Composite solid electrolyte material introducing ionic filler, preparation method and application

Abstract

The application discloses a composite solid electrolyte material with introduced ion filler, a preparation method and application, and preparation raw materials include a polymer electrolyte, a lithium salt, a filler and a solvent, and the preparation method is as follows: (1) the filler is uniformly mixed with monomers, a free radical polymerization initiator, azobisisobutyronitrile, is added to obtain a composite; (2) the composite is uniformly mixed with the lithium salt in a solvent to obtain a mixture; and (3) the mixture is dried into a film to obtain the composite solid electrolyte material. Before a polymer matrix is formed, inorganic filler particles are preferentially introduced, uniformly mixed, and then heated to initiate polymerization to form a polymer-inorganic composite, and then the polymer-inorganic composite is dissolved into a film, a lithium ion fast transmission channel is constructed, lithium ion transmission efficiency is improved, the ionic conductivity of the polymer electrolyte itself is significantly improved, the polymer electrolyte can replace a separator and an electrolyte in a traditional battery at room temperature, and a full solid-state battery can be cycled at a wide temperature.

Description

Technical Field

[0001] This invention belongs to the field of solid electrolyte materials technology, specifically relating to a composite solid electrolyte material with ion filler incorporated, its preparation method, and its application. Background Technology

[0002] Currently, the development of electrochemical energy storage devices, as a key component of energy storage and conversion, has attracted much attention. Electrolytes, as crucial components responsible for ion transport in energy devices, directly affect the performance of batteries, capacitors, and other devices. Traditional lithium-ion batteries use carbonate electrolytes, which pose risks such as flammability, volatilization, and leakage at high temperatures, and are also highly corrosive, limiting the development of carbonate electrolytes in some important applications. Therefore, more stable and safer electrolytes are needed to replace them. Solid electrolytes, due to their excellent chemical, thermal, and mechanical stability, show great potential in energy storage devices such as batteries.

[0003] Polymer electrolytes are flexible and bendable, maintaining good interfacial contact with electrodes. Compared to inorganic electrolytes, polymer electrolytes have better processing performance, making them potential for industrial production. Organic-inorganic composite solid electrolytes have become a research hotspot. By rationally combining organic and inorganic materials, the advantages of both can be fully utilized to obtain high-performance solid electrolytes. By controlling the morphology and structure of the organic-inorganic interface, the ion transport performance of solid electrolytes can be enhanced, and the interfacial stability with electrodes can be improved. Organic-inorganic composite solid electrolytes not only help improve the cycle life and safety of devices, but also provide new solutions for the development of high-energy-density and high-power-density energy storage devices.

[0004] However, common composite electrolytes suffer from weak interfacial interactions between the filler and the polymer, resulting in a relatively high impedance at the electrolyte-electrode interface. This limits the improvement in electrochemical performance of the polymer electrolyte by the filler. Furthermore, existing composite polymer electrolyte materials lack microstructure control and the design of rapid ion transport channels, leading to poor performance of organic-inorganic composite polymer electrolytes in practical applications. Therefore, it is necessary to propose a novel composite solid-state electrolyte material. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a composite solid electrolyte material with ion-filled fillers, its preparation method, and its application. Before the formation of the polymer matrix, inorganic filler particles are preferentially introduced, mixed uniformly, and then thermally polymerized to form a polymer-inorganic composite. This composite is then dissolved to form a film, constructing a rapid lithium-ion transport channel, improving lithium-ion transport efficiency, and significantly enhancing the ionic conductivity of the polymer electrolyte itself. It can replace the separator and electrolyte in traditional batteries at room temperature, enabling all-solid-state batteries to cycle over a wide temperature range.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a composite solid electrolyte material incorporating an ion-filler, the raw materials including a polymer electrolyte, a lithium salt, a filler, and a solvent, wherein the polymer electrolyte is polyvinyl carbonate or polyacrylonitrile, and the filler is a sulfide solid electrolyte Li₂. 10 SnP2S 12 The solvent is N,N-dimethylformamide and / or dimethyl sulfoxide; the steps are as follows:

[0008] (1) Filler Li 10 SnP2S 12 The monomer was mixed thoroughly, and the free radical polymerization initiator azobisisobutyronitrile was added. The mixture was reacted at 60–80 °C for 1–24 h to obtain the polymer electrolyte / Li 10 SnP2S 12 complex;

[0009] (2) Polymer electrolyte / Li 10 SnP2S 12 The complex and lithium salt are uniformly mixed in a solvent to obtain a mixture;

[0010] (3) The mixture is dried into a film to obtain a composite solid electrolyte material.

[0011] Preferably, in step (1), the mass ratio of the free radical polymerization initiator azobisisobutyronitrile to the monomer is 1:(271-1355).

