CN109004229B - Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery - Google Patents

Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery Download PDF

Info

Publication number
CN109004229B
CN109004229B CN201810877700.7A CN201810877700A CN109004229B CN 109004229 B CN109004229 B CN 109004229B CN 201810877700 A CN201810877700 A CN 201810877700A CN 109004229 B CN109004229 B CN 109004229B
Authority
CN
China
Prior art keywords
additive
lithium ion
positive electrode
electrode material
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.)
Active
Application number
CN201810877700.7A
Other languages
Chinese (zh)
Other versions
CN109004229A (en
Inventor
曾丹黎
张斌
孙玉宝
陈奇
刘光鹏
张俊峰
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.)
China University of Geosciences
Original Assignee
China University of Geosciences
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 China University of Geosciences filed Critical China University of Geosciences
Priority to CN201810877700.7A priority Critical patent/CN109004229B/en
Publication of CN109004229A publication Critical patent/CN109004229A/en
Application granted granted Critical
Publication of CN109004229B publication Critical patent/CN109004229B/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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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)
  • Composite Materials (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

The invention relates to a lithium ion battery anode material additive, an anode material thereof and a lithium ion secondary battery, belonging to the technical field of electrochemistry. The additive of the positive electrode material of the lithium ion battery is a conductive polymer monomer unit containing carboxyl, the additive is lithiated and then is prepared into slurry together with a binder, a conductive agent and an active material, and then an electrode plate is prepared to assemble the battery. The additive can carry out in-situ electrochemical polymerization in the battery through the charging and discharging process to form a positive electrode system with a more stable structure. The additive can introduce a conductive polymer containing high-concentration carboxyl in situ in the battery, and the lithium iron phosphate button battery assembled by the additive has small impedance, higher specific capacity, better rate performance and cycling stability, and good application prospect.

