A polymer electrolyte containing an ionic aggregate, a method for preparing the same, and a lithium metal battery

Abstract

The application discloses an ion aggregate-containing polymer electrolyte, a preparation method thereof and a lithium metal battery. The ion aggregate-containing polymer electrolyte comprises polyvinylidene fluoride, a lithium salt, an organic solvent and a diluent. The organic solvent is used for dissociating the lithium salt to form a contact ion pair. The diluent does not have the ability to coordinate with lithium ions in the lithium salt. The diluent is used for promoting the contact ion pair to be converted into an ion aggregate and promoting the ion aggregate to be uniformly distributed in a polyvinylidene fluoride skeleton. The polymer electrolyte disclosed by the application can be well matched with a lithium metal negative electrode and a high-nickel ternary positive electrode, so that the assembled battery has excellent cycle stability in a wide temperature range of-30 DEG C to 60 DEG C, and has a good application prospect in the field of batteries.

Description

Technical Field

[0001] This invention relates to the technical field of lithium metal batteries, and in particular to a polymer electrolyte containing ion aggregates, its preparation method, and a lithium metal battery thereof. Background Technology

[0002] The development of new energy industries such as portable electronic products and electric vehicles has placed higher demands on the energy density and safety of lithium-ion batteries. Traditional lithium-ion batteries with graphite as the negative electrode can no longer meet these needs. Lithium metal anodes, due to their high theoretical capacity (3860 mAh g / g), are a more suitable choice. –1 It is considered the most promising anode material due to its low operating voltage (-3.04 vs. SHE) and can be used in high energy density lithium metal batteries, such as ternary lithium metal batteries and lithium-sulfur batteries.

[0003] However, the practical application of lithium metal faces several challenges. First, the uneven distribution of ions and electrons at the lithium metal / electrolyte interface leads to the growth of lithium dendrites, which can easily puncture the separator, causing internal short circuits and other safety issues, as well as the formation of dead lithium. Second, lithium metal exhibits high reactivity with the electrolyte due to its strong reducing properties. Continuous side reactions result in the loss of active lithium and an increase in battery impedance, ultimately leading to low coulombic efficiency and poor cycle stability. Therefore, developing solid-state electrolytes with high chemical stability and inherent safety to replace liquid electrolytes is an effective way to achieve high-performance lithium metal batteries.

[0004] Solid-state polymer electrolytes possess advantages such as good flexibility, good electrode contact, and low preparation cost, making them the most promising solid-state electrolyte system for early industrialization. However, polymer electrolytes, represented by polyethylene oxide (PEO), are hampered by low room-temperature ionic conductivity, low oxidation potential, and poor mechanical properties, hindering large-scale application. Although strategies such as incorporating inorganic fast ion conductor fillers, polymer molecular structure design, copolymerization, and crosslinking can effectively improve ionic conductivity, these methods still fall short of achieving polymer electrolytes suitable for practical lithium metal batteries.

[0005] It should be noted that the information disclosed in the background section above is only for understanding the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a polymer electrolyte containing ion aggregates, a method for preparing the same, and a lithium metal battery.

[0007] The present invention adopts the following technical solution:

[0008] In a first aspect, a polymer electrolyte containing ion aggregates is provided, comprising polyvinylidene fluoride, a lithium salt, an organic solvent, and a diluent, wherein the organic solvent is used to dissociate the lithium salt to form contact ion pairs, the diluent does not have the ability to coordinate with lithium ions in the lithium salt, and the diluent is used to promote the conversion of the contact ion pairs into ion aggregates and to promote the uniform distribution of the ion aggregates in the polyvinylidene fluoride backbone.

[0009] In a second aspect, a method for preparing the polymer electrolyte described in the first aspect is provided, comprising the following steps:

[0010] S1. Mix polyvinylidene fluoride and lithium salt and dissolve them in an organic solvent to obtain a uniform and transparent precursor solution;

[0011] S2. The precursor solution is dried to obtain a polymer film containing organic solvent;

[0012] S3. Add the diluent to the polymer membrane so that the diluent is fully absorbed by the polymer membrane to obtain the polymer electrolyte.