[0012] Preferably, in step (1), in the polymer electrolyte / Li 10 SnP2S 12 In the composite, the filler Li 10 SnP2S 12 The mass of polymer electrolyte / Li 10 SnP2S 12 The total mass of the complex is 0.05% to 0.5%.

[0013] Preferably, in step (2), the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex to the lithium salt is 1:(0.5~2).

[0014] Preferably, in step (2), the solvent reacts with the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex is (15-20 ml): 1 g.

[0015] Preferably, the lithium salt includes one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluorophosphate, lithium difluorooxalate borate, and lithium dioxalate borate.

[0016] Preferably, in step (3), the mixture is poured onto a polypropylene plate and dried in an anhydrous and oxygen-free environment.

[0017] More preferably, in step (3), the drying temperature is 60 to 100°C, and the drying time is 6 to 24 hours.

[0018] In a second aspect, the present invention provides a composite solid electrolyte material incorporating ion packing material, prepared by the above-described preparation method.

[0019] Preferably, the composite solid electrolyte material is in the form of a film with a thickness of 50–400 μm.

[0020] In a third aspect, the present invention provides an application of a composite solid electrolyte material incorporating ion fillers, wherein the composite solid electrolyte material is applied in the fields of ion conductors or lithium-ion batteries.

[0021] Beneficial effects:

[0022] This invention first mixes the filler with vinylene carbonate monomer to form a composite, and then uses a polymer electrolyte / Li 10 SnP2S 12 The composite uses a polymer electrolyte as a matrix, and then innovatively dissolves the filler-containing composite and lithium salt in DMF, allowing the filler Li to... 10 SnP2S 12 Reaction with solvents causes the originally solid filler to partially transform into Sn within the polymer electrolyte. 4+ S 2- PO4 3- In the presence of various forms of ions, after the lithium salt dissolves, Sn 4+Ions can anchor more anions, thereby enabling more lithium ions to participate in ion transport. The introduction of ions creates more lithium ion fast transport regions with the polymer electrolyte matrix and residual solvent, forming a lithium ion fast transport network, which promotes lithium ion transport. It can replace the separator and electrolyte in traditional batteries at room temperature, enabling all-solid-state batteries to cycle over a wide temperature range. Attached Figure Description

[0023] Figure 1 These are scanning electron microscope images of the surface and cross-section of the composite polymer solid electrolyte material prepared in Example 1;

[0024] Figure 2 The graphs show the conductivity of the composite polymer solid electrolytes prepared under different conditions in Examples 1, 2, 3, 4, and Comparative Examples 1 and 2 as a function of temperature.

[0025] Figure 3 This is a schematic diagram showing the ionic conductivity of composite polymer solid electrolytes with different filler contents prepared in Examples 1, 5, 6, 7, 8 and Comparative Example 1 at 30°C.

[0026] Figure 4 This is a schematic diagram showing the ionic conductivity of different composite polymer solid electrolytes prepared in Comparative Examples 2, 3, 4, 5, 6, 7, and 8 at 30°C.

[0027] Figure 5 The graph shows the cycle performance of an all-solid-state lithium metal battery assembled using the composite polymer solid electrolyte, lithium iron phosphate cathode, and lithium metal anode prepared in Example 1 at 30°C.

[0028] Figure 6 The graph shows the charge-discharge cycle performance of a lithium symmetric battery using the composite polymer solid electrolyte prepared in Example 1. Detailed Implementation

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0030] This invention proposes a composite solid electrolyte material incorporating ion-filled materials. The raw materials include a polymer electrolyte, a lithium salt, a filler, and a solvent. The polymer electrolyte is polyvinyl carbonate or polyacrylonitrile (PAN). The lithium salt includes one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate (LiOTf), lithium bis(fluorosulfonyl)imide (LiFSI), lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium difluorooxalate borate (LiODFB), and lithium dioxalate borate (LiBOB). The filler is a sulfide solid electrolyte, Li. 10 SnP2S 12 The solvent is N,N-dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO).

[0031] Preferably, the composite solid electrolyte material is in the form of a film with a thickness of 50–400 μm.

[0032] This invention also proposes a preparation method for the above-mentioned composite solid electrolyte material, comprising the following steps:

[0033] (1) Filler Li 10 SnP2S 12 The monomer was mixed thoroughly, and the free radical polymerization initiator azobisisobutyronitrile was added. The mixture was reacted at 60–80 °C for 1–24 h to obtain the polymer electrolyte / Li 10 SnP2S 12 complex;

[0034] (2) Polymer electrolyte / Li 10 SnP2S 12 The complex and lithium salt are uniformly mixed in a solvent to obtain a mixture;

[0035] (3) The mixture is dried into a film to obtain a composite solid electrolyte material.

