CN116031473A - PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery - Google Patents

PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery Download PDF

Info

Publication number
CN116031473A
CN116031473A CN202211601958.7A CN202211601958A CN116031473A CN 116031473 A CN116031473 A CN 116031473A CN 202211601958 A CN202211601958 A CN 202211601958A CN 116031473 A CN116031473 A CN 116031473A
Authority
CN
China
Prior art keywords
inorganic oxide
peo
solid electrolyte
based composite
lithium
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.)
Pending
Application number
CN202211601958.7A
Other languages
Chinese (zh)
Inventor
霍延平
李辉学
许希军
吴泽佳
赵经纬
籍少敏
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.)
Guangdong University of Technology
Original Assignee
Guangdong University of Technology
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 Guangdong University of Technology filed Critical Guangdong University of Technology
Priority to CN202211601958.7A priority Critical patent/CN116031473A/en
Publication of CN116031473A publication Critical patent/CN116031473A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Landscapes

  • Conductive Materials (AREA)

Abstract

The patent application discloses a PEO-based composite solid electrolyte containing inorganic oxide, a preparation method thereof and a polymer solid lithium battery. The PEO-based composite electrolyte containing inorganic oxide consists of a polymer matrix, inorganic oxide, lithium salt and an organic solvent. The composite electrolyte is prepared by mixing inorganic oxide Ga 2 O 3 And lithium salt is blended into the organic polymer PEO chain segment, and then the uniform and flat solid electrolyte without solvent is obtained through a casting method and volatilization. Ga in the composite electrolyte 2 O 3 Can promote the decomposition of lithium salt, destroy chemical cross-linking between polymer chains and promote the migration number of ions; promoting solidsElectrolyte film (SEI) forms and produces Li-Ga alloy, inhibits the reaction of electrolyte and electrode and lithium dendrite growth, promotes the stability of electrode and electrolyte interface. The composite electrolyte has good voltage stability and electrochemical performance, and has good application prospect and economic value in the fields of intelligent electronic equipment, new energy batteries, high-voltage energy storage equipment and the like.

