CN111403804B - Polymer-based composite solid electrolyte film and preparation method thereof - Google Patents

Polymer-based composite solid electrolyte film and preparation method thereof Download PDF

Info

Publication number
CN111403804B
CN111403804B CN202010135737.XA CN202010135737A CN111403804B CN 111403804 B CN111403804 B CN 111403804B CN 202010135737 A CN202010135737 A CN 202010135737A CN 111403804 B CN111403804 B CN 111403804B
Authority
CN
China
Prior art keywords
polymer
magnetic
solid electrolyte
fiber
composite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010135737.XA
Other languages
Chinese (zh)
Other versions
CN111403804A (en
Inventor
张鑫
汪思威
吴睿鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wuhan University of Technology WUT
Original Assignee
Wuhan University of Technology WUT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wuhan University of Technology WUT filed Critical Wuhan University of Technology WUT
Priority to CN202010135737.XA priority Critical patent/CN111403804B/en
Publication of CN111403804A publication Critical patent/CN111403804A/en
Application granted granted Critical
Publication of CN111403804B publication Critical patent/CN111403804B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention relates to a polymer-based composite solid electrolyte film using magnetic composite fiber as filler and a preparation method thereof, and the polymer-based composite solid electrolyte film comprises the following components: a magnetic composite fiber; and a polymer matrix in which lithium salt is dissolved, wherein the volume ratio of the magnetic composite fibers is 0.5-2%, the volume ratio of the polymer is 99.5-98%, and the magnetic composite fibers are vertically oriented in the polymer matrix. The method comprises the following steps: 1) preparing the precursor sol into the magnetic composite fiber by an electrostatic spinning method and a calcining process; 2) the polymer matrix dissolved with lithium salt and the magnetic composite fiber are compounded again to form a film, and a magnetic field is introduced for orientation regulation. The process can control the distribution and orientation of the filler in the composite film, thereby improving the mechanical and electrical properties of the composite film by regulating and controlling the distribution structure of the filler and finally improving the room-temperature ionic conductivity of the solid electrolyte film.