[0036] Taking vinylene carbonate as a polymer electrolyte as an example, this invention first mixes the filler with a vinylene carbonate monomer solution, and then forms a new composite through thermally initiated polymerization. Then, it innovatively combines the polymer electrolyte / Li 10 SnP2S 12 The composite matrix and lithium salt dissolve together in the solvent, allowing the filler Li to... 10 SnP2S 12 It further reacts with a solvent (such as DMF) to form Sn. 4+ S 2- PO4 3- Ions in the same form. Then the solvent is dried out on a heating stage. However, it is worth noting that due to the complex structure of DMF with lithium ions, DMF will not be completely dried. After the electrolyte film is formed, Sn in the electrolyte film... 4+Lithium ions can anchor the anions in the original lithium salt, promoting the appearance of more free lithium ions in the electrolyte membrane. On the other hand, the filler Li... 10 SnP2S 12 Reaction with the solvent also results in the formation of some free lithium ions, leading to a greater number of lithium ions participating in ion transport. During transport within the electrolyte membrane, lithium ions complex with the C=O matrix of the polymer matrix and the C=O groups in DMF. Meanwhile, S... 2- PO4 3- In subsequent electrochemical cycles, the lithium ions combine, promoting the formation of an SEI film containing Li₂S, Li₃P, and other substances, thus improving the stability of the electrolyte membrane on the lithium metal side. This invention introduces ions through the reaction of the filler and solvent, generating more free lithium ions with the polyvinyl carbonate matrix and residual solvent, forming a fast-transfer region and network for lithium ions, thereby promoting lithium ion transport.

[0037] During the preparation process, the filler is uniformly mixed with polyvinyl carbonate, and then reacts with DMF in the subsequent mixing process with the solvent to form various ionic fillers that are uniformly dispersed in the polyvinyl carbonate matrix. The introduced ions are uniformly dispersed in the composite solid electrolyte material, forming a rapid ion transport region together with the residual solvent, which has a significant effect on improving the ionic conductivity in lithium-ion batteries.

[0038] In existing composite electrolyte materials, inorganic filler particles are generally uniformly dispersed in the polymer electrolyte, utilizing the fast transport region at the interface between the polymer electrolyte and the inorganic filler to promote improved ionic conductivity. This invention, however, dissolves the inorganic filler, utilizing the residual solvent in the composite solid electrolyte material and the reaction between the solvent and the filler to form ion-level filler. The introduction of ion-level filler constructs a rapid lithium-ion transport channel, improving lithium-ion transport efficiency and significantly enhancing the ionic conductivity of the polymer electrolyte itself. This allows the composite solid electrolyte material prepared by this invention to replace the separator and electrolyte in traditional batteries at room temperature, enabling all-solid-state batteries to cycle over a wide temperature range. Since there is no liquid electrolyte in the battery, no additional temperature control system is required.

[0039] In step (1), the preferred reaction temperature and reaction time are 12-24 h at 60 °C and 1-12 h at 80 °C.

[0040] In a preferred embodiment, in step (1), the mass ratio of the free radical polymerization initiator azobisisobutyronitrile to the monomer is 1:(271-1355), preferably 1:500.

[0041] In a preferred embodiment, in step (1), in the polymer electrolyte / Li 10 SnP2S 12In the composite, the filler Li 10 SnP2S 12 The mass of polymer electrolyte / Li 10 SnP2S 12 The filler Li accounts for 0.05% to 0.5% of the total mass of the composite, more preferably. 10 SnP2S 12 The mass of polymer electrolyte / Li 10 SnP2S 12 The total mass of the complex is 0.1% to 0.5%.

[0042] In a preferred embodiment, in step (2), the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex to the lithium salt is 1:(0.5~2).

[0043] In a preferred embodiment, in step (2), the solvent reacts with the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex is (12-20 ml): 1 g.

[0044] In a preferred embodiment, in step (3), the mixture is poured onto a polypropylene plate and dried in an anhydrous and oxygen-free environment at a temperature of 60–100°C for 6–24 hours.

[0045] The composite solid electrolyte material prepared by this invention has a strength of 1.5 × 10⁻⁶ at 30°C. -3 S cm -1 With its high ionic conductivity and electrochemical window of approximately 4.6V, it can be applied in the fields of ionic conductors or lithium-ion batteries.

[0046] Taking the application of this invention in the field of lithium-ion batteries as an example, the composite solid electrolyte material prepared by this invention serves as a solid electrolyte and is located between the positive and negative electrodes.

[0047] The technical solution of the present invention will be described in detail below with specific embodiments.

[0048] The raw materials used in Examples 1-8 are as follows:

[0049] Organic monomer solution: vinylene carbonate, purchased from Aladdin.

[0050] Initiator: Azobisisobutyronitrile (AIBN), purchased from Aladdin.