[0013] Thirdly, a lithium metal battery is provided, comprising a polymer electrolyte containing ion aggregates as described in the first aspect.

[0014] The present invention has the following beneficial effects:

[0015] The polymer electrolyte containing ion aggregates provided by this invention is a composite solid electrolyte comprising polyvinylidene fluoride (PVDF), lithium salt, organic solvent, and diluent. The organic solvent can dissociate the lithium salt to form contact ion pairs, which are distributed within the PVDF framework, thereby enabling ion transport. The diluent does not have the ability to coordinate with lithium ions, but it can promote the conversion of contact ion pairs into ion aggregates. Furthermore, the diluent molecules coat the ion aggregates, effectively weakening the interaction between the ion aggregates and PVDF, thus significantly improving ion conductivity and achieving high-flux ion transport. The diluent promotes the uniform distribution of ion aggregates within the PVDF framework, thereby achieving uniform lithium-ion transport channels. The diluent in the polymer electrolyte containing ion aggregates exhibits high electrochemical stability and non-flammability. The ion aggregates generate a LiF-rich interfacial mesophase at the lithium metal and high-voltage cathode interface, effectively improving the cycle stability of the high-voltage lithium metal battery. The high-nickel ternary lithium metal battery assembled with the polymer electrolyte containing ion aggregates exhibits excellent electrochemical cycle performance and safety performance over a wide temperature range of -30℃ to 60℃. Attached Figure Description

[0016] Figure 1 The thermogravimetric curve of the polymer film obtained in Example 1 of the present invention is shown.

[0017] Figure 2 This is a comparison of the ionic conductivity and activation energy of Example 1 and Comparative Example 1 of the present invention.

[0018] Figure 3a This is the Raman spectrum of Comparative Example 1 of the present invention.

[0019] Figure 3b This is the Raman spectrum of Embodiment 1 of the present invention.

[0020] Figure 4a This is the lithium-ion transference number test result of Example 1 of the present invention.

[0021] Figure 4b This is the lithium-ion transference number test result of Comparative Example 1 of this invention.

[0022] Figure 5 These are constant current charge-discharge test diagrams of lithium-lithium symmetric batteries assembled in Embodiment 1 and Comparative Example 1 of the present invention.

[0023] Figure 6a This is a scanning electron microscope image of the lithium-lithium symmetric battery assembled in Comparative Example 1 of this invention after cycling.

[0024] Figure 6b This is a scanning electron microscope image of the lithium-lithium symmetric battery assembled in Embodiment 1 of the present invention after cycling.

[0025] Figure 7 This is a cycle test diagram of the NCM811 lithium metal battery assembled in Example 1 and Comparative Example 1 of the present invention at room temperature (25°C).

[0026] Figure 8 This is a high-temperature (60°C) cycle test diagram of the NCM811 lithium metal battery assembled in Embodiment 1 of the present invention.

[0027] Figure 9 This is a low-temperature (-30°C) cycle performance test diagram of the NCM811 lithium metal batteries assembled in Example 1 and Comparative Example 1 of the present invention.

[0028] Figure 10 This is a cycle performance test diagram of the high energy density NCM811 lithium metal pouch battery assembled in Embodiment 2 of the present invention. Detailed Implementation

[0029] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention. Unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0030] This invention provides a polymer electrolyte containing ion aggregates, comprising polyvinylidene fluoride, lithium salt, organic solvent, and diluent. The organic solvent is used to dissociate the lithium salt to form contact ion pairs. The diluent does not have the ability to coordinate with lithium ions in the lithium salt. The diluent is used to promote the conversion of the contact ion pairs into ion aggregates and to promote the uniform distribution of the ion aggregates in the polyvinylidene fluoride backbone.