Description

Polymer-based composite solid electrolyte film and preparation method thereof
Technical Field
The invention belongs to the technical field of solid electrolyte material preparation, and particularly relates to a polymer-based composite solid electrolyte film adopting magnetic composite fibers as a filler and a preparation method thereof.
Background
As an important electrochemical energy storage device, a lithium battery has high energy density, low self-discharge effect and high charging and discharging characteristics, so that the lithium battery is widely applied to portable electronic devices such as mobile phones and notebook computers, and occupies a large share in electric vehicles. In the field of energy storage device materials, with the development of electronic equipment in recent years, widely used energy storage devices are developed towards high energy storage, miniaturization and environmental protection. The electrolyte material of the traditional lithium ion battery consists of an organic solvent dissolved with lithium salt, has the dangers of electrolyte leakage, combustion and even explosion, has high packaging requirements on the battery, and has the problems of easy generation of lithium dendrite, unstable electrolyte, easy decomposition and the like in the using process. On the contrary, the solid electrolyte does not contain liquid components, so that the dangers of electrolyte combustion, explosion and the like can be effectively avoided, and the volume of the whole battery can be compressed to be small due to the fact that the solid electrolyte does not contain liquid components, so that the energy density of the battery is improved; however, the solid electrolyte has poor contact with the electrodes, resulting in large interfacial contact resistance, resulting in low room temperature ionic conductivity. The polymer material is widely applied to solid electrolyte materials due to the advantages of easy processing, good flexibility, light weight, good compatibility with electrodes, capability of being made into large-area films and the like. The polymer material is selected from the group consisting of: light weight, easy processing, low cost, good mechanical property, low glass transition temperature and the like. The polymer solid electrolyte has lower contact resistance between electrodes and better thermodynamic property, but the room-temperature ionic conductivity of the polymer solid electrolyte is lower, and the mechanical property of the polymer solid electrolyte is still to be improved so as to inhibit the problem of lithium dendrite and prevent the occurrence of electrolyte membrane rupture and anode and cathode short circuit caused by collision in the use process of a battery. Research shows that the addition of a certain amount of small-sized inorganic ceramic filler can reduce the crystallinity of the polymer and promote the motion of polymer chain segments, and certain groups of the inorganic ceramic filler possibly have interaction with the polymer matrix and lithium salt, and the interaction is favorable for the dissociation of the lithium salt and the inhibition of the recrystallization kinetic process of the polymer, so that the lithium ion carrier concentration and the motion capability of amorphous chain segments of the polymer are increased, and the room-temperature ionic conductivity is improved.
At present, a lot of progress is made in the research work of polymer matrix composite solid electrolyte materials, and most of the work is to select a polymer matrix with low glass transition temperature (Tg) and low crystallinity at room temperature from the aspects of polymer matrix, inorganic ceramic filler and interaction of the polymer matrix and the inorganic ceramic filler, select a fast ion conductor filler capable of transmitting lithium ions, perform surface modification by means of atomic deposition (ALD) and the like, design favorable interaction and accelerate lithium ion conduction. Zhang et al, studied tantalum-doped lithium lanthanum zirconium oxide (Li)6.75La3Zr1.75Ta0.25O12) The relationship between the synergistic coupling effect with polyvinylidene fluoride (PVDF) and the ionic conductivity, mechanical strength and thermodynamic stability of the electrolyte. The research finds that: the La atom in the LLZTO can generate a coordination effect with an N atom and a C ═ O functional group in a solvent molecule, such as nitrogen-nitrogen Dimethylformamide (DMF), so that the N atom is in an electron-rich state, the Lewis base characteristic is shown, the dehydrofluorination behavior of a PVDF chain is induced, and the interaction among the PVDF, lithium salt and the LLZTO chain segment can be activated by the partially modified PVDF chain segment, so that the ionic conductivity, the mechanical property and the thermal stability of the composite electrolyte are improved. Yi et al, studied barium titanate (BaTiO)3) Shape of nanofiller (nanofiber, nano)Tube, nanoplate) on the performance of polyethylene oxide (PEO) based electrolytes, studies have found: the BaTiO3 nano filler has better affinity with a PEO matrix due to the organic functional groups on the surface, so that the BaTiO3 nano filler can be uniformly distributed in an electrolyte film; adding BaTiO3When the nano-sheet is used, the main XRD diffraction peak intensity of the polymer matrix PEO is lowest, the DSC melting temperature Tm is lowest, namely BaTiO is added3The influence of the reduction effect of the crystallinity of the polymer matrix of the nanosheet is greatest; investigation of the shift of the C-O-C peak in the Infrared Spectroscopy (FTIR) found BaTiO3the-OH and-OR groups on the surface of the nano filler can be combined with O atoms in PEO chain segments of the polymer matrix and Li in lithium salt+Interaction, thereby weakening Li+Complexation with O atoms promotes Li+Transport along the PEO segment; BaTiO 23The nano filler is spontaneously polarized and surface charge induces the formation of an interface, and the formed interface has high dielectric constant and various defects, thereby being beneficial to Li+In which BaTiO is3The nano sheet has the largest specific surface area, is most beneficial to the formation of the interface, so that the ionic conductivity is improved most obviously, and BaTiO3The room-temperature ionic conductivity of the nanosheet-PEO-LiTFSI electrolyte reaches 1.8 multiplied by 10-5S/cm。
