphalt in a mass ratio of 30: 1, mixing at 75 ℃, heating to 400 ℃ after uniformly mixing, carrying out thermal polymerization reaction for 5 h, then treating for 2 h at 450 ℃ and under the vacuum degree of-0.10 MPa to remove light components, and carrying out heat treatment for 10 h at 2800 ℃ to obtain the artificial graphite, wherein the artificial graphite is detected to be graphite fine powder with the mesh number of more than or equal to 400.
Example 4
Preparing a negative electrode material:
the graphite fine powder prepared in example 1 was added to an aqueous glucose solution having a concentration of 28 wt% and uniformly dispersed, and the ratio of the mass of the graphite fine powder to the volume of the aqueous glucose solution was 250 g: 1L to obtain graphite dispersion liquid, carrying out low-temperature coking for 2.5 h at 120 ℃ on the graphite dispersion liquid to obtain pre-sol, adding wheat bran serving as a biomass carrier into the pre-sol, wherein the volume ratio of the mass of the biomass carrier to the pre-sol is 180 g: and 1L, soaking and adsorbing until the biomass carrier is saturated, filtering the biomass carrier, and putting the biomass carrier into an argon protective atmosphere to sequentially carry out secondary thermal coking at 200 ℃ for 2.5 h and sintering and curing at 1050 ℃ for 2.5 h to obtain the powdery negative electrode material.
Example 5
Preparing a negative electrode material:
the graphite fine powder prepared in example 2 was added to an aqueous glucose solution having a concentration of 25 wt% and uniformly dispersed, and the ratio of the mass of the graphite fine powder to the volume of the aqueous glucose solution was 200 g: 1L to obtain graphite dispersion liquid, carrying out low-temperature coking for the graphite dispersion liquid for 3 h at 110 ℃ to obtain pre-sol, adding shaddock peel into the pre-sol as a biomass carrier, wherein the volume ratio of the mass of the biomass carrier to the pre-sol is 160 g: and 1L, soaking and adsorbing until the biomass carrier is saturated, filtering the biomass carrier, and putting the biomass carrier into an argon protective atmosphere to sequentially carry out secondary thermal coking at 190 ℃ for 3 h and sintering and curing at 1020 ℃ for 2.5 h to obtain the powdery negative electrode material.
Example 6
Preparing a negative electrode material:
the graphite fine powder prepared in example 3 was added to an aqueous glucose solution having a concentration of 30 wt% and uniformly dispersed, and the ratio of the mass of the graphite fine powder to the volume of the aqueous glucose solution was 300 g: 1L to obtain graphite dispersion liquid, carrying out low-temperature coking for the graphite dispersion liquid for 2 h at 130 ℃ to obtain pre-sol, adding tea leaves into the pre-sol to serve as a biomass carrier, wherein the volume ratio of the mass of the biomass carrier to the pre-sol is 200 g: 1L, soaking and adsorbing until the biomass carrier is saturated, filtering out the biomass carrier, and putting the biomass carrier into an argon protective atmosphere to sequentially carry out secondary thermal coking at 210 ℃ for 2 h and sintering and solidifying at 1080 ℃ for 2 h to obtain the powdery negative electrode material.
Example 7
The preparation method of the silicon-carbon composite sol comprises the following steps:
a) mixing ethyl orthosilicate, absolute ethyl alcohol and toluene according to a mass ratio of 9:100:0.15 to prepare a solution A; mixing 1.0 mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 25:100:7 to prepare a solution B; carrying out ultrasonic oscillation treatment on the solution A at 55 ℃, and dripping the solution B into the solution A with the mass being 3.5 times of that of the solution B at the speed of 0.8 mL/s; adding sodium bicarbonate with the mass being 0.02 time of that of the solution A into the solution A while dropwise adding the solution B, and stirring for 3 hours after dropwise adding to prepare silica sol;
b) and mixing nano carbon sol and the silica sol, and uniformly stirring and stirring to obtain the carbon/silicon composite sol with the carbon-silicon mass ratio of 2: 1.
Example 8
