CN107316993B - Preparation method of lithium titanate negative electrode material and lithium titanate negative electrode material prepared by adopting method - Google Patents
Preparation method of lithium titanate negative electrode material and lithium titanate negative electrode material prepared by adopting method Download PDFInfo
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- H01M4/00—Electrodes
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- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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- 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
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Abstract
The invention belongs to the field of energy storage research, and particularly relates to a preparation method of a lithium titanate negative electrode material, which mainly comprises the following steps of 1, dry-mixing a power source substance 1, nano lithium titanate particles and graphite particles until the power source substance, the nano lithium titanate particles and the graphite particles are uniformly mixed; step 2, adding the electrolyte 1 and then continuously mixing to form an ion channel, and stripping graphite particles under the action of a power source substance to form a graphite sheet layer opening structure; under the mixed acting force, the nano lithium titanate particles are continuously filled into the opening structure of the graphite sheet layer; and 3, removing electrolyte components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material. When the method is used for preparing the lithium titanate negative electrode, opening of a graphite particle sheet layer and filling of lithium titanate nano particles can be simultaneously carried out, so that the filling is carried out more smoothly, and the lithium titanate negative electrode material is ensured to have excellent electrochemical performance.
Description
Technical Field
The invention belongs to the technical field of energy storage materials, and particularly relates to a preparation method of a lithium titanate negative electrode material and the lithium titanate negative electrode material prepared by the method.
Background
Since birth, lithium ion batteries have revolutionary changes in the field of energy storage due to their advantages of rapid charging and discharging, good low-temperature performance, large specific energy, small self-discharge rate, small volume, light weight, and the like, and are widely used in various portable electronic devices and electric vehicles. However, with the improvement of living standard of people, higher user experience puts higher requirements on the lithium ion battery: faster charging and discharging (such as 5C or even 10C), wider temperature range (such as minus thirty degrees centigrade), and the like; in order to solve the above problems, it is necessary to find a new electrode material having more excellent properties.
The current commercialized lithium ion battery cathode material is mainly graphite, but cannot meet the urgent needs of users due to low charge and discharge speed (generally, the charge and discharge speed is within 1C) and poor low-temperature performance (generally, the use temperature is above-10 ℃); therefore, development of an anode material having a higher charge/discharge rate and used in a wider temperature range is urgently needed. As a negative electrode material of a lithium ion battery, lithium titanate has been attracting attention: the charge and discharge speed can be more than 10 ℃, and the material still can exert more ideal capacity at the temperature of minus 30 ℃, so the material is one of the optimal choices of the new generation of fast-charging anode materials.
However, the lithium titanate material particles have poor conductivity, so that the internal resistance of the battery after the battery is assembled is high, and gas is easily generated in the charging and discharging process, so that the use of the battery is influenced, and the wider application of the battery is limited. In order to solve the problems, the prior art mainly comprises the steps of nano-crystallization of lithium titanate particles, addition of a conductive material with excellent conductive performance into lithium titanate material particles and the like so as to improve the conductive performance of the whole particles of the lithium titanate material; meanwhile, the coating technology is adopted, so that the problem of gas generation in the process of using the material after being prepared into a battery is solved.
However, the lithium titanate particles with the nano structure are easy to agglomerate and have high dispersion difficulty; the commonly used conductive agent materials are generally small in size (nanometer), large in specific surface area and difficult to disperse. However, in order to maximize the conductive effect of the conductive agent and to prepare a lithium titanate secondary particle material with better performance, it is necessary to ensure that the nano lithium titanate particles and the conductive agent are uniformly dispersed. Meanwhile, the contact area between the nano-structure lithium titanate material and the conductive agent is small, and the gap is large, so that the contact resistance is relatively large, the nano-structure lithium titanate material is easy to contact with an electrolyte to generate gas, the prepared battery has high internal resistance, and the gas production rate is larger in the using process, so that the electrochemical performance of the lithium titanate negative electrode material is influenced.
In view of the above, there is a need for a lithium titanate negative electrode material and a preparation method thereof, which can uniformly disperse two materials (nano lithium titanate particles and conductive networks) with high dispersion difficulty, and ensure that the two materials are tightly connected together, thereby preparing a lithium titanate negative electrode material with excellent performance.
Disclosure of Invention
The invention aims to: aiming at the defects of the prior art, the preparation method of the lithium titanate negative electrode material mainly comprises the following steps of 1, dry-mixing a power source substance 1, nano lithium titanate particles and graphite particles until the power source substance, the nano lithium titanate particles and the graphite particles are uniformly mixed; step 2, adding the electrolyte 1 and then continuously mixing to form an ion channel, and stripping graphite particles under the action of a power source substance to form a graphite sheet layer opening structure; under the mixed acting force, the nano lithium titanate particles are continuously filled into the opening structure of the graphite sheet layer;
or
Step 1', uniformly mixing nano lithium titanate particles, graphite particles and electrolyte 2 for later use; step 2 ', assembling the power source substance 2 and the product obtained in the step 1' into paired electrodes, applying current between the two electrodes, and stripping graphite particles to form a graphite sheet layer opening structure; then, continuously filling nano lithium titanate particles into the opening structure of the graphite sheet layer;
and 3, removing electrolyte components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material.
When the method is used for preparing the lithium titanate negative electrode, opening of a graphite particle sheet layer and filling of lithium titanate nano particles can be simultaneously carried out, so that the filling is carried out more smoothly, and the lithium titanate negative electrode material is ensured to have excellent electrochemical performance.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a lithium titanate negative electrode material mainly comprises the following steps:
step 1, dry-mixing a power source substance 1, nano lithium titanate particles and graphite particles until the power source substance, the nano lithium titanate particles and the graphite particles are uniformly mixed;
step 2, adding the electrolyte 1 and then continuously mixing to form an ion channel, and stripping graphite particles under the action of a power source substance to form a graphite sheet layer opening structure; under the mixed acting force, the nano lithium titanate particles are continuously filled into the opening structure of the graphite sheet layer;
or
Step 1', uniformly mixing nano lithium titanate particles, graphite particles and electrolyte 2 for later use;
step 2 ', assembling the power source substance 2 and the product obtained in the step 1' into paired electrodes, applying current between the two electrodes, and stripping graphite particles to form a graphite sheet layer opening structure; then, continuously filling nano lithium titanate particles into the opening structure of the graphite sheet layer;
and 3, removing electrolyte components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material.
As an improvement of the preparation method of the lithium titanate negative electrode material, the power source substance 1 in the step 1 is a pre-lithium-intercalation negative electrode material (such as lithium-intercalation graphite, a lithium-intercalation silicon-based material, a lithium-rich material and the like) or/and a metallic lithium material.
As an improvement of the preparation method of the lithium titanate negative electrode material, in the step 2, the electrolyte 1 comprises a solute and a solvent, and the solvent comprises a graphite intercalation or/and stripping functional component; in the step 1', the electrolyte 2 comprises a solute and a solvent, and the solvent comprises a graphite intercalation or/and exfoliation functional component.
As an improvement of the preparation method of the lithium titanate negative electrode material, the solute is a lithium ion battery electrolyte solute; the solvent contains at least one of alkali metal elements, alkaline earth metal elements, metal chlorides (such as ZrCl4, CrCl3, CoCl3 and the like), chlorides (such as MoF6, WF6 and the like), rare earth elements (such as Sm, Eu, Tm, Yb and the like), halogen elements (such as F, Cl and the like), pseudohalogens (such as Br2, ICl, IF5 and the like), strong acids (such as H2SO4, HNO3 and the like) and propylene carbonate.
As an improvement of the preparation method of the lithium titanate negative electrode material, the power source substance 2 in the step 2' comprises a lithium-rich substance or/and a metal substance as an electrode material; the lithium-rich material comprises LiM1O2、LiMn2-XM2xO4、LiNixM31-xO2、Li3-xM4xN、LiFePO4、Li2FeO4、Li7-xMnxN4、Li3-xFexN2、Li2S、Li2S2And LiNixMnyCozO2Wherein M1 is at least one of Co, Ni, Mn and Cu, at least one of Cr and Fe, M2 is at least one of Ni, Co, Cu, Cr, Fe and V, M3 is at least one of Co, Mn, Cu, Cr, Fe, V, La, Al, Mg, Ga and Zn, M4 is at least one of Co, Ni, Cu, Cr and V, x + y + z is 1, and x, y and z are not less than zero; the metal substance used as the electrode material comprises at least one of metal lithium, metal sodium, metal potassium, metal magnesium, metal aluminum and metal zinc.
As an improvement of the preparation method of the lithium titanate negative electrode material, a surface active substance, a conductive agent component and non-lithium titanate negative electrode nano-particles (which are not required to be stripped by a power source substance) can be added in the step 1 or the step 1';
as an improvement of the preparation method of the lithium titanate negative electrode material, the surfactant comprises at least one of a wetting agent, a dispersing agent, a penetrating agent, a solubilizer, a cosolvent and a cosolvent; the conductive agent component comprises at least one of super conductive carbon, acetylene black, carbon nano tubes, Ketjen black and conductive carbon black; the non-lithium titanate negative electrode nano-particles comprise at least one of natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, petroleum coke, carbon fibers, pyrolytic resin carbon, silicon carbon negative electrode materials and alloy negative electrode materials.
As an improvement of the preparation method of the lithium titanate negative electrode material, a polymer monomer can be added in the step 1 or the step 1'; at this time, after completion of the filling, it is necessary to initiate polymerization of the monomer, followed by step 3.
As an improvement of the preparation method of the lithium titanate negative electrode material, the polymer monomer comprises acrylate, methacrylate, styrene, acrylonitrile, methacrylonitrile, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, divinylbenzene, trimethylolpropane trimethacrylate, methyl methacrylate, N-dimethylacrylamide, N-acryloyl morpholine, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl N-acrylate, cyclohexyl 2-acrylate, dodecyl acrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, neopentyl glycol diacrylate, 1, 6-hexanediol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, at least one of ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol acrylate, bis-trihydroxypropane tetraacrylate, pentaerythritol triacrylate, trimethylolpropane trimethacrylate, propoxylated glycerol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol tetraacrylate; the initiating reaction is added with an initiator, wherein the initiator is at least one of cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, di-tert-butyl peroxide, dibenzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.
The invention also comprises a lithium titanate negative electrode material which comprises a core structure and a shell structure, wherein the core structure is a secondary particle structure and comprises a main electric conducting network with a porous structure and nano primary particles filled in the porous main electric conducting network; the main power transmission network is a porous structure which is obtained by stripping a graphite part, has openings between graphite sheet layers and is connected with the sheet layers; the main conducting network and the nanometer primary particles are tightly connected together.
The invention has the advantages that:
1. stripping the graphite particles by using an electrochemical method to obtain porous graphite with openings between the sheets; the electrochemical stripping method is mild, the stripping degree is easy to control (the stripping current, the stripping time and the like are controlled for accurate control), and the openings between the graphite sheet layers are stripped while the graphite sheet layers are not stripped and shed completely;
2. when the method is used for preparing the lithium titanate cathode, the opening of the graphite particle sheet layer and the filling of the lithium titanate nanoparticles can be simultaneously carried out, namely, the opening of the graphite sheet layer is a little, and the filling of the lithium titanate nanoparticles is a little; the filling method can prevent the graphite flake layer from being bent inwards by the nano particles in the filling process so as to prevent the blockage of the hole channel and avoid the insufficient filling; therefore, the filling is carried out more smoothly and more fully, so that the lithium titanate negative electrode material is ensured to have excellent electrochemical performance;
3. the invention can also use the high molecular monomer with very low viscosity as the reactant for stirring and dispersing, which can greatly reduce the dispersion difficulty and ensure that the high molecular monomer is uniformly dispersed on the surface of the primary nano particle;
4. according to the invention, the high-molecular monomer is polymerized in situ and then carbonized to construct the conductive network, so that components in secondary particles such as primary nanoparticles and conductive agent components can be tightly bonded together, and the electrochemical performance of each primary particle can be fully exerted in the circulation process.
Detailed Description
The present invention and its advantageous effects will be described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.
Comparative example, a lithium titanate secondary particulate material having a particle diameter of 10 μm was prepared;
step 1, mixing: lithium titanate with the particle size of 100nm, conductive carbon black, sodium dodecyl sulfate, polyvinylpyrrolidone and NMP (solid content is 0.5%) are mixed and stirred for 10 hours according to the mass ratio of the lithium titanate, the conductive carbon black, the sodium dodecyl sulfate and the polyvinylpyrrolidone, wherein the mass ratio of the lithium titanate, the conductive carbon black, the sodium dodecyl sulfate and the polyvinylpyrrolidone is 94:4.9:1:0.1, and the slurry is obtained.
Step 2, preparing secondary particles: adjusting spray drying conditions to prepare lithium titanate secondary particles with the particle diameter of 10 mu m; and then coating and carbonizing to obtain the lithium titanate negative electrode material.
Example 1 is different from the comparative example in that the present example includes the following steps:
step 1, dry-mixing metal lithium powder, lithium titanate with the diameter of 100nm and graphite particles with the particle size of6 mu m until the metal lithium powder, the lithium titanate and the graphite particles are uniform;
step 2, selecting an electrolyte with lithium hexafluorophosphate as a salt and PC as a solvent, adding the electrolyte into the mixture, continuously stirring, peeling graphite particles by the PC under the action of metal lithium powder to form an open structure, and filling lithium titanate particles into the open structure;
and 3, removing electrolyte components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material.
The rest is the same as the comparative example and is not described again.
Example 2 is different from the comparative example in that the present example includes the following steps:
step 1, mixing and kneading lithium titanate with the diameter of 100nm, graphite particles with the particle size of6 microns and electrolyte taking lithium hexafluorophosphate as salt PC as a solvent until the lithium titanate, the graphite particles and the electrolyte are uniform;
step 2, assembling a counter electrode by taking lithium iron phosphate as a power source substance, then forming the counter electrode with the substance obtained in the step 1, switching on an external circuit, charging by using a current of 1A, and stripping graphite particles to form a graphite sheet layer opening structure; then, continuously filling nano lithium titanate particles into the opening structure of the graphite sheet layer;
and 3, removing electrolyte components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material.
The rest is the same as the comparative example and is not described again.
Embodiment 3 is different from embodiment 1 in that this embodiment includes the following steps:
step 1, dry-mixing and kneading metal lithium powder, lithium titanate with the diameter of 100nm, methyl methacrylate, sodium dodecyl sulfate and graphite particles with the particle size of6 mu m until the metal lithium powder, the lithium titanate, the methyl methacrylate, the sodium dodecyl sulfate and the graphite particles are uniform;
step 2, selecting an electrolyte with lithium hexafluorophosphate as a salt and PC as a solvent, adding the electrolyte into the mixture, continuously stirring, peeling graphite particles by the PC under the action of metal lithium powder to form an open structure, and filling lithium titanate particles into the open structure;
step 3, dissolving tert-butyl peroxybenzoate in PC to form an initiator solution, adding the initiator solution after the filling in the step 3 is finished, increasing the temperature, promoting a polymer monomer to generate a polymerization reaction, and forming a polymer network structure between lithium titanate particles and a porous graphite skeleton;
and 4, removing electrolyte components, and performing coating and carbonization (simultaneously carbonizing the polymer) to obtain the lithium titanate negative electrode material.
The rest is the same as the embodiment 1, and the description is omitted.
Embodiment 4 is different from embodiment 1 in that this embodiment includes the following steps:
step 1, dry-mixing and kneading metal lithium powder, lithium titanate with the diameter of 100nm, artificial graphite (the surface of the artificial graphite is coated, the mass ratio of the lithium titanate to the artificial graphite is 9:1), methyl methacrylate, PVP, sodium dodecyl benzene sulfonate and graphite particles with the particle size of6 mu m until the metal lithium powder, the lithium titanate with the diameter of 100nm and the artificial graphite are uniform;
step 2, selecting an electrolyte with lithium hexafluorophosphate as a salt and PC as a solvent, adding the electrolyte into the mixture, continuously stirring, peeling graphite particles by the PC under the action of metal lithium powder to form an open structure, and filling lithium titanate particles into the open structure;
step 3, dissolving tert-butyl peroxybenzoate in PC to form an initiator solution, adding the initiator solution after the filling in the step 3 is finished, increasing the temperature, promoting a polymer monomer to generate a polymerization reaction, and forming a polymer network structure between lithium titanate particles and a porous graphite skeleton;
and 4, removing electrolyte components, and performing coating and carbonization (simultaneously carbonizing the polymer) to obtain the lithium titanate negative electrode material. The rest is the same as the embodiment 1, and the description is omitted.
Embodiment 5 differs from embodiment 1 in that this embodiment includes the following steps:
step 1, dry-mixing pre-intercalated lithium graphite, lithium titanate with the diameter of 100nm and graphite particles with the particle size of6 mu m until the pre-intercalated lithium graphite, the lithium titanate and the graphite particles are uniform;
step 2, selecting chlorosulfonic acid as a stripping substance, slowly adding concentrated sulfuric acid to the stripping substance to obtain a mixed solution, adding the mixed solution to the mixed solution, and continuously stirring, wherein the chlorosulfonic acid strips graphite particles to form an open structure, and lithium titanate particles are filled into the open structure;
and 3, removing acid liquid components after filling, and performing coating and carbonization to obtain the lithium titanate negative electrode material.
The rest is the same as the comparative example and is not described again.
Assembling the battery: stirring the lithium titanate negative electrode material prepared in comparative example and example 1-example 5 with a conductive agent, a binder and a solvent to obtain electrode slurry, and then coating the electrode slurry on a current collector to form a negative electrode; assembling the negative electrode, the positive electrode (lithium cobaltate is used as an active substance) and the isolating membrane to obtain a bare cell, and then bagging to perform top side sealing, drying, liquid injection, standing, formation, shaping and degassing to obtain a finished battery.
And (3) testing the material performance:
and (3) gram capacity test: the gram capacity test of the battery cores prepared from the lithium titanate materials in the examples and the comparative examples is carried out in an environment at 25 ℃ according to the following procedures: standing for 3 min; charging to 2.8V at a constant current of 1C and charging to 0.1C at a constant voltage of 2.8V; standing for 3 min; discharging the 1C at constant current to 1.5V to obtain discharge capacity D1; standing for 3 min; charging the 1C to 2.35V by constant current; and (3) standing for 3min, completing the capacity test, and dividing the weight of the lithium titanate material in the cathode electrode piece by D1 to obtain the gram capacity of the cathode, wherein the obtained result is shown in Table 1.
Testing internal resistance: the internal resistance of the battery cells prepared from the lithium titanate materials in the examples and the comparative examples is tested in an environment at 25 ℃ according to the following procedures: standing for 3 min; charging to 2.35V at a constant current of 1C and charging to 0.1C at a constant voltage of 2.35V; standing for 3 min; and testing the DCR value of the battery cell by adopting an electrochemical workstation, wherein the obtained result is shown in table 1.
And (3) rate performance test: the rate capability test of the battery cell prepared from the lithium titanate materials of the examples and the comparative examples is carried out in an environment of 25 ℃ according to the following procedures: standing for 3 min; charging to 2.8V at a constant current of 1C and charging to 0.1C at a constant voltage of 2.8V; standing for 3 min; discharging to 1.5V at constant current of 0.5C to obtain discharge capacity D1; standing for 3 min; charging to 2.8V at a constant current of 1C and charging to 0.1C at a constant voltage of 2.8V; standing for 3 min; discharging at constant current of 5C to 1.5V to obtain discharge capacity D2; standing for 3 min; rate performance testing was then completed and the cell rate performance was D2/D1 x 100% with the results shown in table 1.
And (3) carrying out cycle test on the battery cells prepared from the lithium titanate materials of the examples and the comparative examples in an environment at 25 ℃ according to the following flow: standing for 3 min; charging to 2.8V at a constant current of 1C and charging to 0.1C at a constant voltage of 2.8V; standing for 3 min; discharging the 1C at constant current to 1.5V to obtain discharge capacity D1; standing for 3min, charging to 2.8V at constant current of 1C and charging to 0.1C at constant voltage of 2.8V; standing for 3 min; discharging to 1.5V at constant current at 1C to obtain discharge capacity Di; standing for 3min "and repeating 999 times to obtain D1000, then completing the cycle test, and calculating the capacity retention rate to be D1000/D1 × 100%, and obtaining the results shown in Table 1.
And (3) evaluating the gas production: and observing the appearance of the battery subjected to the cycle test, and judging the gas production amount of the battery. The results are shown in Table 1.
From table 1, the lithium titanate negative electrode material with excellent performance can be prepared, and the battery core assembled by taking the lithium titanate negative electrode material as the negative electrode active substance has excellent electrochemical performance.
TABLE 1 electrochemical properties of assembled cells made of lithium titanate negative electrode materials prepared in different comparative examples and examples
Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (6)
1. A preparation method of a lithium titanate negative electrode material is characterized by mainly comprising the following steps:
step 1, dry-mixing a power source substance 1, nano lithium titanate particles and graphite particles until the power source substance, the nano lithium titanate particles and the graphite particles are uniformly mixed;
step 2, adding the electrolyte 1 and then continuously mixing to form an ion channel, and stripping graphite particles by electrolyte components under the action of a power source substance to form a graphite sheet layer opening structure; under the mixed acting force, the nano lithium titanate particles are continuously filled into the opening structure of the graphite sheet layer;
or
Step 1', uniformly mixing nano lithium titanate particles, graphite particles and electrolyte 2 for later use;
step 2 ', assembling the power source substance 2 and the product obtained in the step 1' into paired electrodes, applying current between the two electrodes, and stripping graphite particles to form a graphite sheet layer opening structure; then, continuously filling nano lithium titanate particles into the opening structure of the graphite sheet layer;
step 3, removing electrolyte components after filling, and performing coating and carbonization to obtain a lithium titanate negative electrode material;
the lithium titanate negative electrode material comprises a core structure and a shell structure, wherein the core structure is a secondary particle structure and comprises a main electric conducting network with a porous structure and nano primary particles filled in the pore structure of the main electric conducting network; the main power transmission network is a porous structure which is obtained by stripping a graphite part, at least one part of a sheet layer and a sheet layer in the same graphite are connected together, and an opening is formed between the sheet layers; the main conducting network and the nanometer primary particles are tightly connected together;
step 1, the power source substance 1 is a pre-lithium-intercalation negative electrode material or/and a metallic lithium material;
the power source substance 2 in the step 2' comprises a lithium-rich substance or/and a metal substance as an electrode material;
in the step 2, the electrolyte 1 comprises a solute and a solvent, wherein the solvent comprises graphite intercalation or/and stripping functional components; in the step 1', the electrolyte 2 comprises a solute and a solvent, wherein the solvent comprises a graphite intercalation or/and exfoliation functional component;
polymer monomers are also added in the step 1 or the step 1'; at this time, after completion of the filling, it is necessary to initiate polymerization of the polymer monomer, followed by step 3.
2. A preparation method of a lithium titanate negative electrode material as claimed in claim 1, characterized in that the solute is a lithium ion battery electrolyte solute; the solvent contains propylene carbonate.
3. The method for preparing the lithium titanate negative electrode material as claimed in claim 1, wherein the lithium-rich material comprises LiM1O2、LiMn2-XM2xO4、LiNixM31-xO2、Li3-xM4xN、LiFePO4、Li2FeO4、Li7-xMnxN4、Li3-xFexN2、Li2S、Li2S2And LiNixMnyCozO2At least one of lithium-rich graphite and lithium-rich silicon, wherein M1 is at least one of Co, Ni, Mn, Cu, Cr and Fe, M2 is at least one of Ni, Co, Cu, Cr, Fe and V, M3 is at least one of Co, Mn, Cu, Cr, Fe, V, La, Al, Mg, Ga and Zn, M4 is at least one of Co, Ni, Cu, Cr and V, and x + y + z is 1; the metal substance used as the electrode material comprises at least one of metal lithium, metal sodium, metal potassium, metal magnesium, metal aluminum and metal zinc.
4. The preparation method of the lithium titanate negative electrode material as claimed in claim 1, wherein a surface active substance, a conductive agent component and non-lithium titanate negative electrode nanoparticles are further added in step 1 or step 1'.
5. A method for preparing a lithium titanate negative electrode material as claimed in claim 4, wherein the surface active substance comprises at least one of a wetting agent, a dispersing agent, a penetrating agent, a solubilizing agent, a cosolvent, and a cosolvent; the conductive agent component comprises at least one of super conductive carbon, acetylene black, carbon nano tubes and Ketjen black; the non-lithium titanate negative electrode nano-particles comprise at least one of natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, petroleum coke, carbon fibers, pyrolytic resin carbon, silicon carbon negative electrode particles and alloy negative electrode materials.
6. The method for preparing the lithium titanate negative electrode material of claim 1, wherein the polymer monomer comprises methacrylate, styrene, acrylonitrile, methacrylonitrile, divinylbenzene, trimethylolpropane trimethacrylate, N-dimethylacrylamide, N-acryloylmorpholine, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl N-acrylate, cyclohexyl 2-acrylate, dodecyl acrylate, ethylene glycol dimethacrylate, neopentyl glycol diacrylate, 1, 6-hexanediol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol acrylate, bis-trimethylolpropane tetraacrylate, pentaerythritol triacrylate, propoxylated glycerol triacrylate, di-trimethylolpropane tetraacrylate, and mixtures thereof, At least one of tris (2-hydroxyethyl) isocyanurate triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol tetraacrylate; the initiating reaction is added with an initiator, wherein the initiator is at least one of cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, di-tert-butyl peroxide, dibenzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.
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| CN103183331A (en) * | 2011-12-28 | 2013-07-03 | 清华大学 | Preparation method for graphene |
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