Researchers have found that rapid lithium ion transport can be achieved by designing the size, shape, etc. of the interface between the polymer matrix and the inorganic ceramic filler, thereby improving the room temperature ionic conductivity of the electrolyte. Liu et al, studied the effect of ceramic nanofibers that are not aligned on the ionic conductivity of a composite polymer electrolyte. The research finds that: when the ceramic nano-fiber filler forms an included angle of 0 degree with the normal direction of the electrode surface in the polymer matrix, namely Li+The shortest rapid conduction path along the fiber-polymer interface is compared to the pure polymer electrolyte without filler (4.31X 10)-7S/cm), random arrangement of fiber filler, and composite polymer electrolyte (7.82 x 10)-6S/cm), the ionic conductivity of the composite polymer electrolyte with good arrangement and shortest rapid conduction path is greatly improved, and the ionic conductivity at room temperature reaches 5.02 multiplied by 10-5S/cm, and the corresponding mechanical property and the cycling stability are also improved.Zhang et Al, which studied the effect of continuous vertically aligned nano-scale ceramic-polymer interfaces on the ionic conductivity of composite solid polymer electrolytes, first designed alumina (Al) with different nanotube sizes2O3) Ceramic disk, then laminating polyethylene oxide-lithium bistrifluoromethanesulfonimide (PEO-LiTFSI) solid polymer electrolyte film at 65 ℃ under Al2O3Finally, the laminated film and the ceramic disk are put into a 215 ℃ vacuum furnace to ensure that the electrolyte is fully melted and permeated into Al2O3A composite solid polymer electrolyte with vertical and continuous nanometer-sized interface in the nanometer pipeline, and a strong Lewis acid-AlF is deposited on the nanometer pipeline by adopting an atomic deposition technology (ALD)3Further research shows that: for pure polymer electrolyte (PEO-LiTFSI) Li+The transport of (a) can only be achieved by ether oxygen assisted hopping or polymer chain segment movement; composite solid polymer electrolyte (PEO-LiTFSI-Al)2O3) With two kinds of Li+Conduction pathways, the first being Li induced by ether oxygen or polymer segmental motion+Transport, the second is along the ceramic-polymer interface. Finally, Al of the nano-tube with reasonable smaller size is selected2O3Ceramic chip and nano-tube surface modification by ALD, PEG with small molecular weight is selected as polymer matrix to obtain room temperature ionic conductivity of 5.82 × 10-4S/cm of composite solid polymer electrolyte.
Disclosure of Invention
The present invention is directed to the above-mentioned prior art, and an object of the present invention is to provide a polymer-based composite solid electrolyte thin film and a method for preparing the same, which can shorten a lithium ion transmission path, achieve rapid transmission of lithium ions, and improve room temperature ionic conductivity of a solid electrolyte.
The technical scheme adopted by the invention for solving the technical problems is as follows: a polymer-based composite solid electrolyte membrane having a composition comprising: a magnetic composite fiber; and a polymer matrix in which lithium salt is dissolved, wherein the volume ratio of the magnetic composite fibers is 0.5-2%, the volume ratio of the polymer is 99.5-98%, and the magnetic composite fibers are vertically oriented in the polymer matrix.
According to the scheme, the magnetic composite fiber is composed of a 1-dimensional fiber substrate and 0-dimensional magnetic oxide particles filled in the fiber, the fiber substrate is made of lanthanum lithium titanate, the 0-dimensional magnetic oxide particles are ferroferric oxide nano particles, and the lithium salt is bis (trifluoromethane) sulfonyl imide lithium.
According to the scheme, the diameter of the magnetic composite fiber is 200 nm-1 μm, the length of the magnetic composite fiber is 1 μm-20 μm, and the diameter of the filled 0-dimensional magnetic oxide particles is 20 nm.
According to the scheme, the polymer matrix is made of one or more materials of polyvinylidene fluoride (PVDF), polyethylene oxide (PEO) and Polyacrylonitrile (PAN).
According to the scheme, the thickness of the composite solid electrolyte membrane is 20-60 mu m.
According to the scheme, the volume ratio of the filled 0-dimensional magnetic oxide particles to the 1-dimensional fiber matrix in the magnetic composite fiber is 1: 2.
The preparation method of the polymer-based composite solid electrolyte film comprises the following steps:
1) preparing the precursor sol into the magnetic composite fiber by an electrostatic spinning method and a calcining process;
2) the polymer matrix dissolved with lithium salt and the magnetic composite fiber are compounded again to form a film, and a magnetic field is introduced for orientation regulation.
According to the scheme, the polymer matrix and the magnetic composite fiber are compounded again to form the membrane, and the membrane is prepared by a solution casting method and a method of introducing an external magnetic field vertical to the upper surface and the lower surface of an electrolyte membrane in the solvent drying process.
According to the scheme, the precursor sol is prepared by the following method: lithium nitrate and lanthanum nitrate hexahydrate are used as Li and La sources, are weighed according to the molar ratio of excess of 10% of Li, are dissolved in DMF and acetic acid, tetrabutyl titanate is added as a Ti source after being dissolved completely, LLTO stock solution is obtained after being stirred completely, then a proper amount of ferroferric oxide nano particles are added, and after being stirred uniformly, polyvinylpyrrolidone is added finally, and spinning precursor sol is obtained after being stirred completely.
In the composite solid polymer electrolyte, the lithium ion transmission path is mainly as follows: passing through a polymer phase; passing through a ceramic phase; ③ through a polymer/ceramic interface. And because of the excellent electrochemical property of the ceramic phase, lithium ions tend to pass through the ceramic phase and a polymer/ceramic interface, so that the rapid lithium ion transmission path can be shortened by designing the vertical orientation arrangement of the ceramic filler in the polymer matrix, and the further improvement of the ionic conductivity of the composite solid polymer electrolyte is realized. Therefore, based on the idea of designing an interface between a polymer matrix and an inorganic ceramic filler which are perpendicular to the outside of the surface of the solid electrolyte film, the invention designs a novel composite solid electrolyte film preparation process, which not only can prepare an organic-inorganic composite solid electrolyte film with high quality, but also can regulate and control the distribution and orientation of the inorganic filler in the polymer composite material, thereby preparing the composite solid electrolyte film with a specific composite structure.
The invention firstly prepares the magnetic composite fiber, and compounds the processed magnetic composite fiber with the polymer matrix, and the magnetic nano composite fiber is vertically arranged in the polymer matrix under the auxiliary action of an external magnetic field, thereby shortening the transmission path of lithium ions, realizing the rapid transmission of lithium ions, improving the room temperature ionic conductivity of the polymer matrix composite solid electrolyte, and simultaneously, because the ceramic filler is arranged along the outside direction of the electrolyte film surface, the mechanical property of the electrolyte film in the outside direction is further improved, which is beneficial to inhibiting the growth of lithium dendrite in the circulation process of the battery.