Description

PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery
Technical Field
The patent application relates to the technical field of solid-state lithium batteries, in particular to a PEO-based composite solid electrolyte containing inorganic oxide, a preparation method and application thereof.
Background
Under the promotion of green development theory and 'double carbon' strategy, the development and utilization of renewable energy sources such as solar energy, wind energy and tidal energy become research focuses, and the utilization of clean energy sources requires secondary batteries with good safety, high energy density and high voltage as energy storage and conversion devices.
Lithium Ion Batteries (LIBs) attract the eyes of more and more researchers in the energy storage field due to the advantages of long cycle life, high output voltage, environmental friendliness, high energy density and the like. The safety problems of the current lithium ion batteries using liquid electrolytes still prevent the further development of the lithium ion batteries. Studies have shown that lithium dendrite growth in organic liquid electrolytes is unavoidable during charge/discharge. In addition, liquid electrolytes suffer from a number of inherent disadvantages including being prone to leakage and flammability.
In recent years, a strategy of replacing organic liquid electrolytes by Solid State Electrolytes (SSEs) has attracted considerable attention from researchers. Among the numerous solid electrolytes, polyethylene oxide has good flexibility, good compatibility with electrodes and lower manufacturing costs, but its lower ionic conductivity (10 -8 -10 -6 S cm-1), slower ion migration rates and a narrower electrochemical stability window limit practical applications. Chinese patent CN114976215a discloses a ceramic composite solid electrolyte containing inorganic nano-oxide particles. By dispersing nano ceramic particles in N, NAnd (3) in dimethylformamide, then, carrying out electrostatic spinning, and finally, casting the PEO polymer-lithium salt solution in the electrostatic spinning, so that the flexibility and the ionic conductivity of the electrolyte are improved. CN113270639a discloses a PEO-based solid electrolyte and a method for preparing the same. Through a method of in-situ growth, MOFs are grown on the surface of electrostatic spinning, then ionic liquid is poured into MOFs pipelines, and finally solid electrolyte is obtained through PEO polymer-lithium salt solution casting, so that wettability and ionic conductivity of an interface between the electrolyte and an electrode are improved. CN114883646a discloses a composite solid electrolyte, a preparation method and application thereof. By adopting inorganic ceramic filler and high-voltage additive to cooperatively modify PEO-based polymer electrolyte and porous high-voltage-resistant PVDF-based solid electrolyte coating, the ionic conductivity and high-voltage resistance of the electrolyte are improved.
The modification of PEO-based composite solid electrolyte improves the ionic conductivity and flexibility of the composite electrolyte to a certain extent, but has the problems of complex preparation process, poor stability of the interface between the electrolyte and the electrode, reaction between the electrolyte and the electrode and the like, resulting in increased battery impedance, cycle life, reduced coulombic efficiency and the like.
Content of the patent application
In order to overcome at least one problem in the prior art, the application provides a PEO-based composite solid electrolyte containing inorganic oxide, so as to solve the problems of poor interface stability between the electrolyte and an electrode, reaction between the electrolyte and the electrode and the like in the prior art.
In another aspect, the present application also provides a method of preparing the above inorganic oxide-containing PEO-based composite solid electrolyte.
It is yet another object of the present application to provide a polymer solid state lithium battery comprising a stainless steel plate or lithium iron phosphate positive electrode, the above inorganic oxide containing PEO-based composite solid state electrolyte, and a lithium metal negative electrode.
In order to solve the technical problems, the technical scheme adopted by the patent application is as follows:
an inorganic oxide-containing PEO-based composite solid electrolyte comprising PEO with different weight average molecular weight polymers, inorganic oxide, lithium salt and solvent, wherein the molar ratio of PEO to lithium salt (EO: li+) is (12-18): 1, wherein the inorganic oxide accounts for (0-20%) of the mass ratio of the system, and the solvent consumption is 5-15 mL.
The preparation method of the PEO-based composite solid electrolyte containing the inorganic oxide specifically comprises the following steps:
s1, weighing PEO, inorganic oxide and lithium salt in a certain mass ratio, adding the PEO, the inorganic oxide and the lithium salt into a solvent according to a certain sequence, stirring at room temperature to obtain uniform and dispersed slurry, and then obtaining uniform, dispersed and bubble-free slurry through ultrasonic treatment;
s2, casting the slurry on a flat polytetrafluoroethylene plate in a glove box, volatilizing for a certain time at normal temperature (25 ℃) and 65 ℃ respectively, and volatilizing for a certain time again in the glove box.
Compared with the prior art, the beneficial effect of this patent application is:
the application provides inorganic oxide-containing PEO-based composite solid electrolyte, wherein Ga 2 O 3 The lithium salt has the effect of Lewis acid and alkali, so that the decomposition of the lithium salt can be promoted; second Ga 2 O 3 The Lewis acidic groups on the surface can break chemical cross-linking between polymer chains, promote segment movement and increase ion migration number. Next, ga is prepared 2 O 3 Contains a large amount of oxygen vacancies, can interact with lithium salt, promote the further decomposition of lithium salt and promote the ion migration number. Notably, ga 2 O 3 Can chemically react with lithium metal, promote the formation of a solid electrolyte membrane (SEI) and a Li-Ga alloy, inhibit the reaction of electrolyte and an electrode and the growth of lithium dendrite, and promote the stability of an interface between the electrode and the electrolyte.