[0051] Lithium salt: Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), purchased from Aladdin.

[0052] Organic solvent: N,N-dimethylformamide (DMF), 99.8% anhydrous, purchased from Aladdin.

[0053] Inorganic filler Li 10 SnP2S 12 Preparation:

[0054] Under an argon atmosphere, Li₂S, P₂S₅, and SnS₂ powders of appropriate masses were weighed according to the molar mass ratio of Li₂S:P₂S₅:SnS₂ = 5:1:1. To ensure the reaction proceeds fully and to reduce impurities, an additional 2% by mass of Li₂S powder was added.

[0055] To ensure uniform powder mixing and further improve product purity, the powder was added to a zirconia planetary ball mill jar and uniformly mixed and refined using vacuum ball milling. The mass ratio of grinding balls to mixed powder was 40:1, the milling time was 4 hours, and the rotation speed was 400 rpm.

[0056] Approximately 0.5g of the powder obtained after ball milling was uniformly poured into a cold-pressing mold and pressed at 5t for 1 minute. The resulting block sample was then crushed and placed into a quartz tube for vacuum sealing. Finally, heat treatment was performed to complete the preparation. The heat treatment process was as follows: the temperature was increased to 600℃ at a rate of 0.5℃ / min, held for 24 hours, and then cooled in the furnace.

[0057] Example 1

[0058] (1) Measure 5 ml (i.e., 6.775 g) of vinylene carbonate monomer and mix it with 0.01 g of Li 10 SnP2S 12 After the powder is mixed evenly, 0.005 g of initiator azobisisobutyronitrile is added, and the mixture is kept at 80 °C for 3 h. Through thermally initiated polymerization, vinylene carbonate is polymerized into polyvinyl carbonate, thus obtaining the polymer electrolyte / Li 10 SnP2S 12 Complex.

[0059] (2) Weigh 1g of polymer electrolyte / Li 10 SnP2S 12 The complex and 2g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were dissolved in 20mL (i.e., 18.96g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12h to obtain a mixture.

[0060] (3) The mixture was poured onto a clean polypropylene plate and then dried at 60°C for 12 hours under an argon atmosphere to obtain a product containing Li. 10 SnP2S 12 Polyvinyl carbonate-based composite solid electrolyte with filler.

[0061] The surface and cross-sectional morphology of the composite solid electrolyte prepared in Example 1 are as follows: Figure 1 As shown.

[0062] The composite solid electrolyte prepared in Example 1 was sandwiched between two polished stainless steel substrates to form a blocking electrode. The composite solid electrolyte in the blocking electrode was subjected to AC impedance analysis at different temperatures using an electrochemical workstation in a constant temperature chamber, thus obtaining the corresponding ionic conductivity at different temperatures. The conductivity of the composite polymer electrolyte prepared in Example 1 over a wide temperature range is shown in the figure below. Figure 2 As shown.

[0063] The composite solid electrolyte prepared in Example 1 was assembled with lithium iron phosphate as the positive electrode and lithium metal as the negative electrode to form an all-solid-state lithium metal battery. Its cycle performance at 30°C and 2C conditions is as follows: Figure 5 As shown. After 5000 cycles, the discharge specific capacity is 90.8 mAh·g. -1 The remaining capacity is approximately 73%.

[0064] The composite polymer electrolyte prepared in Example 1 was assembled with lithium metal to form a lithium symmetric battery, which performed well at 30°C and 0.1 mA·cm⁻¹. -2 Cyclic performance under certain conditions, such as Figure 6 As shown, it can operate stably for 1000 hours.

[0065] Example 2

[0066] (1) Same as step (1) in Example 1, to obtain polymer electrolyte / Li 10 SnP2S 12 Complex.

[0067] (2) Weigh 1g of polymer electrolyte / Li 10 SnP2S 12 The complex and 1.5 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were dissolved in 18 mL (i.e., 17.04 g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12 h to obtain a mixture.

[0068] (3) The mixture was poured onto a clean polypropylene plate. Then, it was dried at 60°C for 12 hours under an argon atmosphere to obtain the composite solid electrolyte of Example 2.

[0069] The method used in Example 1 to test the ionic conductivity versus temperature curve is the same. The conductivity versus temperature of the composite solid electrolyte prepared in Example 2 over a wide temperature range is shown below. Figure 2 As shown.

[0070] Example 3

[0071] (1) Same as step (1) in Example 1, to obtain polymer electrolyte / Li 10 SnP2S 12 Complex.

[0072] (2) Weigh 1g of polymer electrolyte / Li 10 SnP2S 12 The complex and 1 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were dissolved in 15 mL (i.e., 14.22 g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12 h to obtain a mixture.

