CN111509203A - Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof - Google Patents

Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof Download PDF

Info

Publication number
CN111509203A
CN111509203A CN202010301089.0A CN202010301089A CN111509203A CN 111509203 A CN111509203 A CN 111509203A CN 202010301089 A CN202010301089 A CN 202010301089A CN 111509203 A CN111509203 A CN 111509203A
Authority
CN
China
Prior art keywords
polypyrrole
positive electrode
electrode material
doped
preparation
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
CN202010301089.0A
Other languages
Chinese (zh)
Inventor
沈建新
李亮
许海洋
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.)
Jiangxi Batewei New Energy Technology Co ltd
Original Assignee
Jiangxi Batewei New Energy Technology 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 Jiangxi Batewei New Energy Technology Co ltd filed Critical Jiangxi Batewei New Energy Technology Co ltd
Priority to CN202010301089.0A priority Critical patent/CN111509203A/en
Publication of CN111509203A publication Critical patent/CN111509203A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—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
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • 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

Landscapes

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

Abstract

The invention belongs to the field of battery materials, and provides a polypyrrole-doped shell layer composite positive electrode material and a preparation method thereof. The method comprises the steps of mixing a doping agent, a pyrrole monomer, carbon-coated lithium iron phosphate and a dispersing agent to obtain a mixed solution, mixing an oxidant and the mixed solution, and then carrying out oxidation polymerization reaction to generate the polypyrrole-doped shell layer composite anode material. The polypyrrole is doped in the carbon shell layer of the existing carbon-coated lithium iron phosphate, so that the surface coating layer is more compact, the lithium iron phosphate anode can be effectively prevented from being corroded by electrolyte in the circulation process to cause irreversible damage to the crystal structure, a smooth and flat SEI film is formed on the cathode, and the electrochemical performance of the battery is further improved.