Drawings
FIG. 1 (a) is a scanning electron microscope image of the surface of the composite solid electrolyte prepared in example 1.
FIG. 1 (b) is a scanning electron micrograph of a cross section of the composite solid electrolyte prepared in example 1.
FIG. 2 shows the inorganic oxide Ga prepared in example 1 2 O 3 Is a scanning electron microscope image of (c).
FIG. 3 shows the inorganic oxide Ga prepared in example 1 2 O 3 Oxygen vacancy test patterns of (2).
FIG. 4 is a graph showing ionic conductivity at various temperatures of the polymer electrolytes prepared in example 1 and comparative example.
Fig. 5 is a graph of stress strain testing of the polymer electrolyte prepared in example 1 and comparative example.
FIG. 6 is a differential scanning calorimeter test plot of the polymer electrolytes prepared in example 1 and comparative example.
FIG. 7 is a graph showing ion migration numbers of polymer electrolytes prepared in example 1 and comparative example.
FIG. 8 shows the polymer electrolytes prepared in example 1 and comparative example applied to solid-state batteries at 60℃of 0.2mAcm -2 Electrochemical cycling performance graph.
Fig. 9 is an electrochemical cycle performance chart of the polymer electrolytes prepared in example 1 and comparative example applied to a solid-state battery at 60C, 0.5C.
Detailed Description
Embodiments of the present application will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustration of the present application and should not be construed as limiting the scope of the present application. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
It should be noted that:
in this patent application, all the embodiments mentioned herein and the preferred methods of implementation can be combined with each other to form new solutions, if not specifically stated.
In this application, unless otherwise indicated, the various reactions or steps may be performed sequentially or sequentially. Preferably, the reaction processes herein are performed sequentially.
Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any method or material similar or equivalent to those described may be used in the present application.
The present application provides an inorganic oxide-containing PEO-based composite solid electrolyte comprising PEO of different weight average molecular weight polymers, an inorganic oxide, a lithium salt, and a solvent, wherein the PEO is mixed with a lithium salt (EO: li + ) The molar ratio of (2) to (18): 1, wherein the inorganic oxide accounts for (0-20%) of the mass ratio of the system, and the solvent consumption is 5-15 mL.
In some preferred embodiments, the PEO of different weight average molecular weight polymers has a molecular weight of at least one of 30-110W and the inorganic oxide is B 2 O 3 、Ga 2 O 3 、In 2 O 3 The lithium salt is at least one of lithium bistrifluoromethylsulfonyl imide, lithium hexafluorophosphate and lithium bisoxalato borate, and the solvent is at least one of anhydrous acetonitrile and anhydrous N, N-dimethylformamide.
The application provides a preparation method of the PEO-based composite solid electrolyte containing inorganic oxide, which can be simply called a solvent casting method, and specifically comprises the following steps:
s1, weighing PEO, inorganic oxide and lithium salt in a certain mass ratio, adding the PEO, the inorganic oxide and the lithium salt into a solvent according to a certain sequence, stirring at room temperature to obtain uniform and dispersed slurry, and then obtaining uniform, dispersed and bubble-free slurry through ultrasonic treatment;
s2, casting the slurry on a flat polytetrafluoroethylene plate in a glove box, volatilizing for 12-24 hours at normal temperature (25 ℃) and 65 ℃, and volatilizing for 24-72 hours again in the glove box.
In some preferred embodiments, the agitation rate described in step S1 is 300-500rmp.
In some preferred embodiments, the casting temperature described in step S2 is 25℃and the casting rate is 5-10 mL/min.
In some preferred embodiments, the glove box atmosphere described in step S2 is H 2 O＜0.1ppm，O 2 ＜0.1ppm。
In some preferred embodiments, pretreatment is required before the inorganic oxide is added to ensure removal of moisture and other solvents.
In some more preferred embodiments, the inorganic oxide is required to be dried in vacuo at 100℃for 12 to 24 hours before addition.
In some preferred embodiments, the slurry is ultrasonically removed from bubbles for 0.5 to 1 hour after the inorganic oxide is added in step S1, and then the remaining material is added.
In some preferred embodiments, the inorganic oxide is prepared by the steps of:
s01, through weighing a certain proportion of gallium nitrate nonahydrate and hexamethylenetetramine, adding a certain proportion of deionized water, transferring to a reaction kettle, and then carrying out hydrothermal synthesis, washing, centrifugation, vacuum drying and calcination to obtain Ga 2 O 3 The reaction temperature is 120 ℃, and the reaction time is 24 hours;
s02, carrying out post-treatment on the crude product obtained in the step S01, wherein the post-treatment comprises washing with absolute ethyl alcohol, centrifuging, vacuum drying at 80 ℃, and finally calcining in a tube furnace at a temperature rising rate of 5 ℃/min, wherein the calcining temperature is 400 ℃ and the gas is 99.99% high-purity N 2 Calcining for 10h under the atmosphere.
In some more preferred embodiments, in the step S01, the molar ratio of the gallium nitrate nonahydrate to the hexamethylenetetramine is 1:2.5, and the molar ratio of the gallium nitrate nonahydrate to the deionized water is 1.0g:20ml.
In some more preferred embodiments, in the step S01, the specification of the hydrothermal synthesis reaction kettle is 85mL.