[0073] (3) The mixture was poured onto a clean polypropylene plate. Then, it was dried at 60°C for 12 hours under an argon atmosphere to obtain the composite solid electrolyte of Example 3.

[0074] The method used in Example 1 to test the ionic conductivity versus temperature curve is the same. The conductivity versus temperature of the composite solid electrolyte prepared in Example 3 over a wide temperature range is shown below. Figure 2 As shown.

[0075] The composite solid electrolyte prepared in Example 3 was assembled with lithium iron phosphate as the positive electrode and lithium metal as the negative electrode to form an all-solid-state lithium metal battery. After 500 cycles at 30°C and 1C, it still retained 138.3 mAh·g. -1 The specific discharge capacity.

[0076] Example 4

[0077] (1) Same as step (1) in Example 1, to obtain polymer electrolyte / Li 10 SnP2S 12 Complex.

[0078] (2) Weigh 1g of polymer electrolyte / Li 10 SnP2S 12 The complex and 0.5 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were dissolved in 12 mL (i.e., 11.376 g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12 h to obtain a mixture.

[0079] (3) The mixture was poured onto a clean polypropylene plate. Then, it was dried at 60°C for 12 hours under an argon atmosphere to obtain the composite solid electrolyte of Example 4.

[0080] The method used in Example 1 to test the ionic conductivity versus temperature curve is the same. The conductivity versus temperature of the composite solid electrolyte prepared in Example 4 over a wide temperature range is shown below. Figure 2 As shown.

[0081] Example 5

[0082] (1) Measure 5 ml (i.e., 6.775 g) of vinylene carbonate monomer and mix it with 0.005 g of Li 10 SnP2S 12 After the powder is mixed evenly, 0.005 g of azobisisobutyronitrile (AIBN) initiator is added. The mixture is kept at 80°C for 3 hours to thermally initiate polymerization of vinylene carbonate into polyvinyl carbonate, thus obtaining the polymer electrolyte / Li 10 SnP2S 12 Complex.

[0083] (2) Weigh 1g of polymer electrolyte / Li 10 SnP2S 12 The complex and 2g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were dissolved in 20mL (i.e., 18.96g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12h to obtain a mixture.

[0084] (3) The mixture was poured onto a clean polypropylene plate. Then, it was dried at 60°C for 12 hours under an argon atmosphere to obtain a product containing Li. 10 SnP2S 12 Polyvinyl carbonate-based composite solid electrolyte with filler.

[0085] The method for testing ionic conductivity is the same as in Example 1. The conductivity of the composite solid electrolyte prepared in Example 5 over a wide temperature range is as follows: Figure 3 As shown.

[0086] Example 6

[0087] Measure 5 ml (6.775 g) of vinylene carbonate monomer and mix it with 0.015 g of Li. 10 SnP2S 12 After the powder is mixed evenly, 0.005 g of azobisisobutyronitrile (AIBN) initiator is added. The mixture is kept at 80°C for 3 hours to thermally initiate polymerization of vinylene carbonate into polyvinyl carbonate, thus obtaining the polymer electrolyte / Li 10 SnP2S 12 Complex.

[0088] The subsequent steps are the same as in Example 1, and a composite solid electrolyte is obtained.

[0089] The method for testing ionic conductivity is the same as in Example 1. The conductivity of the composite polymer electrolyte prepared in Example 6 over a wide temperature range is as follows: Figure 3 As shown.

[0090] Example 7

[0091] Measure 5 ml (6.775 g) of vinylene carbonate monomer and mix it with 0.02 g of Li. 10 SnP2S 12 After the powder is mixed evenly, 0.005 g of azobisisobutyronitrile (AIBN) initiator is added. The mixture is kept at 80°C for 3 hours to thermally initiate polymerization of vinylene carbonate into polyvinyl carbonate, thus obtaining the polymer electrolyte / Li 10 SnP2S 12 Complex.

[0092] The subsequent steps are the same as in Example 1, and a composite solid electrolyte is obtained.

[0093] The method for testing ionic conductivity is the same as in Example 1. The conductivity of the composite solid electrolyte prepared in Example 7 over a wide temperature range is as follows: Figure 3 As shown.

[0094] Example 8

[0095] Measure 5 ml (6.775 g) of vinylene carbonate monomer and mix it with 0.025 g of Li. 10 SnP2S 12 After the powder is mixed evenly, 0.005 g of azobisisobutyronitrile (AIBN) initiator is added. The mixture is kept at 80°C for 3 hours to thermally initiate polymerization of vinylene carbonate into polyvinyl carbonate, thus obtaining the polymer electrolyte / Li 10 SnP2S 12 Complex.

[0096] The subsequent steps are the same as in Example 1, and a composite solid electrolyte is obtained.