The preparation method of the silicon-carbon composite sol comprises the following steps:
a) mixing ethyl orthosilicate, absolute ethyl alcohol and toluene according to a mass ratio of 8:100:0.1 to prepare a solution A; mixing 0.5 mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 20:100:6 to prepare a solution B; carrying out ultrasonic oscillation treatment on the solution A at 50 ℃, and dripping the solution B into the solution A with 4 times of mass at the speed of 1.0 mL/s; adding sodium bicarbonate with the mass being 0.01 time of that of the solution A into the solution A while dropwise adding the solution B, and stirring for 2 hours after dropwise adding to prepare silica sol;
b) and mixing nano carbon sol and the silica sol, and uniformly stirring and stirring to obtain the carbon/silicon composite sol with the carbon-silicon mass ratio of 1: 1.
Example 9
The preparation method of the silicon-carbon composite sol comprises the following steps:
a) mixing ethyl orthosilicate, absolute ethyl alcohol and toluene according to a mass ratio of 10:100:0.2 to prepare a solution A; mixing 1.5mol/L glacial acetic acid, absolute ethyl alcohol and water according to a mass ratio of 30: mixing 100:8 to prepare a solution B; carrying out ultrasonic oscillation treatment on the solution A at 60 ℃, and dripping the solution B into the solution A with 3 times of mass at the speed of 0.5 mL/s; adding sodium bicarbonate with the mass being 0.03 time of that of the solution A into the solution A while dropwise adding the solution B, and stirring for 4 hours after dropwise adding to prepare silica sol;
b) and mixing nano carbon sol and the silica sol, and uniformly stirring and stirring to obtain the carbon/silicon composite sol with the carbon-silicon mass ratio of 3: 1.
Example 10
A lithium ion battery with high cycle performance and rate performance:
the positive electrode formula is as follows:
94.0 parts by weight of NCA (6: 2: 2), 2.0 parts by weight of carbon nanotubes, 2.0 parts by weight of conductive carbon black and 2.0 parts by weight of a positive electrode binder (PVDF);
the cathode formula is as follows:
95 parts by weight of the negative electrode material (prepared in example 4), 1.5 parts by weight of the negative electrode conductive agent, and 3.5 parts by weight of the negative electrode binder;
wherein the mass ratio of the negative electrode binder is 1:1, wherein the styrene butadiene rubber is a styrene copolymer with the particle size of less than 0.2 mu m, and the pH value of the styrene butadiene rubber is 6.5-7.5;
the diaphragm is a PP diaphragm.
And the anode formula and the cathode formula are uniformly mixed and then coated on the surface of a current collector to respectively obtain an anode and a cathode.
Example 11
A lithium ion battery with high cycle performance and rate performance:
the positive electrode formula is as follows:
90.0 parts by weight of NCA (5: 2: 3), 4.0 parts by weight of carbon nanotubes, 3.0 parts by weight of conductive carbon black and 3.0 parts by weight of a positive electrode binder (PVDF);
the cathode formula is as follows:
90.0 parts by weight of the negative electrode material (obtained in example 4), 3.0 parts by weight of the negative electrode conductive agent, 2.0 parts by weight of the negative electrode binder, and 5.0 parts by weight of the silicon-carbon composite sol (obtained in example 7);
wherein the mass ratio of the negative electrode binder is 1: 0.5 of carboxymethyl cellulose and styrene butadiene rubber, wherein the styrene butadiene rubber is a styrene copolymer with the particle size of less than 0.2 mu m, and the pH value of the styrene butadiene rubber is 6.5-7.5;
the diaphragm is a PE diaphragm.
And the anode formula and the cathode formula are uniformly mixed and then coated on the surface of a current collector to respectively obtain an anode and a cathode.
Example 12
A lithium ion battery with high cycle performance and rate performance:
the positive electrode formula is as follows:
98 parts by weight of NCA (8: 1: 1), 0.1 part by weight of carbon nanotubes, 1.0 part by weight of conductive carbon black and 1.0 part by weight of positive electrode binder (PVDF);
the cathode formula is as follows:
95.8 parts by weight of the negative electrode material (obtained in example 5), 0.2 parts by weight of the negative electrode conductive agent, 1.0 part by weight of the negative electrode binder, and 3.0 parts by weight of the silicon-carbon composite sol (obtained in example 8);
wherein the mass ratio of the negative electrode binder is 1: 0.5 of carboxymethyl cellulose and styrene butadiene rubber, wherein the styrene butadiene rubber is a styrene copolymer with the particle size of less than 0.2 mu m, and the pH value of the styrene butadiene rubber is 6.5-7.5;
the diaphragm is a PP ceramic coating diaphragm.
And the anode formula and the cathode formula are uniformly mixed and then coated on the surface of a current collector to respectively obtain an anode and a cathode.
Example 13
A lithium ion battery with high cycle performance and rate performance:
the procedure is as in example 11, except that: the negative electrode material obtained in example 6 was used as the negative electrode material, and the silicon-carbon composite sol obtained in example 9 was used as the silicon-carbon composite sol.
Comparative example
The following lithium ion battery control groups were set for comparison, respectively:
control group 1: technical scheme of embodiment 1 disclosed in CN 108346799A.
Control group 2: the preparation is the same as that of example 11, except that the negative electrode material is prepared by the following preparation process:
adding the fine graphite powder prepared in example 1 into water, and uniformly dispersing the fine graphite powder, wherein the mass ratio of the fine graphite powder to the water is 250 g: 1L to obtain graphite dispersion liquid, carrying out low-temperature coking for 2.5 h at 120 ℃ on the graphite dispersion liquid to obtain pre-sol, adding wheat bran serving as a biomass carrier into the pre-sol, wherein the volume ratio of the mass of the biomass carrier to the pre-sol is 180 g: and 1L, soaking and adsorbing until the biomass carrier is saturated, filtering the biomass carrier, and putting the biomass carrier into an argon protective atmosphere to sequentially carry out secondary thermal coking at 200 ℃ for 2.5 h and sintering and curing at 1050 ℃ for 2.5 h to obtain the powdery negative electrode material.
Control group 3: the preparation is the same as that of example 11, except that the negative electrode material is prepared by the following preparation process:
the graphite fine powder prepared in example 1 was added to an aqueous glucose solution having a concentration of 28 wt% and uniformly dispersed, and the ratio of the mass of the graphite fine powder to the volume of the aqueous glucose solution was 250 g: 1L to obtain graphite dispersion liquid, carrying out low-temperature coking on the graphite dispersion liquid at 120 ℃ for 2.5 h, mixing the presol subjected to low-temperature coking with equal volume of 28 wt% glucose aqueous solution again, placing the mixture in an argon protective atmosphere, sequentially carrying out secondary thermal coking at 200 ℃ for 2.5 h and sintering and curing at 1650 ℃ for 2.5 h, and obtaining the powdery negative electrode material.
The performance tests of the lithium ion batteries prepared in the above examples 10 to 13 and comparative examples were performed, and the tests included a rate performance test, a normal temperature (20 ℃) cycle test, a low temperature (-10 ℃) cycle test, and a high temperature (80 ℃) cycle test, and the cycle tests were performed under a 1C rate condition. The test results are shown in FIGS. 1 to 4. In the figure: A1-A4 correspond to examples 10-13, respectively, and B1-B3 correspond to control groups 1-3, respectively.
And (3) rate performance test:
the multiplying power performance test is to take and put the mean value of the capacitance by ten charging and discharging cycles under the condition of single rate, and as can be obviously seen from figure 1, the addition and use of the silicon-carbon composite sol greatly improves the capacity of the battery, the capacity of the battery is improved greatly, and the multiplying power performance is improved obviously, the technical scheme of the comparison group 1 generates obvious real-time capacity reduction when 3C charging and discharging is carried out, the reduction rate reaches about 26.98 percent when 10C charging and discharging is carried out, the multiplying power performance is poorer, the comparison group 2 and the comparison group 3 show that the structure of the negative electrode material particles also has larger influence on the multiplying power performance of the battery, particularly under the condition of composite silicon-carbon composite sol, an unreasonable structure can cause the silicon component to generate a great volume expansion rate, so that the silicon component is pulverized, the capacity is sharply reduced, and an avalanche type reaction is initiated to cause the overall performance to be degraded in a cliff type manner.
And (3) normal-temperature cycle performance test:
as is apparent from fig. 2, the capacity of the lithium ion battery prepared by the technical scheme of the present invention decreases from about 500 th cycle, the capacity retention ratio of the battery is high in the first 500 charge-discharge cycles, and can substantially maintain more than 95% of the capacity, while in the subsequent aging, the capacity decreases more stably, and after 800 cycles, the capacity reaches a lower valley level and then remains more smoothly, until 1400 cycles, the capacity can still maintain more than 90%, and the cycle performance is very excellent, while in the comparison group 1, the capacity is maintained only about 70% after 1400 cycles, and a significant decrease is generated, which is the same as in the comparison groups 2 and 3, and the main reason for the rapid decrease of the aging and capacity is the volume expansion of silicon.
Low temperature cycle performance test:
the low-temperature cycle performance test result is shown in fig. 3, and it is obvious from the graph, that the capacity retention tendency of the lithium ion battery prepared by the technical scheme of the invention in fig. 3 is closer to that of fig. 2 at normal temperature, but the difference is that a larger decline gradient exists between 800 cycles and 1000 cycles, the capacity of the battery is kept more stable after about 1000 cycles, while the capacity of the comparison group 1 is better than that of the comparison group 2 and the comparison group 3, but the three groups also have stronger capacity decline, and the cycle performance at low temperature is very limited.
High temperature cycle performance test:
the test result is shown in fig. 4, and the trends of fig. 4 and fig. 3 are closer, except that the decrease of fig. 4 is more gradual, and a low value in the subsequent gradual process is slightly higher than the low value in fig. 3 under the low temperature condition, which indicates that the performance of the lithium ion battery prepared by the technical scheme of the present invention is better than that under the lower temperature condition under the higher temperature condition in practice, in addition, the performance of the control group 2 and the control group 3 is a certain difference at the high temperature, and the performance of the control group 3 is slightly better than that of the control group 2, because the control group 2 has a porous shell structure, but has poor structural stability, has poor coating effect on graphite, and the effect of adsorbing the silicon-carbon composite sol is also reduced, so that the fixing effect and the coating effect on silicon are poor in the practical use process, and the silicon is easy to be crushed after generating severe volume expansion, in contrast, in the control group 3, the glucose aqueous solution is coated in a stacked manner twice, so that although the adsorption and coating of silicon cannot be realized, the stable core-shell structure can reduce the negative effect caused by the volume expansion of silicon to a certain extent.
In conclusion, the lithium ion battery prepared by the invention has very excellent cycle performance and rate capability, can keep extremely high battery capacity after thousands of cycles under low-temperature and high-temperature conditions, and has very excellent effect.