Description

Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery
Technical Field
The invention belongs to the technical field of electrochemistry, and particularly relates to an additive of a lithium ion battery positive electrode material, a positive electrode material coated by a conductive polymer through in-situ polymerization of the additive, and a lithium ion secondary battery prepared from the positive electrode material.
Background
Lithium ion batteries have high energy density, high efficiency, relatively light weight and convenient carrying, thereby becoming a main power source of consumer electronic products. Great efforts are put into both academic circles and industrial circles to further improve the performance of the lithium ion battery so as to meet the requirements of all-electric automobiles, military fields and space fields in future. Although many new electrode materials having high capacity and high rate performance have been developed, the performance of the battery is still limited by the conventional binder. The lack of mechanical bonding between the mixtures of conductive phases and random distribution results in electron transport bottlenecks and poor contact preventing effective contact to the cell components. For an ideal electrode, each active particle should be reasonably shaped, dispersed and connected to a current collector and a solid or liquid electrolyte with low resistance and continuous internal pathways. Therefore, the development of new binder systems that can facilitate electron and ion transport, provide mechanical adhesion and flexibility, enhance surface compatibility, and improve active particle dispersion is particularly important for next generation high energy, high power lithium ion batteries.
Conventional binders exhibit more serious problems when used in ultra-high capacity electrodes with large volume changes in electrochemical processes. These electrode materials tend to produce much higher stresses than graphite, resulting in electrode cracking and delamination. As an improvement over the design of traditional bi-component binders, polymers with high concentrations of carboxyl groups such as carboxymethylcellulose (CMC), poly (acrylic acid) (PAA) and alginates have been investigated as new polymer binders in recent years. These polymers modify the surface of active particles by establishing chemical bonds to promote the formation of a stable solid electrolyte interface film (SEI) between phases and provide a high elastic modulus to accommodate volume changes, thereby greatly improving the stability of high capacity electrodes.
Carbon additives are still very important in two-component binder systems to improve the electrical conductivity of the positive electrode material. Accordingly, one-part multifunctional binder systems based on conductive polymers have recently been proposed and studied because they can enhance electron conductance and have advantages of conventional polymers, and thus can be used as conductive additives and binder components. Different strategies have been developed to change their properties and to give them other new functionalities. Multifunctional binders are designed by molecular modification, in which different functional groups are introduced onto the conducting polymer backbone to achieve functions such as tunable conductivity, mechanical adhesion, and electrolyte absorption.
According to the above characteristics, a conductive polymer containing a high concentration of carboxyl functional groups can be studied as an electrode multifunctional binder. General mass synthesis ofThe polymer is prepared by chemical oxidation method using common oxidant such as ferric ion (Fe)3+) Peroxosulfate radical (S)2O8 2-) Etc., which requires the use of large amounts of oxidizing agents (such as FeCl)3Generally 4 times equivalent) and the yield is not high, lacking some practicality. In addition, impurity ions are inevitably introduced in the method, and the impurity ions are not easy to remove, so that the performance of the battery is influenced to a certain degree. Electrochemical polymerization is also a method for synthesizing conductive macromolecules, and the method has the advantages of rapid reaction, no introduction of other metal ions, high purity of the prepared conductive macromolecules, complex operation, large amount of supporting electrolytes and high-purity solvents, low yield and efficiency due to the fact that the polymers are only deposited on the surface of an electrode, and unsuitability for large-scale preparation.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a novel positive electrode additive, and a positive electrode material coated by a conductive high molecular polymer can be obtained by in-situ electrochemical polymerization. In addition, the invention also comprises the method for introducing the conductive high molecular polymer containing high-concentration carboxyl into the lithium ion electrode material, the cathode material prepared by the method and the lithium ion battery thereof.