[0097] The method for testing ionic conductivity is the same as in Example 1. The conductivity of the composite solid electrolyte prepared in Example 8 over a wide temperature range is as follows: Figure 3 As shown.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 1 is that no inorganic filler was added. Specifically:

[0100] Measure 5 ml of vinylene carbonate monomer and add 0.005 g of azobisisobutyronitrile (AIBN) initiator. Incubate at 80 °C for 3 h to polymerize vinylene carbonate into polyvinyl carbonate via thermal initiation, thus obtaining polyvinyl carbonate.

[0101] Weigh 1g of polyvinyl carbonate and 2g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), dissolve them in 20mL (18.96g) of N,N-dimethylformamide (DMF), and stir continuously at room temperature for 12h. Then pour the solution onto a clean polypropylene plate. Dry the solution at 60℃ for 12h under an argon atmosphere to obtain the solid electrolyte.

[0102] The method for testing ionic conductivity is the same as in Example 1. The conductivity of the solid electrolyte prepared in Comparative Example 1 over a wide temperature range is as follows: Figure 2 , Figure 3 As shown.

[0103] Comparative Example 2

[0104] The preparation of polyvinyl carbonate was the same as that of Comparative Example 1, except that no inorganic filler was added in this comparative example.

[0105] Weigh 1g of polyvinyl carbonate and 1g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), dissolve them in 20mL (18.96g) of N,N-dimethylformamide (DMF), and stir continuously at room temperature for 12h. Then pour the solution onto a clean polypropylene plate. Dry the solution at 60℃ for 12h under an argon atmosphere to obtain the solid electrolyte.

[0106] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the solid electrolyte prepared in Comparative Example 2 at 30°C is as follows: Figure 4 As shown.

[0107] Comparative Example 3

[0108] The filler used in this comparative example was tin trifluoromethanesulfonate (Sn(OTf)2), purchased from Aladdin.

[0109] The preparation of polyvinyl carbonate was the same as that of Comparative Example 1.

[0110] Weigh 1g of polyvinyl carbonate, 1g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.005g of tin trifluoromethanesulfonate (Sn(OTf)2). Dissolve both in 20mL (18.96g) of N,N-dimethylformamide (DMF) and stir continuously at room temperature for 12h. Then pour the solution onto a clean polypropylene plate. Dry the solution at 60℃ for 12h under an argon atmosphere to obtain the solid electrolyte.

[0111] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the solid electrolyte prepared in Comparative Example 3 at 30°C is as follows: Figure 4 As shown.

[0112] Comparative Example 4

[0113] The filler used in this comparative example is tin disulfide (SnS2), which was purchased from Aladdin.

[0114] The preparation of polyvinyl carbonate was the same as that of Comparative Example 1.

[0115] Weigh 1g of polyvinyl carbonate, 1g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.005g of tin disulfide (SnS2). Dissolve both in 20mL (18.96g) of N,N-dimethylformamide (DMF) and stir continuously at room temperature for 12h. Then, pour the solution onto a clean polypropylene plate. Dry the plate at 60℃ for 12h under an argon atmosphere to obtain the solid electrolyte.

[0116] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the solid electrolyte prepared in Comparative Example 4 at 30°C is as follows: Figure 4 As shown.

[0117] Comparative Example 5

[0118] In this comparative example, the polymer electrolyte was polyvinylidene fluoride (PVDF), no inorganic filler was used, and it was purchased from Aladdin.

[0119] Weigh 1g of polyvinylidene fluoride and 1g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), dissolve them in 20mL (18.96g) of N,N-dimethylformamide (DMF), and stir continuously at room temperature for 12h. Then, pour the solution onto a clean polypropylene plate. Dry the solution at 60℃ for 12h under an argon atmosphere to obtain the polyvinylidene fluoride polymer solid electrolyte.

[0120] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the solid electrolyte prepared in Comparative Example 5 at 30°C is as follows: Figure 4 As shown.

[0121] Comparative Example 6

[0122] In this comparative example, the polymer electrolyte is polyvinylidene fluoride (PVDF).

[0123] Weigh out 1g of polyvinylidene fluoride and 0.005g of inorganic filler Li. 10 SnP2S 12 The three compounds, along with 1 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), were dissolved in 20 mL (18.96 g) of N,N-dimethylformamide (DMF) and stirred continuously at room temperature for 12 h. The solution was then poured onto a clean polypropylene plate and dried at 60 °C for 12 h under an argon atmosphere to obtain the composite solid electrolyte.

[0124] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the composite solid electrolyte prepared in Comparative Example 6 at 30°C is as follows: Figure 4 As shown.

[0125] Comparative Example 7

[0126] In this comparative example, the polymer electrolyte was polyethylene oxide (PEO), purchased from Aladdin; the solvent was anhydrous acetonitrile (AN), with a purity of 99.8% anhydrous and H2O < 0.003%, purchased from Aladdin.