[0031] In some embodiments, the diluent is at least one selected from 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE), 2,2,2-trifluoroethyl ether, 1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane, and fluorobenzene.

[0032] In some embodiments, the organic solvent is at least one selected from N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), diethylene glycol dimethyl ether (G2), triethylene glycol dimethyl ether (G3), tetraethylene glycol dimethyl ether (G4), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), N-methylpyrrolidone (NMP), and propylene carbonate (PC).

[0033] In some embodiments, the lithium salt is at least one of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluorosulfonyl)imide (LiTFSI), and lithium difluorooxalate borate (LiDFOB).

[0034] In some embodiments, the molar ratio of the organic solvent to the diluent is 1:(1-5).

[0035] In some embodiments, the organic solvent in the polymer electrolyte is 5% to 25% by mass.

[0036] In some embodiments, the mass ratio of polyvinylidene fluoride to lithium salt is (1-3):1.

[0037] In some embodiments, the polymer electrolyte is in the form of a film with a thickness of 80-100 μm.

[0038] The present invention also provides a method for preparing the polymer electrolyte, comprising the following steps:

[0039] S1. Mix polyvinylidene fluoride and lithium salt and dissolve them in an organic solvent to obtain a uniform and transparent precursor solution;

[0040] Preferably, in step S1, the mass ratio of polyvinylidene fluoride (PVDF) to lithium salt is (1-3):1. PVDF and lithium salt are added to an organic solvent and stirred for 6-8 hours until they are completely dissolved, forming a uniform and transparent precursor solution.

[0041] S2. The precursor solution is dried to obtain a polymer membrane containing organic solvent (called PVDF polymer electrolyte membrane);

[0042] Preferably, in step S2, the precursor solution obtained in step S1 can be poured into a glass dish and placed in a forced-air drying oven at 55°C for 20 to 24 hours to obtain a PVDF polymer electrolyte membrane with a thickness of 80 to 100 μm. In the PVDF polymer electrolyte membrane, the organic solvent accounts for 5% to 25% by mass, and the organic solvent can dissociate lithium salt to form contact ion pairs.

[0043] After step S2, the polymer film exhibits a porous spherulite structure, and the contact ion pairs are aggregated on the surface of the spherulites, resulting in an overall non-uniform distribution.

[0044] S3. Add (e.g., drip) the diluent to the polymer membrane so that it is fully absorbed by the polymer membrane to obtain the polymer electrolyte. The polymer electrolyte is in the form of a film with a thickness of 80-100 μm. The mass percentage of organic solvent in the polymer electrolyte is also 5%-25%.

[0045] In step S3, the introduction of the diluent promotes the uniform distribution of ion aggregates within the polyvinylidene fluoride (PVDF) framework, thereby achieving uniform lithium-ion transport channels. The diluent, lacking the ability to coordinate with lithium ions, promotes the conversion of contact ion pairs into ion aggregates. Furthermore, the diluent molecules coat the ion aggregates, effectively weakening the interaction between the ion aggregates and PVDF, thus significantly improving ionic conductivity and achieving high-flux ion transport. The diluent in the polymer electrolyte containing ion aggregates exhibits high electrochemical stability and non-flammability. The ion aggregates generate a LiF-rich interfacial mesophase at the lithium metal and high-voltage cathode interface, effectively improving the cycle stability of the high-voltage lithium metal battery.

[0046] A specific embodiment of the present invention also provides a lithium metal battery, which includes the aforementioned polymer electrolyte containing ion aggregates. Specifically, the lithium metal battery includes a polymer electrolyte containing ion aggregates, a lithium metal negative electrode, and a positive electrode. The polymer electrolyte containing ion aggregates is placed between the lithium metal negative electrode and the positive electrode. The active material in the positive electrode includes one of lithium cobalt oxide, ternary cathode material, and lithium-rich manganese.