In some more preferred embodiments, in the step S02, the amount of the absolute ethanol is 30-40 mL, the rotation speed of the centrifuge is 7000-8000 rmp, and the centrifugation time is 3-5 min, and the steps are repeated three times.
The present application also provides a polymer solid-state lithium battery comprising a stainless steel plate or a lithium iron phosphate positive electrode, the inorganic oxide-containing PEO-based composite solid-state electrolyte of claim 1, and a lithium metal negative electrode.
In some preferred embodiments, the polymer solid state lithium battery has a charge-discharge voltage in the range of 2.5 to 4.0V.
Next, a method for producing the inorganic oxide-containing PEO-based composite solid electrolyte of the present application will be described in detail with specific examples.
Preparation example
Example 1 preparation of inorganic oxide-containing PEO-based composite solid electrolyte
The preparation method of the PEO-based composite solid electrolyte containing the inorganic oxide specifically comprises the following steps:
(1) Inorganic oxide Ga 2 O 3 Is prepared from the following steps:
s01, weighing 0.835g (3.4 mmol) of gallium nitrate nonahydrate, 1.192g (8.5 mmol) of hexamethylenetetramine, adding 68mL of deionized water into a 100mL beaker, stirring for 30min at a stirring rate of 500rmp, transferring into a 85mL reaction kettle, placing into a blast drying oven at 120 ℃ for reaction for 24h, and cooling to room temperature.
S02, discarding the supernatant in the reaction kettle in the step S01, transferring and precipitating to a 50mL centrifuge tube by using 35mL of absolute ethyl alcohol, placing the centrifuge tube into the centrifuge at the rotating speed of 7500rmp for 3min, discarding the absolute ethyl alcohol, and repeating the operation for three times; transferring the precipitate into a vacuum drying oven at 80 ℃ for drying for 6 hours, and cooling to room temperature; finally transferring the powder into a crucible, placing the crucible into a tube furnace, setting the heating rate to be 5 ℃/min, the calcining temperature to be 400 ℃ and the calcining time to be 10 hours, and setting the gas to be 99.99% of pure N 2 . Collecting calcined solid, namely Ga 2 O 3 。
(2) Preparation of inorganic oxide-containing PEO-based composite solid electrolyte:
s1, 10mL of anhydrous acetonitrile is taken and placed in a 20mL penicillin bottle, and then 0.435g of lithium salt (EO: li) + Add to the bottle, then weigh 0.254g (mass fraction (Wt) =15%) Ga 2 O 3 Added together in a bottle, then the bottle was sonicated for 1h, and finally 1.0g PEO was added (meeting PEO：Li+＝15:1)Stirring was carried out at 500rmp stirring rate for 10h, then at 50rmp stirring rate for 2h, and the bottle was again sonicated for 1h to ensure complete removal of bubbles from the slurry.
S2, the step S1 is carried outCasting the obtained slurry on a smooth and flat polytetrafluoroethylene plate covered with a release film at the temperature of 25 ℃ at the rate of 10 mL/min; then naturally volatilize at 25deg.C for 24H, then volatilize at 65deg.C for 24H, and finally transfer to atmosphere H 2 O＜0.1ppm，O 2 The glove box was volatilized for 48 hours at < 0.1 ppm.
Comparative example
The comparative example provides a method for preparing a solid electrolyte. The comparative example preparation differs from example 1 in that there is no inorganic oxide Ga of example 1 2 O 3 And no inorganic oxide Ga is added in the preparation of the composite solid electrolyte according to example 1 2 O 3 。
Characterization of results:
(1) The inorganic oxide Ga is prepared in example 1 2 O 3 Morphological structure characterization of (2)
Inorganic oxide Ga 2 O 3 The morphological characterization of (c) is tested as follows:
attaching conductive adhesive tape to SEM sample stage, and then paving appropriate amount of Ga 2 O 3 The non-adhered part is blown away by an ear washing ball, and then the sample stage is put into a sample injection bin. Then carrying out vacuumizing operation on the sample bin, setting parameters such as working voltage, working distance and the like, selecting a shooting area, focusing, adjusting parameters such as contrast, brightness and the like, and finally selecting proper magnification to shoot.
As shown in FIG. 1 (a), the composite solid electrolyte prepared in example 1 has a smooth, flat surface, and is an inorganic oxide Ga 2 O 3 Uniformly distributed in the PEO polymer system; as can be seen from fig. 1 (b), the composite solid electrolyte prepared in example 1 has a thickness of 120 μm;
FIG. 2 shows the inorganic oxide Ga prepared in example 1 2 O 3 Is a scanning electron microscope image of Ga synthesized as shown in FIG. 2 2 O 3 The grain diameter is 800-1200nm, and the grain diameter is in a hexagonal prism structure;
FIG. 3 shows the inorganic oxide Ga prepared in example 1 2 O 3 Oxygen vacancy test pattern of (2)Ga is synthesized as shown in FIG. 3 2 O 3 A strong signal was present at a magnetic field strength of 3512G, indicating that the sample had a large number of oxygen vacancies. Thus, it can be explained that Ga in PEO-based composite solid electrolyte prepared in the present patent application 2 O 3 Contains a large amount of oxygen vacancies, can interact with lithium salt, promote the further decomposition of lithium salt and promote the ion migration number.
(2) Solid electrolyte ionic conductivity test
First, in an argon glove box (H 2 O＜0.1ppm，O 2 < 0.1 ppm), stainless steel disks having a thickness of 0.5mm and a diameter of 15.8mm and the solid electrolytes prepared in example 1 and comparative example were assembled into symmetrical cells in the order of negative electrode case-stainless steel disk-solid electrolyte-stainless steel disk-gasket-elastic sheet-positive electrode case, and pressed by a button sealer.
Then, the assembled solid-state battery was put into a blast drying oven at 60 ℃ for standing for 12 hours, cooled at room temperature for 2 hours after being taken out, and then an alternating current impedance spectrum at 20-60 ℃ was measured by a Gamry electrochemical workstation and ion conductivity was calculated.