[0127] 1 g of polyethylene oxide and 0.4 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were weighed and dissolved in 20 mL of anhydrous acetonitrile (AN). The solution was stirred continuously at room temperature for 12 h, and then poured onto a clean polypropylene plate. The solution was then dried at 60 °C for 12 h under an argon atmosphere to obtain the polymer solid electrolyte.

[0128] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the polymer solid electrolyte prepared in Comparative Example 6 at 30°C is as follows: Figure 4 As shown.

[0129] Comparative Example 8

[0130] In this comparative example, the polymer electrolyte is polyethylene oxide (PEO), the solvent is anhydrous acetonitrile (AN), and the inorganic filler is Li. 10 SnP2S 12 .

[0131] Weigh out 1g of polyethylene oxide and 0.005g of inorganic filler Li. 10 SnP2S 12 The three compounds, along with 0.4 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), were dissolved in 20 mL of anhydrous acetonitrile (AN) and stirred continuously at room temperature for 12 h. The solution was then poured onto a clean polypropylene plate and dried at 60 °C for 12 h under an argon atmosphere to obtain the composite solid electrolyte.

[0132] The method for testing ionic conductivity is the same as in Example 1. The ionic conductivity of the polymer electrolyte prepared in Comparative Example 8 at 30°C is as follows: Figure 4 As shown.

[0133] Figure 2 The ionic conductivity of composite polymer solid electrolytes with temperature was compared under different polymer electrolytes, different lithium salt contents, and different preparation methods.

[0134] As can be seen from the figure, the electrolyte with ion-filled filler exhibits higher ionic conductivity. Compared to Comparative Example 1, the ionic conductivity of the composite polymer solid electrolyte in Example 1 is significantly improved at different temperatures. At 30°C, the ionic conductivity of Example 1 is 2.06 × 10⁻⁶. -3 S·cm -1 Compared to 1.13 × 10⁻⁶ in Comparative Example 1 -3 S·cm -1 It increased by about 2 times.

[0135] according to Figure 2 The results show that the ionic conductivity of Examples 3 and 4 is close to that of Comparative Example 1. However, in Examples 3 and 4, the amount of lithium salt and filler (containing lithium) is much lower than that in Comparative Example 1. In the art, increasing the amount of lithium salt will increase the ionic conductivity of solid electrolytes, but it will also increase the weight of solid electrolytes. Examples 3 and 4 can achieve the effect that requires more lithium salt in the prior art by using less lithium salt and filler, which shows that the present invention is beneficial to the research on lightweight solid electrolytes.

[0136] Furthermore, comparing Example 3 and Comparative Example 2, the ionic conductivity after adding the filler increased from 0.82 × 10⁻⁶. -3 S·cm -1 Increased to 1.2×10 -3 S·cm -1 This indicates that filler Li was uniformly added to the polymer polyvinyl carbonate. 10 SnP2S 12 Furthermore, the reaction with DMF effectively improves lithium-ion conductivity, and this effect is observed across different lithium salt contents. This modification has a certain degree of universality. It should be noted that the ionic conductivity mentioned above refers to the conductivity of the lithium salt. Figure 2 The σ in the figure is converted to Logσ for the numerical value of ionic conductivity, and a graph is plotted to obtain the attached figure. Figure 2 .

[0137] As a preferred embodiment, the test results of the lithium metal battery assembled in Example 1 show that the composite solid electrolyte has high ionic conductivity and can achieve excellent cycle stability with high capacity under the given test conditions.

[0138] Examples 1, 5, 6, 7, and 8 compared the ionic conductivity at 30°C for different filler contents with Comparative Example 1. Figure 3 As shown. The filler content in Comparative Example 1 is 0, indicating that Li was added to the polymer electrolyte membrane. 10 SnP2S 12 After the filler reacts with DMF, it can significantly improve the ionic conductivity.

[0139] Comparative Example 3 used a tin-containing filler, tin trifluoromethanesulfonate (Sn(OTf)2), which is soluble in DMF. Using this filler, Sn ions can be directly introduced into the polymer solid electrolyte from the electrolyte membrane. Meanwhile, Comparative Example 4 used a tin-containing filler, tin disulfide, which is insoluble in DMF. The effects of both on the ionic conductivity of the polymer electrolyte are as follows: Figure 4 As shown, at 30°C, the ionic conductivity of the composite polymer solid electrolyte membrane with 0.5% tin trifluoromethanesulfonate by mass was significantly improved. At 30°C, the ionic conductivity increased from 0.82 mS·cm in Comparative Example 2. -1 The efficiency was increased to 1.15 mS·cm in Comparative Example 3. -1 However, after adding tin disulfide, a filler insoluble in DMF, the ionic conductivity of the polymer electrolyte membrane not only failed to increase but actually decreased. This indicates that when Sn ions are present in the electrolyte membrane, a fast lithium-ion transport network is formed, promoting an increase in ionic conductivity.