[0047] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the invention. Unless otherwise stated, reagents, software, and instruments involved in the following embodiments that are not specifically described are all conventional commercially available products or open-source materials.

[0048] Example 1

[0049] This embodiment provides a method for preparing a polymer electrolyte containing ion aggregates and assembling a solid-state lithium metal battery, which includes at least the following steps:

[0050] (1) Weigh 405 mg of polyvinylidene fluoride (PVDF) powder with a molecular weight of 600,000 and 270 mg of lithium bis(fluorosulfonyl)imide (LIFSI) and dissolve them in 15 mL of N,N-dimethylformamide (DMF). Stir at room temperature for 8 hours until PVDF and LiFSI are completely dissolved to obtain a homogeneous and transparent precursor solution.

[0051] (2) Pour the precursor solution obtained in step (1) into a glass petri dish and dry it in a 55°C oven for 24 hours to obtain a PVDF polymer electrolyte membrane. Cut it into a circular piece with a diameter of 19 mm and dry it in an inert atmosphere for later use.

[0052] (3) First, weigh 100 mg of PVDF (binder) and place it in a stirring flask. Add 2 mL of N-methylpyrrolidone (NMP) and stir on a magnetic stirrer for 2 hours until the PVDF is completely dissolved to obtain a uniform and transparent PVDF binder solution. Then, add 100 mg of SuperP (conductive carbon black) and 800 mg of ternary nickel-cobalt-manganese (NCM811) active material to the binder solution and stir on a high-speed defoamer at 1200 rpm / min for 15 minutes to obtain the positive electrode slurry.

[0053] (4) Coat the positive electrode slurry obtained in step (3) onto aluminum foil, dry it in an 80°C forced-air oven for more than 6 hours, cut it into round pieces with a diameter of 12 mm to obtain NCM811 positive electrode sheets, bake them in a 120°C vacuum oven for 1 hour, and store them in an inert atmosphere in a glove box for later use.

[0054] (5) Add 8 μL of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) to the polymer membrane obtained in step (2) to obtain a polymer electrolyte membrane containing ion aggregates with a thickness of 85 μm.

[0055] (6) Assemble the NCM811 positive electrode sheet prepared in step (4), the polymer electrolyte membrane containing ion aggregates prepared in step (5), and lithium metal to obtain a lithium metal coin cell.

[0056] Example 2

[0057] The difference between Example 2 and Example 1 is that the cutting size of the PVDF polymer electrolyte membrane in step (2) is replaced with 4.0cm*4.5cm, the cutting size of the positive electrode in step (3) is replaced with 3.5cm*4.0cm, the amount of TTE added in step (5) is replaced with 50μL, and the lithium metal button cell is replaced with a pouch cell. The remaining steps are the same as in Example 1.

[0058] Example 3

[0059] The difference between Example 3 and Example 1 is that the DMF solvent is replaced with N,N-dimethylacetamide, while the remaining steps are the same as in Example 1.

[0060] Example 4

[0061] The difference between Example 4 and Example 1 is that the DMF solvent is replaced with diethylene glycol dimethyl ether, while the remaining steps are the same as in Example 1.

[0062] Example 5

[0063] The difference between Example 5 and Example 1 is that the DMF solvent is replaced with propylene carbonate, while the remaining steps are the same as in Example 1.

[0064] Example 6

[0065] The difference between Example 6 and Example 1 is that the NCM811 positive electrode active material is replaced with a lithium-rich manganese positive electrode active material, while the remaining steps are the same as in Example 1.

[0066] Example 7

[0067] The difference between Example 7 and Example 1 is that the NCM811 positive electrode active material is replaced with LiCoO2 active material, while the remaining steps are the same as in Example 1.

[0068] Example 8

[0069] The difference between Example 8 and Example 1 is that the NCM811 positive electrode active material is replaced with LiCoO2 active material, and the diluent is replaced with 1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane instead of TTE. The remaining steps are the same as in Example 1.