The invention has the following effective effects: (1) the preparation process is simpler, and the thickness of the film can be effectively controlled; (2) the general composite solid electrolyte film preparation process can only prepare composite films with randomly dispersed fillers, and the process can control the distribution and orientation of the fillers in the composite films, so that the mechanical and electrical properties of the composite films can be improved by regulating and controlling the distribution structure of the fillers, and the room temperature ionic conductivity of the solid electrolyte films is finally improved.
Drawings
FIG. 1 is a scanning electron microscope picture before calcination of the composite nanofiber prepared by the electrospinning method in example 1;
FIG. 2 is a scanning electron microscope picture and an EDS picture of the composite nanofiber prepared by the electrospinning method in example 1 after calcination;
FIG. 3 is a scanning electron microscope image of the cross section of the solid electrolyte thin film with randomly distributed fibers and vertically oriented fibers prepared by casting after mixing PVDF and composite fibers with different contents in example 2, example 3, example 4 and example 5;
FIG. 4 is an AC impedance spectrum of a composite solid electrolyte having fiber volume fractions of 0 vol%, 0.5 vol%, 1 vol%, and 2 vol% in example 2, example 3, example 4, and example 5, respectively;
fig. 5 is a graph showing changes in room temperature ionic conductivity with respect to the fiber content of the solid electrolyte in which the fiber volume fractions of example 2, example 3, example 4, and example 5 were 0 vol%, 0.5 vol%, 1 vol%, and 2 vol%, respectively, in the random distribution and the vertical orientation distribution of the fibers.
FIG. 6 is a graph showing cell performance at room temperature of solid electrolytes in which the fiber volume fractions are 0 vol%, 0.5 vol%, 1 vol%, and 2 vol%, respectively, in examples 2, 3, 4, and 5, and in which the fibers are randomly distributed and vertically aligned.
Detailed Description
With gamma-Fe2O3The preparation process of the composite fiber and the polymer-based solid electrolyte film thereof comprises the following steps:
(1) preparing precursor sol for composite fiber spinning with gamma-Fe2O3nanoparticles/Li0.33La0.557TiO3Preparation of magnetic nanocomposite fibers as an example: firstly, measuring a certain amount of lithium nitrate and lanthanum nitrate hexahydrate, wherein the mass of lithium is 10 wt% more, the lithium nitrate and the lanthanum nitrate hexahydrate are used for compensating the lithium loss in the subsequent high-temperature sintering process, and the molar ratio of the rest Li to La is 0.33: 0.557, dissolving in a certain amount of DMF and acetic acid, adding a certain amount of tetrabutyl titanate until the solution is completely dissolved, wherein the molar ratio of La to Ti is 0.557:1, adding a certain amount of acetylacetone until the solution is uniformly stirred to obtain stock solution LLTO, then taking a certain amount of the stock solution, adding an equal amount of DMF, and weighing a proper amount of Fe3O4And (3) crushing cells of the nano particles, adding the mixed solution obtained in the previous step, uniformly stirring, finally adding polyvinylpyrrolidone (PVP, M is 1300000), and stirring to a uniform and stable state to form the spinning precursor sol.
(2) And transferring the spinning precursor sol into an injector, performing electrostatic spinning at the voltage of 1kV/cm, and obtaining a precursor of the composite fiber in a roller receiving mode.
(3) And (3) sintering the composite fiber precursor at the temperature rise rate of 5 ℃/min for 2h at 850 ℃ to obtain the composite fiber.
(4) The magnetic composite fiber is treated by means of ultrasonic treatment, drying and the like, added into completely dissolved PVDF and LiTFSI solution, uniformly stirred, prepared into a film with a certain thickness by a solution casting method, and introduced with an external magnetic field with proper magnetic field intensity vertical to the upper surface and the lower surface of an electrolyte film while being dried in vacuum at 80 ℃ to finally prepare the solid electrolyte film with the magnetic composite fiber filler in vertical orientation arrangement in a polymer matrix.
The invention is further illustrated by the following examples:
example 1:
weighing 1.045g of lithium nitrate and 5.47g of lanthanum nitrate hexahydrate, dissolving in 5ml of DMF and 2ml of acetic acid, stirring to be in a uniform stable state, adding 10.419g of tetrabutyl titanate, continuously stirring to be in a uniform stable state to obtain a stock LLTO solution, taking 3ml of the stock solution, adding 0.5g of Fe3O4The nano particles are added after 300W power cell pulverization in 3ml DMF for 8hStirring the 3ml of LLTO stock solution taken out in the last step for 30min, adding 0.5g of PVP, stirring for 3h to form stable sol, transferring the sol into an injector for electrostatic spinning, performing electrostatic spinning under an electric field of 1kV/cm, changing the sol every 30min, and collecting the electrostatic spun fiber by a roller in a manner of collecting the electrostatic spun fiber, wherein the fiber before calcination has a diameter of about 1 mu m and Fe is observed as a scanning electron microscope picture 13O4The nano particles are uniformly attached to the surface of the fiber; and then calcining the fiber at 800 ℃ for 2h at the heating rate of 5 ℃/min to obtain the final magnetic composite fiber. The morphology of the obtained magnetic composite fiber is as shown in a Scanning Electron Microscope (SEM) 2, the diameter of the calcined fiber is reduced to about 200nm, and the uniform distribution of magnetic particles on the surface of the fiber can be seen in an EDS energy spectrum.
Comparative example 2:
weighing 1g of PVDF powder and 0.33g of LiTFSI in a glove box, dissolving in 10ml of DMF solvent, fully stirring for 24h, carrying out solution-casting, and drying at 80 ℃ for 24h to obtain the PVDF/LiTFSI solid polymer electrolyte film. As in fig. 3 a0、a1It can be seen that the cross section of the pure PVDF/LiTFSI solid polymer electrolyte membrane is dense, and no significant holes are generated, which is beneficial to the transmission of lithium ions.
Example 3:
taking 0.05g of the magnetic composite fiber in the embodiment 1 to be placed in 50ml of ethanol, carrying out ultrasonic treatment for 2min under 40W power, then carrying out centrifugation and drying treatment to obtain a short magnetic composite fiber with the size of 1-20 mu m, measuring 3ml of DMF solvent, adding 0.014g of the composite fiber, carrying out ultrasonic treatment for 2min under 40W, then adding the composite fiber into sol dissolved with PVDF and LiTFSI which are uniformly stirred in advance, stirring for 5h to a uniform and stable state, then carrying out tape casting on the mixed solution, drying for 24h at 80 ℃, normally drying one part of the mixed solution, introducing a parallel magnetic field with proper magnetic field intensity along the upper surface and the lower surface of an electrolyte film while drying the other part of the mixed solution, and obtaining the composite solid electrolyte film with the volume fraction of 0.5 vol% and with the fibers in random distribution orientation and the fibers in vertical orientation arrangement. As in b of FIG. 30、b1It can be seen that the fibrous filler in the composite electrolyte thin film is oriented by the magnetic fieldClearly showing a vertically oriented alignment trend (graph b)0Shown), the fiber filler obviously shows random distribution and has a tendency of parallel distribution along the surface in the composite electrolyte film which is not regulated by the magnetic field. (FIG. b)1Shown in
Example 4:
taking 0.05g of the composite fiber in the embodiment 1, placing the composite fiber in 50ml of ethanol, carrying out ultrasonic treatment for 2min under 40W power, carrying out centrifugation and drying treatment to obtain a short magnetic composite fiber with the size of 1-20 mu m, measuring 3ml of DMF solvent, adding 0.028g of the composite fiber, carrying out ultrasonic treatment for 2min under 40W, adding the composite fiber into sol dissolved with PVDF and LiTFSI which are uniformly stirred in advance, stirring for 5h to a uniform and stable state, carrying out tape casting on the mixed solution, drying for 24h at 80 ℃, carrying out normal drying on one part, introducing a parallel magnetic field with appropriate magnetic field intensity along the upper surface and the lower surface of an electrolyte film while drying the other part, and obtaining the composite solid electrolyte film with the volume fraction of 1 vol% and with the fibers randomly distributed and oriented and the fibers in vertical oriented arrangement. As in c of FIG. 30、c1It can be seen that the fibrous filler in the composite electrolyte thin film oriented by the magnetic field apparently shows a vertical orientation alignment tendency (graph c)0Shown), the fiber filler obviously shows random distribution and has a tendency of parallel distribution along the surface in the composite electrolyte film which is not regulated by the magnetic field. (FIG. c)1Shown) at the same time, due to the increase of the content of the fibrous filler, the filler begins to agglomerate in the polymer matrix, which is not beneficial to the transmission of lithium ions.
Example 5:
putting 0.05g of the composite fiber in the embodiment 1 into 50ml of ethanol, performing ultrasonic treatment for 2min under 40W power, performing centrifugation and drying treatment to obtain a short magnetic composite fiber with the size of 1-20 mu m, measuring 3ml of DMF solvent, adding 0.056g of the composite fiber, performing ultrasonic treatment for 2min under 40W, adding the mixture into sol dissolved with PVDF and LiTFSI which is stirred uniformly in advance, stirring for 5h to a uniform and stable state, casting the mixed solution, drying for 24h at 80 ℃, normally drying one part, introducing a parallel magnetic field with appropriate magnetic field intensity along the upper surface and the lower surface of an electrolyte film while drying the other part, and obtaining the fiber with the volume fraction of 2vol percentThe dimension is randomly distributed and oriented, and the fiber is vertically oriented and arranged. As in d of FIG. 30、 d1It can be seen that the fibrous filler in the composite electrolyte thin film subjected to magnetic field orientation clearly exhibits a tendency of homeotropic alignment (graph d)0Shown), the fiber filler obviously shows random distribution and has a tendency of parallel distribution along the surface in the composite electrolyte film which is not regulated by the magnetic field. (FIG. d)1Shown) and, due to the further increase of the content of the fibrous filler, the agglomeration phenomenon of the filler in the polymer matrix is severe, and the cross section of the electrolyte membrane begins to appear obvious holes.
Example 6:
a LiCoO was assembled in a glove box from the pure PVDF/LiTFSI solid polymer electrolyte film of example 2 and the composite solid electrolyte film of example 4 in which the fibers having a filler content of 1 vol% were randomly distributed and oriented and the fibers were arranged in a vertical orientation2The Li cell was cycled at 0.1C rate for 30 cycles, comparing the cycling performance of the three cells. As shown in FIG. 6, it can be seen that pure PVDF/LiTFSI solid polymer electrolyte battery has poor cycle performance due to low room temperature ionic conductivity, and the capacity after 30 cycles is 119.8mAh g from the first cycle-1Attenuation was 38.0mAh g-1(see FIG. 6 a); the 1 vol% fiber randomly distributed and oriented composite solid electrolyte battery has obviously improved battery cycle performance due to the improvement of room temperature ionic conductivity, and the capacity after 30 circles is 113.9mAh g of the first circle-1Attenuation is 111.4mAh g-1However, the cycling of the battery is less stable due to the redox reaction between the LLTO and Li metal in the composite fiber (see fig. 6 b); the 1 vol% fiber out-of-plane distribution oriented composite solid electrolyte battery has obviously improved cycle performance due to further improvement of room temperature ionic conductivity, and the capacity after 30 circles is 117.0mAh g of the first circle-1It became 119.5mAh g-1And when the fibers are vertically oriented along the electrolyte membrane, the contact area between the composite fibers and Li metal is smaller, so that a large amount of reaction between the fiber filler and the Li metal is avoided, and the cycle performance of the battery is more stable and excellent. (see FIG. 6c)
Fig. 4 is an ac impedance spectrum of the electrolyte thin films prepared in examples 2, 3, 4, and 5, the bulk impedance of the electrolyte film can be obtained according to the ac impedance spectrum, and then the peak ion conductivity of each electrolyte thin film is calculated according to an ion conductivity calculation formula as shown in fig. 5, it can be found that, after the ceramic filler is added, the ion conductivity of the composite solid dielectric thin film is higher than that of a pure polymer electrolyte thin film, and in all components, the ion conductivity of the composite solid electrolyte thin film in which the fibers are vertically oriented and arranged is further improved, and is higher than that of a composite solid electrolyte thin film in which the fibers of the same component are randomly distributed.