Description

Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof
Technical Field
The invention belongs to the technical field of battery materials, and particularly relates to a polypyrrole-doped shell layer composite positive electrode material and a preparation method thereof.
Background
The lithium ion battery is a novel energy storage device, has the advantages of light weight, small volume, high energy density and the like, and is widely used in electronic products such as mobile phones, computers and the like, but higher requirements on battery cost, safety, stability and the like are provided as the times develop, and particularly, the lithium ion battery with high power and high energy density is urgently needed as the new energy automobiles develop4L FP) has the advantages of high energy density and theoretical capacity, long cycle life, abundant resources, low price, good safety and the like, and is considered to be one of more ideal positive materials of power lithium batteries.
However, lithium iron phosphate is a semiconductor compound with an olivine structure, so that the problems of poor electronic conductivity and low lithium ion diffusion coefficient exist, and the fast charge and fast discharge of lithium iron phosphate under high current are seriously restricted. Although lithium iron phosphate has a strong P-O covalent bond, it can bring excellent thermal stability and safety. However, in the long-cycle process, due to some side reactions, the transition metal iron (Fe) on the surface of the lithium iron phosphate is dissolved, thereby seriously affecting the performance of the material. Diffusion of dissolved iron to the negative electrode promotes thickening of the growth of the SEI film, resulting in deterioration of battery performance. The coating method is a modification method which is commonly used at present, and commonly used coating materials comprise carbon and metal materials. Although carbon-coated lithium iron phosphate and metal-coated lithium iron phosphate have certain improvements in capacitance and conductivity, the requirements of fast charge and fast discharge of lithium iron phosphate under large flow rate cannot be met.
Disclosure of Invention
The invention aims to provide a polypyrrole-doped shell layer composite cathode material and a preparation method thereof, which can prevent a lithium iron phosphate cathode from being corroded by electrolyte in a circulation process to cause irreversible damage to a crystal structure.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of a polypyrrole-doped shell layer composite positive electrode material, which comprises the following steps:
(1) mixing a dopant, a pyrrole monomer, carbon-coated lithium iron phosphate and a dispersant to obtain a mixed solution;
(2) and mixing an oxidant and the mixed solution for oxidation polymerization reaction to generate the polypyrrole-doped shell layer composite anode material.
Preferably, the mass ratio of the dopant to the pyrrole monomer to the oxidant is (1-3): 1:1.5.
Preferably, the mass ratio of the pyrrole monomer to the carbon-coated lithium iron phosphate is (1-10): 100.
preferably, the dopant is one or more of sodium p-toluenesulfonate, sodium benzenesulfonate, sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid.
Preferably, the dispersant is methanol, ethanol or acetone.
Preferably, the oxidant is one of ferric chloride, ammonium superphosphate, hydrogen peroxide and potassium iodate.
Preferably, the oxidative polymerization reaction is carried out for 3-8 h under the ice bath condition.
Preferably, after the oxidative polymerization reaction is completed, sequentially performing suction filtration and drying on the obtained mixed system to obtain the polypyrrole-doped shell layer composite positive electrode material.
The invention also provides a polypyrrole-doped shell layer composite anode material, which takes lithium iron phosphate as a core and a polypyrrole-doped carbon layer as a shell.
The polypyrrole-doped shell layer composite cathode material provided by the invention is prepared by doping polypyrrole into the carbon shell layer of the existing carbon-coated lithium iron phosphate, so that the surface coating layer of the lithium iron phosphate can be more compact, the lithium iron phosphate cathode can be effectively prevented from being corroded by electrolyte in the circulation process to cause irreversible damage to a crystal structure, and meanwhile, the polypyrrole-doped shell layer composite cathode material is beneficial to forming a smooth and flat SEI film on a cathode to further promote the improvement of the electrochemical performance of a battery.
Drawings
FIG. 1 is a graph of discharge capacities of L FP and PPy-L FP of different polypyrrole coating amounts cycled 500 times at 1C;
FIG. 2 is an SEM photograph of L FP and PPy-L FP, FIG. 2a is an SEM photograph of L FP, and FIG. 2b is an SEM photograph of Mn-L FP;
FIG. 3 is an infrared spectrum of L FP and PPy-L FP;
FIG. 4 is High Resolution Transmission Electron Microscope (HRTEM) and high angle annular dark field scanning transmission electron microscope (HAADF-STEM) images of L FP and PPy-L FP, FIG. 4a is an HRTEM image of L FP, FIG. 4(b-c) is an HAADF-STEM image of L FP, FIG. 4d is an HRTEM image of PPy-L FP, and FIG. 4(e-f) is an HAADF-STEM image of PPy-L FP;
FIG. 5 is an HRTEM image of L FP after 500 cycles at 1C and an HAADF-STEM image of PPy-L FP after 500 cycles at 1C, FIG. 5a is an HRTEM image of L FP after 500 cycles at 1C, FIG. 5(b-C) is an HRTEM image in which FIG. 5a is partially enlarged, FIG. 5(g-h) is an FTT image corresponding to FIG. 5b and FIG. 5C, respectively, and FIG. 5(d-f) is an HAADF-STEM image of PPy-L FP after 500 cycles at 1C;
FIG. 6 shows the lithium metal negative electrode after L FP and PPy-L FP cycles, FIG. 6a shows the lithium metal negative electrode of L FP, and FIG. 6b shows the lithium metal negative electrode of PPy-L FP.
Detailed Description
The polypyrrole-doped shell layer composite cathode material and the preparation method thereof provided by the invention have excellent electrochemical performance and are simple. Researches show that polypyrrole (PPy) has good conductivity and a stable structure, and the polypyrrole can improve the conductivity of the material by coating the polypyrrole on the surface of the lithium iron phosphate, reduce the corrosion of electrolyte and improve the rate performance and long-cycle stability of the lithium iron phosphate.