Claims (9)

1. A lithium ion battery with high cycle performance and rate capability is characterized in that,
comprises a positive electrode, a negative electrode and a diaphragm;
the positive electrode formula comprises:
a ternary positive electrode material, carbon nanotubes and conductive carbon black;
the negative electrode formula comprises:
a negative electrode material and a negative electrode conductive agent;
the negative electrode material is core-shell structure particles formed by coating graphite with amorphous carbon, and the preparation method comprises the following steps:
dissolving an organic carbon source in a solvent to prepare an organic carbon solution, adding fine graphite powder into the organic carbon solution, uniformly dispersing to obtain a graphite dispersion solution, carrying out low-temperature coking on the graphite dispersion solution to obtain a pre-sol, adding a biomass carrier into the pre-sol, soaking and adsorbing until the biomass carrier is saturated, filtering out the biomass carrier, and sequentially carrying out secondary thermal coking, sintering and curing to obtain the powdery anode material.
2. The lithium ion battery with high cycle performance and rate capability of claim 1,
the positive electrode formula is as follows:
90-98 parts by weight of a ternary positive electrode material, 0.1-4.0 parts by weight of a carbon nano tube, 1.0-3.0 parts by weight of conductive carbon black and 1.0-3.0 parts by weight of a positive electrode binder;
the cathode formula is as follows:
90-97 parts by weight of a negative electrode material, 0.2-3.0 parts by weight of a negative electrode conductive agent and 1.0-6.0 parts by weight of a negative electrode binder.
3. The lithium ion battery with high cycle performance and rate capability of claim 1 or 2,
the negative electrode formulation further includes:
3.0-5.0 parts by weight of silicon-carbon composite sol.
4. The lithium ion battery with high cycle performance and rate capability of claim 3,
the preparation method of the silicon-carbon composite sol comprises the following steps:
a) mixing tetraethoxysilane, absolute ethyl alcohol and toluene according to the mass ratio of (8-10) to (100) (0.1-0.2) to prepare a solution A; mixing 0.5-1.5 mol/L of glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of (20-30) to (6-8) to prepare a solution B; carrying out ultrasonic oscillation treatment on the solution A at 50-60 ℃, and dripping the solution B into the solution A with the mass of 3-4 times of that of the solution B at the speed of 0.5-1.0 mL/s; dropwise adding the solution B, adding sodium bicarbonate with the mass being 0.01-0.03 time of that of the solution A into the solution A, and stirring for 2-4 hours after dropwise adding to prepare silica sol;
b) and mixing the nano carbon sol and the silica sol, and uniformly stirring and mixing to obtain the carbon/silicon composite sol with the carbon-silicon mass ratio (1-3): 1.
5. The lithium ion battery with high cycle performance and rate capability of claim 1 or 2,
the shell structure of the anode material has a porous structure.
6. The lithium ion battery with high cycle performance and rate capability of claim 1,
the organic carbon solution is a glucose solution, wherein the concentration of glucose is 25-30 wt%;
the particle size of the graphite fine powder is less than or equal to 50 mu m;
the biomass carrier comprises shaddock peel, straw, wheat bran or tea residue.
7. The lithium ion battery with high cycle performance and rate capability of claim 1,
the low-temperature coking is carried out at the temperature of 110-130 ℃ and the heat is preserved for 2-3 h;
the secondary thermal coking is carried out at the temperature of 190-210 ℃ for 2-3 h;
the sintering and curing are carried out at 1020-1080 ℃ for 2-2.5 h;
and the low-temperature coking, the secondary thermal coking and the sintering and curing are all carried out in a protective atmosphere.
8. The lithium ion battery with high cycle performance and rate capability of claim 1,
the ternary cathode material is NCA or NCM.
9. The lithium ion battery with high cycle performance and rate capability of claim 1,
the diaphragm is a PP diaphragm, a PE diaphragm, a PP ceramic coating diaphragm, a PE ceramic coating diaphragm, a PP ceramic + PVDF coating diaphragm or a PE ceramic + PVDF coating diaphragm.
CN202010599920.5A 2020-06-28 2020-06-28 Lithium ion battery with high cycle performance and rate performance Active CN111900454B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010599920.5A CN111900454B (en) 2020-06-28 2020-06-28 Lithium ion battery with high cycle performance and rate performance