[0140] Comparative Examples 5 and 6 used different polymer matrices—polyvinylidene fluoride (PVDF). Based on the data from Comparative Examples 5 and 2, it can be seen that... Figure 4 It is evident that polyvinylidene fluoride (PVDF) has a weaker lithium-ion transport capacity compared to polyvinyl carbonate (PVC), and the ionic conductivity of both is significantly lower than that of PVC-based polymer electrolytes at different temperatures. However, when DMF is used as a solvent and Li is added... 10 SnP2S 12 Even after the filler was added, the ionic conductivity still showed a certain improvement. At 30℃, the ionic conductivity increased from 0.33 mS·cm. -1 Increased to 0.43 mS·cm -1 .

[0141] Comparative Examples 7 and 8 selected those that could not be used with Li. 10 SnP2S 12 Anhydrous acetonitrile was used as the solvent in the reaction to prepare the electrolyte membrane. The chosen polymer matrix was the most common polyethylene oxide. The difference between the two examples of polymer electrolytes is that a small amount of Li was still added in Comparative Example 8. 10 SnP2S 12 Filler. The ionic conductivity of both at 30℃ is as follows: Figure 4 As shown. The ionic conductivity of the polymer electrolyte in Comparative Example 7 is approximately 8.1 × 10⁻⁶ at 30 °C. -3 mS·cm -1 The polymer electrolyte in Comparative Example 8 had an ionic conductivity of 7.8 × 10⁻⁶. -3 mS·cm -1 Li 10 SnP2S 12It cannot react with the solvent AN, but exists in the electrolyte membrane in the form of particles. It cannot provide Sn ions to the electrolyte membrane, and the ionic conductivity is not significantly improved.

[0142] The above embodiments and comparative examples, from four aspects—different solid polymer matrices, different lithium salt contents, different filler contents, and different methods of preparing composite polymer electrolytes—specifically demonstrate the universality and effectiveness of the present invention's technology for preparing polymer solid electrolytes with ion-filled materials in improving the electrochemical performance of polymer-based composite solid electrolytes. This is uniquely advantageous for achieving rapid lithium-ion transport in the polymer matrix, ultimately leading to improved ionic conductivity and battery performance.

[0143] The embodiments provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention, and the descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a composite solid electrolyte material incorporating ion packing, characterized in that, The raw materials include a polymer electrolyte, a lithium salt, a filler, and a solvent. The polymer electrolyte is polyvinyl carbonate or polyacrylonitrile, and the filler is a sulfide solid electrolyte, Li. 10 SnP2S 12 The solvent is N,N-dimethylformamide and / or dimethyl sulfoxide; The steps are as follows: (1) Filler Li 10 SnP2S 12 The monomer was mixed thoroughly, and the free radical polymerization initiator azobisisobutyronitrile was added. The mixture was reacted at 60–80 °C for 1–24 h to obtain the polymer electrolyte / Li 10 SnP2S 12 complex; (2) Polymer electrolyte / Li 10 SnP2S 12 The complex and lithium salt are uniformly mixed in a solvent to obtain a mixture; (3) The mixture is dried into a film to obtain a composite solid electrolyte material; In step (1), in the polymer electrolyte / Li 10 SnP2S 12 In the composite, the filler Li 10 SnP2S 12 The mass of polymer electrolyte / Li 10 SnP2S 12 0.05–0.5% of the total mass of the complex; In step (2), the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex to the lithium salt is 1:(0.5~2).

2. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the free radical polymerization initiator azobisisobutyronitrile to the monomer is 1:

500.

3. The preparation method according to claim 1, characterized in that, In step (2), the solvent reacts with the polymer electrolyte / Li 10 SnP2S 12 The mass ratio of the complex is (15-20 ml): 1 g.

4. The preparation method according to claim 1, characterized in that, In step (3), the lithium salt includes one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluorophosphate, lithium difluorooxalate borate, and lithium dioxalate borate.

5. The preparation method according to claim 1, characterized in that, In step (3), the drying temperature is 60-100℃ and the drying time is 6-24h.

6. A composite solid electrolyte material incorporating ion-filled material, characterized in that, It is prepared by the preparation method according to any one of claims 1-5.

7. The composite solid electrolyte material according to claim 6, characterized in that, The composite solid electrolyte material is in the form of a film with a thickness of 50–400 μm.

8. An application of a composite solid electrolyte material incorporating ion-filled material, characterized in that, The composite solid electrolyte material as described in claim 6 or 7 is applied to the fields of ion conductors or lithium-ion batteries.

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