Therefore, the invention provides a preparation method of a polypyrrole-doped shell layer composite anode material, which comprises the following steps:
(1) mixing a dopant, a pyrrole monomer, carbon-coated lithium iron phosphate and a dispersant to obtain a mixed solution;
(2) and mixing an oxidant and the mixed solution, and then carrying out oxidative polymerization reaction to generate the polypyrrole-doped shell layer composite anode material.
According to the invention, a doping agent, a pyrrole monomer, carbon-coated lithium iron phosphate and a dispersing agent are mixed to obtain a mixed solution.
As a preferred scheme, the doping agent and the pyrrole monomer are dispersed in the dispersing agent, and then the carbon-coated lithium iron phosphate is added to obtain the mixed solution.
The carbon-coated lithium iron phosphate provided by the invention is prepared from a commercially available product.
In the invention, the dopant is preferably one or more of sodium p-toluenesulfonate, sodium benzenesulfonate, sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid, and is further preferably sodium p-toluenesulfonate. The dopant of the present invention can improve the conductivity of the material.
In the present invention, the dispersant is preferably methanol, ethanol, or acetone, and more preferably ethanol. The invention has no special requirement on the dosage of the dispersant, and can disperse uniformly.
In the invention, the doping agent, the pyrrole monomer and the carbon-coated lithium iron phosphate are preferably dispersed in the dispersing agent in a stirring manner.
After the mixed solution is obtained, the oxidant and the mixed solution are mixed for oxidation polymerization reaction to generate the polypyrrole-doped shell layer composite anode material.
In the present invention, the oxidizing agent is preferably dissolved in the solvent to prepare an oxidizing agent solution, and then the oxidizing agent solution is added to the mixed solution.
In the present invention, the oxidizing agent is preferably one of ferric chloride, ammonium superphosphate, hydrogen peroxide, and potassium iodate, more preferably ferric chloride, and still more preferably ferric chloride hexahydrate.
In the present invention, the solvent is preferably ethanol, acetone, or methanol, and more preferably ethanol. The invention has no special requirement on the dosage of the solvent and can be dissolved.
In the present invention, the oxidizing agent solution is preferably added dropwise to the mixed solution, and more preferably dropwise.
The polypyrrole/polypyrrole composite material is prepared by adding a pyrrole monomer and an oxidant into a mixed solution, then instantly initiating an oxidative polymerization reaction, and having a fast reaction speed.
In the invention, the mass ratio of the dopant, the pyrrole monomer and the oxidant is preferably (1-3): 1:1.5, more preferably (1.5 to 2.5): 1:1.5, still more preferably 2:1: 1.5.
in the invention, the mass ratio of the pyrrole monomer to the carbon-coated lithium iron phosphate is preferably (1-10): preferably 100, more preferably (3-7): 100, and still more preferably 6: 100.
In the present invention, the time for the oxidative polymerization reaction is preferably 3 to 8 hours, more preferably 4 to 6 hours, and still more preferably 5 hours.
In the present invention, the oxidative polymerization is preferably carried out under ice bath conditions.
According to the invention, after the oxidative polymerization reaction is finished, the obtained mixed system is preferably subjected to suction filtration and drying in sequence.
In the present invention, it is preferable that the substance after suction filtration is washed and then dried, and the washing liquid for washing is preferably ethanol.
In the present invention, the number of washing is preferably 1 to 3, and more preferably 2.
In the invention, the drying temperature is preferably 50-80 ℃, and more preferably 60 ℃; the drying time is preferably 8-12, and more preferably 10 h.
In the present invention, the drying is performed in a vacuum drying oven.
The invention also provides a polypyrrole-doped shell layer composite positive electrode material (PPy-L FP), which takes lithium iron phosphate as a core and takes a polypyrrole-doped carbon layer as a shell.
The polypyrrole-doped shell composite cathode material and the preparation method thereof provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1
In this example, sodium p-toluenesulfonate, pyrrole monomer and FeCl were taken in a mass ratio of 2:1:1.53·6H2O, firstly dispersing sodium p-toluenesulfonate and a pyrrole monomer in ethanol, stirring, then adding the carbon-coated lithium iron phosphate into the solution according to the mass ratio of the pyrrole monomer to the carbon-coated lithium iron phosphate of 6:100, and continuously stirring to obtain a mixed solution; then FeCl is added3·6H2Dissolving O in ethanol to prepare ferric chloride solution, dropwise adding the ferric chloride solution into the mixed solution under the ice bath condition, reacting for 5 hours, finally performing suction filtration, washing the solid substance subjected to suction filtration with ethanol for 2 times, and then drying the solid substance in a vacuum drying oven at 60 ℃ for 10 hours to obtain PPy-L FP., wherein the coating amount of polypyrrole in the PPy-L FP material prepared by the embodiment is 5.2% by thermogravimetric analysis.
Example 2
In this example, sodium benzenesulfonate, pyrrole monomer and FeCl were taken in a mass ratio of 1:1:1.53·6H2O, firstly dispersing sodium benzenesulfonate and a pyrrole monomer in acetone, stirring, then adding carbon-coated lithium iron phosphate into the solution according to the mass ratio of the pyrrole monomer to the carbon-coated lithium iron phosphate of 3:100, and continuously stirring to obtain a mixed solution; then FeCl is added3·6H2Dissolving O in ethanol to prepare ferric chloride solution, dropwise adding the ferric chloride solution into the mixed solution under the ice bath condition, reacting for 6 hours, finally performing suction filtration, washing the solid substance subjected to suction filtration by using ethanol for 1 time, and then drying the solid substance in a vacuum drying oven at 50 ℃ for 12 hours to obtain PPy-L FP., wherein the coating amount of polypyrrole in the PPy-L FP material prepared by the embodiment is 2.3% by adopting a thermogravimetric analysis method.
Example 3