[0070] Example 9

[0071] The difference between Example 9 and Example 1 is that the NCM811 positive electrode active material is replaced with LiCoO2 active material, and the diluent is replaced with fluorobenzene instead of TTE. The remaining steps are the same as in Example 1.

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 1 is that no TTE diluent was added to the PVDF polymer electrolyte membrane prepared in Comparative Example 1, while the remaining steps were the same as in Example 1.

[0074] Thermogravimetric analysis of the PVDF polymer electrolyte membrane prepared in step (2) of Example 1 was performed under a nitrogen atmosphere. (See attached document.) Figure 1 It was found that the DMF solvent content in the PVDF polymer electrolyte membrane was 18 wt%.

[0075] This invention compares the ionic conductivity and activation energy of the polymer electrolyte containing ion aggregates prepared in Example 1 at different temperatures with those in Comparative Example 1. (See reference...) Figure 2 The results showed that the addition of diluent could effectively improve the ionic conductivity of the electrolyte and reduce the activation energy by homogenizing the distribution of lithium ion aggregates in the PVDF framework and weakening the interaction between the ion aggregates and PVDF.

[0076] The solvation structures of the electrolytes prepared in Example 1 and Comparative Example 1 were investigated by Raman spectroscopy in this invention. (See reference...) Figure 3a and 3b The results showed that the addition of a diluent could convert contact ion pairs in the PVDF polymer electrolyte membrane into ion aggregates, thereby effectively improving the stable interface construction ability of lithium-ion complexes at the positive and negative electrode interfaces. Further, see [reference needed]. Figure 4a and 4b The solvation structure dominated by ion aggregates enables the polymer electrolyte containing ion aggregates in Example 1 to exhibit a lithium-ion transference number as high as 0.5.

[0077] This invention evaluates the stability of lithium-lithium symmetric batteries assembled with electrolytes prepared in Example 1 and Comparative Example 1 for lithium metal anodes. (See reference...) Figure 5 At 0.5mA cm – 2 The current density and 0.5 mAh cm⁻¹ – 2 At the deposition level, the polymer electrolyte containing ion aggregates prepared in Example 1 exhibited a cycle life of up to 4000 hours, while the PVDF polymer electrolyte membrane without diluent failed after only 200 hours of cycling. Furthermore, both symmetrical batteries were disassembled, and the surface morphology of the lithium metal was characterized using scanning electron microscopy. (See [reference needed]). Figure 6a and 6bThe symmetric battery assembled using the electrolyte in Example 1 exhibits a dense and smooth lithium deposition morphology, while the symmetric battery assembled using the electrolyte in Comparative Example 1 shows more accumulation of by-reaction products and lithium dendrite formation. These results indicate that the uniform lithium-ion flow resulting from the introduction of a diluent and the regulation of the solvation structure effectively suppress by-reactions between the electrolyte and lithium metal and the growth of lithium dendrites.

[0078] The present invention tested the cycle performance of the NCM811 lithium metal batteries assembled in Example 1 and Comparative Example 1 at room temperature. (See reference...) Figure 7 The NCM811 lithium metal battery in Example 1 can operate stably for 1000 cycles at room temperature with a 70% capacity retention rate, while Comparative Example 1 experienced short-circuit failure within 200 cycles.

[0079] The present invention tested the cycle performance of the NCM811 lithium metal battery in Example 1 at 60°C, see reference. Figure 8 The NCM811 lithium metal battery in Example 1 can operate stably at a high rate of 5C for 300 cycles at 60°C, demonstrating the applicability of the electrolyte and battery of the present invention in high-temperature application scenarios.

[0080] The present invention tested the cycle performance of the NCM811 lithium metal battery in Example 1 at -30°C, see reference. Figure 9 The NCM811 lithium metal battery in Example 1 can operate stably for 400 cycles at -30°C, demonstrating the applicability of the electrolyte and battery of the present invention in low-temperature application scenarios.