As shown in FIG. 4, the inorganic oxide Ga-containing material prepared in example 1 2 O 3 PEO-based composite solid electrolyte of (shown by "PEO/LiTFSI/15% Ga% 2 O 3 "representative") were compared to inorganic oxide-free PEO-based composite solid electrolyte prepared in comparative examples at various temperatures (shown as "PEO/LiTFSI/0% Ga% 2 O 3 "representative of) exhibit higher ionic conductivity. Wherein the inorganic oxide Ga-containing material prepared in example 1 is at 60 DEG C 2 O 3 The ion conductivity of PEO-based composite solid electrolyte can reach 4.85 x 10 -4 S cm -1 。
The inorganic oxide Ga-containing material provided by the application patent can be proved by the solid electrolyte ion conductivity test 2 O 3 The PEO-based composite solid electrolyte has higher ion conductivity than the PEO-based composite solid electrolyte without inorganic oxide.
FIG. 5 is a graph of example 1 (in the figure, "PEO-LiTFSI-15% Ga 2 O 3 "representative of) and comparative examples(indicated by "PE0-LiTFSI" in the figure) prepared polymer electrolyte stress strain test chart. As shown in FIG. 5, the PEO-based composite solid electrolyte prepared in example 1 was prepared by adding the inorganic oxide gallium oxide Ga 2 O 3 After that, the elongation at break is larger and the tensile force can be borne more, thus proving that the patent of the application provides the inorganic oxide Ga 2 O 3 The PEO-based composite solid electrolyte has better flexibility than the PEO-based composite solid electrolyte without inorganic oxide.
(3) Solid electrolyte DSC test
The inorganic oxide Ga prepared in example 1 2 O 3 PEO-based composite solid electrolyte (shown in the figure as "PEO-LiTFSI-15% Ga 2 O 3 "representative") and inorganic oxide-free PEO-based composite solid electrolyte prepared in comparative example (represented by "PEO-LiTFSI" in the drawing) were cut into 0.3 x 0.3mm sheets, placed in an aluminum crucible, and then placed in METTLER TOLEDO DSC3 at 10℃for min -1 The rate of temperature rise was measured at a glass transition temperature (Tg) and a melting point (Tm) in the range of-80 to 100deg.C.
As shown in FIG. 6, the inorganic oxide-containing Ga prepared in example 1 was compared with the Tg (-47.1 ℃) and Tm (53.3 ℃) of the inorganic oxide-free PEO-based composite solid electrolyte prepared in comparative example 2 O 3 The PEO-based composite solid electrolyte of (C) has a lower Tg (-51.2 ℃) and Tm (44.9 ℃).
Through the DSC test of the solid electrolyte, the patent application contains inorganic oxide Ga 2 O 3 The PEO-based composite solid electrolyte has higher thermal stability, increased application range and improved safety.
(4) Solid electrolyte ion migration number test
In an argon glove box (H 2 O＜0.1ppm，O 2 < 0.1 ppm), lithium sheets 0.55mm in thickness and 12.5mm in diameter, and solid electrolytes prepared in example 1 and comparative example were assembled into 2032 symmetrical batteries in the order of negative electrode case-lithium sheet-solid electrolyte-lithium sheet-gasket-elastic sheet-positive electrode case, and pressed with a button sealer.
Putting the assembled solid-state batteryStanding in a 60 deg.C air drying oven for 12 hr, taking out, cooling at room temperature for 2 hr, and measuring its alternating current impedance spectrum at 60 deg.C by using Gamry electrochemical workstation to obtain R 0 In the frequency range of 0.1-10 6 Hz. Then testing CA curve, test potential is 10mV, recording time is 4000s, recording initial current is I 00 The steady-state current is I ss Ac impedance value R after stabilization s 。
As shown in FIG. 7 (a), the inorganic oxide Ga-containing material prepared in example 1 2 O 3 The ion migration number of the PEO-based composite solid electrolyte was 0.272, which is 0.119 higher than that of the inorganic oxide-free PEO-based composite solid electrolyte prepared in the comparative example (as shown in fig. 7 (b)).
The inorganic oxide Ga-containing material provided by the present application can be proved by the solid electrolyte ion migration number test 2 O 3 The PEO-based composite solid electrolyte has higher ion migration number compared with the PEO-based composite solid electrolyte without inorganic oxide, and the increase of the ion migration number indicates that the addition of gallium oxide can promote lithium ion conduction, thereby further indicating that the electrolyte performance is better, and the reason is deeply that the inorganic oxide Ga 2 O 3 The lithium salt has the effect of Lewis acid and alkali, so that the decomposition of the lithium salt can be promoted; second Ga 2 O 3 The Lewis acidic groups on the surface can break chemical cross-linking between polymer chains, promote segment movement and increase ion migration number.
(5) Test of lithium stability by precipitation of solid electrolyte for lithium symmetric battery
In an argon glove box (H 2 O＜0.1ppm，O 2 < 0.1 ppm), lithium sheets 0.55mm in thickness and 12.5mm in diameter, and solid electrolytes prepared in example 1 and comparative example were assembled into 2032 symmetrical batteries in the order of negative electrode case-lithium sheet-solid electrolyte-lithium sheet-gasket-elastic sheet-positive electrode case, and pressed with a button sealer.
The assembled solid-state battery was placed in a blow-drying oven at 60℃for 12 hours, and then measured by Land battery testers (Land CT 2003A) for a current density of 0.2mAcm at 60℃for stable lithium removal by precipitation -2 。
As shown in FIG. 8 (a), the inorganic oxide Ga-containing material prepared in example 1 2 O 3 The PEO-based composite solid electrolyte assembled lithium symmetric battery (shown as 'Li/PLGa 15/Li' in the figure) can be at 0.2mA cm -2 While the comparative example shown in fig. 8 (b) produced a PEO-based composite solid electrolyte lithium-containing symmetric cell without inorganic oxide (denoted by "Li/PL0/Li" in the figure) with a stable cycle time of less than 130h, the stable cycle was over 500h without short circuit.