In this example, according to a mass ratio of 2.5:1:1.5, sodium dodecyl benzene sulfonate, a pyrrole monomer and ammonium superphosphate are taken, firstly, the sodium dodecyl benzene sulfonate and the pyrrole monomer are dispersed in methanol and stirred, then, carbon-coated lithium iron phosphate is taken according to a mass ratio of 10:100 of the pyrrole monomer and the carbon-coated lithium iron phosphate and is added into the solution and is continuously stirred to obtain a mixed solution, then, the ammonium superphosphate is dissolved in ethanol to obtain an ammonium superphosphate solution, the ammonium superphosphate solution is dropwise added into the mixed solution under an ice bath condition to react for 8 hours, finally, after suction filtration, the solid matter after suction filtration is washed with ethanol for 3 times, and then, the solid matter is dried in a vacuum drying box at 80 ℃ for 8 hours to obtain PPy-L FP., and the coating amount of polypyrrole in the PPy-L FP material prepared in this example is 8.5% by thermogravimetric analysis.
Experimental example 1
The test is carried out on the discharge capacity of the L FP material and the PPy-L FP materials prepared in the examples 1 to 3 when the materials are cycled for 500 times under 1C, from the graph shown in FIG. 1, the cycle performance of the L FP material is the worst, and the PPy-L FP materials prepared in the examples 1 to 3, of which the polypyrrole doping amounts are 5.2%, 2.3% and 8.5%, respectively, have better stability and higher discharge capacity, wherein the PPy-L FP material with the polypyrrole doping amount of 5.2% is the best, from the graph, the PPy-L FP material with the polypyrrole doping amount of 2.3% is higher, but the PPy-L FP material with the polypyrrole doping amount of 5.2% has better stability, but the discharge capacity is not as good as the PPy-L FP material with the polypyrrole doping amount of 8.5%, so that the PPy-L FP material prepared in the example 1 of the invention has the best discharge capacity of 5.2% and has the better stability as well as the PPy-L FP material with the polypyrrole doping amount of 5.2% and the optimal discharge capacity.
Experimental example 2
According to the result of experiment 1, this experimental example carried out the structural analysis of the PPy-L FP material with 5.2% polypyrrole doping amount prepared in example 1 of the present invention.
FIG. 2 is a Scanning Electron Microscope (SEM) image of L FP and PPy-L FP, and it can be seen from FIG. 2a that L FP is a rod-shaped structure with a length of 400-500 nm, and the material after polypyrrole doping modification still has a rod-shaped structure (FIG. 2b), and the morphology has no obvious change, which indicates that the polypyrrole doping shell layer has no obvious influence on the morphology of L FP material.
FIG. 3 is an infrared spectrum of PPy-L FP of 1233cm in PPy-L FP-1And 1385cm-1The peak is respectively the stretching vibration peak of C ═ N and C-N, 1561cm-1The absorption peak is caused by the vibration of C-C in the pyrrole ring. The existence of the polypyrrole is proved by the existence of characteristic peaks such as C-C, C-N, C ═ N and the like.
FIG. 4 is a High Resolution Transmission Electron Microscope (HRTEM) and high angle annular dark field scanning transmission electron microscope (HAADF-STEM) image of L FP and PPy-L FP, wherein a carbon coating layer with a thickness of 3nm is formed on the L FP surface as seen in FIG. 4a, and a mixed coating layer of polypyrrole and carbon with a thickness of 7nm is formed on the PPy-L FP surface as seen in FIG. 4d, and the structure is more compact, FIG. 4(b-c) shows that the L FP material is an olivine structure with regular arrangement, and FIG. 4(e-f) shows that the crystal structure of lithium iron phosphate is not changed by doping polypyrrole after modification.
Experimental example 3
In the experiment, a high-resolution transmission electron microscope (HRTEM) and a high-angle annular dark field scanning transmission electron microscope (HAADF-STEM) are used to explore the crystal structure change of L FP and PPy-L FP prepared in example 1 in an atomic scale in a circulation process under 1C, from fig. 5a, an amorphous phase of 30nm appears on the surface of L FP, fig. 5b corresponds to an amorphous region of the outermost layer in ferrous phosphate after reaction, fig. 5g corresponds to Fourier transform (FTT) of the outermost layer, further proves that the outermost layer is an amorphous phase, fig. 5C corresponds to an amorphous and olivine mixed region of the secondary layer, fig. 5h corresponds to Fourier transform (FTT) of the secondary layer, and can show that the crystallinity is poor, further proves that the amorphous and amorphous mixed region is a crystalline state, the olivine lithium phosphate is a one-dimensional lithium ion transmission channel, the diffusion coefficient of lithium ions is low, after L FP material is circulated under 1C for 500 times, the surface of the olivine structure is changed into a lithium ion diffusion channel, further, the lithium diffusion coefficient is further reduced, and the electrochemical corrosion inhibition of the growth of the PPy-6 FP is still shown in a mixed crystal structure of FP, and the electrochemical corrosion of PPy-6F is improved in a diagram of a mixed electrolyte solution containing no electrolyte, which is shown that the FP, and a mixed electrolyte is improved by a little FP, and a little more excellent electrochemical corrosion inhibition effect is shown in fig. 3 f is shown in fig. 5 f is shown in fig. 3 f.
Experimental example 4
After the cycle of experimental example 1, the L FP and the negative electrode with 5.2% of polypyrrole doping amount of PPy-L FP were subjected to electron microscope scanning, as shown in fig. 6, it can be seen that the solid electrolyte film (SEI) film on the surface of the lithium negative electrode corresponding to L FP chaps, while the surface of the lithium negative electrode corresponding to PPy-L FP is still smooth and flat.
According to the embodiment, the polypyrrole is doped in the carbon shell of the existing carbon-coated lithium iron phosphate, the original rod-shaped structure and olivine structure of the lithium iron phosphate are still maintained, the surface coating layer can be more compact, the lithium iron phosphate anode can be effectively prevented from being corroded by electrolyte in the circulation process, the crystal structure is damaged irreversibly, a smooth and flat SEI film is formed on the cathode, and the electrochemical performance of the battery is further improved.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (9)

1. A preparation method of a polypyrrole-doped shell layer composite positive electrode material is characterized by comprising the following steps:
(1) mixing a dopant, a pyrrole monomer, carbon-coated lithium iron phosphate and a dispersant to obtain a mixed solution;
(2) and mixing an oxidant and the mixed solution for oxidation polymerization reaction to generate the polypyrrole-doped shell layer composite anode material.
2. The preparation method of the polypyrrole-doped shell composite cathode material of claim 1, wherein the mass ratio of the dopant, the pyrrole monomer and the oxidant is (1-3): 1: 1.5.
3. the preparation method of the polypyrrole-doped shell layer composite positive electrode material of claim 1, wherein the mass ratio of the pyrrole monomer to the carbon-coated lithium iron phosphate is (1-10): 100.
4. the preparation method of the polypyrrole-doped shell composite cathode material of claim 1 or 2, wherein the dopant is one or more of sodium p-toluenesulfonate, sodium benzenesulfonate, sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid.
5. The preparation method of the polypyrrole-doped shell composite positive electrode material of claim 1 or 2, wherein the dispersant is methanol, ethanol or acetone.
6. The method for preparing the polypyrrole-doped shell composite positive electrode material according to claim 1 or 2, wherein the oxidant is one of ferric chloride, ammonium superphosphate, hydrogen peroxide and potassium iodate.
7. The preparation method of the polypyrrole-doped shell layer composite positive electrode material of claim 1, wherein the oxidative polymerization reaction is carried out for 3-8 hours under an ice bath condition.
8. The preparation method of the polypyrrole-doped shell composite positive electrode material of claim 1 or 7, wherein after the oxidative polymerization reaction is completed, the obtained mixed system is sequentially subjected to suction filtration and drying to obtain the polypyrrole-doped shell composite positive electrode material.
9. The polypyrrole-doped shell layer composite positive electrode material prepared by the preparation method of the polypyrrole-doped shell layer composite positive electrode material disclosed by any one of claims 1 to 8 is characterized in that the polypyrrole-doped shell layer composite positive electrode material takes lithium iron phosphate as a core and takes a polypyrrole-doped carbon layer as a shell.
CN202010301089.0A 2020-04-16 2020-04-16 Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof Pending CN111509203A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010301089.0A CN111509203A (en) 2020-04-16 2020-04-16 Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010301089.0A CN111509203A (en) 2020-04-16 2020-04-16 Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof

Publications (1)

Publication Number Publication Date
CN111509203A true CN111509203A (en) 2020-08-07

Family

ID=71864809

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010301089.0A Pending CN111509203A (en) 2020-04-16 2020-04-16 Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111509203A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112271293A (en) * 2020-08-14 2021-01-26 安徽德亚电池有限公司 Preparation method of high-conductivity lithium iron phosphate cathode material

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4847115A (en) * 1987-08-10 1989-07-11 Rockwell International Corporation Chemical synthesis of conducting polypyrrole using uniform oxidant/dopant reagents
US20160055984A1 (en) * 2014-08-21 2016-02-25 Council Of Scientific & Industrial Research P-toluenesulfonate doped polypyrrole/carbon composite electrode and a process for the preparation thereof
CN106044736A (en) * 2016-06-01 2016-10-26 河南工程学院 Preparing method of iron-phosphate-and-nitrogen-doping-modified graphene lithium iron phosphate

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4847115A (en) * 1987-08-10 1989-07-11 Rockwell International Corporation Chemical synthesis of conducting polypyrrole using uniform oxidant/dopant reagents
US20160055984A1 (en) * 2014-08-21 2016-02-25 Council Of Scientific & Industrial Research P-toluenesulfonate doped polypyrrole/carbon composite electrode and a process for the preparation thereof
CN106044736A (en) * 2016-06-01 2016-10-26 河南工程学院 Preparing method of iron-phosphate-and-nitrogen-doping-modified graphene lithium iron phosphate

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YUN-HUI HUANG等: "High-Rate LiFePO4 Lithium Rechargeable Battery Promoted by Electrochemically Active Polymers", 《CHEMISTRY OF MATERAILS》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112271293A (en) * 2020-08-14 2021-01-26 安徽德亚电池有限公司 Preparation method of high-conductivity lithium iron phosphate cathode material

Similar Documents

Publication Publication Date Title
Zhang et al. Ultra-high mass-loading cathode for aqueous zinc-ion battery based on graphene-wrapped aluminum vanadate nanobelts
CN108598390B (en) Preparation method of positive electrode material for lithium-sulfur battery and lithium-sulfur battery
CN109326784B (en) Phosphorus doped MoS2Preparation method and application of loaded graphene nanosheet
CN110212192A (en) A kind of adjustable nano ferriferrous oxide composite material and preparation method of cladding carbon layers having thicknesses and application
CN108598405B (en) Preparation method of three-dimensional graphene tin oxide carbon composite negative electrode material
CN109802127B (en) Preparation method of silver-doped ferroferric oxide nano composite material
US11664494B2 (en) Composite material including selenium, method of fabricating the same, lithium ion and lithium selenium secondary batteries including the same, and lithium ion capacitor including the same
CN114512653A (en) Preparation method of nitrogen-doped MXene-loaded molybdenum disulfide composite material, product and application of product
CN114122394B (en) Polyoxazine material and preparation method and application thereof
CN111509203A (en) Polypyrrole-doped shell layer composite positive electrode material and preparation method thereof
CN113782718A (en) High-voltage lithium ion battery material, lithium ion battery and preparation method thereof
CN110783549B (en) Polypyrrole-coated sulfur-doped cobalt-based carbon nanocage material, and preparation method and application thereof
Cai et al. Hydrothermal synthesis of β-MnO 2 nanorods for highly efficient zinc-ion storage
CN115259222B (en) Intercalation vanadate composite nano material and preparation method and application thereof
CN113921812B (en) Ultra-high power density sodium ion battery and preparation method thereof
CN114464787A (en) Lithium-sulfur battery positive electrode material coated with emeraldine-based polymer in multi-dimensional mode and preparation method of lithium-sulfur battery positive electrode material
CN114256459A (en) Fluoro-mixed ferric manganese sodium pyrophosphate binary positive electrode material, preparation method and application thereof in sodium ion battery
CN114204030A (en) Modification method of lithium ferric manganese phosphate positive electrode material
CN113903915A (en) Preparation method of graphene-coated porous lead oxide-lead sulfide composite material
CN113991096A (en) Vanadium pentoxide nanobelt with hydrogen bond network and preparation and application thereof
CN113346081A (en) Method for preparing carbon-coated ternary cathode nano material by alkyne oxidation
CN108305992B (en) Carbon-coated lithium ion battery electrode material and preparation method thereof
CN114050266B (en) Selenium disulfide composite nitrogen-doped reduced graphene oxide positive electrode material, preparation method thereof, lithium-selenium disulfide battery and power-related equipment
CN115744989B (en) Alpha-MoO3Nanobelt, preparation method and energy storage application of nanobelt in proton battery
CN116564717B (en) Bi-based composite electrode material, preparation method and application 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
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200807