CN107302081A - Negative material and preparation method thereof, battery and preparation method thereof - Google Patents

Abstract

The embodiment of the present invention discloses a negative electrode material and a manufacturing method thereof, a battery and a manufacturing method thereof. The negative electrode material includes: a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell Only electrons and ions can be allowed to pass through, wherein the theoretical capacity of the carbon-containing core body for lithium ions is greater than that of the shell for lithium ions, and the deformation of the shell is smaller than that of the shell under charge and discharge conditions. The deformation of the carbon-containing core body, so that the battery made of the negative electrode material provided by the embodiment of the present invention can not only have the high capacity and high conductivity of the carbon-containing core body, but also use the shell to control the The isolation of carbon-containing nuclei avoids the problems of low first efficiency and poor cycle life of the battery made of the carbon-containing nuclei due to poor compatibility between the carbon-containing nuclei and the electrolyte, and improves the efficiency of the battery. capacity.

Description

Negative electrode material and manufacturing method thereof, battery and manufacturing method thereof

technical field

The invention relates to the technical field of batteries, in particular to a negative electrode material and a manufacturing method thereof, and a battery and a manufacturing method thereof.

Background technique

Commercial lithium battery graphite anode materials have many advantages such as long cycle life, high first efficiency, low cost, environmental friendliness and easy processing, and have been widely used in portable electronic devices, electric vehicles and energy storage fields. However, graphite has low theoretical specific capacity (about 372mAh/g), poor compatibility with electrolyte, and poor rate characteristics. Although the compatibility of graphite and electrolyte has been improved through carbon coating technology, its rate performance It has been difficult to improve, and the capacity is close to the limit, making it a bottleneck for increasing battery capacity. Therefore, developing new negative electrode materials has become a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

In order to solve the above technical problems, embodiments of the present invention provide a negative electrode material and a manufacturing method thereof, a battery and a manufacturing method thereof, so as to increase the capacity of the battery.

In order to solve the above problems, the embodiments of the present invention provide the following technical solutions:

In the first aspect, the embodiment of the present invention provides a negative electrode material, including: a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell can only allow electrons and ions to pass through; wherein, the The theoretical capacity of the carbon-containing core body for lithium ions is greater than that of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a state of charging and discharging.

With reference to the first aspect, in the first possible implementation manner, it should be pointed out that the shell will not be deformed in the charging and discharging state, wherein the shell is a titanium dioxide shell or a lithium titanate shell body.

In combination with the first aspect, in the second possible implementation, it should be pointed out that the theoretical capacity of the carbon-containing core material is greater than 372mAh/g. Optionally, the carbon-containing core material includes: At least one of graphene, hard carbon, soft carbon, fullerene, carbon nanotube or carbon fiber, and the carbon-containing nucleus also includes a doping material, and the constituent elements of the doping material include N, At least one of P, B, S, O, F, Cl and H.

In combination with the first aspect, in the third possible implementation manner, it should be pointed out that the carbon-containing core body and the shell are spherical structures, and the diameter of the shell is in the range of 200nm to 10000nm, including Endpoint value; the range of the thickness of the shell is 1nm-20nm, including the endpoint value.

With reference to the first aspect, in a fourth possible implementation manner, the mass ratio of the shell to the carbon-containing core is between 1:10-1:100, inclusive.

In a second aspect, an embodiment of the present invention provides a method for manufacturing an anode material, the method comprising:

Using nanoscale carbon-containing nuclei and organic monomer solutions to carry out emulsion polymerization to obtain carbon-nuclear nano-polymer microspheres, the surface of the carbon-nuclear nano-polymer microspheres is hydrophilic;

Using the carbon-containing core nanopolymer microspheres and an organic solution containing a predetermined substance to obtain carbon-containing core nano-polymer particles wrapped with a shell, the shell is used to isolate the carbon-containing core, Only electrons and ions are allowed to pass through;

removing the polymer in the shell-wrapped carbon-containing core nanopolymer particles to obtain shell-wrapped carbon-containing core nano-particles to obtain a negative electrode material for a battery;

Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a charging and discharging state.

In conjunction with the second aspect, in the first possible implementation, it should be pointed out that the use of nano-scale carbon-containing nuclei and organic monomer solution for emulsion polymerization to obtain carbon-containing nucleosome nanopolymer microspheres includes:

Disperse the nano-scale carbon-containing nuclei uniformly in the organic monomer solution, then add the mixed solution into deionized water, carry out stirring reaction under the surfactant, and carry out emulsion polymerization under the action of the initiator to obtain the Carbon nucleosome nanopolymer microspheres.

Optionally, the mass of the nanoscale carbon-containing nuclei ranges from 1 g to 5 g, inclusive; the volume of the organic monomer solution ranges from 20 ml to 50 ml, inclusive.

In conjunction with the second aspect, in the second possible implementation, it should be pointed out that the use of carbon-containing core nanopolymer microspheres and an organic solution containing a preset substance to obtain a carbon-containing core wrapped in a shell Bulk nanopolymer particles include:

The carbon-nuclear nano-polymer particle containing the carbon-nuclear nano-polymer and tetrabutyl titanate ethanol solution is used to obtain the carbon-nuclear nano-polymer particle wrapped with a titanium dioxide shell.

In a third aspect, an embodiment of the present invention provides a method for manufacturing a battery, the method comprising:

Apply the negative electrode material, conductive carbon black and polyvinylidene fluoride provided by any of the above items on the copper foil current collector according to the preset mass ratio, and dry in vacuum to obtain the battery sheet;

A battery is formed by using the battery sheet, the opposite electrode, the battery diaphragm and the electrolyte.

In a fourth aspect, an embodiment of the present invention provides a battery, which includes the negative electrode material provided by any one of the above items.

Compared with the prior art, the above-mentioned technical solution has the following advantages:

The negative electrode material provided by the embodiment of the present invention includes: a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell can only allow electrons and ions to pass through, wherein the carbon-containing core body The theoretical capacity for lithium ions is greater than the theoretical capacity for lithium ions of the shell, and in the charging and discharging state, the deformation of the shell is smaller than the deformation of the carbon-containing core body, so that the The battery made of the negative electrode material can not only have the high capacity and high conductivity of the carbon-containing core body, but also use the shell to isolate the carbon-containing core body, avoiding the The liquid compatibility is not good, which leads to the problems of low first efficiency and poor cycle life of the battery made by using the carbon-containing core body, and improves the capacity of the battery.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of the negative electrode material provided by one embodiment of the present invention;

Fig. 2 is the flow chart of the negative electrode material manufacturing method provided by one embodiment of the present invention;

FIG. 3 is a flowchart of a battery manufacturing method provided by an embodiment of the present invention.

detailed description

As mentioned in the background art section, the development of new negative electrode materials has become a technical problem to be solved urgently by those skilled in the art.

The inventor found that there are two types of research directions for new negative electrode materials, one is brand new negative electrode materials, including: alloys, oxides, sulfides, etc. These materials have high theoretical capacity and good insertion/extraction capabilities For example, the volume change of lithium titanate-based materials is very small during charging and discharging, has a stable discharge platform, does not form an SEI film (solid electrolyte interface, solid electrolyte interface film), and has high Coulombic efficiency, but the material has low reversible capacitance. , low electrical conductivity; the other is a new form of carbon materials, including: graphene, hard carbon, soft carbon, carbon nanotubes, carbon fibers, etc., taking graphene as an example, its electrical conductivity is high, but it is compatible with the electrolyte The capacity is not good, the first effect is low, and the cycle life is poor.

In view of this, an embodiment of the present invention provides a negative electrode material, including: a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell can only allow electrons and ions to pass through;

Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a charging and discharging state.

Correspondingly, an embodiment of the present invention also provides a method for manufacturing an anode material, including:

Using nanoscale carbon-containing nuclei and an organic monomer solution to carry out emulsion polymerization to obtain carbon-nuclear nano-polymer microspheres, the surface of the carbon-nuclear nano-polymer microspheres has hydrophilicity;

Using the carbon-containing core nanopolymer microspheres and an organic solution containing a predetermined substance to obtain carbon-containing core nano-polymer particles wrapped with a shell, the shell is used to isolate the carbon-containing core, Only electrons and ions are allowed to pass through;

removing the polymer in the shell-wrapped carbon-containing core nanopolymer particles to obtain shell-wrapped carbon-containing core nano-particles to obtain a negative electrode material for a battery;

Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a charging and discharging state.

In addition, an embodiment of the present invention also provides a battery manufacturing method and a battery manufactured by the manufacturing method, wherein the manufacturing method includes: mixing the above-mentioned negative electrode material, conductive carbon black, and polyvinylidene fluoride according to a preset mass ratio Both are coated on the copper foil current collector and dried in vacuum to obtain battery sheets;

A battery is formed by using the battery sheet, the opposite electrode, the battery diaphragm and the electrolyte.

In the negative electrode material and its manufacturing method provided by the embodiments of the present invention, the negative electrode material includes a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell can only allow electrons and ions to pass through, Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than the deformation of the carbon-containing core body in a charging and discharging state, so that The battery made of the negative electrode material provided by the embodiment of the present invention can not only have the high capacity and high conductivity of the carbon-containing core body, but also use the shell to isolate the carbon-containing core body, avoiding the The carbon-containing nuclei have poor compatibility with the electrolyte, which leads to the problems of low first efficiency and poor cycle life of the battery made of the carbon-containing nuclei, and improves the capacity of the battery.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

The embodiment of the present invention provides a negative electrode material. As shown in FIG. The carbon-containing core body 1 is isolated from the external environment, allowing only electrons and ions to pass through; wherein, the theoretical capacity of the carbon-containing core body 1 for lithium ions is greater than the theoretical capacity of the shell 2 for lithium ions, And in the charging and discharging state, the deformation of the shell 2 is smaller than the deformation of the carbon-containing core body 1 .

It should be noted that, in the embodiment of the present invention, since the carbon-containing core body 1 has the characteristics of high capacity and good conductivity, the negative electrode material provided by the embodiment of the present invention also has high capacity and good conductivity features. In addition, in the embodiment of the present invention, the surface of the carbon-containing core body 1 is also wrapped with a shell 2, and the shell 2 is used to isolate the carbon-containing core body 1, allowing only electrons and ions to pass through, so that The battery made of the negative electrode material provided by the embodiment of the present invention can not only avoid the capacity attenuation caused by the contact between the carbon-containing core body 1 and the electrolyte and other materials, but also ensure the transmission rate of electrons and ensure the use of the Conductivity of batteries made of negative electrode materials.

Moreover, in the embodiment of the present invention, the deformation of the shell 2 in the charging and discharging state is smaller than the deformation of the carbon-containing core body 1 in the charging and discharging state, thereby alleviating the The problems of low first effect and poor cycle type caused by large deformation in the discharge state improve the performance of the battery made of the negative electrode material.

On the basis of the above-mentioned embodiments, in one embodiment of the present invention, the casing 2 has little deformation or even no deformation in the state of charge and discharge, so as to relieve the damage caused by the carbon-containing nuclei to the greatest extent. 1. The problem of low first effect and poor cycle type caused by large deformation under charge and discharge state.

On the basis of any of the above-mentioned embodiments, in a specific embodiment of the present invention, the shell 2 is a titanium dioxide shell or a lithium titanate shell, but the present invention does not limit this, depending on the situation Certainly.

On the basis of any of the above embodiments, in one embodiment of the present invention, the theoretical capacity of the material of the carbon-containing core body 1 is greater than 372mAh/g, so as to ensure the theoretical capacity of the battery made of the negative electrode material. Optionally, the material of the carbon-containing core body 1 includes: at least one of graphene, hard carbon, soft carbon, fullerene, carbon nanotube or carbon fiber, which is not limited in the present invention. It depends.

It should be noted that, on the basis of the above embodiments, in one embodiment of the present invention, the carbon-containing nuclei 1 may also contain a dopant material, specifically, the constituent elements of the dopant material can be Including at least one of N, P, B, S, O, F, Cl and H.

On the basis of any of the above embodiments, in one embodiment of the present invention, the carbon-containing core body 1 and the shell 2 are spherical structures, and the spherical structures are nanostructures. Optionally, the The diameter of the casing 2 ranges from 200nm to 10000nm, including the endpoint value, that is, including 200nm and 10000nm, so as to reduce the gap between adjacent spherical structures when a plurality of spherical structures are stacked when using the negative electrode material to make a battery, Therefore, under the same volume, the number of spherical structures that can be stacked is increased, and the battery capacity is increased. Optionally, the diameter of the shell 2 ranges from 200nm to 1000nm, including 200nm and 1000nm, for example, it can be 300nm, 500nm or 800nm, which is not limited in the present invention and depends on the situation.

On the basis of any of the above-mentioned embodiments, in one embodiment of the present invention, the thickness range of the casing 2 is 1nm-20nm, including the endpoint value, that is, including 1nm and 20nm, so as to ensure that the negative electrode material conductivity. Optionally, the thickness of the shell 2 may be 5nm, 10nm or 15nm, etc., which is not limited in the present invention, and depends on specific circumstances.

On the basis of any of the above embodiments, in one embodiment of the present invention, the mass ratio of the shell 2 to the carbon-containing core body 1 is between 1:10-1:100, including endpoint values, Under the premise of ensuring the isolation effect of the shell 2 on the carbon-containing core body 1, the conductivity and theoretical capacity of the negative electrode material can be improved. Optionally, the mass ratio of the shell 2 to the carbon-containing core body 1 can be 1:10, 1:30, 1:50, 1:80 or 1:100, etc., which is not covered by the present invention. Limited, as the case may be.

In addition, an embodiment of the present invention also provides a battery, which includes: the negative electrode material provided in any one of the above-mentioned embodiments. Optionally, the negative electrode sheet of the battery, the positive electrode sheet, the battery separator, the non-aqueous electrolyte and the casing, wherein the negative electrode sheet includes: a current collector and a negative electrode material coated on the current collector, and the negative electrode The material is the negative electrode material provided in any one of the above-mentioned embodiments of the present invention.

It should be noted that although the battery in the embodiment of the present invention is described using a lithium battery as an example, the negative electrode material provided in the embodiment of the present invention is not limited to the field of lithium batteries, but can also be applied to other battery fields. For example, in the field of solar cells, the present invention is not limited thereto, and it depends on the circumstances.

In the negative electrode material provided by the embodiment of the present invention and the battery comprising the negative electrode material, it includes a carbon-containing core body 1 and a shell 2 wrapped on the surface of the carbon-containing core body 1, and the shell 2 is used for the The carbon-containing core body 1 is isolated, allowing only electrons and lithium ions to pass through, wherein the theoretical capacity of the carbon-containing core body 1 for lithium ions is greater than the theoretical capacity of the shell 2 for lithium ions, and in the charging and discharging state Next, the deformation of the casing 2 is smaller than that of the carbon-containing core body 1, so that the battery made of the negative electrode material provided by the embodiment of the present invention can have both the high capacity and the high capacity of the carbon-containing core body 1 High conductivity, and the shell 2 can be used to isolate the carbon-containing core body 1, so as to avoid the battery made of the carbon-containing core body 1 due to the contact between the carbon-containing core body 1 and the electrolyte. The problems of low first effect and poor cycle life improve the capacity of the battery.

Correspondingly, an embodiment of the present invention also provides a method for manufacturing an anode material, as shown in FIG. 2 , the method includes:

S1: Emulsion polymerization is carried out by using nanoscale carbon-containing nuclei and organic monomer solutions to obtain carbon-nuclear nano-polymer microspheres, and the surface of the carbon-nuclear nano-polymer microspheres is hydrophilic.

It should be noted that in the emulsion polymerization, the monomers are dispersed in water to form an emulsion with the help of an emulsifier and mechanical stirring, and then an initiator is added to initiate the polymerization of the monomers. In one embodiment of the present invention, the use of nano-scale carbon-containing nuclei and organic monomer solution to carry out emulsion polymerization to obtain nano-polymer microspheres containing carbon-nuclei, said carbon-nuclear nano-polymer microspheres Hydrophilic properties of spherical surfaces include:

Disperse the nanoscale carbon-containing nuclei uniformly in the organic monomer solution, then add the mixed solution into deionized water, carry out stirring reaction under the action of surfactant, and carry out emulsion polymerization under the action of initiator, The nanometer polymer microsphere containing the carbon core body is obtained, and the surface of the nanometer polymer microsphere containing the carbon core body is hydrophilic.

Specifically, in one embodiment of the present invention, the nano-scale carbon-containing nuclei are uniformly dispersed in the organic monomer solution, and then the mixed solution is added to deionized water, and under the action of a surfactant, a stirring reaction is carried out, and Under the action of an initiator, emulsion polymerization is carried out to obtain carbon-containing nuclei nanopolymer microspheres, including: uniformly dispersing nano-scale carbon-containing nuclei in styrene liquid, and then adding styrene to vigorously stirred deionized water, Stir and emulsify, then add potassium sulfate, stir and react to obtain polystyrene nanoscale microsphere emulsion containing carbon-containing nuclei, finally add potassium chloride solution to break the emulsion and filter, wash and dry to obtain polystyrene nano-sized microspheres containing carbon-containing nuclei. Styrene nanoscale microspheres. It should be noted that, in this embodiment, the deionized water is pre-added with a surfactant and an alkaline solution.

Optionally, the mass range of the nano-scale carbon-containing nuclei is: 1g-5g, including the endpoint value 1g and 5g; the volume range of the organic monomer solution is 20ml-50ml, including the endpoint value 20ml and 50ml; the surfactant is sodium dodecylbenzenesulfonate, and its quality range is 0.9g-2g; the alkaline solution is sodium hydroxide or aluminum oxide, and its quality range is It is 3g-5g. However, the present invention is not limited thereto, and it depends on the circumstances.

It should be noted that, on the basis of any of the above-mentioned embodiments, in one embodiment of the present invention, the surface of the nanopolymer microspheres containing carbon-containing nuclei obtained after emulsion polymerization is hydrophilic; In another embodiment of the present invention, the surface of the nanopolymer microsphere containing carbon-containing nuclei obtained after emulsion polymerization does not have hydrophilicity. In the embodiment of the present invention, the method also includes: using a modifier to modify the The surface of the nano-polymer microsphere containing carbon nuclei is treated to make it hydrophilic. Specifically, in one embodiment of the present invention, the use of modifiers to treat the surface of the carbon-containing core nanopolymer microspheres to make them hydrophilic includes: making the carbon-containing core nanometer The polymer microspheres are dispersed in ethanol, and the modifying agent is added to stir evenly to make the surface hydrophilic.

Optionally, the modifying agent may be concentrated sulfuric acid, sodium vinylbenzene sulfonate or γ-aminopropyltriethoxysilane (KH550), which is not limited in the present invention and depends on the circumstances.

S2: Using the carbon-containing core nanopolymer microspheres and an organic solution containing preset substances to obtain carbon-containing core nanopolymer particles wrapped with a shell, the shell is used to isolate the carbon-containing core A body that allows only electrons and ions to pass through.

It should be noted that, in the embodiment of the present invention, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and in the charging and discharging state, the deformation of the shell is less than Deformation of the carbon-containing nuclei.

On the basis of any of the above embodiments, in one embodiment of the present invention, the use of the carbon-containing core nanopolymer microspheres and an organic solution containing a predetermined substance to obtain a carbon-containing The core nanopolymer particles include: mixing and stirring the carbon-containing core nanopolymer microspheres and an alcohol (such as methanol, ethanol, etc.) solution of tetrabutyl titanate to obtain carbon-containing particles wrapped with a titanium dioxide shell. Nucleosome nanopolymer particles.

Specifically, in one embodiment of the present invention, using the carbon-containing core nano-polymer microspheres and an organic solution containing a predetermined substance, the carbon-containing core nano-polymer particles wrapped with a shell specifically include:

The ethanol solution dispersed with tetrabutyl titanate is slowly added into the solution of the carbon-nuclear nano-polymer microspheres, stirred vigorously, and then filtered to obtain the carbon-nuclear nano-polymer particles wrapped with shells.

S3: removing the polymer in the shell-wrapped carbon-core-containing nanopolymer particles to obtain shell-wrapped carbon-core-containing nanoparticles to prepare a negative electrode material for a battery.

In one embodiment of the present invention, the removal method of the polymer in the carbon-containing core nanopolymer particle is dissolution. In another embodiment of the present invention, the polymer in the carbon-containing core nanopolymer particle The removal method of the substance is sintering. In other embodiments of the present invention, the polymer in the carbon-containing nano-polymer particles can also be removed by other methods, which is not limited in the present invention, depending on the circumstances. .

Specifically, in one embodiment of the present invention, the polymer in the carbon-containing core nanopolymer particles wrapped with the shell is removed to obtain the carbon-containing core nano-particles wrapped with the shell, and the Obtained battery negative electrode materials include:

The carbon-containing core nano-polymer particles wrapped with the shell are placed in tetrahydrofuran, and magnetically stirred to dissolve and remove the polymer in the carbon-containing core nano-polymer particles wrapped with the shell, and the surface coated with The carbon-containing core nanoparticle of the shell is used to prepare the negative electrode material of the battery.

It should be noted that, in order to further improve the isolation performance of the shell to the carbon-containing core body, after obtaining the carbon-containing core body nanoparticles coated with a shell on the surface, before making the lithium battery negative electrode material, it also includes: The carbon-containing core structure particle wrapped with the shell is sintered to obtain the carbon-containing core structure nano-particle wrapped with the dense shell, and the carbon-containing core structure particle wrapped with the dense shell is used as a negative electrode material.

In addition, an embodiment of the present invention also provides a method for manufacturing a battery, as shown in FIG. 3 , the method includes:

S4: Apply the negative electrode material, conductive carbon black, and polyvinylidene fluoride provided by any of the above-mentioned embodiments of the present invention on the copper foil current collector according to a preset mass ratio, and dry in vacuum to obtain a battery sheet.

Specifically, in an optional embodiment of the present invention, the negative electrode material, conductive carbon black and polyvinylidene fluoride provided by any of the above-mentioned embodiments of the present invention are all applied to the On the copper foil current collector, vacuum dry at 120° to obtain battery sheets.

S5: forming a battery by using the battery sheet, counter electrode, battery separator and electrolyte. Optionally, the counter electrode is lithium metal, the battery separator is celgard C2400; the electrolyte is 1.3 mol/L LiPF6 EC and DEC solutions. Wherein, the volume ratio of EC (vinyl ester) and DEC (diethyl carbonate) in EC and DEC solution is 3:7. Since the method of making batteries using negative electrode materials is well known to those skilled in the art, the present invention will not repeat them in detail.

In the manufacturing method of the negative electrode material provided by the embodiment of the present invention, the negative electrode material includes a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell is used to isolate the carbon-containing core body , can only allow electrons and ions to pass through, wherein the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and in the state of charge and discharge, the deformation of the shell is less than the specified deformation of the carbon-containing core body, so that the battery made of the negative electrode material provided by the embodiment of the present invention can not only have the high capacity and high conductivity of the carbon-containing core body, but also use the shell to The carbon-containing nuclei are isolated, avoiding the problems of low first efficiency and poor cycle life of the battery made of the carbon-containing nuclei due to the contact between the carbon-containing nuclei and the electrolyte, and improving the capacity of the battery .

In the following, taking the lithium battery as an example, the negative electrode material and the manufacturing method of the battery provided in the embodiment of the present invention will be described in combination with specific examples.

In the first specific embodiment of the present invention, the manufacturing method of the negative electrode material includes:

S101: Disperse 1g of nanoscale graphene in 20ml of styrene liquid, then add styrene into 250ml of deionized water with vigorous stirring, stir and emulsify, then add 0.5g of potassium persulfate, heat up to 70°C, stir for 14 hours Stop reaction afterward, obtain the polystyrene nano-microsphere emulsion that comprises graphene, add a small amount of 50% potassium chloride solution demulsification and filter again, and wash, dry and obtain 6.5g nano-polystyrene microsphere that comprises graphene, Wherein, 0.9g sodium dodecylbenzenesulfonate and 3g sodium hydroxide have been added in advance to dissolve in the deionized water;

S102: Disperse 3g of nano-polystyrene microspheres containing graphene in 30ml of ethanol, add 0.6g of KH550 and stir evenly, then slowly add 6ml of ethanol solution dispersed with 0.6ml of tetrabutyl titanate into the above solution, and stir vigorously for 2h After filtering, the graphene-polystyrene spherical core-shell particles coated with a dense titanium dioxide shell are obtained;

S103: Take 10ml of the graphene-polystyrene spherical core-shell particles coated with a dense titanium dioxide shell prepared in S102 and place them in 20mL of tetrahydrofuran, and magnetically stir for 2 hours to dissolve and remove the polystyrene core, and obtain a shell coated with titanium dioxide Graphene nanoparticles, and sintered at 450 ° C for 10 hours to obtain graphene nanoparticles wrapped with anatase structure titanium dioxide shell, the graphene nanoparticles wrapped with anatase structure titanium dioxide shell can be used as a lithium battery Negative material.

S104: Mix the negative electrode material prepared in S103, conductive carbon black, and polyvinylidene fluoride in N-methylpyrrolidone according to the mass ratio of 85:10:5, and evenly apply it on the copper foil current collector, and vacuum bake at 120°C Dry, obtain electrode sheet, be assembled into button cell then in glove box and test, wherein, in described button cell, counter electrode adopts lithium metal, battery separator is celgard 2400, and electrolytic solution is the EC of LiPF6 of 1.3mol/L and DEC (volume ratio 3:7) solution.

It can be seen from the test that the 1C capacity of the button battery prepared in the first embodiment of the present invention reaches 600mAh/g, the 30C capacity retention rate is 60%, and the first effect can reach 80%.

In the second specific embodiment of the present invention, the manufacturing method of the negative electrode material includes:

S201: Disperse 1g of nano-scale nitrogen-doped graphene in 20ml of styrene liquid, then add styrene into 250ml of deionized water with vigorous stirring, stir and emulsify, then add 0.5g of ammonium persulfate, heat up to 80°C, and stir to react After 24 hours, the reaction was stopped to obtain a polystyrene nanosphere emulsion containing nitrogen-doped graphene, and then a small amount of 50% potassium chloride solution was added to break the emulsion and filtered, and washed and dried to obtain 6.8g containing nitrogen-doped graphene. Nano-polystyrene microspheres of heterographene, wherein, 0.9g sodium dodecylbenzenesulfonate and 3g sodium hydroxide have been added in advance to dissolve in the deionized water;

S202: Take 3g of graphene-containing nano-polystyrene microspheres and disperse them in 30ml of ethanol, add 0.6g of KH550 and stir evenly, then slowly add 6ml of ethanol solution dispersed with 0.6ml of tetrabutyl titanate into the above solution, and stir vigorously for 2h After filtration, nitrogen-containing doped graphene-polystyrene spherical core-shell particles coated with a dense titanium dioxide shell are obtained;

S203: Take 10ml of the mixed solution of nitrogen-doped graphene-polystyrene spherical core-shell particles coated with a dense titanium dioxide shell prepared in S202 and place it in 20mL of tetrahydrofuran, stir magnetically for 2 hours to dissolve and remove the polystyrene core, and obtain Nitrogen-doped graphene nanoparticles coated with a titanium dioxide shell, and sintered at 450 ° C for 10 hours to obtain nitrogen-doped graphene nanoparticles wrapped with an anatase structure titanium dioxide shell, said wrapped with anatase Nitrogen-doped graphene nanoparticles with structured titania shells can be used as anode materials for lithium batteries.

S204: Mix the negative electrode material prepared in S203, conductive carbon black, and polyvinylidene fluoride in N-methylpyrrolidone according to the mass ratio of 85:10:5, and evenly apply them on the copper foil current collector, and vacuum bake at 120°C Dry, obtain electrode sheet, be assembled into button cell then in glove box and test, wherein, in described button cell, counter electrode adopts lithium metal, battery separator is celgard 2400, and electrolytic solution is the EC of LiPF6 of 1.3mol/L and DEC (volume ratio 3:7) solution.

It can be seen from the test that the 1C capacity of the button battery prepared in the second embodiment of the present invention reaches 650mAh/g, the 30C capacity retention rate is 65%, and the first effect can reach 83%.

In the third specific embodiment of the present invention, the manufacturing method of the negative electrode material includes:

S301: Disperse 1g of nano-scale nitrogen-doped graphene in 20ml of styrene liquid, then add styrene into 250ml of deionized water with vigorous stirring, stir and emulsify, then add 0.5g of ammonium persulfate, heat up to 80°C, and stir to react After 24 hours, the reaction was stopped to obtain a polystyrene nanosphere emulsion containing nitrogen-doped graphene, and then a small amount of 50% potassium chloride solution was added to break the emulsion and filtered, and washed and dried to obtain 6.8g containing nitrogen-doped graphene. Nano-polystyrene microspheres of heterographene, wherein, 0.9g sodium dodecylbenzenesulfonate and 3g sodium hydroxide have been added in advance to dissolve in the deionized water;

S302: Disperse 3g of nano-polystyrene microspheres containing graphene in 30ml of ethanol, add 0.6g of KH550 and stir evenly, then slowly add 6ml of ethanol solution dispersed with 0.6ml of tetrabutyl titanate into the above solution, and stir vigorously for 2h After filtration, nitrogen-containing doped graphene-polystyrene spherical core-shell particles coated with a dense titanium dioxide shell are obtained;

S303: Take 10 g of the nitrogen-doped graphene-polystyrene spherical core-shell particles coated with dense titanium dioxide shells prepared in S202 and directly sinter them at 450°C for 10 hours to obtain nitrogen-containing particles coated with anatase structure titanium dioxide shells. Doped with graphene nanoparticles, the nitrogen-containing doped graphene nanoparticles wrapped with an anatase structure titanium dioxide shell can be used as a lithium battery negative electrode material.

S304: Mix the negative electrode material prepared in 303, conductive carbon black, and polyvinylidene fluoride in N-methylpyrrolidone according to the mass ratio of 85:10:5, and evenly apply it on the copper foil current collector, and vacuum bake at 120°C Dry, obtain electrode sheet, be assembled into button cell then in glove box and test, wherein, in described button cell, counter electrode adopts lithium metal, battery separator is celgard 2400, and electrolytic solution is the EC of LiPF6 of 1.3mol/L and DEC (volume ratio 3:7) solution.

It can be seen from the test that the 1C capacity of the button battery prepared in the third embodiment of the present invention reaches 550mAh/g, the 30C capacity retention rate is 60%, and the first effect can reach 82%.

In the first comparative example of the present invention, the manufacturing method of battery and negative electrode material thereof comprises:

S401: Add 20ml of styrene liquid into 250ml of deionized water with vigorous stirring, stir and emulsify, then add 0.5g of ammonium persulfate, heat up to 80°C, stir and react, stop the reaction after 24 hours, and obtain polystyrene nanosphere emulsion, Then add a small amount of 50% potassium chloride solution to break the emulsion and filter, wash and dry to obtain 7g nano-polystyrene microspheres, wherein, 0.9g sodium dodecylbenzenesulfonate and 3g hydroxide have been added in advance in the deionized water Sodium dissolved;

S402: Take 3g of nano-polystyrene microspheres and disperse them in 30ml of ethanol, add 0.6g of KH550 and stir evenly, then slowly add 6ml of ethanol solution dispersed with 0.6ml of tetrabutyl titanate into the above solution, stir vigorously for 2h, and then filter to obtain Polystyrene spherical core-shell particles coated with a dense titanium dioxide shell;

S403: Take 10 ml of the polystyrene spherical core-shell particles coated with a dense titanium dioxide shell prepared in S402, place them in 20 mL of tetrahydrofuran, and magnetically stir for 2 hours to dissolve and remove the polystyrene core to obtain hollow titanium dioxide shell nanoparticles, and Sintering at 450° C. for 10 hours yields titanium dioxide shell nanoparticles with anatase structure, which are used as negative electrode materials for lithium batteries.

S404: Mix the negative electrode material prepared in S403, conductive carbon black, and polyvinylidene fluoride in N-methylpyrrolidone according to the mass ratio of 85:10:5, and evenly apply them on the copper foil current collector, and vacuum bake at 120°C Dry, obtain electrode sheet, be assembled into button cell then in glove box and test, wherein, in described button cell, counter electrode adopts lithium metal, battery separator is celgard 2400, and electrolytic solution is the EC of LiPF6 of 1.3mol/L and DEC (volume ratio 3:7) solution.

It can be seen from the test that the 1C capacity of the button battery prepared in the first comparative example of the present invention reaches 169mAh/g, the 30C capacity retention rate is 70%, and the first effect can reach 95%.

In the second comparative example of the present invention, the manufacturing method of battery and negative electrode material thereof comprises:

S501: Mix the graphene material with conductive carbon black and polyvinylidene fluoride in N-methylpyrrolidone according to the mass ratio of 85:10:5 and evenly coat it on the copper foil current collector, and dry it in vacuum at 120°C to obtain The electrode sheet is then assembled into a button cell in the glove box for testing, wherein the counter electrode adopts lithium metal, the battery separator is celgard 2400, and the electrolyte is 1.3mol/L LiPF6 EC and DEC (volume ratio is 3:7 ) solution.

It can be seen from the test that the 1C capacity of the button battery prepared in the second comparative example of the present invention reaches 900mAh/g, the 30C capacity retention rate is 40%, and the first effect can reach 45%.

From the comparison of the above specific examples and comparative examples, it can be known that the negative electrode material and its manufacturing method provided by the examples of the present invention are not simply mixing two materials, but adopting a core-shell structure, which retains both the core material and the shell material. advantages, and avoid the defects of the core material and the shell material, and obtain complementary effects, so that in the negative electrode material and its manufacturing method provided by the embodiment of the present invention, the carbon-containing core material is protected by a dense shell , to avoid the trouble of the SEI film on the core material, and also have the characteristics of high capacity and high conductivity of the carbon-containing core material.

Moreover, in the negative electrode material provided by the embodiment of the present invention and the manufacturing method thereof, the shell material has a good electron transmission rate, so that the battery made of the negative electrode material provided by the embodiment of the present invention has a fast charging function.

It should be noted that although the negative electrode material manufacturing method provided in the embodiment of the present invention is described by taking a lithium battery as an example, the application of the negative electrode material provided by the present invention is not limited thereto, and can also be applied to other solar cells, etc. The field of batteries, depending on the situation.

In summary, in the negative electrode material and its manufacturing method and the battery and its manufacturing method according to the embodiment of the present invention, the negative electrode material includes a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, and the shell Used to isolate the carbon-containing core body, allowing electrons and ions to pass through, wherein the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and in the charge and discharge state, The deformation of the shell is smaller than the deformation of the carbon-containing core body, so that the battery made of the negative electrode material provided by the embodiment of the present invention can not only have the high capacity and high conductivity of the carbon-containing core body, but also The shell can be used to isolate the carbon-containing core body, avoiding the low first efficiency and poor cycle life of the battery made of the carbon-containing core body due to the good compatibility between the carbon-containing core body and the electrolyte The problem is to increase the capacity of the battery.

Each part in this manual is described in a progressive manner, and each part focuses on the difference from other parts, and the same and similar parts of each part can be referred to each other.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (14)

1. A negative electrode material, characterized in that, comprising: a carbon-containing core body and a shell wrapped on the surface of the carbon-containing core body, the shell can only allow electrons and ions to pass through; Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a charging and discharging state. 2 . The negative electrode material according to claim 1 , wherein the casing does not deform in a charging and discharging state. 3 . 3. The negative electrode material according to claim 1 or 2, characterized in that, the shell is a titanium dioxide shell or a lithium titanate shell. 4. The negative electrode material according to any one of claims 1-3, the material containing carbon nuclei comprises: at least one of graphene, hard carbon, soft carbon, fullerenes, carbon nanotubes or carbon fibers . 5. Negative electrode fabricator according to claim 4, is characterized in that, also comprises doping material in the described carbon-containing nuclei, and the composition element of described doping material comprises N, P, B, S, O, At least one of F, Cl and H. 6. The negative electrode material according to any one of claims 1-5, characterized in that, the carbon-containing core body and the shell are spherical structures, and the diameter of the shell is in the range of 200nm to 10000nm, Include endpoint values. 7. The negative electrode material according to claim 6, characterized in that, the thickness of the casing ranges from 1 nm to 20 nm, both inclusive. 8. The negative electrode material according to any one of claims 1-7, characterized in that the mass ratio of the shell to the carbon-containing core is between 1:10-1:100, inclusive. 9. A method for making an anode material, characterized in that the method comprises: Using nanoscale carbon-containing nuclei and organic monomer solutions to carry out emulsion polymerization to obtain carbon-nuclear nano-polymer microspheres, the surface of the carbon-nuclear nano-polymer microspheres is hydrophilic; Using the carbon-containing core nanopolymer microspheres and an organic solution containing a predetermined substance to obtain carbon-containing core nano-polymer particles wrapped with a shell, the shell is used to isolate the carbon-containing core, Only electrons and ions are allowed to pass through; removing the polymer in the shell-wrapped carbon-containing core nanopolymer particles to obtain shell-wrapped carbon-containing core nano-particles to obtain a negative electrode material for a battery; Wherein, the theoretical capacity of the carbon-containing core body for lithium ions is greater than the theoretical capacity of the shell for lithium ions, and the deformation of the shell is smaller than that of the carbon-containing core body in a charging and discharging state. 10. preparation method according to claim 9, is characterized in that, described utilization nanoscale carbon-containing nucleus body and organic monomer solution carry out emulsion polymerization, obtain carbon-containing nucleus body nanopolymer microsphere comprising: Disperse the nano-scale carbon-containing nuclei uniformly in the organic monomer solution, then add the mixed solution into deionized water, carry out stirring reaction under the surfactant, and carry out emulsion polymerization under the action of the initiator to obtain the Carbon nucleosome nanopolymer microspheres. 11. The production method according to claim 10, characterized in that, the quality range of the nano-scale carbon-containing nuclei is: 1g-5g, including the endpoint value; the value of the volume of the organic monomer solution The range is 20ml-50ml inclusive. 12. The preparation method according to any one of claims 9-11, characterized in that, the utilization of carbon-containing nucleosome nanopolymer microspheres and an organic solution containing a preset substance obtains a carbon-containing shell wrapped with a shell. Core nanopolymer particles include: The carbon-nuclear nano-polymer particle containing the carbon-nuclear nano-polymer and tetrabutyl titanate ethanol solution is used to obtain the carbon-nuclear nano-polymer particle wrapped with a titanium dioxide shell. 13. A method for manufacturing a battery, characterized in that the method comprises: Apply the negative electrode material, conductive carbon black and polyvinylidene fluoride according to the preset mass ratio on the copper foil current collector according to claims 1-8, and vacuum dry to obtain battery sheets; A battery is formed by using the battery sheet, the opposite electrode, the battery diaphragm and the electrolyte. 14. A battery, characterized in that it comprises the negative electrode material according to any one of claims 1-8.