Claims (6)

1. A polymer-based composite solid electrolyte membrane having a composition comprising: a magnetic composite fiber; and a polymer matrix in which lithium salt is dissolved, wherein the volume ratio of the magnetic composite fibers is 0.5-2%, the volume ratio of the polymer is 99.5-98%, and the magnetic composite fibers are vertically oriented in the polymer matrix; the magnetic composite fiber consists of a 1-dimensional fiber matrix and 0-dimensional magnetic oxide particles filled in the fiber, wherein the fiber matrix is made of lanthanum lithium titanate, the 0-dimensional magnetic oxide particles are ferroferric oxide nano particles, and the lithium salt is bistrifluoromethanesulfonylimide lithium; the diameter of the magnetic composite fiber is 200 nm-1 μm, the length of the magnetic composite fiber is 1 μm-20 μm, and the diameter of the filled 0-dimensional magnetic oxide particles is 20 nm; in the magnetic composite fiber, the volume ratio of the filled 0-dimensional magnetic oxide particles to the 1-dimensional fiber matrix is 1: 2.
2. The polymer-based composite solid electrolyte membrane according to claim 1, wherein the polymer matrix is made of one or more materials selected from polyvinylidene fluoride, polyethylene oxide, and polyacrylonitrile.
3. The polymer-based composite solid electrolyte membrane according to claim 1, characterized in that the thickness of the composite solid electrolyte membrane is 20 μm to 60 μm.
4. The method for producing a polymer-based composite solid electrolyte membrane according to claim 1, comprising the steps of:
1) preparing the precursor sol into the magnetic composite fiber by an electrostatic spinning method and a calcining process;
2) the polymer matrix dissolved with lithium salt and the magnetic composite fiber are compounded again to form a film, and a magnetic field is introduced for orientation regulation.
5. The method for producing a polymer-based composite solid electrolyte membrane according to claim 4, wherein the polymer matrix and the magnetic composite fiber are again compounded to form a membrane by a solution casting method and an external magnetic field is introduced perpendicularly to the upper and lower surfaces of the electrolyte membrane during solvent drying.
6. The method for producing a polymer-based composite solid electrolyte membrane according to claim 4 or 5, characterized in that the precursor sol is produced by: lithium nitrate and lanthanum nitrate hexahydrate are used as Li and La sources, are weighed according to the molar ratio of excess of 10% of Li, are dissolved in DMF and acetic acid, tetrabutyl titanate is added as a Ti source after being dissolved completely, LLTO stock solution is obtained after being stirred completely, then a proper amount of ferroferric oxide nano particles are added, and after being stirred uniformly, polyvinylpyrrolidone is finally added, and spinning precursor sol is obtained after being stirred completely.
CN202010135737.XA 2020-03-02 2020-03-02 Polymer-based composite solid electrolyte film and preparation method thereof Active CN111403804B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010135737.XA CN111403804B (en) 2020-03-02 2020-03-02 Polymer-based composite solid electrolyte film and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010135737.XA CN111403804B (en) 2020-03-02 2020-03-02 Polymer-based composite solid electrolyte film and preparation method thereof