The above test of the stability of lithium deposition and removal for lithium symmetric batteries by using solid electrolyte can prove that the patent of the application provides a lithium-ion battery containing inorganic oxide Ga 2 O 3 Has higher electrolyte ion-conducting stability than inorganic oxide-free PEO-based composite solid electrolyte due to Ga 2 O 3 Can chemically react with lithium metal, promote the formation of a solid electrolyte membrane (SEI) and a Li-Ga alloy, inhibit the reaction of electrolyte and an electrode and the growth of lithium dendrite, and promote the stability of an interface between the electrode and the electrolyte.
(6) Electrochemical performance testing of solid state electrolytes for full cells
In an argon glove box (H 2 O＜0.1ppm，O 2 < 0.1 ppm), a lithium sheet having a thickness of 0.55mm and a diameter of 12.5mm, the solid electrolytes prepared in example 1 and comparative example, and a surface density of 2.5mg cm -2 The lithium iron phosphate positive plate is assembled with 2032 battery according to the sequence of the negative electrode shell, the lithium iron phosphate plate, the solid electrolyte, the lithium iron phosphate plate, the gasket, the elastic sheet and the positive electrode shell, and is tightly pressed by a button sealing machine.
The assembled solid-state battery was placed in a blow-drying oven at 60℃for 12 hours, and then the cyclic stability current at 60℃was measured to be 0.5C by Land battery testers (Land CT 2003A).
As shown in FIG. 9, the inorganic oxide Ga-containing material prepared in example 1 2 O 3 PEO-based composite solid electrolyte assembled full cell (shown as "PEO-LiTFSI-Ga) 2 O 3 "representative of) can be cycled steadily for 100 turns at a current of 0.5C while still retaining 146.5mAh g -1 Is prepared according to the comparative example withoutThe capacity of a PEO-based composite solid electrolyte assembled full cell of inorganic oxide (represented by "PEO-LiTFSI" in the figure) is only 140.3mAh g -1 。
The above-mentioned electrochemical performance test by using a solid electrolyte for a full cell can prove that the patent of the present application provides an inorganic oxide Ga-containing material 2 O 3 The PEO-based composite solid electrolyte of the (2) has higher stability compared with the PEO-based composite solid electrolyte without inorganic oxide, and can be matched with a commercial electrode; in addition, ga 2 O 3 Can chemically react with lithium metal to promote the formation of a solid electrolyte membrane (SEI) and the formation of Li-Ga alloy, thereby improving the stability of the cycling battery, and further improving the cycling stability of the full-sinking battery.
The application provides a PEO-based composite solid electrolyte containing inorganic oxide, a preparation method thereof and a polymer solid lithium battery, which comprise PEO, inorganic oxide, lithium salt and solvent with different weight average molecular weights, wherein the molar ratio of PEO to lithium salt (EO: li+) is (12-18): 1, wherein the inorganic oxide accounts for (0-20%) of the mass ratio of the system, and the solvent consumption is 5-15 mL.
PEO (polyethylene oxide) based composite solid electrolyte containing inorganic oxide in the present patent application is prepared by mixing inorganic oxide Ga 2 O 3 And lithium salt is blended into the organic polymer PEO chain segment, and then the uniform and flat solid electrolyte without solvent is obtained through a casting method and volatilization. Ga in the composite electrolyte 2 O 3 Can promote the decomposition of lithium salt, destroy chemical cross-linking between polymer chains and promote the migration number of ions; promoting the formation of a solid electrolyte membrane (SEI) and producing Li-Ga alloy, inhibiting the reaction of an electrolyte and an electrode and the growth of lithium dendrite, and improving the stability of an interface between the electrode and the electrolyte;
the composite solid electrolyte has good voltage stability and electrochemical performance, and has good application prospect and economic value in the fields of polymer solid lithium batteries, especially intelligent electronic equipment, new energy batteries, high-voltage energy storage equipment and the like:
1. by inorganic oxide Ga 2 O 3 Morphological structure characterization experiments of (2)And FIG. 3 shows Ga in PEO-based composite solid electrolyte prepared by the present application 2 O 3 Contains a large amount of oxygen vacancies, can interact with lithium salt, promote the further decomposition of lithium salt and promote the migration number of ions;
2. as can be seen from solid electrolyte ion conductivity test experiments and FIG. 4, the patent of the application provides a solid electrolyte containing inorganic oxide Ga 2 O 3 The PEO-based composite solid electrolyte has higher ion conductivity than the PEO-based composite solid electrolyte without inorganic oxide;
3. as can be seen from the stress-strain test experiment of the polymer electrolyte and FIG. 5, the inorganic oxide Ga-containing material provided by the patent application 2 O 3 The PEO-based composite solid electrolyte has better flexibility compared with the PEO-based composite solid electrolyte without inorganic oxide;
4. as can be seen from the solid electrolyte DSC test experiment and FIG. 6, the inorganic oxide Ga is contained in the present patent application 2 O 3 The PEO-based composite solid electrolyte has higher thermal stability, the application range is increased, and the safety is improved;
5. as can be seen from the solid electrolyte ion migration number test experiment and FIG. 7, the inorganic oxide Ga is contained in the present patent application 2 O 3 The PEO-based composite solid electrolyte has higher ion migration number;
6. as can be seen from the test experiment of the lithium precipitation stability of the solid electrolyte for the lithium symmetric battery and the FIG. 8, the Ga containing inorganic oxide provided by the patent application 2 O 3 PEO-based composite solid electrolyte of (2) has higher electrolyte conductive ion stability than PEO-based composite solid electrolyte without inorganic oxide because of Ga 2 O 3 Can chemically react with lithium metal, promote the formation of a solid electrolyte membrane (SEI) and a Li-Ga alloy, inhibit the reaction of electrolyte and an electrode and the growth of lithium dendrite, and promote the stability of an interface between the electrode and the electrolyte;