In a common lithium ion secondary battery system, the charge/discharge voltage of a positive electrode active material (for example, lithium iron phosphate, lithium manganate, lithium cobaltate, ternary material, etc.) is usually 2.5 to 4.5V (with respect to Li)+Li) which corresponds exactly to the voltage range for electrochemical oxidative polymerization of conjugated units of conductive polymers such as thiophene, aniline, pyrrole, etc. and their substitutes. Thus, the charging and discharging process of the battery provides the necessary conditions for electrochemical polymerization of such conjugated units. The method is characterized in that micromolecular conjugated monomers are added in the preparation process of the positive electrode slurry, in-situ electrochemical polymerization is carried out in the charging and discharging process of the battery to prepare the conductive polymer for coating and bonding of the active material, and the strategy of in-situ polymerization is different from that of directly adding polymers outside, so that more effective polymer coating and more stable electrode structure can be realized.
In a first aspect of the invention, an additive for a positive electrode material of a lithium ion battery is provided, wherein the additive is a conjugated unit capable of electrochemical polymerization, and the conjugated unit can be subjected to in-situ electrochemical polymerization in the battery.
Further, the conjugated unit in the above technical scheme is any one of thiophene, pyrrole heterocyclic conductive polymer monomers or benzene, aniline, alkylbenzene, and alkoxybenzene aromatic conductive polymer monomers, and the structural formula of the conjugated unit is represented by a general formula one, a general formula two, or a general formula three in formula one.
Further, the conductive polymer monomer in the above technical solution contains one carboxyl group or a plurality of carboxyl groups.
Figure BDA0001753697500000031
Further preferably, the conductive polymer monomer in the above technical solution is preferably any one of 3-thiopheneacetic acid, N-pyrrolepropionic acid, and 3-pyrrolecarboxylic acid (see examples 1 to 4), and the structures thereof are respectively represented by A, B, C, D in formula two:
Figure BDA0001753697500000032
in a second aspect of the present invention, there is provided a method for preparing a positive electrode material for a lithium ion battery, comprising the above additive, the method comprising the steps of:
(1) lithiation of conductive polymer monomer: reacting carboxyl groups in the conductive polymer monomer with lithium hydroxide (LiOH) according to a ratio of 1: lithiating in solvent water in a mass ratio of 0.9, and evaporating the solvent after the lithiation reaction is finished to prepare a conductive polymer monomer subjected to carboxyl lithiation;
(2) preparing a positive electrode material from an active material, conductive C powder, a binder and an additive, and assembling electrode plates into the button cell. Wherein: the additive is a conductive polymer monomer after carboxyl lithiation prepared in the step (1).
Further, according to the technical scheme, the content of the additive is 1-10% based on the total weight of the cathode material.
Furthermore, the content of the additive in the technical scheme is 5%.
Preferably, in the above technical scheme, the active material is lithium iron phosphate (LiFePO)4) The conductive C powder is acetylene black, and the binder is polyvinylidene fluoride (PVDF).
Further preferably, the mass ratio of the lithium iron phosphate to the acetylene black to the polyvinylidene fluoride to the additive in the technical scheme is 70:20:5: 5.
And carrying out electrochemical in-situ polymerization on the conductive polymer monomer under the voltage condition of 2.5-4.3V to obtain the conductive polymer coated positive electrode material. The reaction process is shown in figure 1.
In a third aspect of the present invention, a lithium ion secondary battery is provided, where the lithium ion secondary battery includes a positive electrode material, a negative electrode material, an electrolyte, a diaphragm, and a battery case, and the positive electrode material is the above-mentioned positive electrode material of the lithium ion secondary battery.
Compared with the prior art, the invention has the following beneficial effects:
(1) the conductive polymer is prepared by carrying out in-situ electrochemical polymerization on an additive under a certain potential on a lithiated conductive polymer monomer (the additive disclosed by the invention). The method for introducing the conductive polymer is simple and easy to operate, and overcomes the defect that the performance of the battery is reduced because the conductive polymer binder synthesized by the traditional chemical oxidation method contains impurity ions.
(2) The conductive polymer can realize in-situ coating of the active material, and simultaneously can play a role in bonding, so that the electrode structure is more stable, and the multiplying power and the cycle performance of the battery are facilitated.
(3) Due to the existence of the lithium carboxylate and the characteristics of the conductive polymer, the in-situ polymerized material can not only conduct lithium ions, but also conduct electrons, so that the lithium ion battery containing the additive can obtain more efficient ion/electron transmission;
(4) compared with a lithium ion battery without the additive, the lithium ion battery assembled by the additive has the advantages of smaller battery impedance, higher specific discharge capacity, better rate capability, better cycle stability and more excellent comprehensive performance;
(5) the additive, especially the lithium iron phosphate button cell added with 3-thiophene malonic acid, has higher capacity, better rate performance and cycling stability;
(6) the lithium ion battery assembled by the additive has excellent comprehensive performance, can be applied to portable handheld electronic products or electric vehicles, and has good market prospect.
Drawings
FIG. 1 is a diagram of the lithiation and reaction process of the additive of example 1 of the present invention: lithiating 3-thiophene malonic acid to obtain 3-thiophene malonic acid dilithium (3TPMALI), and then assembling the battery and carrying out electrochemical polymerization in the charging and discharging processes of the battery.
FIG. 2 is a comparison graph of cyclic voltammograms of the lithium ion batteries manufactured in example 1 and comparative example 1 of the present invention at a sweep rate of 0.5 mV/s.
Fig. 3 is a graph comparing impedance curves of lithium ion batteries manufactured in example 1 and comparative example 2 of the present invention before battery cycling.
Fig. 4 is a graph comparing impedance curves of the lithium ion batteries manufactured in example 1 of the present invention and comparative example 2 after battery cycling.
Fig. 5 is a graph showing the rate performance comparison of the lithium ion batteries manufactured in example 1 of the present invention and comparative example 2.
Fig. 6 is a graph comparing the cycle performance at 1C rate of lithium ion batteries manufactured in example 1 of the present invention and comparative example 2.
Detailed Description
The technical solution of the present invention is further explained in detail by the following specific examples and the accompanying drawings. The following embodiments are merely exemplary of the present invention, which is not intended to limit the present invention in any way, and those skilled in the art may modify the present invention in many ways by applying the teachings set forth above to equivalent embodiments with equivalent modifications. Any simple modification or equivalent changes made to the following embodiments according to the technical essence of the present invention, without departing from the technical spirit of the present invention, fall within the scope of the present invention.
Example 1
The embodiment is a lithium ion battery anode material additive, an anode and a lithium secondary battery thereof, wherein the additive is a conductive polymer monomer unit containing high-concentration carboxyl. 3-Thiophenemelanedioic acid (3TPA) was selected for this example and the reaction scheme is shown in FIG. 1.
The lithiation process of the 3-thiophene malonic acid comprises the following specific steps:
lithiation of 3-thiophenedicarboxylic acid: 0.8618g (0.01mol) of 3-thiophene malonic acid and 0.4800g (0.02mol) of lithium hydroxide (LiOH) are lithiated in solvent water for 3 hours, and after the lithiation reaction is finished, the solvent is evaporated to dryness to prepare the 3-thiophene lithium malonate (3 TPMALI).
The preparation steps of the lithium ion battery anode material of the embodiment are as follows:
0.1402g of lithium iron phosphate (LiFePO)4) 0.0401g acetylene black, 0.0103g polyvinylidene fluoride (PVDF) and 0.0102g lithium 3-thiophenecarboxylate (3TPMALI) mentioned above were dissolved in N-methylpyrrolidone (NMP) in proportions of 70 wt%, 20 wt%, 5 wt% and 5 wt% to prepare a slurry, which was coated on an aluminum foil, dried and cut into a circular electrode piece of 15mm diameter.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Electrochemical polymerization: polymerization was performed using cyclic voltammetry. When cyclic voltammetry scanning is carried out at a scanning rate of 0.5mV/s and in a voltage range of 2.5-4.3V, the 3-thiophene lithium malonate (3TPMALI) starts to polymerize at about 3.7V and is completely polymerized at 4.3V.
Comparative example 1
The specific embodiment of the comparative example is that the redox activity of the material itself is explored by assembling a button cell with the above synthesized 3TPMALi as the active material of the positive electrode.
The preparation steps of the lithium ion battery anode material of the comparative example are as follows:
0.0701g of 3TPMALI, 0.0202g of acetylene black and 0.0101g of polyvinylidene fluoride (PVDF) are dissolved in N-methyl pyrrolidone (NMP) according to the proportion of 70 wt%, 20 wt% and 10 wt% to prepare slurry, the slurry is coated on an aluminum foil, and the aluminum foil is dried and cut into a circular electrode plate with the diameter of 15 mm.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Cyclic voltammetry curve testing: and performing cyclic voltammetry scanning at a scanning rate of 0.5mV/s and a voltage range of 2.5-4.3V, wherein the 3TPMALI starts oxidative polymerization at about 3.7V and is completely oxidized and polymerized at 4.3V. The overall process is not redox reversible.
Comparative example 2
The embodiment of this comparative example is a comparison of the redox performance of the iron lithium battery without the addition of the above synthesized 3TPMALi and the iron lithium battery with the addition of the lithium 3-thiophenepropanedioate.
The preparation steps of the lithium ion battery anode material of the comparative example are as follows:
0.0703g of lithium iron phosphate (LiFePO)4) 0.0204g of acetylene black and 0.0103g of polyvinylidene fluoride (PVDF) are dissolved in N-methyl pyrrolidone (NMP) according to the proportion of 70 wt%, 20 wt% and 10 wt% to prepare slurry, and the slurry is coated on an aluminum foil, dried and cut into circular electrode plates with the diameter of 15 mm.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Cyclic voltammetry curve testing: and performing cyclic voltammetry scanning at a scanning rate of 0.5mV/s within a voltage range of 2.5-4.3V, wherein the ferric lithium battery without the addition of 3-thiophene lithium malonate shows a cyclic voltammetry curve of a normal ferric lithium battery.
FIG. 2 is a comparison graph of cyclic voltammograms of the lithium ion batteries manufactured in example 1 and comparative example 1 of the present invention at a sweep rate of 0.5 mV/s. The solid line in fig. 2 is the cyclic voltammetry of the lithium ion battery fabricated in comparative example 1, showing that 3TPMALi starts electrochemical polymerization at around 3.7V and the process is irreversible; in fig. 2, dotted lines are cyclic voltammetry curves of the first and second circles of the lithium ion battery manufactured in example 1, respectively, the first circle of the curve indicates that the battery has an additional oxidation process besides the normal redox curve of the lithium iron phosphate battery, which indicates that electrochemical polymerization occurs in the battery by 3 TPMALi; the second round of the curve indicates that the electrochemical polymerization of 3TPMALi is complete in the first round and the process is not reversible.
Fig. 3 is a graph comparing impedance curves of lithium ion batteries manufactured in example 1 and comparative example 2 of the present invention before battery cycling. It was found by comparison that the battery of example 1 had a smaller diameter, i.e., a smaller charge transfer resistance, than the high frequency region semicircular portion of the battery of comparative example 2 before the battery was cycled. The charge transfer impedance of the battery after the 3TPMALI is added is 34 omega, and the charge transfer impedance of the blank battery is 59 omega, which shows that the charge transfer impedance of the battery can be obviously reduced by adding the 3TPMALI, thereby being beneficial to the transmission of lithium ions during the charge and discharge of the battery, reducing the kinetic limitation of the battery in the working process and optimizing the electrochemical performance.
FIG. 4 is a graph comparing the impedance curves of lithium ion batteries fabricated in example 1 and comparative example 2 of the present invention after battery cycling; after the battery is subjected to a constant current charge and discharge test at a rate of 1C, the charge transfer impedance of the battery in example 1 is also obviously lower than that of the battery in example 2, and the charge transfer impedance of the two batteries is also reduced, possibly because the battery is in an internal component adjustment stage, and the factors guiding the result are the penetration of electrolyte into the electrode, the distribution of electrode materials, the compaction of an electrode structure and the like.
FIG. 5 is a graph comparing the rate performance of lithium ion batteries manufactured in example 1 and comparative example 2 according to the present invention; in the figure, when the multiplying power is 0.2C, 0.5C and 1C, the specific discharge capacity of the battery of the embodiment 1 is obviously higher than that of the battery of the comparison example 2, and the specific discharge capacity is relatively gentle; when the multiplying power is 2C, the discharge specific capacities of the two batteries are obviously reduced; when the multiplying power reaches more than 5C, the specific capacities of the two batteries are obviously attenuated, and the numerical difference of the specific capacities of the two batteries is gradually reduced.
Fig. 6 is a graph comparing the cycle performance at 1C rate of lithium ion batteries manufactured in example 1 of the present invention and comparative example 2. It can be seen from the graph that the first discharge specific capacity of the battery of example 1 was 168mAh g-1While the first discharge specific capacity of the battery of comparative example 2 was 133mAh g-1The first discharge specific capacity of the battery added with 3TPMALI is higher than 35mAhg-1The reason is that the additive accelerates the deintercalation rate of lithium ions during the operation of the battery, so that the electrochemical reaction is more sufficient. The discharge specific capacity is unstable in the first few cycles of the battery introduced with the additive, the main reason is that the battery does not completely enter an activated state, a stable SEI film is not completely formed, and the battery tends to a stable state, a capacity curve becomes stable and a capacity retention rate is stable along with the increase of the number of cycles. After 300 cycles, the specific discharge capacity of the battery with the addition of 3TPMALI is 155mAh g-1The capacity retention rate is 92.3 percent, and the specific discharge capacity of the blank battery is 118mAh g-1The capacity retention rate was 88.7%. The battery using 3TPMALI as the additive has higher specific discharge capacity, reduced capacity attenuation in the circulation process, reduced migration resistance in the process of lithium ion extraction, and reduced damage to the lithium iron phosphate structure, thereby ensuring the specific discharge capacity of the battery.
Example 2
The embodiment is a lithium ion battery anode material additive, an anode and a lithium secondary battery thereof, wherein the additive is a conductive polymer monomer unit containing high-concentration carboxyl, and is specifically prepared by lithiating a 3-thiophene acetic acid monomer to form 3-thiophene lithium acetate and performing electrochemical in-situ polymerization. The structural formula of the 3-thiopheneacetic acid monomer is shown as a formula B in the invention.
The lithiation process of the 3-thiopheneacetic acid monomer is as follows:
lithiation of 3-thiopheneacetic acid monomer: 1.4205g (0.01mol) of 3-thiophene acetic acid monomer and 0.2403g (0.01mol) of lithium hydroxide (LiOH) are dissolved in water for lithiation, the lithiation time is 3 hours, and after the lithiation reaction is finished, the solvent is evaporated to dryness to prepare the 3-thiophene acetic acid monomer.
The preparation steps of the lithium ion battery anode material of the embodiment are as follows:
0.1403g of lithium iron phosphate (LiFePO)4) 0.0404g of acetylene black, 0.0103g of polyvinylidene fluoride (PVDF) and the pyrrole-3-lithium acetate are dissolved in N-methylpyrrolidone (NMP) according to the proportion of 70 wt%, 20 wt%, 5 wt% and 5 wt% to prepare slurry, the slurry is coated on an aluminum foil, and the aluminum foil is dried and cut into a circular electrode slice with the diameter of 15 mm.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Electrochemical polymerization: polymerization was performed using cyclic voltammetry. When cyclic voltammetry scanning is carried out at a scanning rate of 0.5mV/s and in a voltage range of 2.5-4.3V, the pyrrole-3-lithium acetate starts to polymerize at about 3.7V and is completely polymerized at 4.3V. Similar results to example 1.
Example 3
The embodiment is a lithium ion battery anode material additive, an anode thereof and a lithium secondary battery, wherein the additive is a conductive polymer monomer unit containing carboxyl, and is specifically prepared by lithiating an N-pyrrole propionic acid monomer to form lithium N-pyrrole propionate and performing electrochemical in-situ polymerization. The structural formula of the N-pyrrole propionic acid monomer is shown as a formula C.
The lithiation process of the N-pyrrole propionic acid comprises the following specific steps:
lithiation of N-pyrrole propionic acid: 1.3903g (0.01mol) of N-pyrrole propionic acid and 0.2401g (0.01mol) of hydrogen hydroxide are dissolved in water for lithiation, the lithiation time is 3 hours, and after the lithiation reaction is finished, the solvent is evaporated to dryness to prepare the lithium N-pyrrole propionate.
The preparation steps of the lithium ion battery anode material of the embodiment are as follows: 0.1402g of lithium iron phosphate (LiFePO)4) 0.0402g of acetylene black, 0.0104g of polyvinylidene fluoride (PVDF) and the abovementioned lithium 0.0102g N-pyrrolidinopropionate in a ratio of 70 wt%, 20 wt%, 5 wt% and 5 wt%The resulting slurry was dissolved in N-methylpyrrolidone (NMP) to prepare a slurry, coated on an aluminum foil, dried, and cut into a circular electrode sheet having a diameter of 15 mm.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Electrochemical polymerization: polymerization was performed using cyclic voltammetry. And performing cyclic voltammetry scanning at a scanning rate of 0.5mV/s and a voltage range of 2.5-4.3V, wherein the polymerization of the lithium N-pyrrole propionate starts to be completed at about 3.6V and reaches 4.3V. Similar results to example 1.
Example 4
The embodiment is a lithium ion battery anode material additive, an anode thereof and a lithium secondary battery, wherein the additive is a carboxyl-containing conductive polymer monomer unit, and is specifically prepared by lithiating 3-pyrrole carboxylic acid to form lithium 3-pyrrole carboxylate and performing electrochemical in-situ polymerization. The lithiation process of the 3-pyrrole formic acid is specifically as follows:
lithiation of 3-Pyrrolecarboxylic acid: 1.0802g (0.01mol) of 3-pyrrole acetic acid and 0.2402g (0.01mol) of lithium hydroxide are dissolved in water for lithiation, the lithiation time is 3 hours, and after the lithiation reaction is finished, the solvent is evaporated to dryness to prepare the lithium 3-pyrrole formate.
The preparation steps of the lithium ion battery anode material of the embodiment are as follows:
0.1400g of lithium iron phosphate (LiFePO)4) 0.0403g of acetylene black, 0.0102g of polyvinylidene fluoride (PVDF) and 0.0102g of the lithium 3-pyrrolidone formate are dissolved in N-methylpyrrolidone (NMP) according to the proportion of 70 wt%, 20 wt%, 5 wt% and 5 wt% to prepare slurry, the slurry is coated on an aluminum foil, and the aluminum foil is dried and cut into circular electrode plates with the diameter of 15 mm.
Assembling the prepared positive electrode material into a CR2025 button cell, wherein: the negative electrode is a metal lithium sheet, the diaphragm is a polypropylene film (PP film), and the electrolyte solution is 1M LiPF6in EC/DMC(1:1,vol％)。
Electrochemical polymerization: polymerization was performed using cyclic voltammetry. And performing cyclic voltammetry scanning at a scanning rate of 0.5mV/s and a voltage range of 2.5-4.3V, wherein the 3-pyrrole formic acid starts to polymerize at about 3.6V and is completely polymerized at 4.3V. Similar results to example 1.

Claims (9)

1. The additive for the positive electrode material of the lithium ion battery is characterized in that: the additive is a conjugated unit capable of electrochemical polymerization, the conjugated unit being capable of in situ electrochemical polymerization in the cell; wherein: the conjugated unit is any one of thiophene, pyrrole heterocyclic conductive polymer monomers or benzene, aniline, alkylbenzene and alkoxy benzene aromatic conductive polymer monomers, and the structural formula of the conjugated unit is shown as a general formula I, a general formula II or a general formula III in the formula I:
Figure FDA0002947675410000011
2. the lithium ion battery positive electrode material additive according to claim 1, wherein: the conductive polymer monomer contains one carboxyl or a plurality of carboxyl.
3. The lithium ion battery positive electrode material additive according to claim 1, wherein: the conductive polymer monomer is any one of 3-thiophene malonic acid, 3-thiophene acetic acid, N-pyrrole propionic acid and 3-pyrrole formic acid, and the structure of the conductive polymer monomer is respectively represented by A, B, C, D in formula II:
Figure FDA0002947675410000012
4. a method for preparing a positive electrode material of a lithium ion battery containing the additive according to any one of claims 1 to 3, wherein the method comprises the following steps: the method comprises the following steps:
(1) lithiation of conductive polymer monomer: and (3) reacting carboxyl in the additive with lithium hydroxide according to the ratio of 1: lithiating in solvent water in a mass ratio of 0.9, and evaporating the solvent after the lithiation reaction is finished to prepare a conductive polymer monomer subjected to carboxyl lithiation;
(2) preparing an active material, conductive C powder, a binder and the additive lithiated in the step (1) into a positive electrode material, and assembling electrode plates into a button cell;
(3) and (3) charging and discharging the battery prepared in the step (2) for a plurality of times at 2.5-4.3V, so that the conductive polymer monomer, namely the lithiated additive, is subjected to electrochemical in-situ polymerization.
5. The method for preparing the positive electrode material of the lithium ion battery according to claim 4, wherein: based on the total weight of the cathode material, the content of the additive is 1-10%.
6. The method for preparing the positive electrode material of the lithium ion battery according to claim 5, wherein: the content of the additive is 5% based on the total weight of the cathode material.
7. The method for preparing the positive electrode material of the lithium ion battery according to claim 4, wherein: the active material is lithium iron phosphate, the conductive C powder is acetylene black, and the binder is polyvinylidene fluoride.
8. The method for preparing the positive electrode material of the lithium ion battery according to claim 7, wherein: the mass ratio of the lithium iron phosphate to the acetylene black to the polyvinylidene fluoride to the additive is 70:20:5: 5.
9. A lithium ion secondary battery characterized in that: the lithium ion secondary battery comprises a positive electrode material, a negative electrode material, electrolyte, a diaphragm and a battery shell, wherein the positive electrode material is the lithium ion battery positive electrode material prepared by the method of claim 4.
CN201810877700.7A 2018-08-03 2018-08-03 Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery Active CN109004229B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810877700.7A CN109004229B (en) 2018-08-03 2018-08-03 Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810877700.7A CN109004229B (en) 2018-08-03 2018-08-03 Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery

Publications (2)

Publication Number Publication Date
CN109004229A CN109004229A (en) 2018-12-14
CN109004229B true CN109004229B (en) 2021-07-13

Family

ID=64595174

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810877700.7A Active CN109004229B (en) 2018-08-03 2018-08-03 Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery

Country Status (1)

Country Link
CN (1) CN109004229B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110444766B (en) * 2019-08-14 2021-09-21 创普斯(深圳)新能源科技有限公司 Ternary positive pole piece and method for improving high-temperature cycle performance of positive pole piece
CN111029158B (en) * 2019-12-22 2021-12-17 北京蒙京石墨新材料科技研究院有限公司 Lithium ion supercapacitor lithium pre-embedding method
CN111342130A (en) * 2020-03-04 2020-06-26 多氟多新能源科技有限公司 High-voltage-resistant lithium ion battery electrolyte matched with silicon-carbon cathode
CN112615046B (en) * 2020-11-27 2023-11-21 辽宁科技大学 Method for in-situ regulation and control of solid electrolyte interface layer of lithium battery
CN112885985B (en) * 2021-02-01 2022-08-30 中南大学 Positive pole piece and preparation method thereof, electrochemical energy storage device and pre-metallization method of electrochemical energy storage device
CN114420929B (en) * 2021-12-09 2023-11-03 万向一二三股份公司 Preparation method of solid battery containing conductive polymer binder
CN116613321A (en) * 2023-07-18 2023-08-18 宁德时代新能源科技股份有限公司 Composite cathode material, additive, cathode plate, secondary battery and electricity utilization device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466135A (en) * 2014-12-15 2015-03-25 中信大锰矿业有限责任公司大新锰矿分公司 Method for coating conductive polymer on Ni-Co-Mn acid lithium positive electrode material
WO2016169398A1 (en) * 2015-04-22 2016-10-27 北京有色金属研究总院 In-situ crosslinking polymer binder for lithium-ion battery, and electrode manufactured by using same
CN106410165A (en) * 2016-11-30 2017-02-15 荆门市格林美新材料有限公司 Method for coating regenerated nickel-cobalt-manganese ternary battery electrode by in-situ electrochemical polymerization

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466135A (en) * 2014-12-15 2015-03-25 中信大锰矿业有限责任公司大新锰矿分公司 Method for coating conductive polymer on Ni-Co-Mn acid lithium positive electrode material
WO2016169398A1 (en) * 2015-04-22 2016-10-27 北京有色金属研究总院 In-situ crosslinking polymer binder for lithium-ion battery, and electrode manufactured by using same
CN106410165A (en) * 2016-11-30 2017-02-15 荆门市格林美新材料有限公司 Method for coating regenerated nickel-cobalt-manganese ternary battery electrode by in-situ electrochemical polymerization

Also Published As

Publication number Publication date
CN109004229A (en) 2018-12-14

Similar Documents

Publication Publication Date Title
CN109004229B (en) Lithium ion battery positive electrode material additive, positive electrode material thereof and lithium ion secondary battery
CN101699590B (en) Hybrid supercapacitor
CN110429269B (en) High-nickel ternary cathode material coated by polymer blend and preparation method thereof
US20230282836A1 (en) Lithium metal negative electrode plate, electrochemical apparatus, and electronic device
US20050186474A1 (en) Positive electrodes for lithium batteries and their methods of fabrication
US20230127888A1 (en) Secondary battery with improved high-temperature and low-temperature properties
EP4220759A1 (en) Lithium metal negative electrode plate, electrochemical apparatus, and electronic device
CN107507961B (en) Preparation method of conductive polymer modified lithium ion battery positive pole piece
CN111934020B (en) High-pressure-resistant all-solid-state lithium battery interface layer and in-situ preparation method and application thereof
CN110400923B (en) Battery negative electrode material, negative electrode material slurry, negative electrode plate and electrochemical battery
KR101645773B1 (en) Electrode active material slurry and secondary battery comprising the same
CN104170130A (en) Cathode active material composition and lithium secondary battery comprising same
CN115566170A (en) Preparation method of high-energy-density quick-charging lithium ion battery cathode material
CN116314817A (en) Positive pole piece and electrochemical device thereof
CN115411228A (en) Lithium iron manganese phosphate positive plate and preparation method thereof
CN102569724B (en) Preparation method for composite material used for anode of lithium ion battery
CN105845886A (en) Negative electrode material for ion battery and preparation method of negative electrode material
WO2018168520A1 (en) Binder composition for non-aqueous electrolyte batteries, and binder aqueous solution for non-aqueous electrolyte batteries, slurry composition for non-aqueous electrolyte batteries, electrode for non-aqueous electrolyte batteries and non-aqueous electrolyte battery each utilizing said binder composition
CN109167036B (en) TiN and conductive polymer composite modified lithium ion layered ternary positive electrode material and preparation method thereof
CN116364930A (en) Compound additive and electrochemical device using same
CN114456356B (en) Polyperylene tetracarboxylic diimide, preparation method thereof and application thereof in lithium/sodium battery
Zhang et al. Ion-compensation regime between electrolyte and cathode to prepare advanced lithium metal batteries
WO2014006973A1 (en) Electrode for electricity storage devices, electricity storage device using same, and method for producing same
CN112467222B (en) Button secondary battery
CN112952100A (en) Cobalt-free anode material slurry and 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
GR01 Patent grant
GR01 Patent grant