[0081] The present invention tested the cycle performance of the high-energy-density NCM811 lithium metal pouch battery in Example 2 at room temperature, see reference. Figure 10 The pouch cell in Example 2 can operate stably for 450 cycles with 80% capacity retention, demonstrating the availability of the electrolyte of the present invention in high-energy-density lithium metal pouch cells.

[0082] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. An ion cluster-containing polymer electrolyte, characterized by, The polymer electrolyte comprises polyvinylidene fluoride, lithium salt, organic solvent, and diluent, and is prepared by the following method: S1. Polyvinylidene fluoride and lithium salt are mixed and dissolved in an organic solvent to obtain a uniform and transparent precursor solution, wherein the organic solvent is used to dissociate the lithium salt to form contact ion pairs; S2. The precursor solution is dried to obtain a polymer film containing organic solvent. The polymer film has a porous spherulite structure, and the contact ion pairs are aggregated on the surface of the spherulites, and are unevenly distributed overall. S3. Add the diluent to the polymer membrane, allowing the diluent to be fully absorbed by the polymer membrane to obtain the polymer electrolyte. The diluent does not have the ability to coordinate with lithium ions in the lithium salt. The diluent is used to promote the conversion of the contact ion pairs into ion aggregates, and the diluent molecules coat the ion aggregates, effectively weakening the interaction force between the ion aggregates and polyvinylidene fluoride, and promoting the uniform distribution of the ion aggregates in the polyvinylidene fluoride skeleton, thereby achieving a uniform lithium ion transport channel.

2. The polymer electrolyte according to claim 1, wherein The diluent is at least one of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE), 2,2,2-trifluoroethyl ether, 1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane, and fluorobenzene.

3. The polymer electrolyte according to claim 1, wherein The organic solvent is at least one selected from N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), diethylene glycol dimethyl ether (G2), triethylene glycol dimethyl ether (G3), tetraethylene glycol dimethyl ether (G4), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), N-methylpyrrolidone (NMP), and propylene carbonate (PC).

4. The polymer electrolyte according to claim 1, wherein The lithium salt is at least one of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluorosulfonyl)imide (LiTFSI), and lithium difluorooxalate borate (LiDFOB).

5. The polymer electrolyte as described in claim 1, characterized in that, The molar ratio of the organic solvent to the diluent is 1:(1~5).

6. The polymer electrolyte according to claim 1, wherein In the polymer electrolyte, the organic solvent has a mass percentage of 5% to 25%.

7. The polymer electrolyte according to claim 1, wherein The mass ratio of polyvinylidene fluoride to lithium salt is (1~3):

1.

8. The polymer electrolyte according to claim 1, wherein The polymer electrolyte is in the form of a film with a thickness of 80-100 μm.

9. A method for preparing the polymer electrolyte according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Polyvinylidene fluoride and lithium salt are mixed and dissolved in an organic solvent to obtain a uniform and transparent precursor solution, wherein the organic solvent is used to dissociate the lithium salt to form contact ion pairs; S2. The precursor solution is dried to obtain a polymer film containing organic solvent. The polymer film has a porous spherulite structure, and the contact ion pairs are aggregated on the surface of the spherulites, and are unevenly distributed overall. S3. Add the diluent to the polymer membrane, allowing the diluent to be fully absorbed by the polymer membrane to obtain the polymer electrolyte. The diluent does not have the ability to coordinate with lithium ions in the lithium salt. The diluent is used to promote the conversion of the contact ion pairs into ion aggregates, and the diluent molecules coat the ion aggregates, effectively weakening the interaction force between the ion aggregates and polyvinylidene fluoride, and promoting the uniform distribution of the ion aggregates in the polyvinylidene fluoride skeleton, thereby achieving a uniform lithium ion transport channel.

10. A lithium metal battery, characterized in that, Polymer electrolytes including ion-containing aggregates as described in any one of claims 1 to 8.

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