Non-combustible and high-pressure-resistant gel electrolyte

Abstract

The invention discloses a non-combustible and high-pressure-resistant gel electrolyte, and relates to the technical field of gel electrolytes.The non-combustible and high-pressure-resistant gel electrolyte is prepared through the following steps that 1, 1, 3, 5-trioxane and succinonitrile are selected according to the mass ratio of (1-9): (9-1) to be prepared into a deep eutectic solvent; step 2, taking the deep eutectic solution obtained in the step 1 as a solvent, selecting an acrylate polymer monomer and a urethane acrylate monomer to dissolve according to a molar ratio of 1: 1, and then adding a thermal initiator and a lithium salt to obtain a precursor solution; and 3, uniformly pouring the precursor solution obtained in the step 2 on a polytetrafluoroethylene template, uniformly scraping by using a scraper, and drying in a drying oven to finally obtain the non-flammable and high-pressure-resistant gel electrolyte. Therefore, the invention provides the non-combustible and high-pressure-resistant gel electrolyte, and the DES is used as the solvent, has the characteristics of high decomposition temperature and difficulty in vaporization, and solves the problems of non-combustible and non-high-temperature-resistant characteristics of the gel electrolyte in the prior art, so that the safety and the performance of the battery are improved.

Description

Technical Field

[0001] The present application relates to the technical field of gel electrolytes, and in particular to a non-flammable, high-voltage resistant gel electrolyte. Background Art

[0002] Gel polymer electrolytes (GPEs) have the advantages of both traditional electrolytes and all-solid polymer electrolytes, with the characteristics of high ionic conductivity, flexible and adjustable electrolyte / electrode interface, and no risk of liquid leakage. They have attracted much attention in the research of high specific energy and high safety solid-state lithium metal batteries. In the currently available gel electrolytes, they usually contain polymer solid phase components and free liquid phase components. Usually, the free liquid phase components will vaporize or even decompose when the battery temperature rises to 80°C, which makes the gel electrolyte battery also have safety risks.

[0003] Deep eutectic solvents (DES) have similar properties to ionic liquids. They are in liquid state at room temperature and are mainly composed of hydrogen bond donors and hydrogen bond acceptors. They have a lower melting point than monomer components. The preparation process of deep eutectic solvents is low-cost and low-toxic. They usually have high solubility and stability and can dissolve most organic matter well. During the heating process, since there are no free liquid molecules, there is no vaporization process. Its decomposition temperature is usually between 200 and 300°C, which is safer than traditional liquid solvents. Summary of the invention

[0004] The purpose of the present application is to provide a non-flammable, high-pressure resistant gel electrolyte to solve the non-flammable and high-temperature resistant characteristics of the gel electrolyte in the prior art, thereby improving the safety and performance of the battery.

[0005] The present application discloses a non-flammable, high-pressure resistant gel electrolyte, which comprises the following steps:

[0006] Step 1, selecting 1,3,5-trioxane and succinonitrile in a mass ratio of 1-9:9-1 to prepare a deep eutectic solvent;

[0007] Step 2: using the deep eutectic solution obtained in step 1 as a solvent, dissolving an acrylate polymer monomer and a polyurethane acrylate monomer in a molar ratio of 1:1, and then adding a thermal initiator and a lithium salt to obtain a precursor solution;

[0008] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, apply it evenly with a scraper, and place it in an oven for drying to finally obtain a non-flammable, high-pressure resistant gel electrolyte.

[0009] Preferably, in step 2, the acrylate polymer monomer includes one or more of PEGDA, PEGMA, and PEGD MA; and the polyurethane acrylate monomer includes PUA.

[0010] Preferably, in step 2, the lithium salt includes LiTFSI, LiFSI, LiDFOB, LiBF4, and LiPF6.

[0011] Preferably, in step 2, the total dispersion concentration of the acrylic ester polymer monomer and the polyurethane acrylate monomer is 0.1 mol / L.

[0012] Preferably, in step 1, the mass ratio of 1,3,5-trioxane to succinonitrile is 1:1.

[0013] Preferably, in step 2, the thermal initiator is azobisisobutyronitrile;

[0014] Preferably, in step three, the scraper height is 10-500um.

[0015] Preferably, in step three, the temperature of the oven is preferably 60° C., and the heating time is 1 hour.

[0016] The present application provides a non-flammable, high-voltage resistant gel electrolyte prepared by the above method.

[0017] Therefore, the present application adopts the above-mentioned non-flammable, high-pressure resistant gel electrolyte, which has the following beneficial effects:

[0018] 1. The present invention utilizes the non-flammable and high stability properties of deep eutectic solvents to synthesize and prepare non-flammable and high-voltage resistant gel electrolytes, thus solving the safety issues of traditional gel electrolytes.

[0019] 2. When the deep eutectic solvent is prepared with 1,3,5-trioxane and succinonitrile in a mass ratio of 1:1, its thermal stability is optimal. DETAILED DESCRIPTION

[0020] Example 1

[0021] Step 1: accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:9; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0022] Step 2: Using the deep eutectic solution obtained in step 1 as a solvent, acrylate polymer monomer (PEGDA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiTFSI salt solution is added to the system.

[0023] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0024] Example 2

[0025] Step 1: accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 3:7; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0026] Step 2: Using the deep eutectic solution obtained in step 1 as a solvent, acrylate polymer monomer (PEGDA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiTFSI salt solution is added to the system.

[0027] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0028] Example 3

[0029] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0030] Step 2: Using the deep eutectic solution obtained in step 1 as a solvent, acrylate polymer monomer (PEGDA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiTFSI salt solution is added to the system.

[0031] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0032] Example 4

[0033] Step 1: Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 7:3; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0034] Step 2: Using the deep eutectic solution obtained in step 1 as a solvent, acrylate polymer monomer (PEGDA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiTFSI salt solution is added to the system.

[0035] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0036] Example 5

[0037] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 9:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0038] Step 2: Using the deep eutectic solution obtained in step 1 as a solvent, acrylate polymer monomer (PEGDA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiTFSI salt solution is added to the system.

[0039] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0040] The decomposition temperatures of the deep eutectic solvents of Examples 1-5 are shown in Table 1.

[0041] Table 1. Decomposition temperatures of deep eutectic solvents with different mass ratios of TXE and SN

[0042] Mass ratio (TXE:SN) Decomposition temperature(℃) 1：9 235 3：7 247 1：1 262 7：3 243 9：1 217

[0043] Example 6

[0044] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0045] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are dissolved in a molar ratio of 1:0, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiFSI salt solution is added to the system.

[0046] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0047] Example 7

[0048] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0049] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are dissolved in a molar ratio of 7:3, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiFSI salt solution is added to the system.

[0050] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0051] Example 8

[0052] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0053] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiFSI salt solution is added to the system.

[0054] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0055] Example 9

[0056] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0057] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are dissolved in a molar ratio of 3:7, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiFSI salt solution is added to the system.

[0058] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0059] Example 10

[0060] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0061] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are dissolved in a molar ratio of 0:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiFSI salt solution is added to the system.

[0062] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0063] The Young's modulus and ionic conductivity of the gel electrolytes of Examples 6-10 are shown in Table 2.

[0064] Table 2 Young's modulus and ionic conductivity of gel electrolytes

[0065]

[0066]

[0067] Embodiment 11

[0068] Step 1. Accurately weigh 1,3,5-trioxane (TXE) and succinonitrile (SN) according to the target mass ratio of 1:1; then mix the weighed 1,3,5-trioxane (TXE) and succinonitrile (SN) and stir evenly to ensure that the two substances are fully mixed until a uniform transparent liquid is formed.

[0069] Step 2: Using the deep eutectic solution obtained in step 1 as the solvent, acrylate polymer monomer (PEGMA) and polyurethane acrylate monomer (PUA) are selected and dissolved in a molar ratio of 1:1, and the total dispersed concentration of the two is 0.1 mol / L. Further, 0.1 mmol / L of thermal initiator azobisisobutyronitrile (AIBN) is added, and finally 1 mol / L of LiBF4 salt solution is added to the system.

[0070] Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, and apply it evenly with a scraper with a scraper height of 10-500um. Then, place it in an oven at 60°C for 1h to obtain a non-flammable, high-voltage resistant gel electrolyte.

[0071] Comparative Example 1

[0072] 1M LiFSI is dissolved in a solution of 1,3-dioxolane DOL:ethylene glycol dimethyl ether DME (1:1 vol), and added to the battery as an electrolyte. After heating at 50°C, DOL undergoes in-situ ring-opening polymerization to form a PDOL gel electrolyte. The voltage resistance range and decomposition temperature values ​​of the PDOL gel electrolyte and the gel electrolyte of the present application are shown in Table 3.

[0073] Table 3, Results of the gel electrolytes of Comparative Example 1 and Example 3

[0074] Gel electrolyte type Withstand voltage range(V) Decomposition temperature(℃) PDOL gel electrolyte 4.3 85 Deep eutectic electrolyte 4.8 173

[0075] Therefore, the present application provides a non-flammable, high-voltage resistant gel electrolyte. DES as a solvent has excellent solubility properties and can dissolve a variety of compounds. At the same time, the deep eutectic solvent has excellent high-voltage resistance. It has a higher decomposition temperature, which enhances its thermal stability. The lithium ion transport chain segments contained in the acrylic polymer can provide excellent lithium ion conductivity. The polyurethane polymer has good flexibility and toughness, providing excellent mechanical properties for the polymer chain segments, thereby improving the safety and performance of the battery.

[0076] In the description of this specification, the description with reference to the terms "an experimental example", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the experimental example or example are included in at least one experimental example or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0077] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A non-flammable, high-voltage resistant gel electrolyte, It is characterized in that The non-flammable, high-voltage resistant gel electrolyte comprises the following steps: Step 1, selecting 1,3,5-trioxane and succinonitrile in a mass ratio of 1-9:9-1 to prepare a deep eutectic solvent; Step 2: using the deep eutectic solution obtained in step 1 as a solvent, dissolving an acrylate polymer monomer and a polyurethane acrylate monomer in a molar ratio of 1:1, and then adding a thermal initiator and a lithium salt to obtain a precursor solution; Step 3: Pour the precursor solution obtained in step 2 evenly onto the polytetrafluoroethylene template, apply it evenly with a scraper, and place it in an oven for drying to finally obtain a non-flammable, high-pressure resistant gel electrolyte.

2. A non-flammable, high-voltage resistant gel electrolyte according to claim 1, It is characterized in that In step 2, the acrylate polymer monomer includes one or more of PEGDA, PEGMA, and PEGDMA; and the polyurethane acrylate monomer includes PUA.

3. A non-flammable, high-voltage resistant gel electrolyte according to claim 1, It is characterized in that In step 2, the lithium salt includes LiTFSI, LiFSI, LiDFOB, LiBF 4 , LiPF 6 .

4. A non-flammable, high-voltage resistant gel electrolyte according to claim 3, It is characterized in that In step 2, the total dispersion concentration of the acrylic ester polymer monomer and the polyurethane acrylate monomer is 0.1 mol / L.

5. A non-flammable, high-voltage resistant gel electrolyte according to claim 3, It is characterized in that In step 1, the mass ratio of 1,3,5-trioxane to succinonitrile is 1:

1.

6. A non-flammable, high-voltage resistant gel electrolyte according to claim 1, It is characterized in that In step 2, the thermal initiator is azobisisobutyronitrile.

7. A non-flammable, high-voltage resistant gel electrolyte according to claim 1, It is characterized in that In step three, the scraper height is 10-500um.

8. A non-flammable, high-pressure resistant gel electrolyte according to claim 1, It is characterized in that In step 3, the temperature of the oven is preferably 60° C. and the heating time is 1 hour.

9. A non-flammable, high-voltage resistant gel electrolyte. It is characterized in that Prepared by the preparation method according to any one of claims 1 to 8.

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