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010599920.5A CN111900454B (en) 2020-06-28 2020-06-28 Lithium ion battery with high cycle performance and rate performance

Publications (2)

Publication Number Publication Date
CN111900454A true CN111900454A (en) 2020-11-06
CN111900454B CN111900454B (en) 2021-11-23

Family

ID=73207204

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010599920.5A Active CN111900454B (en) 2020-06-28 2020-06-28 Lithium ion battery with high cycle performance and rate performance

Country Status (1)

Country Link
CN (1) CN111900454B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103078090A (en) * 2013-03-01 2013-05-01 湖州创亚动力电池材料有限公司 Lithium ion power battery composite cathode material and its preparation method
CN108270007A (en) * 2017-01-03 2018-07-10 神华集团有限责任公司 Carbon raw material composition and its application and carbon material and its preparation method and application and negative electrode of lithium ion battery and lithium ion battery
CN108346799A (en) * 2017-01-23 2018-07-31 万向二三股份公司 A kind of lithium ion battery of high-energy density wide temperature range
CN108832092A (en) * 2018-06-11 2018-11-16 深圳市贝特瑞新能源材料股份有限公司 Core-shell structure multi-element composite material, preparation method and the lithium ion battery comprising the multi-element composite material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103078090A (en) * 2013-03-01 2013-05-01 湖州创亚动力电池材料有限公司 Lithium ion power battery composite cathode material and its preparation method
CN108270007A (en) * 2017-01-03 2018-07-10 神华集团有限责任公司 Carbon raw material composition and its application and carbon material and its preparation method and application and negative electrode of lithium ion battery and lithium ion battery
CN108346799A (en) * 2017-01-23 2018-07-31 万向二三股份公司 A kind of lithium ion battery of high-energy density wide temperature range
CN108832092A (en) * 2018-06-11 2018-11-16 深圳市贝特瑞新能源材料股份有限公司 Core-shell structure multi-element composite material, preparation method and the lithium ion battery comprising the multi-element composite material

Also Published As

Publication number Publication date
CN111900454B (en) 2021-11-23

Similar Documents

Publication Publication Date Title
CN114142011B (en) Hard carbon composite material and preparation method and application thereof
CN109473658B (en) Preparation method of lithium ion battery cathode material and lithium ion battery using same
CN114447305B (en) Multi-carbon-based quick-charge anode composite material and preparation method thereof
CN101459238A (en) Manufacturing method for high capacity composite electrode of lithium ionic cell
CN115566170B (en) Preparation method of high-energy-density quick-charging lithium ion battery anode material
CN110993884A (en) Lithium ion battery negative electrode slurry, preparation method, negative electrode plate and battery
CN115714170B (en) Preparation method of high-energy-density quick-charge anode material
CN115188949A (en) Preparation method of mesocarbon microbead-silicon carbon composite negative electrode material
CN114843483B (en) Hard carbon composite material and preparation method and application thereof
CN114920242B (en) Preparation method of high-capacity graphite composite material
CN111900454B (en) Lithium ion battery with high cycle performance and rate performance
CN113764645B (en) Preparation method of hard carbon composite material with three-dimensional structure
CN115528231A (en) Quick-filling graphite composite material and preparation method thereof
CN114975974A (en) High-energy-density graphite composite material, preparation method thereof and lithium ion battery
CN107425184A (en) A kind of silicon porous carbon electrode material and its preparation method and application
CN112366363A (en) Preparation method of high-temperature-resistant lithium ion battery
CN114162814A (en) Modification method of graphite
CN111900345B (en) Silicon-carbon anode material with core-shell structure
CN111916817B (en) Lithium ion battery with high capacity and cycle performance
CN116344779B (en) Lithium battery composite negative electrode material and lithium battery
CN117613252B (en) Silicon-carbon composite material for lithium ion battery with high specific energy density and preparation method thereof
CN113258069B (en) Negative electrode active material, method for preparing same, negative electrode, and secondary battery
CN115472809B (en) Preparation method of graphite composite material with high first efficiency
CN116230911B (en) High-power silicon-carbon negative electrode composite material and preparation method thereof
CN116240415A (en) Porous metal doped silica composite material and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant