CN112164803B - Three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material and preparation method thereof - Google Patents
Three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material and a preparation method thereof. The three-dimensional dielectric polyacrylonitrile is specifically three-dimensional dielectric oxidized polyacrylonitrile with oxygen-containing polar functional groups on the surface; the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver is used as a host material; the host material has an electronic conductivity of 107S/m～109S/m; in the composite material, the three-dimensional dielectric oxidation state polyacrylonitrile is used as a framework and an ion transmission channel of the composite material, the nano-silver is used as a nucleation site, and the content of the nano-silver accounts for 5wt% -30 wt% of the host material.
Description
Technical Field
The invention relates to the technical field of materials, in particular to a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material and a preparation method thereof.
Background
The growth of the consumer market for electronic products and electric vehicles has prompted the rapid development of high energy density energy storage devices. Metallic lithium anodes are considered as one of the ultimate targets of anode materials due to their extremely high theoretical capacity of 3860mAh/g, and lowest redox potential (-3.04Vvs standard hydrogen electrode). Currently, LiNi is used as a material0.9Co0.1O2As a positive electrode, the solution of metallic lithium as a negative electrode has attracted extensive attention by researchers and is considered as a solution for next-generation high energy density lithium ion batteries. But its commercial application is severely inhibited by the unrestricted growth of metallic lithium dendrites and by the unrestricted volume expansion of the electrode material.
In order to solve the above-mentioned key problems, various modification schemes have been tried in the industry, such as optimizing the electrolyte system, employing surface protection, lithium metal alloying, three-dimensional current collectors, etc., which improve the electrochemical performance of metallic lithium to various degrees. The three-dimensional current collector is used as an effective modification strategy, so that the effective current density can be reduced, and the volume expansion can be relieved. However, the traditional three-dimensional current collector faces the serious problems of uneven distribution of the top electric field and top deposition of the lithium metal, and the performance of the current collector is greatly influenced.
Disclosure of Invention
The embodiment of the invention provides a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material and a preparation method thereof, and the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material not only can effectively solve the critical problems of lithium dendrite growth, volume expansion and the like existing in the conventional lithium metal negative electrode material, but also has high cycle stability.
In a first aspect, embodiments of the present invention provide a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material, where the three-dimensional dielectric polyacrylonitrile is specifically a three-dimensional dielectric oxidized polyacrylonitrile having an oxygen-containing polar functional group on the surface; the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver is used as a host material; the host material has an electronic conductivity of 107S/m～109S/m；
In the composite material, the three-dimensional dielectric oxidation state polyacrylonitrile is used as a framework and an ion transmission channel of the composite material, the nano-silver is used as a nucleation site, and the content of the nano-silver accounts for 5wt% -30 wt% of the host material.
In a second aspect, the embodiment of the present invention provides a preparation method of the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material according to the first aspect, the preparation method includes:
mixing polyacrylonitrile, a solvent and a silver source under an inert atmosphere to obtain a mixed solution;
carrying out electrostatic spinning on the obtained mixed solution to obtain three-dimensional interwoven polyphenyl nitrile/silver salt compound composite nanowires;
carrying out heat treatment on the obtained polyphenylenenitrile/silver salt compound composite nanowire at 300-400 ℃ for 3-6 hours, wherein in the heat treatment process, silver compound salts are reduced to simple substance silver, and oxygen-containing polar functional groups are added on the surface of the polyphenylenenitrile to obtain a three-dimensional dielectric oxidation state polyacrylonitrile/nano-silver host material;
and carrying out electrochemical compounding on the obtained three-dimensional dielectric oxidation state polyacrylonitrile/nano silver host material and lithium metal to obtain the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-lithium metal composite material.
Preferably, the solvent is one or a mixture of several of N, N-dimethylformamide, acetone and hexafluoroisopropanol, and the silver source is silver nitrate and/or silver sulfate; the silver salt compound is silver nitrate and/or silver sulfate.
Preferably, the step of mixing polyacrylonitrile, a solvent and a silver source to obtain a mixed solution specifically comprises:
dissolving 0.1-1 g of polyacrylonitrile and 0.02-3 g of silver source in 10mL of solvent, stirring and dissolving at a stirring speed of 0-800 r/min, and standing at room temperature after all the polyacrylonitrile and the silver source are dissolved to obtain the mixed liquid.
Preferably, the voltage of the electrostatic spinning is 15kV to 20kV, the needle distance is 15cm, and the humidity is lower than 50%.
Preferably, the heat treatment atmosphere is an air atmosphere;
the heating process is also included before the heat treatment process, and the heating rate is 2 ℃/min to 5 ℃/min; and after the heat treatment process, a cooling process is also included, and the cooling rate is natural cooling.
Preferably, the electrochemical recombination is specifically electrochemical lithium plating, and the surface capacity is 4mAh/cm2The current is 0.5mA/cm2。
In a third aspect, an embodiment of the present invention provides a lithium metal secondary battery, including the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material described in the first aspect.
Preferably, the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material is used for a battery cathode or anode.
In a fourth aspect, an embodiment of the present invention provides a method for manufacturing a lithium metal secondary battery, including:
in a glove box under inert atmosphere, LiNi0.9Co0.1O2The positive electrode material, the conductive agent and the binder are uniformly mixed by grinding according to the mass ratio of (8-10) to (1-2) to 1, and the mixture is coated on an aluminum foil to prepare a positive electrode plate; wherein the conductive agent is acetylene black and/or conductive carbon black SuperP; the binder is one or a mixture of more of polyacrylic acid, polytetrafluoroethylene and polyvinylidene fluoride;
and drying the obtained positive electrode plate at 80-100 ℃, cutting to obtain the positive electrode plate, and assembling the positive electrode plate and a negative electrode plate made of the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium composite material into the lithium secondary battery.
The three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material provided by the embodiment of the invention has the following beneficial effects:
1. the three-dimensional dielectric oxidation state polyacrylonitrile serving as a skeleton structure of the material can provide a stable host structure, remarkably relieves volume expansion caused by metal lithium deposition in a circulation process, and obviously promotes the circulation stability of a metal lithium cathode;
2. due to the low electronic conductivity of the three-dimensional dielectric oxidation state polyacrylonitrile skeleton, the ideal bottom-up deposition mode of the metal lithium can be induced, and a large number of ion channels can be provided, so that the circulation stability of the metal lithium cathode is promoted;
3. the three-dimensional dielectric oxidation state polyacrylonitrile skeleton has a large number of oxygen-containing functional groups on the surface, so that the wettability of the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium cathode and an organic electrolyte is obviously improved, and the electrode is ensured to be in good contact with the electrolyte;
4. the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite negative electrode contains a large amount of nano silver particles, and the nano silver particles effectively reduce nucleation potential of metal lithium and obviously improve coulomb efficiency in a circulation process;
5. the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium composite negative electrode fully combines the advantages of a three-dimensional current collector in regulating and controlling the deposition behavior of metal lithium and inhibiting side reactions in alloying, and realizes that the metal lithium is at 4mA/cm2High current density and 4mAh/cm2Stable cycling at high surface capacity provides a new visual angle for the research on the protection of the metallic lithium cathode;
6. the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite material is used as a negative electrode material, so that the lithium metal secondary battery with the energy density of more than 350Wh/kg can be obtained.
Drawings
The technical solutions of the embodiments of the present invention are further described in detail with reference to the accompanying drawings and embodiments.
FIG. 1 is a flow chart of a method for preparing a three-dimensional dielectric oxidized polyacrylonitrile/nano silver-lithium metal composite material according to an embodiment of the present invention;
FIG. 2 is an X-ray diffraction pattern (XRD) of a three-dimensional dielectric oxidized polyacrylonitrile/nano-silver material in example 1 of the present invention;
FIG. 3 is a surface topography of a three-dimensional dielectric oxidized polyacrylonitrile/nano-silver material in example 1 of the present invention;
FIG. 4 is a graph comparing the cycling performance of the symmetrical cell using the three-dimensional dielectric oxidized polyacrylonitrile/nanosilver-lithium metal in example 1 of the present invention with that of the symmetrical cell using unmodified lithium metal in comparative example 1;
FIG. 5 is a comparison graph of the cycle performance of the three-dimensional dielectric oxidized polyacrylonitrile/nano silver-metallic lithium composite negative electrode-Cu | Li in example 2 of the present invention and the half-cell of Cu | Li in comparative example 2;
FIG. 6 is a capacity-voltage curve of example 2 of the present invention and comparative example 2;
fig. 7 is a graph comparing the cycle performance of the lithium metal secondary batteries of example 3 of the present invention with that of comparative example 3.
Detailed Description
The invention is further illustrated by the following figures and specific examples, but it should be understood that these examples are for the purpose of illustration only and are not to be construed as in any way limiting the present invention, i.e., as in no way limiting its scope.
The three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material is specifically three-dimensional dielectric oxidized polyacrylonitrile with oxygen-containing polar functional groups on the surface;
wherein, the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver is used as a host material; the electronic conductivity of the host material was 107S/m～109S/m；
In the composite material, three-dimensional dielectric oxidation state polyacrylonitrile is used as a framework and an ion transmission channel of the composite material, nano silver is used as a nucleation site, and the content of the nano silver accounts for 5-30 wt% of the host material.
The preparation method of the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material electrode material comprises the following steps:
specifically, the method comprises the following steps: dissolving 0.1-1 g of polyacrylonitrile and 0.02-3 g of silver source in 10mL of solvent, stirring and dissolving at a stirring speed of 0-800 r/min, and standing at room temperature after all the polyacrylonitrile and the silver source are dissolved to obtain a mixed liquid.
Wherein the solvent is one or a mixture of more of N, N-dimethylformamide, acetone and hexafluoroisopropanol, and the silver source is silver nitrate and/or silver sulfate; the silver salt compound is silver nitrate and/or silver sulfate.
wherein the voltage of electrostatic spinning is 15 kV-20 kV, the distance of a needle is 15cm, and the humidity is lower than 50%.
wherein the heat treatment is performed in an air atmosphere.
In the heat treatment process, the silver compound salt is reduced into simple substance silver, and oxygen-containing polar functional groups are added on the surface of the polyphenylenenitrile.
The heating process is also included before the heat treatment process, and the heating rate is 2 ℃/min to 5 ℃/min; the heat treatment process also comprises a temperature reduction process, and the temperature reduction rate is natural cooling.
And 140, carrying out electrochemical compounding on the obtained three-dimensional dielectric oxidation state polyacrylonitrile/nano silver host material and lithium metal to obtain the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-lithium metal composite material.
Specifically, the electrochemical composition is electrochemical lithium plating, and the surface capacity is 4mAh/cm2The current is 0.5mA/cm2。
The invention prepares materials by using the methods of electrostatic spinning and low-temperature sintering, and has the advantages of simple preparation method, low cost, good synthesis consistency and the like.
The three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite material provided by the embodiment can be used as an electrode material of a lithium battery.
Among them, the method for using it in the lithium metal secondary battery may include:
1. in a glove box under inert atmosphere, LiNi0.9Co0.1O2The positive electrode material, the conductive agent and the binder are uniformly mixed by grinding according to the mass ratio of (8-10) to (1-2) to 1, and the mixture is coated on an aluminum foil to prepare a positive electrode plate; wherein the conductive agent is acetylene black and/or conductive carbon black SuperP; the binder is one or a mixture of more of polyacrylic acid, polytetrafluoroethylene and polyvinylidene fluoride;
2. and drying the obtained positive electrode plate at 80-100 ℃, cutting to obtain the positive electrode plate, and assembling the positive electrode plate and a negative electrode plate made of the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium composite material into the lithium secondary battery.
In order to better understand the technical scheme provided by the present invention, the following description will be made by using specific examples to illustrate a specific process for preparing a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material by applying the method provided by the above embodiments of the present invention, and a method for applying the same to a lithium metal secondary battery and battery characteristics. The following examples and comparative examples were all conducted in a glove box under an inert atmosphere.
Example 1
The embodiment provides a lithium-lithium symmetric battery applying a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material cathode, and a preparation method of the lithium-lithium symmetric battery comprises the following steps:
(1) dissolving 0.5g of polyacrylonitrile and 0.05g of silver nitrate in 10mL of Dimethylformamide (DMF) to obtain a uniform solution;
(2) carrying out electrostatic spinning on the solution (the voltage is 15kV, the needle head distance is 15cm, and the liquid inlet speed is 0.5mL/h) to obtain a three-dimensional interweaving precursor;
(3) heating the precursor to 350 ℃ at a heating rate of 2 ℃/min in the air, preserving heat for 3 hours to obtain a three-dimensional dielectric oxidation state polyacrylonitrile/nano-silver host material, drying at 80 ℃ for 12 hours, cutting to obtain small wafers, and performing electrochemical composite deposition to obtain 4mAh/cm2And (5) lithium metal, and finally obtaining the electrode plate.
(4) The two sides of the battery are both provided with the pole pieces, 1MLiTFSI and 1, 3-Dioxolane (DOL)/ethylene glycol dimethyl ether (DME) (v: v is 1:1) are mixed to prepare electrolyte, and a polypropylene (PP) diaphragm is used for assembling the lithium-lithium symmetric battery in an Ar atmosphere glove box with water and oxygen content lower than 1 ppm.
The X-ray diffraction pattern (XRD) of the three-dimensional dielectric oxidized polyacrylonitrile/nano-silver host material in the step (3) is shown in fig. 2, and the XRD diffraction peak shows that the prepared three-dimensional dielectric oxidized polyacrylonitrile/nano-silver host material has a characteristic diffraction peak of elemental silver, which indicates that the ionic state is converted into the elemental state after the oxidation treatment at 350 ℃. The existence of the simple substance silver is beneficial to reducing the nucleation barrier of the metal lithium and inhibiting the side reaction in the electrochemical process in the deposition process of the metal lithium.
FIG. 3 shows the surface morphology of the prepared three-dimensional dielectric oxidized polyacrylonitrile/nano-silver host material. The three-dimensional dielectric oxidation state polyacrylonitrile/nano-silver host material obtained by electrostatic spinning has a good 3D coaxial interweaving structure formed by oxidized polyacrylonitrile nano-fibers, has no obvious silver agglomerate particles, and shows that the nano-silver particles are well distributed on a skeleton structure. The good skeleton structure not only provides a space for alleviating volume expansion, but also can improve the cycling stability of the electrode material by virtue of good chemical stability.
To illustrate the properties of the composite material provided in this example by comparison, comparative example 1 was used for comparison.
Comparative example 1
Lithium is adopted as electrodes on two sides of the battery, 1M LiTFSI and DOL/DME (v: v ═ 1:1) are mixed to prepare electrolyte, and a PP diaphragm is used in an Ar atmosphere glove box with water and oxygen content lower than 1ppm to assemble the lithium-symmetric battery.
FIG. 4 is a graph comparing the cycling performance of the symmetrical cell using the three-dimensional dielectric oxidized polyacrylonitrile/nanosilver-lithium metal in example 1 of the present invention with that of the symmetrical cell using unmodified lithium metal in comparative example 1; in this figure and the following figures 5 to 7, the example is denoted by # 1, the comparative example is denoted by # 2, and the description thereof will not be repeated.
It can be seen that at 1mA/cm2Current density of 4mAh/cm2Under the surface capacity of the composite electrode, the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium composite electrode can be stably circulated, the overpotential is low, and the overpotential does not have the trend of obvious increase along with the deepening of the circulation depth. Meanwhile, the overpotential of the unmodified metal lithium electrode is obviously higher than that of the unmodified metal lithium electrode, and the polarization is gradually and obviously increased.
Example 2
The embodiment provides a lithium-copper half-cell using a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material as a positive electrode, and the preparation method comprises the following steps:
(1) dissolving 0.5g of polyacrylonitrile and 0.05g of silver nitrate in 10mL of DMF to obtain a uniform solution;
(2) carrying out electrostatic spinning on the solution (the voltage is 15kV, the needle head distance is 15cm, and the liquid inlet speed is 0.5mL/h) to obtain a three-dimensional interweaving precursor;
(3) and (3) heating the precursor to 350 ℃ at a heating rate of 2 ℃/min in the air, preserving the heat for 3 hours to obtain a three-dimensional dielectric oxidation state polyacrylonitrile/nano-silver host material, drying for 12 hours at 80 ℃, cutting to obtain a pole piece, covering the cut pole piece on copper foil, and obtaining the positive pole piece.
(4) The positive pole piece and the metal lithium are used as the negative pole piece, and 1M LiPF6Mixing with EC/DMC (v: v ═ 1:1) to prepare electrolysisAnd assembling the lithium-copper half cell by using a PP diaphragm in an Ar atmosphere glove box with water and oxygen content lower than 1 ppm.
To illustrate the properties of the composite material provided in this example by comparison, comparative example 2 was used for comparison.
Comparative example 2
Copper foil is used as a positive pole piece, metal lithium is used as a negative pole piece, and 1M LiPF6Mixing the lithium-copper semi-cell with EC/DMC (v: v ═ 1:1) to prepare an electrolyte, and assembling the electrolyte into a lithium-copper semi-cell by using a PP diaphragm in an Ar atmosphere glove box with water and oxygen content lower than 1 ppm.
FIG. 5 is a comparison graph of the cycle performance of the three-dimensional dielectric oxidized polyacrylonitrile/nano silver-metallic lithium composite negative electrode-Cu | Li in example 2 of the present invention and the half-cell of Cu | Li in comparative example 2; the results show that at 1mA/cm2Current density of 1mAh/cm2Under the surface capacity of the composite material, the cycle performance of the half-cell of the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium electrode is obviously superior to that of an unmodified Cu I Li half-cell. After 60 cycles, the coulombic efficiency of the unmodified Cu | | | Li half-cell decreased from 94.5% to 78.4%. On the contrary, the stable cycle of the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-Cu | Li half-cell exceeds 150 circles and the coulombic efficiency is as high as 97.1%.
FIG. 6 is a capacity-voltage curve of example 2 of the present invention and comparative example 2; the result shows that the modified electrode has better electrode dynamic performance, and the deposition of the metallic lithium has smaller nucleation barrier.
Example 3
The embodiment provides a lithium metal secondary battery applying a three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material cathode, and a preparation method of the lithium metal secondary battery comprises the following steps:
(1) dissolving 0.5g of polyacrylonitrile and 0.05g of silver nitrate in 10ml of DMF to obtain a uniform solution;
(2) carrying out electrostatic spinning on the solution (the voltage is 15kV, the needle head distance is 15cm, and the liquid inlet speed is 0.5mL/h) to obtain a three-dimensional interweaving precursor;
(3) heating the precursor to 350 ℃ in air at a heating rate of 2 ℃/min, and preserving the heat for 3 hours to obtain a three-dimensional dielectric oxidation stateBaking polyacrylonitrile/nano silver host material at 80 deg.C for 12 hr, cutting to obtain pole piece, covering the cut pole piece on copper foil, and electrochemical composite depositing for 4mAh/cm2And obtaining the negative pole piece by using the metal lithium.
(4) Reacting LiNi0.9Co0.1O2Grinding and uniformly mixing the positive electrode material, conductive carbon black and polytetrafluoroethylene according to the mass ratio of 9:1.5:1, coating the mixture on an aluminum foil to prepare a positive electrode plate, completely drying the electrode plate at 80 ℃ for 12 hours, and using the negative electrode plate to prepare a 1MLiPF6Mixing with EC/DMC (v: v ═ 1:1) to prepare electrolyte, and assembling the electrolyte into a lithium ion battery by using a PP diaphragm in an Ar atmosphere glove box with water and oxygen content lower than 1 ppm.
The above experiments were all conducted in a glove box under an inert atmosphere.
To illustrate the properties of the composite material provided in this example by comparison, comparative example 3 was used for comparison.
Comparative example 3
Reacting LiNi0.9Co0.1O2The mass ratio of the positive electrode material to the conductive agent to the binder is 9:1.5:1, the positive electrode material, the conductive agent and the binder are uniformly ground and mixed, the mixture is coated on an aluminum foil to prepare a positive electrode plate, the positive electrode plate is thoroughly dried at the temperature of 80 ℃ for 12 hours, metal lithium is used as a negative electrode plate, and 1M LiPF6Mixing with EC/DMC (v: v ═ 1:1) to prepare electrolyte, and assembling the electrolyte into a lithium ion battery by using a PP diaphragm in an Ar atmosphere glove box with water and oxygen content lower than 1 ppm.
Fig. 7 is a graph comparing the cycle performance of the lithium metal secondary batteries of example 3 of the present invention with that of comparative example 3. The results show that the three-dimensional dielectric oxidized polyacrylonitrile/nano silver-Li LiNi of example 30.9Co0.1O2The full battery can release 194.4mAh/g of specific discharge capacity in the first circle, still can keep 167.8mAh/g of specific discharge capacity after being cycled for 100 weeks, and the capacity retention rate is 86.3%. This slight capacity fade is primarily a structural degradation of the positive electrode material during cycling. Therefore, the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite negative electrode has good cycling stability. In contrast, Li | LiNi of comparative example 30.9Co0.1O2The full battery releases 193.8mAh/g of specific discharge capacity in the first circle, and can only keep 129.8mAh/g of specific discharge capacity after being cycled for 100 weeks, and the capacity retention rate is only 66.9%. This sharp capacity fade is mainly caused by the continuous side reaction and lithium dendrite growth on the negative side during cycling.
Therefore, the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material provided by the embodiment of the invention has the following beneficial effects by intersecting with the conventional commonly used electrode material:
1. the three-dimensional dielectric oxidation state polyacrylonitrile serving as a skeleton structure of the material can provide a stable host structure, remarkably relieves volume expansion caused by metal lithium deposition in a circulation process, and obviously promotes the circulation stability of a metal lithium cathode;
2. due to the low electronic conductivity of the three-dimensional dielectric oxidation state polyacrylonitrile skeleton, the ideal bottom-up deposition mode of the metal lithium can be induced, and a large number of ion channels can be provided, so that the circulation stability of the metal lithium cathode is promoted;
3. the three-dimensional dielectric oxidation state polyacrylonitrile skeleton has a large number of oxygen-containing functional groups on the surface, so that the wettability of the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium cathode and an organic electrolyte is obviously improved, and the electrode is ensured to be in good contact with the electrolyte;
4. the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite negative electrode contains a large amount of nano silver particles, and the nano silver particles effectively reduce nucleation potential of metal lithium and obviously improve coulomb efficiency in a circulation process;
5. the three-dimensional dielectric oxidation polyacrylonitrile/nano silver-metal lithium composite negative electrode fully combines the advantages of a three-dimensional current collector in regulating and controlling the deposition behavior of metal lithium and inhibiting side reactions in alloying, and realizes that the metal lithium is at 4mA/cm2High current density and 4mAh/cm2Stable cycling at high surface capacity provides a new visual angle for the research on the protection of the metallic lithium cathode;
6. the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite material is used as a negative electrode material, so that the lithium metal secondary battery with the energy density of more than 350Wh/kg can be obtained.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. The preparation method of the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material is characterized in that the three-dimensional dielectric polyacrylonitrile is specifically three-dimensional dielectric oxidized polyacrylonitrile with oxygen-containing polar functional groups on the surface; the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver is used as a host material; the host material has an electronic conductivity of 107S/m~109 S/m；
The three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material is obtained by electrochemical compounding of a three-dimensional dielectric oxidized polyacrylonitrile/nano silver host material and lithium metal, and the lithium metal is induced to deposit from bottom to top by the three-dimensional dielectric oxidized polyacrylonitrile;
in the composite material, the three-dimensional dielectric oxidized polyacrylonitrile serves as a framework and an ion transmission channel of the composite material, the nano-silver serves as a nucleation site, and the content of the nano-silver accounts for 5-30 wt% of the host material;
the preparation method comprises the following steps:
mixing polyacrylonitrile, a solvent and a silver source under an inert atmosphere to obtain a mixed solution;
carrying out electrostatic spinning on the obtained mixed solution to obtain three-dimensional interwoven polyphenyl nitrile/silver salt compound composite nanowires;
carrying out heat treatment on the obtained polyphenylenenitrile/silver salt compound composite nanowire at the temperature of 300-400 ℃ for 3-6 hours, wherein in the heat treatment process, silver compound salts are reduced to simple substance silver, and oxygen-containing polar functional groups are added on the surface of the polyphenylenenitrile to obtain a three-dimensional dielectric oxidation state polyacrylonitrile/nano silver host material;
and carrying out electrochemical compounding on the obtained three-dimensional dielectric oxidation state polyacrylonitrile/nano silver host material and lithium metal to obtain the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-lithium metal composite material.
2. The preparation method according to claim 1, wherein the solvent is one or a mixture of N, N-dimethylformamide, acetone and hexafluoroisopropanol, and the silver source is silver nitrate and/or silver sulfate; the silver salt compound is silver nitrate and/or silver sulfate.
3. The preparation method according to claim 1, wherein the mixing polyacrylonitrile, the solvent and the silver source to obtain the mixed solution specifically comprises:
dissolving 0.1-1 g of polyacrylonitrile and 0.02-3 g of silver source in 10mL of solvent, stirring and dissolving at a stirring speed of 0-800 r/min, and standing at room temperature after all the polyacrylonitrile and the silver source are dissolved to obtain the mixed solution.
4. The preparation method of claim 1, wherein the electrostatic spinning voltage is 15kV to 20kV, the needle distance is 15cm, and the humidity is less than 50%.
5. The production method according to claim 1, wherein an atmosphere of the heat treatment is an air atmosphere;
the heating process is also included before the heat treatment process, and the heating rate is 2-5 ℃/min; and after the heat treatment process, a cooling process is also included, and the cooling rate is natural cooling.
6. The method of claim 1, wherein the electrochemical recombination is specifically electrochemical lithium plating with a surface capacity of 4mAh/cm2The current is 0.5mA/cm2。
7. A lithium metal secondary battery, characterized in that the lithium metal secondary battery comprises the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material prepared by the preparation method of claim 1.
8. The lithium metal secondary battery of claim 7, wherein the three-dimensional dielectric polyacrylonitrile/nano silver-lithium composite material is used for a battery negative electrode or positive electrode.
9. A method for preparing a lithium metal secondary battery according to claim 7 or 8, comprising:
in a glove box under inert atmosphere, LiNi0.9Co0.1O2The positive electrode material, the conductive agent and the binder are uniformly mixed by grinding according to the mass ratio of (8-10) to (1-2) to 1, and the mixture is coated on an aluminum foil to prepare a positive electrode plate; wherein the conductive agent is acetylene black and/or conductive carbon black Super P; the binder is one or a mixture of more of polyacrylic acid, polytetrafluoroethylene and polyvinylidene fluoride;
and drying the obtained positive electrode plate at 80-100 ℃, cutting to obtain the positive electrode plate, and assembling the positive electrode plate and a negative electrode plate made of the three-dimensional dielectric oxidation state polyacrylonitrile/nano silver-metal lithium composite material into the lithium secondary battery.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103160053A (en) * | 2012-12-07 | 2013-06-19 | 河南城建学院 | Preparation method of polyacrylonitrile electromagnetic shielding nanocomposite |
| CN103606689A (en) * | 2013-11-14 | 2014-02-26 | 清华大学 | Method for preparing carbon nanofiber based non-noble-metal catalyst through oxidation improved electrostatic spinning |
| CN107039652A (en) * | 2017-03-24 | 2017-08-11 | 江苏乐能电池股份有限公司 | A kind of preparation method of high security trielement composite material |
| CN108232117A (en) * | 2018-01-27 | 2018-06-29 | 浙江大学 | A kind of lithium metal battery negative material and its preparation method and application |
| CN209104268U (en) * | 2017-11-08 | 2019-07-12 | 株式会社Lg化学 | Electrode with three-dimensional structure and the electrochemical appliance comprising it |
| CN110690420A (en) * | 2019-09-11 | 2020-01-14 | 清华大学深圳国际研究生院 | Composite material cathode, battery and preparation method thereof |
| CN111129516A (en) * | 2019-12-30 | 2020-05-08 | 易航时代(北京)科技有限公司 | Silver-loaded hollow carbon nanofiber composite catalyst and preparation method and application thereof |
| CN111557056A (en) * | 2018-10-18 | 2020-08-18 | 株式会社Lg化学 | Three-dimensional structure electrode and electrochemical device including the same |
Family Cites Families (3)
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| CN101373829B (en) * | 2008-10-07 | 2011-05-11 | 深圳市贝特瑞新能源材料股份有限公司 | Titanium-series cathode active material and preparation method thereof, titanium-series lithium ion power battery |
| CN103779090A (en) * | 2012-10-26 | 2014-05-07 | 海洋王照明科技股份有限公司 | Polymer dielectric, preparation method for the same, super capacitor and application thereof |
| US10914637B2 (en) * | 2018-06-23 | 2021-02-09 | Massachusetts Institute Of Technology | Ultrasensitive thermo-mechanical bolometer |
-
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Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103160053A (en) * | 2012-12-07 | 2013-06-19 | 河南城建学院 | Preparation method of polyacrylonitrile electromagnetic shielding nanocomposite |
| CN103606689A (en) * | 2013-11-14 | 2014-02-26 | 清华大学 | Method for preparing carbon nanofiber based non-noble-metal catalyst through oxidation improved electrostatic spinning |
| CN107039652A (en) * | 2017-03-24 | 2017-08-11 | 江苏乐能电池股份有限公司 | A kind of preparation method of high security trielement composite material |
| CN209104268U (en) * | 2017-11-08 | 2019-07-12 | 株式会社Lg化学 | Electrode with three-dimensional structure and the electrochemical appliance comprising it |
| CN108232117A (en) * | 2018-01-27 | 2018-06-29 | 浙江大学 | A kind of lithium metal battery negative material and its preparation method and application |
| CN111557056A (en) * | 2018-10-18 | 2020-08-18 | 株式会社Lg化学 | Three-dimensional structure electrode and electrochemical device including the same |
| CN110690420A (en) * | 2019-09-11 | 2020-01-14 | 清华大学深圳国际研究生院 | Composite material cathode, battery and preparation method thereof |
| CN111129516A (en) * | 2019-12-30 | 2020-05-08 | 易航时代(北京)科技有限公司 | Silver-loaded hollow carbon nanofiber composite catalyst and preparation method and application thereof |
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