Publications (2)

Publication Number Publication Date
CN111403804A CN111403804A (en) 2020-07-10
CN111403804B true CN111403804B (en) 2021-09-21

Family

ID=71428535

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010135737.XA Active CN111403804B (en) 2020-03-02 2020-03-02 Polymer-based composite solid electrolyte film and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111403804B (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111816916B (en) * 2020-07-22 2022-05-31 珠海冠宇电池股份有限公司 Composite solid electrolyte membrane, preparation method thereof and lithium ion battery
CN113140786A (en) * 2021-03-15 2021-07-20 佛山仙湖实验室 Solid electrolyte and preparation method and application thereof
CN113594539B (en) * 2021-06-22 2023-02-17 上海电气集团股份有限公司 Composite electrolyte with gradient structure, solid-state battery and preparation method and application of composite electrolyte
NL2029308B1 (en) * 2021-10-01 2023-04-12 Lionvolt B V Hybrid solid electrolyte and battery comprising hybrid solid electrolyte
NL2029311B1 (en) * 2021-10-01 2023-04-12 Lionvolt B V Hybrid solid electrolyte and battery
WO2023055234A1 (en) * 2021-10-01 2023-04-06 Lionvolt B.V. Hybrid solid electrolyte and battery
CN113871700B (en) * 2021-10-09 2023-09-26 桂林理工大学 Composite solid electrolyte material of LLTO matrix with directional ordered structure, preparation method and application
CN114335709B (en) * 2021-12-14 2023-07-04 湘潭大学 Preparation method of polymer-based solid electrolyte membrane and battery
CN114744289A (en) * 2022-04-11 2022-07-12 湖南立方新能源科技有限责任公司 Magnetic composite solid electrolyte membrane, preparation method and method for preparing solid lithium metal battery
CN115483432B (en) * 2022-09-28 2024-01-09 哈尔滨工业大学 Composite solid electrolyte and preparation method thereof
CN115911577B (en) * 2022-11-24 2023-06-16 昆明理工大学 Preparation method of solid sodium ion battery