7. as can be seen from the electrochemical performance test experiment of the solid electrolyte for the full cell and fig. 9, the patent of the present application provides a solid electrolyte containing inorganic oxide Ga 2 O 3 PEO of (E)The PEO-based composite solid electrolyte which is relatively free of inorganic oxide can match commercial electrodes with higher stability; in addition, ga 2 O 3 Can chemically react with lithium metal to promote the formation of a solid electrolyte membrane (SEI) and the formation of Li-Ga alloy, thereby improving the stability of the cycling battery, and further improving the cycling stability of the full-sinking battery.
In summary, the present application provides inorganic oxide-containing PEO-based composite solid electrolyte in which Ga 2 O 3 The lithium salt has the effect of Lewis acid and alkali, so that the decomposition of the lithium salt can be promoted; second Ga 2 O 3 The Lewis acid groups on the surface can destroy chemical crosslinking among polymer chains, promote chain segment movement and increase ion migration number; next, ga is prepared 2 O 3 Contains a large amount of oxygen vacancies, can interact with lithium salt, promote the further decomposition of lithium salt and promote the ion migration number.
Notably, ga 2 O 3 Can chemically react with lithium metal, promote the formation of a solid electrolyte membrane (SEI) and form Li-Ga alloy, inhibit the reaction of electrolyte and an electrode and the growth of lithium dendrite, promote the stability of an interface between the electrode and the electrolyte, and avoid the reaction of the electrolyte and the electrode.
In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present patent application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While several embodiments of the present patent application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A PEO-based composite solid state electrolyte comprising an inorganic oxide, characterized by: comprises PEO with different weight average molecular weight polymers, inorganic oxide, lithium salt and solvent, wherein the PEO is mixed with lithium salt (EO: li + ) The molar ratio of (2) to (18): 1, wherein the inorganic oxide accounts for (0-20%) of the mass ratio of the system, and the solvent consumption is 5-15 mL.
2. The inorganic oxide-containing PEO-based composite solid state electrolyte of claim 1 wherein: the molecular weight of the PEO polymer with different weight average molecular weight is at least one of 30W to 110W, and the inorganic oxide is B 2 O 3 、Ga 2 O 3 、In 2 O 3 The lithium salt is at least one of lithium bistrifluoromethylsulfonyl imide, lithium hexafluorophosphate and lithium bisoxalato borate, and the solvent is at least one of anhydrous acetonitrile and anhydrous N, N-dimethylformamide.
3. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 2, characterized in that: the method comprises the following steps:
s1, weighing PEO, inorganic oxide and lithium salt in a certain mass ratio, adding the PEO, the inorganic oxide and the lithium salt into a solvent according to a certain sequence, stirring at room temperature to obtain uniform and dispersed slurry, and then obtaining uniform, dispersed and bubble-free slurry through ultrasonic treatment;
s2, casting the slurry on a flat polytetrafluoroethylene plate in a glove box, volatilizing for 12-24 hours at normal temperature (25 ℃) and 65 ℃, and volatilizing for 24-72 hours again in the glove box.
4. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 3, wherein: the casting temperature in the step S2 is 25 ℃, and the casting rate is 5-10 mL/min.
5. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 3, wherein: the inorganic oxide is prepared by the steps of:
s01, carrying out hydrothermal synthesis on gallium nitrate nonahydrate, hexamethylenetetramine and deionized water, wherein the reaction temperature is 120 ℃, and the reaction time is 24 hours;
s02, carrying out post-treatment on the crude product obtained in the step S01, wherein the post-treatment comprises washing with absolute ethyl alcohol, centrifuging, vacuum drying at 80 ℃, and finally heating at a rate of 5 ℃/min in a tube furnace, at 400 ℃ and under N 2 Calcining for 10h under the atmosphere.
6. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 5, wherein: in the step S02, the dosage of the absolute ethyl alcohol is 30-40 mL, the rotating speed of a centrifugal machine is 7000-8000 rmp, and the centrifugal time is 3-5 min.
7. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 3, wherein: the inorganic oxide needs to be dried in vacuo at 100 ℃ for 12 hours before being added.
8. The method for producing an inorganic oxide-containing PEO-based composite solid electrolyte according to claim 3, wherein: after the inorganic oxide is added in the step S1, the slurry is required to be ultrasonically removed from bubbles for 0.5 to 1 hour, and then the rest materials are added.
9. A polymer solid state lithium battery characterized by: the polymer solid lithium battery comprises a stainless steel plate or a lithium iron phosphate positive electrode, the inorganic oxide-containing PEO-based composite solid electrolyte of claim 1, and a lithium metal negative electrode.
10. The polymer solid state lithium battery of claim 9, wherein: the charge-discharge voltage range of the polymer solid lithium battery is 2.5-4.0V.
CN202211601958.7A 2022-12-13 2022-12-13 PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery Pending CN116031473A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211601958.7A CN116031473A (en) 2022-12-13 2022-12-13 PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211601958.7A CN116031473A (en) 2022-12-13 2022-12-13 PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery

Publications (1)

Publication Number Publication Date
CN116031473A true CN116031473A (en) 2023-04-28

Family

ID=86078595

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211601958.7A Pending CN116031473A (en) 2022-12-13 2022-12-13 PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery

Country Status (1)

Country Link
CN (1) CN116031473A (en)

Similar Documents

Publication Publication Date Title
WO2020073915A1 (en) Lithium ion battery negative electrode material and non-aqueous electrolyte battery
CN108649190A (en) Vertical graphene with three-dimensional porous array structure/titanium niobium oxygen/sulphur carbon composite and its preparation method and application
CN112909234A (en) Preparation method and application of lithium cathode or sodium cathode
CN107248569B (en) Antimony/nitrogen-doped carbon composite prepared by taking 1-ethyl-3-methylimidazol dicyandiamide as carbon source and preparation method and application thereof
CN109037664A (en) A kind of carbon-coated Mo of N doping2The preparation method of C/C functional composite material and its application in lithium-sulfur cell
CN108394884A (en) A kind of preparation method of chitosan-based high-specific surface area nitrogen/phosphor codoping carbon nanosheet
CN107093739B (en) Potassium manganese oxide for potassium ion battery anode material and preparation method thereof
CN112467200B (en) Lithium fluoride/lithium lanthanum titanate nanofiber solid electrolyte interface material and preparation method and application thereof
CN112538692B (en) Co-Mn bimetallic organic framework derived porous carbon fiber and preparation method and application thereof
CN112331830A (en) Preparation method of graphene-coated nickel-cobalt-manganese ternary positive electrode material
EP2793302B1 (en) Si/C COMPOSITE , METHOD OF PREPARATION THE SAME, AND ANODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY INCLUDING THE Si/C COMPOSITE
CN107482188B (en) Hollow core-shell structure composite material and preparation method and application thereof
CN113782718B (en) High-voltage lithium ion battery material, lithium ion battery and preparation method thereof
CN111416107A (en) Fibrous sodium vanadium fluorophosphate cathode material and preparation method and application thereof
CN111326706B (en) Carbon-coated niobium pentoxide composite reduced graphene oxide material, preparation and application
CN103972580B (en) A kind of lithium-sulfur cell
CN110311111A (en) N adulterates CNT in-stiu coating Co nano particle composite material and preparation and application
CN107119349B (en) A kind of carbon coating Na2Li2Ti6O14Nanofiber and preparation method thereof
CN110980698A (en) H1.07Ti1.73O4Preparation method of/rGO compound sodium ion battery anode material
CN115714172A (en) Preparation method of hollow graphene @ IVA group oxide composite material, product and application thereof
CN114203994B (en) Preparation method and application of positive electrode material of lithium-sulfur battery
CN112751004B (en) LixSi composite material, preparation method thereof and lithium ion battery anode material
CN116031473A (en) PEO-based composite solid electrolyte containing inorganic oxide, preparation method thereof and polymer solid lithium battery
CN113201808A (en) Porous fiber silicon-oxygen negative electrode composite material and preparation method thereof
CN109148862A (en) A kind of preparation and its application of Zn-Co-O/C lithium ion battery negative material

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