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7709115B2 (en) * 1994-08-25 2010-05-04 University Of Iowa Research Foundation Methods for forming magnetically modified electrodes and articles produced thereby
JP2005332722A (en) * 2004-05-21 2005-12-02 Toyota Motor Corp Separator for fuel cell and its manufacturing method
CN100450933C (en) * 2006-12-15 2009-01-14 清华大学 Manufacture method of lithium lanthanum titanium oxide
JP5163439B2 (en) * 2008-11-19 2013-03-13 Ｔｄｋ株式会社 FIBER-CONTAINING POLYMER FILM AND METHOD FOR PRODUCING SAME, ELECTROCHEMICAL DEVICE AND METHOD FOR PRODUCING SAME
CN101899725B (en) * 2010-03-31 2014-06-11 清华大学 Nano fiber of metal oxide and preparation method thereof
CN102543449B (en) * 2012-02-03 2013-11-06 中南大学 Solid magnetic polymer electrolyte as well as preparation method and application thereof
JP5812168B2 (en) * 2014-08-25 2015-11-11 大日本印刷株式会社 Manufacturing method of gas diffusion layer for fuel cell
CN107828344B (en) * 2017-11-21 2020-11-03 桂林电子科技大学 One-dimensional micro-nano particle/epoxy resin composite adhesive film arranged along Z direction and preparation method thereof
US10930971B2 (en) * 2018-02-27 2021-02-23 Nissan North America, Inc. Solid-state battery with polymer electrode structure
CN108808109B (en) * 2018-08-21 2021-06-04 电子科技大学 All-solid-state lithium ion battery membrane and preparation method thereof
CN109103505B (en) * 2018-08-21 2021-06-01 电子科技大学 Layered all-solid-state lithium ion battery and preparation method thereof
CN109148944A (en) * 2018-09-30 2019-01-04 中国航发北京航空材料研究院 A kind of composite solid electrolyte of high ionic conductivity and preparation method thereof
CN109301320B (en) * 2018-09-30 2020-12-29 中国航发北京航空材料研究院 Composite solid electrolyte with vertical orientation of inorganic solid electrolyte and preparation method thereof
CN109742332A (en) * 2018-11-23 2019-05-10 颍上北方动力新能源有限公司 A kind of production method of positive plate of lithium battery
CN109913978A (en) * 2019-03-06 2019-06-21 武汉理工大学 A kind of nucleocapsid structure composite fibre and preparation method thereof and the application in polymer matrix flexible composite film

Also Published As

Publication number Publication date
CN111403804A (en) 2020-07-10

Similar Documents

Publication Publication Date Title
CN111403804B (en) Polymer-based composite solid electrolyte film and preparation method thereof
Wu et al. Advances and prospects of PVDF based polymer electrolytes
Li et al. An advance review of solid-state battery: Challenges, progress and prospects
Yang et al. Composite polymer electrolytes with Li7La3Zr2O12 garnet-type nanowires as ceramic fillers: mechanism of conductivity enhancement and role of doping and morphology
JP6389318B2 (en) Positive electrode active material and manufacturing method thereof
Xu et al. Electrospun‐technology‐derived high‐performance electrochemical energy storage devices
Zhou et al. Low-strain titanium-based oxide electrodes for electrochemical energy storage devices: design, modification, and application
Zhu et al. LiNi1/3Co1/3Mn1/3O2/polypyrrole composites as cathode materials for high‐performance lithium‐ion batteries
Shin et al. Effects of TiO 2 Starting Materials on the Solid‐State Formation of Li 4 Ti 5 O 12
Li et al. Approaching high performance PVDF‐HFP based solid composite electrolytes with LLTO nanorods for solid‐state lithium‐ion batteries
Hua et al. Effects of surface lithiated TiO2 nanorods on room‐temperature properties of polymer solid electrolytes
Liu et al. Tailored Synthesis of Coral‐Like CoTiO3/Co3O4/TiO2 Nanobelts with Superior Lithium Storage Capability
Ji et al. Electrospinning preparation of one-dimensional Ce 3+-doped Li 4 Ti 5 O 12 sub-microbelts for high-performance lithium-ion batteries
Maurya et al. Designing Na2Zn2TeO6-embedded 3D-nanofibrous poly (vinylidenefluoride)-co-hexafluoropropylene-based nanohybrid electrolyte via electrospinning for durable sodium-ion capacitors
Sandhya et al. Synthesis and electrochemical characterisation of electrospun lithium titanate ultrafine fibres
Luo et al. A review on modified polymer composite electrolytes for solid-state lithium batteries
Jiang et al. Pyrochlore phase (Y, Dy, Ce, Nd, La) 2Sn2O7 as a superb anode material for lithium-ion batteries
Yin et al. Constructing MOF-derived V2O5 as advanced cathodes for aqueous zinc ion batteries
Liu et al. Fabrication of MnO2-graphene nanocomposite by ripening of amorphous MnO2 in graphene oxide matrix
Khan et al. Garnet/polymer solid electrolytes for high-performance solid-state lithium metal batteries: The role of amorphous Li2O2
Ji et al. Electrospinning preparation of one-dimensional Co 2+-doped Li 4 Ti 5 O 12 nanofibers for high-performance lithium ion battery
Wang et al. Achieving stable interface for lithium metal batteries using fluoroethylene carbonate-modified garnet-type Li6. 4La3Zr1. 4Ta0. 6O12 composite electrolyte
Liang et al. Electrochemical characterization of TiNb2O7 as anode material synthesized using microwave‐assisted microemulsion route
Ramkumar et al. Ternary metal oxide filled PEO-based polymer electrolyte for solid-state lithium metal battery: The role of filler particle size
Luo et al. In situ polyaniline coating of Prussian blue as cathode material for sodium-ion battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant